POLYSOLVAT 16 at JCNS, Workshop 2026

Abstract: Network made of single polymer fails to generate the expected outcome which is essential to the particular application [1-2]. With the expectation of getting enhanced properties, several hybrid networks composed of syndiotactic polystyrene (sPS) and poly(3-alkylthiophene) have been prepared by varying the alkyl chain length from butyl to dodecyl group. These hybrid networks have been investigated by various techniques, such as UV-vis absorption, XRD, AFM. To explore the viscoelastic and microstructural properties, hybrid networks have been thoroughly checked by small amplitude oscillatory shear (SAOS) and large amplitude oscillatory shear (LAOS) and comparative studies have performed to show the enhanced properties with respect to the respective polymer network. Overall, this lecture will provide critical insights of aggregation behavior of P3AT chains into sPS-P3AT hybrid networks and the influence of length of side chains on properties of networks [3-4]. These findings may offer valuable information for the development of hybrid polymer networks for advanced applications.

[1] Y Ding, Y. Wang, C. Liu, J. Deng, S. Qu, Y. Wang, R. Bai, Y. Liu, G. Liu, C. Yue, W. Yu, Z. Zhang and X. Yan., Angew. Chem. Int. Ed., 64, e202510140 (2025).
[2] P. Das, Sk. M. Ahamed, G. L. Dhakar, B. Lala, R. Chatterjee, J. Dash and S. Malik, J. Energy Storage, 114, 115739 (2025).
[3] G. L. Dhakar and S. Malik, J. Phys. Chem. B, 128, 12292-12309 (2024).
[4] G. L. Dhakar and S. Malik, J. Phys. Chem. B, 129, 8050–8064 (2025).

see attached

Shake gel is a kind of polymer/nanoparticle mixture with a distinctive solid-liquid switching ability [1]. It is fluid at rest and can rapidly turn into a gel after shear, and then revert to a liquid upon standing. Previous studies have examined how key parameters such as polymer molecular weight, particle size, and polymer/particle ratio affect the gel formation and rheological properties [2,3].
However, a quantitative understanding of how composition and size collectively govern the gelation boundary remains elusive. Herein, we systematically investigated the phase behavior of shake gels formed by mixing polyethylene glycol(PEG) polymers of various radii of gyration (Rg) with silica nanoparticles of different diameters (d) in water. A series of phase diagrams were constructed with the silica volume fraction ϕsilica as the abscissa and the PEG volume fraction ϕPEG as the ordinate.
Two types of constraints governing gelation were revealed. First, ϕsilica and ϕPEG obey an inverse relationship, (ϕPEG-ϕPEG, c) ⋅ (ϕsilica-ϕsilica, c) ≥ k, where ϕsilica, c and ϕPEG, c are the absolute minimum concentrations of the two components. The concentrations can compensate each other but neither can be infinitely low; otherwise, the system fails to develop a percolating network. Second, the concentration ratio is constrained by a coverage parameter θ = (ϕPEG/ϕsilica) ⋅ (d/Rg). A shake gel forms only when θmin ≤ θ ≤ θmax, corresponding to PEG adsorption on silica surfaces that meets a minimum threshold without reaching saturation. Furthermore, the critical parameters ϕsilica, c, ϕPEG, c, and k all exhibit scaling relations with the dimensionless quantity d/Rg. This result demonstrates that d/Rg is the key scaling variable governing the gelation behavior of PEG/silica systems.
By unifying complex multi-parameter phase diagrams into a single-parameter universal form, we provide a predictive framework that bridges phenomenological observations and scaling theory for polymer-mediated colloidal gelation.

[1] J. Zebrowski, et. al, Colloids Surf. A, 213, 189-197 (2003).
[2] M. Mar Ramos-Tejada, et. al, Colloids Surf. A, 471, 164-169 (2015).
[3] S. Sato, et. al, Molecules, 28, 3555 (2023).

Polymeric aerogels have attracted considerable attention as sustainable porous materials due to their high porosity, ultralow density, large specific surface area, and tunable hierarchical structures. This talk highlights the development of advanced polymeric aerogels for two important applications: energy harvesting and solar-driven atmospheric water harvesting (SAWH) [1]. The first part focuses on a directional freeze-casting approach for fabricating isotropic and anisotropic nylon-11 aerogels. By controlling the freezing temperature, highly aligned pore channels and oriented polar g-phase nylon-11 crystals are obtained, leading to enhanced mechanical properties and piezoelectric performance. These anisotropic aerogels generate output voltages of ~30 V and power densities of 0.1 W m-3. Vacuum-assisted infiltration of PVDF further induces oriented b-phase PVDF, producing self-poled hybrid aerogels with output voltages of ~45 Vpp and peak power densities of 2.2 W m-3. In addition, anisotropic nylon-11 aerogels exhibit strong tribo-positive behavior, delivering up to 277 Vpp in triboelectric nanogenerators, which increases to 650 Vpp upon incorporation of silk nanofibrils. The second part describes biodegradable poly(3-hydroxybutyrate) (PHB)-based composite aerogels for SAWH. These aerogels incorporate MgCl2·6H2O as a hygroscopic component and carbon nanotubes as photothermal converters within a porous PHB network. The resulting materials exhibit high water uptake across a broad humidity range, reaching 1.64 g g-1 at 90% RH and 0.88 g g-1 at 40% RH, together with rapid solar-driven water release at a rate of 1.8 g g-1 h-1 under one-sun irradiation. The aerogels also show excellent cycling stability, fast adsorption-desorption kinetics, and environmental sustainability due to the biodegradability of PHB. Overall, these studies demonstrate how controlling polymer crystallization, pore architecture, and multifunctional hybridization can create sustainable polymeric materials for efficient energy harvesting and atmospheric water generation.

Aerogels are highly porous, ultra-lightweight solid materials and due to their unique physical, chemical, and mechanical properties, they are recognized as promising candidates for many applications such as thermal insulation, catalysis, environmental clean-up, sensors, or gas/energy storage devices [1].
Among aerogels, polymer-based aerogels are particularly interesting as they generally outperform traditional inorganic aerogels by offering superior mechanical properties (can be bent or folded without breaking), tunable molecular designs, and easier manufacturing and shaping and they have driven increasing attention over the last 25 years [1]. These aerogels are obtained by supercritical drying, ambient pressure drying or freeze drying of chemical gels made of permanent covalent cross-linked polymers or physical gels where the gel three-dimensional network is due to electrostatic interactions or to crystalline regions.
In this contribution, different aspects relative to the preparation, the structure, the morphology and the potential applications of covalent and physical aerogels will be discussed. In particular, composite aerogels based on syndiotactic polytyrene (s-PS) with nanoporous crystalline (NC) phase and photocatalysts such as titania and zinc oxide can be easily prepared from composite thermoversible gels. These composite aerogels display a synergistic action, since the NC crystalline aerogel concentrates the pollutants being present in traces in water, while the photocatalyst sites degrade the adsorbed molecules [2,3]. In addition to the high photodegradation efficiency, these aerogels are characterized by a complete reusability without regeneration steps, good chemical stability and excellent mechanical properties, which allow an easy recovery after water treatments. The preparation of highly transparent covalent polydivinylbenzene (PDVB) aerogels doped with 2,5-diphenyloxazole (PPO) and 1,2-bis (5-phenyl-oxazolyl-2)-benzene (POPOP) fluorescent dyes will be also reported. These monolithic aerogels characterized can detect gas radionuclides and therefore support the use of scintillating porous aerogel in the development of sensors for detecting natural and anthropogenic radioactive gases.

[1] S. Takeshita, S. Mine, T. Ono, Angew. Chem. Int. Ed., 64, e202504250 (2025)
[2] O. Sacco, V. Vaiano, C. Daniel, W. Navarra, V. Venditto, Nanomaterials, 9, 1509 (2019)
[3] W. Navarra, O. Sacco, R. Rescigno. C. Daniel, V. Vaiano, D. Pisano, B. Brancato, F. Casertano, M. Raiola, V. Venditto, Catalysis Communications, 180, 106699 (2023)

Retinal neurodegenerative diseases are among the leading causes of irreversible vision loss worldwide. siRNA-based gene therapy has emerged as a promising strategy for the treatment of these disorders by selectively silencing disease-associated genes [1,2]. However, the successful clinical translation of siRNA therapeutics is hindered by ocular physiological barriers and rapid drug clearance. Therefore, the development of multifunctional delivery systems capable of protecting siRNA, while ensuring prolonged ocular residence and controlled release, remains a major challenge.
In this work, a thermoresponsive nanocomposite hydrogel for ocular siRNA delivery was developed by combining Pluronic F127 (PL F127), hyaluronic acid (HA), and zinc oxide nanoparticles (ZnO NPs). PL F127 provides an in situ sol-to-gel transition at physiological ocular temperature [3], whereas HA enhances the viscoelastic and mucoadhesive properties of the formulation [4], improving its retention on the ocular surface. ZnO nanoparticles were incorporated as multifunctional components, providing intrinsic photoluminescence for non-invasive carrier tracking together with antibacterial and antimicrobial properties [5].
The influence of polymer concentration, temperature, and formulation composition on the hydrogel microstructure was systematically investigated by Dynamic Light Scattering, ζ-potential measurements, Small-Angle X-ray Scattering, and Small-Angle Neutron Scattering. Structural analyses identified the 15% (w/v) PL F127 formulation as the optimal composition, exhibiting the most pronounced micellar organization, shorter intermicellar distances, and a higher degree of long-range ordering consistent with FCC-like packing. Importantly, the addition of HA and ZnO NPs preserved the ordered self-assembly of the system, demonstrating the robustness of the hydrogel network. The optimized formulation successfully encapsulated siRNA and exhibited sustained release, supporting its potential as an ocular gene delivery system.
Overall, this work demonstrates that the combination of PL F127, HA, and ZnO NPs yields a multifunctional thermoresponsive hydrogel platform for controlled ocular siRNA delivery, while simultaneously providing intrinsic photoluminescence for carrier tracking.

References:
[1] Marchesi N., Fahmideh F., Boschi F., Pascale A., Barbieri A., Cells, 2021, 10, 9.
[2] Zhang X., Li S., Tang Y., Guo Y., Gao S., AAPS PharmSciTech, 2020, 21, 236.
[3] Clerkin S., Singh K., Winning D., Krupa I., Crean J., Brougham D. F., Wychowaniec J. K., J. Mater. Chem. B 2025, 13, 31.
[4] Wang A., Dong L., Guo Z., Sun W., Mi S., Biomed. Mater. 2022, 17, 4.
[5] Gallucci N., Cangiano A., Russo S., Pota G., Di Girolamo R., Martinez E., Vaxelaire N., Paduano L., Vitiello G., Mater. Chem. Front. 2024, 8, 23.

Flexible sensors require materials that maintain low mechanical hysteresis under cyclic loading to avoid signal drift [1]. Strain-induced crystallization (SIC) has been proven to effectively enhance the toughness of ion gels, but this process inevitably introduces hysteresis [2]. In this study, the kinetics of strain-induced crystallization in tetra-PEG ion gels were controlled by tuning the network strand length. Gels with short strands favor the formation of planar zig-zag crystals, which melted rapidly, whereas gels with long strands promote helix crystals, which melted slowly. In gels dominated by planar zig-zag crystals, rapid crystal melting suppresses bulk energy dissipation while preserving crack-tip toughening, achieving hysteresis below 2% at 1000% strain and a toughness of approximately 7800 J/m². We also establish a linear correlation between mechanical hysteresis and crystallization hysteresis area, providing a quantitative link between crystallization kinetics and macroscopic energy dissipation. These findings demonstrate that controlling crystal melting kinetics is an effective method for achieving both high toughness and low hysteresis in soft materials.

[1] He, J.; Huang, J.; Li, R.; Chen, Z.; Li, Z.; Zhou, R.; Wang, S.; Gao, W.; Guo, C. F.; Pan, C. Sci. Adv. 12, eaea2450 (2026).
[2] Liu, C.; Morimoto, N.; Jiang, L.; Kawahara, S.; Noritomi, T.; Yokoyama, H.; Mayumi, K.; Ito, K. Science, 372, 6546 (2021),

Semicrystalline polymer electrolyte membranes (PEMs) play an important role in fuel cells and many other electrochemical devices. The desired PEM materials should have balanced properties of high conductivity and long-term operating stability in hydrated state. To advance PEMs development, it is crucial to consider not only the new molecular design, but also the creation of robust ion-conducting channels through micro-/nano-phase separation with a deep understanding of structure-property correlations.
In this work, the hierarchical structure of advanced PEMs prepared by radiation-induced graft polymerization technique using a 60Co γ-ray source @ QST-Takasaki, Japan, was investigated in a length scale range of sub- to several hundred-nanometer using the combination of a contrast variation small-angle neutron scattering (SANS) with partial scattering function analysis, atomic force microscopy (AFM), and simulations. Toward applying Materials Informatics, the structural datasets of PEMs were constructed by both scattering data and scattering-validated simulations, relating to the ion conduction efficiency, which is the most required performance of the practical fuel cells. This approach as a new tool and methodology is exciting for accelerating materials discovery and development.

The spread of multidrug-resistant bacteria is largely driven by the overuse and misuse of antibiotics,1 with the aggravating factor of biofilm formation.2 Because the extracellular biofilm matrix acts as a protective barrier, treating these infections is highly challenging, highlighting the need for alternative therapeutic strategies. Lipid-based delivery systems are among the most widely used strategies to overcome multidrug-resistant and biofilm-related infections because of their safety, biodegradability, and favorable physicochemical properties.3 in this context, bacterial extracellular vesicles may represent a promising alternative therapeutic platform. Here, we have characterized the extracellular membrane vesicles produced by the Shewanella vesiculosa bacterium as a possible platform for delivering antibiotics and obtaining information about the vesicles' dimensions and molecular weight. In addition, we have reconstructed the outer membrane of this Gram(-) bacteria, considering the different components, that is, the lipid part, the lipopolysaccharides (LPS), and the capsular polysaccharides (CPS). The information obtained from the chemical-physical characterization of the membrane that mimics the bacterium has allowed us to optimize the preparation of an innovative delivery system, capable of acting as a Trojan horse.

References
1. A. PArmanik, et al., Curr. Microbiol. 2022
2. E. M. Darby. et al., Nat. Rev. Microbiol. 2023
3. X. Lv, et al., Small 2022

Co-crystalline (CC) polymer phases with small guest molecules can be obtained for many regular and stereoregular polymers. This lecture will be devoted to the very limited number of polymer CC phases that, by suitable guest removal procedures, can generate nanoporous-crystalline (NC) phases [1-4]. NC polymer phases, exhibiting density lower than for the corresponding amorphous phases, till now were discovered only for two commercial polymers: syndiotactic polystyrene (δ [1] and ε [2] phases) and poly(2,6-dimethyl-1,4-phenylene)oxide (shortly known as polyphenyleneoxide or PPO, α and β phases [3,4]). Polymer conformations and crystal packing of these NC and corresponding CC phases will be shown.
Three kinds of special morphologies of NC and CC polymers (aerogels, films with planar orientations and films with high-surface area) [5], which are possibly relevant for many applications, will be also discussed.
Several exciting new materials based on NC and CC polymer phases can be achieved. Polymeric NC phases give outstanding performances in the fields of molecular separations, water/air purification and sensorics. Moreover, NC polymer phases can be easily transformed into CC polymer phases with active guest molecules, which are promising for several kinds of advanced applications.

[1] C. De Rosa, G. Guerra, V. Petraccone, B. Pirozzi, Macromolecules, 30, 4147 (1997).
[2] V. Petraccone, O. Ruiz de Ballesteros, O.Tarallo, P. Rizzo, G. Guerra, Chem. Mater., 20, 3663 (2008).
[3] C. Daniel, S. Longo, G. Fasano, J.G. Vitillo, G. Guerra, Chem. Mater., 23, 3195 (2011).
[4] B. Nagendra, A. Cozzolino, C. Daniel, P. Rizzo, G. Guerra, F. Auriemma, C. De Rosa, M.C. DAlterio, O. Tarallo, A. Nuzzo, Macromolecules, 52, 9646 (2019).
[5] B. Nagendra, A. Cozzolino, C. Daniel, P. Rizzo, G. Guerra, Macromolecules, 55, 2983 (2022).

Poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and syndiotactic polystyrene (sPS) are high-performance thermoplastics capable of forming co-crystalline (CC) phases with low-molecular-weight guest molecules. Upon guest removal, these materials transform into nanoporous crystalline (NC) structures that exhibit outstanding sorption properties toward gases and volatile organic compounds (VOCs)[1,2]. While the NC phases of sPS have been widely investigated for applications in purification, catalysis, and active packaging, recent studies have demonstrated that PPO-based NC forms possess lower density and enhanced sorption performance, governed by their crystallinity, morphology, and specific surface area[3,4].
In this work, PPO/atactic polystyrene (PPO/PS) fibers containing NC phases were prepared through guest-induced crystallization of melt-spun amorphous blends. Incorporation of atactic PS improves the processability of PPO by reducing the limitations associated with its high glass transition temperature. The resulting NC fibers exhibit faster sorption kinetics and higher VOC uptake than benchmark NC films, while their low pressure drop and high surface-to-volume ratio make them particularly attractive for purification technologies.
A liquid shear-driven processing route was also employed to fabricate PPO nanomaterials by shearing polymer solutions into a viscous, miscible medium, promoting antisolvent-induced precipitation. By tuning the polymer concentration and shear conditions, nanoribbons and nanofibers with either amorphous or NC morphologies were obtained. The NC nanostructures displayed significantly higher sorption capacities than their amorphous counterparts for representative water pollutants, including perchloroethylene, phenol, and atrazine. Moreover, shear-spun NC nanofibers outperformed conventional melt-spun fibers in pollutant uptake.
Finally, photocatalytic composites based on PPO-ZnO and PPO-g-C3N4/N-TiO2/ Y1.97SiO5:Ce0.03, fabricated using the same shear-driven approach, demonstrated efficient degradation of organic pollutants, including phenol, atrazine, and azo dyes such as Sunset Yellow and Acid Orange 7.
Overall, these findings highlight the potential of nanoporous crystalline polymer fibers and multifunctional photocatalytic composites as scalable platforms for the efficient sorption and degradation of pollutants, offering promising solutions for both water and air purification.
Reference
[1] C. Daniel, P. Antico, G. Guerra, Etched Fibers of Syndiotactic Polystyrene with Nanoporous-Crystalline Phases, Macromolecules 51 (2018) 6138–6148. https://doi.org/10.1021/acs.macromol.8b01044.
[2] C. Daniel, S. Longo, G. Fasano, J.G. Vitillo, G. Guerra, Nanoporous Crystalline Phases of Poly(2,6-Dimethyl-1,4-phenylene)oxide, Chem. Mater. 23 (2011) 3195–3200. https://doi.org/10.1021/cm200546r.
[3] A. Cozzolino, B. Nagendra, P. Rizzo, C. Daniel, G. Guerra, Fast uptake of organic pollutants from dilute aqueous solutions by nanoporous-crystalline PPO films with c-perpendicular orientation, Eur. Polym. J. 161 (2021) 110864.
[4] B. Nagendra, A. Cozzolino, C. Daniel, P. Rizzo, G. Guerra, High Surface Area Nanoporous-Crystalline Polymer Films, Macromolecules 55 (2022). https://doi.org/10.1021/acs.macromol.2c00271.

Emerging contaminants in wastewater have become an important environmental issue, posing substantial risks to aquatic ecosystems and human health. Over the years, several remediation strategies have been explored; among them, adsorption has gained particular attention due to its low operational cost, straightforward implementation, scalability, and the possibility of regenerating and reusing the adsorbent materials. It is essential to find new efficient adsorbent materials that can remove contaminants from wastewater. Numerous polymeric materials have been investigated for sorption applications, but polymers capable of forming nanoporous crystalline (NC) phases have recently attracted growing interest. Among them poly(2,6‑dimethyl‑1,4‑phenylene)oxide (PPO) has emerged as a particularly promising candidate, exhibiting remarkably fast pollutant uptake even from dilute aqueous solutions [1]. In this communication PPO films with NC phases used to remove contaminants such as dyes [2] and organic pollutants (PCE, nicotine), from water will be presented. A sulfonation of the polymer was performed: remarkable and unique results were achieved since kinetic uptakes and removal efficiency were higher due to the sulfonic groups present in the PPO amorphous phase; indeed by enhancing hydrophilicity, and by exposing anionic groups, it can both improve the diffusion of the pollutant molecules in the NC phase and, further to this, it promotes the removal of cationic contaminants by electrostatic interactions.
We acknowledge financial support from the NRRP – Mission 2, Component 2, Investment 3.5 “Research and development on hydrogen”, under the Public Notice of 23 March 2022 of the Italian Ministry of Ecological Transition. Funding was provided for the project “TESLA – Tecnologia Elettrocatalitica diretta di converSione di CO₂ per la produzione di e‑fuels” (CUP F57G25000060006), assigned through Decree No. 385 of 06/10/2025 by the Ministry of Environment and Energy Security (MASE).
[1] A. Cozzolino, European Polymer Journal, 161, 110864 (2021)
[2] D. Riccardi, Colloids and Surfaces A: Physicochemical and Engineering Aspects Journal, 728, 138677 (2026).

E-mail of the corresponding author: driccardi@unisa.it

Please find the abstract attached.

Literature dealing with polyelectrolyte (PE) chains with atomic/molecular compensating ions in solution is vast [1–3]. Studies of PE chains in the presence of charged colloids or nanoparticles (NPs)[4] are less common. Interesting recent examples include PE complexes with gold and silica NPs[3], forming coacervates, or precipitates, with potential applications in phase separation processes, including extraction and depollution[5]. Little research has focused on PE behavior in the presence of molecular colloids, of intermediate size between ions and colloids[6]. Polyhedral oligomeric silsesquioxanes (POSS) are molecular colloids with a size range of 1–3 nm, intermediate between ions and nanoparticles. Their interactions in solution can be tuned via the nature and length of pendant groups attached to the apices of a Si-O central cage. The compounds synthesized in the laboratory are a closed cage containing 8 silicon atoms and are stable in aqueous solution at a pH 2. The size of the Si-O cage was determined using the form factor and measures 0.8 nm. This tunability makes POSS ideal for studying their interactions in aqueous solution to form self-assemblies made of positively or negatively charged POSS with oppositely charged polyelectrolytes (PEs). We explore the POSS/PE assembly of Sodium Polystyrene Sulfonate ([-] charged PE) and primary amine-functionalized POSS. The mixtures form macroscopic aggregates and their structure is analyzed by small angle x-ray scattering (SAXS). The SAXS results obtained for POSS-PSS mixtures show a contribution from the POSS that depends on the [-]/[+] loading ratio. At a remarkable ratio close to 1, all the PSS seems to interact with all the POSS in solution, while at the other ration either PSS or POSS is in excess. Small angle neutron scattering (SANS) would be a technique of choice to identify the contribution and structure of each component using contrast matching. Using these methods, we investigate the influence of ionic strength, charge ratio to determine the key parameters the formation of complex POSS/PE architectures.

Waterborne latex films, obtained from the dispersion of latex particles, are of particular interest due to the non-content of volatile organic compounds (VOC), often mandatory under environmental legislation. To prepare efficient and solvent-free coatings with a low glass-transition temperature but higher mechanical strength, we have integrated hydrophilic layers (Acrylic acid/ Poly(acrylamide)) around the hydrophobic cores (mixture of Methyl methacrylate and Butyl acrylate). Latex particles have been synthesized using emulsion polymerization. Polymer latex films have been prepared in the next step by evaporating water in a humidity chamber. The structure formation of polymer latex films in the dry state (crystallinity) and in the re-swelled state (change in crystallinity and whitening or blushing) has been studied using Small-Angle Neutron Scattering (SANS), which reveals FCC-like structure formation by the latex film, with better ordering in the inclusion of the hydrophilic shell. The interdiffusion between the latex particles has been studied by mixing H/D polymers in the films. The films were annealed at high temperatures to initiate the kinetics of mixing. The presence of hydrophilic hairy layers promotes the interdiffusion of the polymers. The transfer of polymer chains through interparticle boundaries vanishes the crystalline structure and results in the formation continuous material.

Ultra-low-crosslinked (ULC) PNIPAM microgels were complexed with tannic acid through supramolecular hydrogen-bond interactions. Rather than simply introducing additional crosslinks, tannic acid triggers a dramatic restructuring of the initially homogeneous and highly deformable microgels. The particles transform into a kinetically trapped core–shell architecture characterized by a depleted core and a dense outer shell, yielding a supramolecular capsule-like morphology. This structural transition is evidenced by scattering and electron microscopy experiments. Supported by molecular dynamics simulations, we demonstrate that the strong affinity of tannic acid for PNIPAM drives and stabilizes this nonequilibrium restructuring, providing a molecular-level explanation for the observed morphology. More broadly, the resulting architectures provide a sensitive structural readout of polymer–guest affinity, opening new opportunities for probing interactions in ultrasoft polymer networks and for the development of smart supramolecular capsules. As a proof of concept, we further demonstrate the encapsulation of polycationic antimicrobial peptides within the microgels, followed by tannic-acid-induced capsule formation, illustrating how supramolecular restructuring can be exploited to trap and retain functional cargo within soft colloidal carriers.

This contribution addresses the morphological properties of silica nanofillers embedded in styrene-butadiene elastomers and their structural rearrangement upon an applied deformation. Time-resolved ultra-small x-ray scattering (USAXS) patterns have been collected under the effect of a periodic deformation with variable dynamic amplitudes applied in-situ by means of a home-built DMA (Dynamic Mechanical Analysis) rheometer. The correlation between the structural evolution of the filler clusters under large-amplitude oscillatory extension (LAOE), detected by x-ray scattering, and the dynamic-mechanical stress-strain response is accessed by the in-situ configuration. This specific combination of scattering and rheological methods allows a simultaneous identification of the induced structural changes on a microscopic level and the macroscopic mechanical properties. A mathematical scattering model that provides a quantitative description of the filler network evolution under the effect of a dynamic deformation is here introduced. With the aim of addressing the Payne effect and the underlying structural modifications correlated to intra- and inter-filler-aggregate effects, all rubbers were pre-conditioned to suppress stress softening related to the Mullins effect. 2D scattering images as well as the corresponding averaged intensities reveal a re-arrangement of the filler clusters along the direction of the applied dynamic sinusoidal deformation. From the structural study of the filler, a jamming/de-jamming transition between the filler clusters is identified as one contributor to non-linear viscoelastic behavior of the rubber and associated with structural arrest of the dynamics by the percolation of rigid fillers. The dynamic stress response of the full composite shows an onset of non-linear behavior, and odd and even higher harmonics of the fundamental excitation frequency are evidenced.

Poly(ether ether ketone) (PEEK) is of particular interest in the design of chemically stable membranes for use in harsh environments due to its high temperature thermal transitions, high crystallizability, mechanical strength, and low chemical reactivity. Recently, we have discovered that PEEK can be dissolved at elevated temperatures in a non-toxic, benign solvent, 1,3-diphenylacetone (DPA). Upon cooling, these solutions form thermoreversible gels via a thermally induced phase separation (TIPS) process. Morphological analysis using small-angle scattering and scanning electron microscopy shows that these gels contain a hierarchical network of interconnected fibrils of axialitic crystals containing solvent swollen macro-scale and meso-scale pores. Upon introduction of a suitable functionalizing reagent (e.g., a sulfonating reagent), the functionalization is sterically limited to the amorphous chain segments between the crystalline lamella, resulting in a blocky microstructure of the resulting copolymer. Using this method of post-polymerization functionalization, we have synthesized blocky sulfonated SPEEK membranes with remarkably high proton conductivity, rivaling the benchmark Nafion for fuel cell applications. The high mechanical stability of these PEEK gels has also afforded the development of advanced aerogels by solvent extraction with remarkably low thermal conductivity, high porosity, and high surface area. We have also recently discovered that our new benign solvent is ideal for creating new mechanically robust aerogels from waste PET, providing a unique upcycling of single use packaging to long life-time insulation materials.

Quantifying the hydration structure of ionomer membranes remains one of the central challenges in understanding the relationship between nanoscale morphology and proton transport in polymer electrolyte membranes (PEMs). Although extensive studies using calorimetry, FTIR spectroscopy, nuclear magnetic resonance (NMR), and molecular dynamics (MD) simulations have established that water in Nafion exists in distinct populations commonly described as bound and free water, these approaches define hydration from thermodynamic, spectroscopic, dynamical, or computational perspectives. Direct experimental quantification of bound water from a purely structural viewpoint, however, remains largely unavailable. Such structural information is essential for establishing microscopic hydration models and for correlating membrane nanostructure with the performance.
Contrast variation small-angle neutron scattering (CV-SANS), combined with partial scattering function analysis (PSFA), provides a unique opportunity to resolve component-specific structural correlations in multicomponent soft-matter systems. Building upon our previous PSFA framework for hydrated Nafion, an updated methodology with a modified model has been developed in which the conventional side-chain component is replaced by a "hydrated side chain" with a variable number of associated water molecules. By systematically varying the assumed number of associated water molecules and analyzing the corresponding cross-term partial scattering function between hydrated side chains and unassociated water, the ensemble-averaged number of structurally bound water molecules can be determined from the condition where the spatial correlation vanishes at the ionomer peak. This methodology provides, for the first time, an experimentally accessible structural criterion for quantifying bound water directly from neutron scattering measurements.
The methodology has been applied to Nafion membranes over a broad hydration range, from low relative humidity conditions to fully hydration. The analysis reveals a systematic evolution of bound water populations with increasing hydration, yielding quantitative structural information that is consistent with previous calorimetric, FTIR, and MD studies while providing a fundamentally different structural interpretation. The presentation will demonstrate how advanced CV-SANS data analysis can provide quantitative structural descriptors that are inaccessible by conventional scattering analysis and discuss its potential applications to a broad range of hydrated soft-matter systems.

Deuterium labelling is a very powerful tool for neutron scattering techniques, especially on soft matter. The ability to utilize selective contrast variation in order to highlight specific areas within a material or mixture is one of the main benefits of neutron scattering over the corresponding x-ray techniques. This contribution gives a brief introduction in deuteration procedures by H/D exchange and highlights important material classes like surfactants, monomers, polymers and small organic molecules, which are used for example as solvents and ligands. In addition, for polymers, procedures are outlined which allow the synthesis of precisely defined model compounds.

For many decades, researchers have studied polymer solutions using small angle scattering techniques and attempted to explain deviations (i.e., excess scattering) from classical models. While these phenomena are sometimes explained away as uncontrolled experimental factors (e.g., dust), there can be a polymeric origin to the excess scattering, but few interpretable, physics-based models exist to describe it. For example, the Debye-Bueche model provides an ambiguous ‘correlation length’ but no physical origin of low-q excess scattering. In this contribution, we explain two observations of excess scattering in semi-dilute polystyrene solutions: (1) low-q excess scattering indicating long-range concentration fluctuations despite marginally good solvent conditions and (2) excess scattering near q Rg = 1, when crowded by contrast-matched chains. To explain these phenomena, we develop a liquid-state theory (PRISM) based scattering model which describes the scattering over all wavenumbers and all concentrations studied. With this model, we demonstrate that both phenomena can be explained by incorporating end-monomer interactions that account for the non-solvency of the acidic methanol end-groups of the polymer.

Thermo-responsive microgels are colloidal particles, composed by polymer networks, that undergo a sudden change of volume at the so-called volume phase transition temperature (VPTT). This property is of considerable interest across a wide range of fields, and the ability to tune the VPTT is crucial for many applications. In this talk I will present two examples of investigations of microgels combining numerical simulations and neutron scattering experiments.
In the first part, I will focus on microgels based on the polymer poly(N-isopropylacrylamide) (PNIPAM). I will show that these systems exhibit intriguing features even at temperatures well below the VPTT. By comparing atomistic molecular dynamics simulations with neutron scattering experiments, I will provide evidence that PNIPAM microgels undergo a dynamical transition akin to that observed in proteins [1, 2], in which water plays a driving role [3].
In the second part, I will discuss how simulations spanning different length scales can provide valuable insights into the internal topology and phase behavior of copolymer microgels. I will present a multiscale approach that combines monomer-resolved microgel simulations, based on an in silico synthesis protocol capable of realistically reproducing particle structure [4], with atomistic simulations of polymer chains. By directly comparing numerical form factors with experimental data obtained from small-angle neutron scattering experiments, I will show evidence of preferential domain structure in Poly(N-isopropylacrylamide-co-N-isopropylmethacrylamide), P(NIPAM-co-NIPMAM), copolymer microgels [5].

[1] M. Zanatta, L. Tavagnacco, E. Buratti et al., Science Advances, 4, eaat5895 (2018).
[2] L. Tavagnacco, E. Chiessi, M. Zanatta et al., J. Phys. Chem. Lett., 10, 870-876 (2019).
[3] L. Tavagnacco, M. Zanatta, E. Buratti et al., Chemical Science, 15, 9249-9257 (2024).
[4] N. Gnan, L. Rovigatti, M. Bergman, E. Zaccarelli, Macromolecules, 50, 8777-8786 (2017).
[5] L. Tavagnacco, E. Buratti, J. Vialetto, et al., Small, 21, e09795 (2025).

The effects of ionic liquids (ILs) on proteins are well known and widely studied for various applications [1]. Compared to conventional solvents, ILs exhibit several advantageous properties, as liquid state over a wide temperature range, excellent solvation ability, and high thermal stability. Biocompatible ionic liquids (Bio-Ils) retain these properties while maintaining manageable toxicity levels, making them attractive for pharmaceutical applications [2]. In this work, Hamiltonian Replica Exchange Molecular Dynamics were employed to investigate the effect of concentration changes in choline-derived ionic liquids on the stability and structure of Plasmodium falciparum proteins. The proteins AMA1, MSP1, and MSP2 were studied in aqueous solutions of choline geranate (CAGE), choline lactate (CAL), and choline chloride (CACL) at concentrations of 0.125 M, 0.250 M, 0.5 M, 1.0 M, and 2.0 M. Solvation structures were characterized using Kirkwood–Buff integrals (KBIs) [3] that revealed distinct behaviors among the Bio-ILs. CACL behaves similarly to a conventional salt, showing minimal variation in solvation effects of the concentration and acting as a preferentially excluded, protein-stabilizing cosolvent. In contrast, CAGE and CAL exhibit behavior typical of Bio-ILs: their affinities, as quantified by KBIs, vary with concentration. Although they are not completely excluded from the protein surface, their compensated electrostatic interactions, modulated by the nature of both cations and anions, contribute to protein stabilization. The choline cation also exhibits complex behavior, with variations in accumulation at different distances from the protein surface. Structural analyses based on RMSD and RMSF indicate an optimal concentration range to maintain protein structures in their functional conformations without a very high viscosity. In AMA1, key residues in disordered regions: K489, R503, K508, and R512 were stabilized. The spatial distributions of relevant functional groups of each cosolvent were further characterized using Minimum Distance Distribution Functions and KBIs. These approaches enabled a molecular-level understanding of protein–cosolvent interactions and their impact on protein stability.

Aqueous suspension of non-ionic poly(N-isopropylacrylamide) (PNIPAM) microgel particles was synthesized via free-radical precipitation polymerization. On the synthesized PNIPAM microgel particles, a dynamic light scattering experiment was performed, and hydrodynamic radii were determined to be roughly 240 and 125 nm for temperatures of 25C and 40C, respectively [1,2,3]. Dielectric relaxation studies were carried out on a 10wt.% PNIPAM solution prepared in a mixed solvent system of 70% water and 30% methanol, and on the pure solvent mixture, over a broad frequency range of 100 MHz to 50 GHz and at temperatures between 5C to 50C. The dielectric spectra for the pure water-methanol mixture showed a dominant relaxation process associated with the collective reorientation of hydrogen-bonded networks. The relaxation for the polymer solution arises from (i) polymer-solvent coupling and (ii) the restricted dynamics of water molecules confined within the polymer network. Upon increasing the temperature, both samples show decreased relaxation times, implying faster molecular reorientation and a gradual weakening of hydrogen-bond interactions [3]. As the temperature increases, both ε′ and ε″ decrease, indicating reduced dipolar polarization and dielectric loss due. The relaxation peak in ε″ shifts toward higher frequencies with increasing temperature. The findings of this study will be presented.

1. B Vijayakumar et al., Macromolecules, 55, 1218–1229 (2022).
2. B Vijayakumar et al., Physical Chemistry Chemical Physics, 25, 22223-22231(2023).
3. B Vijayakumar et al., Transactions on Dielectrics and Electrical Insulation, 30, 1657-1662 (2023).

The small-angle neutron scattering (SANS) diffractometer KWS-2 [1-4] is dedicated to the investigation of multi-scale morphologies in soft condensed matter and biophysical systems, bridging atomic- and meso-scale structures. By combining pinhole SANS (8 mm spatial resolution) with a focusing mode using MgF₂ lenses and a secondary high-resolution detector (1 mm spatial resolution), as well as wide-angle neutron scattering (WANS) detection (a third detector covering scattering angles up to s ≃ 50°), the instrument provides access to a wide Q range, from 10⁻⁴ to 2.0 Å⁻¹ [5–7]. This can be achieved either with tunable resolution (Δλ/λ between 1% and 10%, adjusted using the time-of-flight (TOF) mode with the resolution chopper) [3, 8] or with enhanced intensity through the focusing mode, which employs a large beam size while maintaining the same Qmin resolution on the main SANS detector as in pinhole mode, yielding up to a tenfold increase in neutron intensity at the sample position [4]. In addition, a secondary background chopper, installed on demand upstream of the sample position, enables TOF measurements in the high-Q regime by separating inelastically scattered neutrons from hydrogenous samples, thereby suppressing the incoherent background [9].
Colloidal, gel, and micellar systems, as well as hierarchically organized semi-crystalline materials such as ion-exchange membranes or complexes formed by polymers in solution with other macromolecular species, particularly benefit from the versatility of the instrument's characterization modes [5–8, 10, 11].
The instrument also provides high-quality data for functionalized nanoparticles and small biological systems, enabling structural analyses with molecular-level discrimination between competing models [12, 13]. Examples of studies on systems relevant to soft matter, biophysics, and materials science, including the availability of in situ SEC, FTIR and UV–Vis spectroscopy at KWS-2, will be discussed [7, 14].

References
[1] A. Radulescu et al., J. Appl. Cryst. 48, 1860 (2015).
[2] J. Houston et al., J. Appl. Cryst. 51, 323 (2018).
[3] A. Radulescu, J. Appl. Cryst. 57, 1040 (2024).
[4] A. Radulescu et al., J. Appl. Cryst. 58, 1582 (2025).
[5] S. J. Talley et al., ACS Appl. Mater. Interfaces 11, 31508 (2019).
[6] B. Krugmann et al., Scientific Reports 10, 16691 (2020).
[7] F. Kaneko et al., Polymer 295, 126771 (2024).
[8] J. Puig-Rigall et al., J. Colloid Interf. Sci. 524, 42 (2018).
[9] L. Balacescu et al., J. Appl. Cryst. 54, 1217 (2021).
[10] M. M. Schiavone et al., J. Appl. Cryst. 56, 947 (2023).
[11] B. Joseph Boniface et al., J. Colloid Interf. Sci. (in press).
[12] Y. Wu et al., Nanoscale 17, 3798 (2025).
[13] X. Liu et al., Angew. Chem. Int. Ed. 64, e202516308 (2025).
[14] E. A. Kelley et al., Soft Matter 15, 1253 (2019).

Transport properties, such as diffusivity and viscosity, govern the rate and efficiency of mass and energy transfer and are of particular relevance in the development of vaccine adjuvants, as they are closely associated with the delivery of these substances within the human body, directly influencing their performance and efficacy [1]. In this work, the transport properties of choline-based ionic liquids (ILs) in aqueous solutions were investigated at different concentrations using molecular dynamics (MD) simulations. 1 μs were performed for binary (ILs + water) and ternary (ILs + water + Plasmodium falciparum proteins PDB IDs: 2J5L, 8DFI, and 4QYO) compositions. To accurately describe transport behavior, non-polarizable force fields were employed for aqueous electrolyte systems [2]. Simulations were carried out using GROMACS, with the TIP4P/2005 water model and scaled-charge OPLS-AA force field. The biocompatible ILs studied included choline chloride (CACL), choline lactate (CAL), and choline geranate (CAGE), at concentrations of 0.125 M, 0.250 M, 0.5 M, 1.0 M, and 2.0 M. Transport properties were obtained through post-processing MD trajectories using Julia programming language and GROMACS tools. Diffusion coefficients directly influence whether adjuvants rapidly disperse at the injection site or remain localized, enabling sustained release. The results indicate an optimal concentration range between 0.125 M and 0.5 M, in which proteins remain stable without excessively high viscosity, which would be undesirable for these applications. In contrast, higher viscosity may hinder diffusion, prolonging residence time and enhancing controlled release [3]. Overall, these results establish a clear molecular-level understanding of the transport properties of choline-based ionic liquids and how it must be carefully balanced to ensure ease of administration and minimize discomfort during injection.

An electrochemistry laboratory is currently being established at JCNS-4 for the preparation and comprehensive characterization of semicrystalline hydrocarbon-based proton exchange membranes for energy applications. The available facilities and methods will be introduced, including a hot press for membrane preparation, a tensile testing machine for producing uniaxially oriented membranes, a portable FTIR spectrometer for chemical and structural characterization, and an LCR meter, conductivity cells, and humidity generators for conductivity measurements under controlled temperature and relative-humidity conditions. A fuel-cell test stand and a hydrolyser, both currently under development, will also be presented, together with their future roles in evaluating membrane performance under practical operating conditions.

Isotactic poly(4-methyl-1-pentene) (P4MP1) is known to absorb various organic solvents, such as alkanes [1]. Although P4MP1 exhibits nearly identical densities in its crystalline and amorphous regions, it has been revealed that solvent absorption predominantly occurs within the amorphous region [2]. However, because isotropic samples were used in Ref. [2], it was difficult to distinguish the structural changes induced by solvent absorption between the crystalline and amorphous regions. Therefore, in this study, we conducted small-angle neutron scattering (SANS) and X-ray diffraction (XRD) experiments using uniaxially stretched P4MP1 samples.
SANS measurements were performed using TAIKAN at J-PARC, and XRD measurements were carried out at BL40B2 of SPring-8. For both techniques, two-dimensional diffraction patterns of the stretched P4MP1 were acquired before solvent immersion and compared with those obtained after immersion. The SANS results revealed the following insights. For the neat P4MP1 sample, no diffraction peaks were observed due to the lack of contrast in the two-dimensional image, resulting from the nearly identical densities of the crystalline and amorphous regions. Upon dropping deuterated decane, the solvent selectively penetrated the amorphous region, generating a contrast that led to the appearance of a peak derived from the lamellar periodic structure exclusively along the stretching direction. This directional dependence indicates the orientation of the lamellar crystals. From the XRD results, a circular first halo was observed at approximately q=0.7Å^(-1) for the neat stretched P4MP1. The absence of orientation in the XRD pattern, contrast to the directional behavior observed in the SANS measurement, indicates that this first halo originates from the microscopic structure within the amorphous region. While it had been suggested that this first halo arises from void spaces between backbones [3], the intensity of the first halo was indeed significantly reduced upon the addition of decane. In the presentation, we will also report on the measurement results obtained from quasi-elastic neutron scattering (QENS).

An in-line size exclusion chromatography - small-angle neutron scattering (SEC-SANS) setup has been implemented at the KWS-2 instrument at MLZ to enable structural investigations of biomolecules under improved sample quality conditions. By coupling SANS measurements with prior chromatographic separation, challenges associated with sample heterogeneity, aggregation and degradation can be effectively addressed.
The performance of the setup was validated using bovine serum albumin (BSA) as a model protein system containing several oligomeric fractions in solution. The resulting data demonstrate effective chromatographic separation of the targeted monomeric fraction together with simultaneous acquisition of reliable scattering profiles.
Furthermore, BSA in the presence of zwitterionic surfactant sulfobetaine (SB3-12) was investigated as a model protein-surfactant system. The SEC-SANS data show changes in scattering profiles with increasing surfactant concentration, indicating structural rearrangements induced by surfactant binding. These measurements demonstrate the capability of the method to selectively obtain scattering from targeted fractions while reducing contributions from coexisting species and aggregates.
Thus, the SEC-SANS setup at KWS-2 expands the possibilities for future biomedical and pharmaceutical research. It is particularly valuable for investigating proteins, therapeutic formulations and complex biomolecular systems where conventional SANS is limited by sample heterogeneity, tendency to aggregation, or degradation.

In SANS, the mesoscopic/nanoscale structure is resolved that then can be connected to macroscopic functions in various applications. Examples are magnetic nanoparticles for hypothermia, proteins in interaction with drugs and proteins for food products, bio-membranes with proteins and/or drugs, and manyfold (micro-) emulsions that serve in life sciences. All these examples deal with microscopic mechanisms that are uncovered using SANS under different conditions. Those mechanisms have direct impact on the way the application is meant. The general understanding of a mechanism allows to tailor details in the microscopic world to make the application more effective, save materials and lead to an environmentally friendly solution.

The customized instrument began user operations in April 2023. As the latest addition to our small-angle scattering instrument family, the new instrument is equipped with a high-flux Metal-Jet source and a movable Eiger2R 4M SAXS detector. It also features a 4-axis motorized WAXS detector and a Bonse-Hart USAXS system, enabling a broad scattering vector q range from 0.0002 to 7 Å⁻¹.
The instrument is enhanced by versatile sample stage supports, various in situ platforms commonly used in SANS experiments, such as rheometers, electromagnets, stopped-flow devices, FT-IR spectrometers, and electrochemical workstations. The extensive array of sample environment accessories allows experiments to be conducted over a temperature range of -150℃ to 1000℃, under diverse conditions including shear, humidity, tensile deformation, as well as coupled techniques such as operando-battery, SEC-SAXS and Raman-SAXS. It will greatly assist users of our neutron scattering facilities in acquiring complementary X-ray structural information and will streamline the selection of suitable samples for neutron instruments, thereby improving the efficiency of our neutron scattering user programs.
KWS-X has provided more than 8,000 hours of beam time to over 100 users and supported more than 120 proposals. Within a short period, it has already contributed to over 40 high-quality publications in renowned journals including Nature Nanotechnology, Nature Communications, Advanced Materials, JACS, Matter, and Angewandte Chemie.

The study of biological systems in all its complexity has proven to be quite difficult. As a result, the use of simpler model systems is common. Two of the central phenomena that are becoming recognized in biological systems are phase separation and self-assembly. In vivo, both of these are common for different types and combinations of proteins and RNA [1]. However, studying these systems directly is difficult and the starting materials can be expensive to obtain.
Synthetic polypeptides, specifically Polyaminoacids, have proven to be a versatile model system for polymer assembly, coacervation and phase separation [2][3]. In this work, Polyarginine and Polyaspartic Acid are combined to study both processes as a function of temperature and salt concentration.
At lower temperatures and with no, very little or a lot of added salt, the self-assembly of the solid phase is studied using primarily X-ray and neutron scattering methods such as SAXS and SANS as well as tensile testing. Large scale structural ordering and self-assembly is observed.
At higher temperatures and/or intermediate salt concentrations, the phase separation of the liquid phases will be studied using microscopy and DLS as well as rheology. The phases are highly concentrated and viscous. This work will also focus on tuning the properties of these phases to mimic specific systems and compare them to simple biological models. In the future, the plan is to also use NSE and QENS to study the internal dynamics of these concentrated phases.

[1] B. Wang, Signal Transduction and Targeted Therapy, 6, 290 (2021).
[2] W.Wenjie, ChemBioChem, 26, e202400773 (2025).
[3] A.Levin, Nature Reviews Chemistry, 4, 615-634 (2020).

Synthetic polypeptides are versatile model systems for investigating electrostatically driven self-assembly, polyelectrolyte complexation, and phase behavior in biomolecular and soft matter systems. Oppositely charged polypeptides such as polyarginine and poly(aspartic acid) provide well defined platforms for studying complex coacervation and liquid-liquid phase separation. However, commercially available materials are expensive, limited in molecular weight range, and often lack comprehensive characterization.
Here, we report the synthesis and optimization of charged polypeptides via N-carboxyanhydride (NCA) ring-opening polymerization. NCA monomers derived from protected ornithine and aspartic acid were synthesized under rigorously anhydrous conditions, with high monomer purity being essential for controlled polymerization. Polymerization conditions were optimized by varying the initiator type, concentration, solvent, and reaction time to obtain polymers with controlled degrees of polymerization and narrow molecular weight distributions.
Polyarginine was prepared by deprotection followed by guanidinylation of polyornithine, whereas poly(aspartic acid) was obtained through deprotection and neutralization of the corresponding precursor, yielding water soluble polyanionic chains. The polymers were characterized by gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy to determine molecular weights and confirm chemical structures. Chiral purity was assessed by ¹³C NMR. These well-defined charged polypeptides provide model systems for investigating polyelectrolyte complex phase behavior, including liquid-liquid phase separation as models for membraneless organelles and solid-phase assemblies analogous to biological materials such as collagen.

Contrast-variation small-angle neutron scattering (CV-SANS) is a powerful tool to evaluate the structure of multi-component systems by decomposing the scattering intensities I measured with different scattering contrasts into partial scattering functions S of self- and cross-correlations between components. The measured I contains a measurement error ΔI, and ΔI results in an uncertainty in the partial scattering functions ΔS. However, the error propagation from ΔI to ΔS has not been quantitatively clarified. Recently, we have established deterministic and statistical approaches to determine ΔS from ΔI [1]. We have applied the mathematical methods to clay/polyethylene glycol aqueous solutions as a model system of nanocomposite gels, and have successfully estimated the errors in S. The quantitative error estimation in S offers a strategy to optimize the combination of scattering contrasts to minimize error propagation. Also, we have improved the estimation of partical scattering functions S, based on Gaussian process regression using prior knowledge about the smoothness and flatness in Q dependence of S [2].

References :
[1] K. Mayumi, T. Oda, S. Miyajima, I. Obayashi, K. Tanaka, “Error evaluation of partial scattering functions obtained from contrast-variation small-angle neutron scattering”, Journal of Applied Crystallography, 58, 4 (2025).
[2] I. Obayashi, S. Miyajima, K. Tanaka, K. Mayumi, “Enhanced estimation method for partial scattering functions in contrast variation small-angle neutron scattering via Gaussian process with prior knowledge of smoothness”, Journal of Applied Crystallography, 58, 976-991 (2025).

Supramolecular peptide assemblies (SPAs) are increasingly recognized as versatile building blocks for biomedical and nanotechnological applications due to their sequence-controlled self-assembly and tunable physicochemical properties [1]. However, establishing clear structure-property relationships that link peptide sequence to supramolecular organization remains challenging and requires an integrated experimental-computational approach. Here, we investigate a library of short peptides that self assemble into fibrillar supramolecular structures through sequence-encoded hydrophobicity gradients. Self-assembly onset is quantified through fluorescence spectroscopy by determining Critical Aggregation Concentrations, while Atomic Force Microscopy, Circular Dichroism, and Fourier-Transform Infrared spectroscopy are used to confirm fibrillar morphologies and reveal sequence-dependent variations in secondary structure. These results demonstrate that subtle sequence modifications strongly influence intermolecular ordering, aggregate size, and critical concentration, with several systems displaying coexisting supramolecular morphologies. To bridge experimental observables with molecular-level insight, we aim to identify experimentally accessible descriptors that correlate with coarse-grained molecular dynamics simulations [2]. Importantly, we seek to establish whether these descriptors can also predict the performance of SPAs as antibacterial materials. This will be directly tested though experiments examining the interaction of selected peptide assemblies with Pseudomonas aeruginosa bacterial strains, allowing us to evaluate how supramolecular organization influences biological response. Overall, this integrative strategy links macroscopic characterization, molecular modelling, and preliminary biological evaluation, providing a rational framework for the design of customizable SPAs with controlled architectures and tailored biological performance [3].

[1] 1. Z. Álvarez, A. N. Kolberg-Edelbrock, I. R. Sasselli, et al., Science, 374, 848–856 (2021).
[2]. T. K. Piskorz, L. Perez-Chirinos, B. Qiao, and I. R. Sasselli, ACS Omega, 9, 31254-31273 (2024).
[3]. A. M. Garcia, M. Melchionna, et al., ACS Nano, 15, 3015–3025 (2021).
strong text

Block polymers (BCPs) are attractive for developing novel materials due to their tunable properties and self-assembly via block chemistry, composition, and molecular weight. However, to harness the unique properties of BCPs in applications, their self-assembly and ordering on long length scales must be controlled. Unfortunately, practical methods for processing BCPs into materials with long-range order remain limited; for example, techniques like magnetic field alignment are typically infeasible because BCPs are weakly diamagnetic and respond minimally to magnetic fields. However, we discovered that magnetic fields induce unexpected self-assembly and ordering in disordered BCP solutions via a new mechanism distinct from domain alignment. This process effectively converts a “non-magnetic” water-like fluid to a soft solid material using only a weak magnet. Here, the formation of stable ordered phases (cubic, cylinder, networks) causes up to a six order-of-magnitude increase in viscosity and modulus. Using a combination of magnetorheology, small angle x-ray scattering, quasi-elastic neutron scattering, and vibrational spectroscopy, we demonstrate that magnetic fields facilitate these phase transitions by altering polymer-solvent interactions, hydrogen bonding, and polymer and solvent mobility – which in turn modify amphiphile packing. By identifying the molecular-scale mechanisms by which magnetic fields alter solvent structure and interactions with macromolecules in solutions, this work can be leveraged to improve chemical separations and to create new polymeric materials for applications in drug delivery, sensing, and catalyst templates.
This work is supported by the National Science Foundation under Grant No. DMR-2143162. We acknowledge the Australian Centre for Neutron Scattering at ANSTO and the Australian Government through the National Collaborative Research Infrastructure Strategy, in supporting the neutron infrastructure used in this work via ACNS proposal 17038.

Pressure is a key variable in the phase behavior of thermoresponsive polymers [1]. In the prototype system poly(N-isopropylacrylamide) (PNIPAM) in aqueous solution, the cloud point temperature, Tcp, depends on pressure, and the coexistence line in the temperature-pressure frame is described by an ellipse with a maximum at ca. 60 MPa and 35 °C. Small-angle neutron scattering (SANS) has shown that, above Tcp, mesoglobules are formed, with their size, water content, and inner structure depending strongly on pressure [2]. Rapid pressure changes (“pressure jumps”) across the coexistence line combined with kinetic SANS (50 ms – 1500 s) allow to resolve the pathway of mesoglobule formation in dependence on the target pressure [3,4]. At low pressure, kinetic factors are important, such as the formation of a polymer-rich, rigid shell, which hampers further growth by coalescence. In contrast, at high pressure, the growth proceeds by diffusion-limited coalescence, due to the weaker dehydration of PNIPAM than at low pressure. Pressure jumps from the two-phase to the one-phase region reveal that the disintegration of the mesoglobules evolves either via chain release from their surface or via swelling, depending on the osmotic pressure of the water [5]. Finally, kinetic processes in solutions of self-assembled micelles, formed by diblock copolymers from a PNIPAM block and a hydrophobic poly(methyl methacrylate) block, are elucidated in dependence on target pressure.

Ionic microgels are highly responsive materials whose structure, interactions, and self-assembly can be tuned by external stimuli. Among these stimuli, electric fields provide a powerful route for directing particle organization and creating non-equilibrium structures. However, understanding how individual microgels respond to external fields in concentrated suspensions remains a significant experimental challenge. In this talk, I will demonstrate how small-angle neutron scattering (SANS), particularly under zero-average contrast (ZAC) conditions, can reveal particle-scale structural changes that govern macroscopic assembly behavior. Using ionic poly(N-isopropylacrylamide-co-acrylic acid) microgels with different crosslinking densities, we investigate the interplay between particle softness, concentration, and applied AC electric fields. For highly crosslinked microgels, SANS measurements provide evidence for field-induced particle deformation from initially spherical to anisotropic shapes. These structural changes correlate with the emergence of unusual self-assembled morphologies, including strings, body-centered-tetragonal clusters, and tubular structures (typically associated with anisotropic particles). In contrast, loosely crosslinked microgels exhibit a markedly different response: neutron and X-ray scattering measurements reveal substantial field-induced particle compression while maintaining isotropic particle symmetry and unchanged interparticle spacing. The results of these studies will be presented.

Concentrated solutions and gels of block copolymer micelles demonstrate both the cohesive strength of solids and the diffusive transport characteristics of liquids, and are subject of theoretical and technological interest [1]. Special attention is devoted to polymers containing a stimuli-responsive "switching" block that imparts the system the ability to undergo sharp, reversible changes in response to variation of external control parameters (e.g. temperature)[2]. In this work we investigate the behaviour of diblock and triblock copolymers containing thermoresponsive poly-N-isopropyl acrylamide (PNIPAM) and persistently hydrophobic polystyrene (PS) blocks, in concentrated water solution [3]. The polymers form spherical micelles in water, whose strucural parameteres have been determined by small-angle neutron scattering (SANS). At high concentration, the micellar samples show a completely different rheological behaviour depending on block size and, most importantly, architecture. In particular, a “soft” gel is formed in triblock-containing samples as the triblocks form junctions bridging different micellar cores. At the microscopic level, the PNIPAM chain mobility is influenced by the size and architecture of the polymer as well as topological constrains induced by the grafting on the PS core. Neutron spin echo (NSE) data shows how the single-chain dynamics is at best described by Zimm with one end fixed and additional internal friction between monomers. A characteristic modulation in the dynamics related to the geometrical arrangement is found. Side chains are mobile but strongly constrained by a much slower backbone. The theoretical approach derived herein can serve as a framework for describing other systems in which polymeric junctions play a significant role [4].

[1] R. Ganguly et al., J. J. Mol. Liq. 2020, 314, 113591. R. Tamate et al., Adv. Mat. 2018, 30, 1802792.
[2] A. Nykänen et al., Macromolecules 2007, 40(16), 5827–5834. S. P. Sridhar et al., Surfaces and Interfaces 2020, 21, 100800. S. Kirkland et al., Biomacromolecules 2008, 9, 481–486.
[3] J. Adelsberger et al., Colloid Polym Sci 2011, 289, 711–720. J. Adelsberger et al., Macromolecules 2010, 43, 2490–2501.
[4] B. Rosi et al., Macromolecules 2025, 12, 13009-13021.

A thermoresponsive polymer, such as poly(isopropyl acrylamide) (PNIPAM), changes state when the temperature crosses its phase transition point. PNIPAM-based polymers exhibit broad hysteresis for the volume phase transition between the swollen and collapsed states. These polymers display atypical behaviors, such as bistability, remanence, information storage capabilities, and memory functions. The behavior of the polymer near the transition point and the long-term stability of swollen or collapsed polymer clusters within the hysteresis temperature range have been thoroughly investigated using scattering and electron microscopy techniques.
The phase transition from the swollen to the collapsed state (and vice versa) has been studied in detail using dynamic light scattering and cryo-TEM. To do so, samples were prepared across the transition point with a small temperature step. The broad hysteresis of PNIPAM-based polymers opens exciting possibilities for achieving bistability, remanence, and efficient, reversible information storage. Our research highlights the potential of PNIPAM and its block copolymers, which significantly expand the hysteresis window and enhance the material's capabilities.
Furthermore, hysteresis is intricately connected to the dynamic assembly and disassembly of cluster domains during phase transitions, paving the way for advanced applications. Imagine writing information thermally with a laser or heated/cooled pen tips on a thin-film backscattering display. The versatility is astounding: not only can the bistable state be changed smoothly by temperature, but also by pH, enabling an AND logic gate function. We also discovered an intriguing memory state. Information can be encoded within the hysteresis window and remain hidden at elevated temperatures, adding a layer of complexity and creativity to information management.

Polysaccharide–protein complexes represent attractive platforms for the encapsulation and delivery of hydrophobic bioactive compounds owing to their biocompatibility, biodegradability, and tunable physicochemical properties. In this study, complexes were formed via electrostatic co-assembly of bovine serum albumin (BSA) with oppositely charged κ- and λ-carrageenan. The effect of carrageenan type and vitamin D3 (VD3) loading on the structural properties and stability of the assemblies was investigated under different conditions.
Structural characterization using scattering and spectroscopic techniques showed complex formation in acidic conditions with similar swollen hierarchical organization, in wich protein constituted the dominant structural component. Incorporation of Vitamin D3 induced structural reorganization of the initially formed complexes, leading to the formation of locally denser domains and larger associates with enhanced stability at neutral pH.
These findings provide insight into the structure and stability of protein–polysaccharide assemblies and their potential as carriers for hydrophobic bioactive compounds.

Neutron and x-ray scattering provide indirect but highly sensitive access to the structure and dynamics of condensed and soft-matter systems. However, extracting physically meaningful parameters from scattering data is a challenging task. Therefore, robust analysis software and intelligent decision-support strategies have become essential components of modern scattering experiments.

At JCNS, we develop data reduction and analysis software frameworks, as well as AI-assisted approaches that support and advance workflows in neutron and x-ray scattering experiments. By integrating these methods into data acquisition and analysis pipelines, we enable on-the-fly data assessment and experiment steering during beam time, as well as efficient and reproducible offline analysis.
In this talk, we will provide an overview of our in-house software tools and AI-assisted solutions, discuss their opportunities and limitations, outline emerging perspectives for data-driven scattering experiments, and present selected examples from our recent work.

The exceptional performance of polymer electrolyte membranes (PEMs) used in energy conversion technologies arises from their microphase-separated morphology that consists of hydrophilic ionic domains containing functional groups that facilitate proton transport under hydrated conditions, and hydrophobic crystalline polymer matrix that provides mechanical integrity and chemical stability. Nafion, a perfluorosulfonic acid (PFSA) ionomer, is widely regarded as the benchmark material for PEM fuel cell and water electrolysis applications. However, despite its advantages, Nafion exhibit several drawbacks. In particular, they belong to the broader class often referred to as “forever chemicals” and consequently, increasing concerns regarding the environmental and potential human health impacts associated with fluorinated compounds may lead to future regulatory restrictions on their use. Therefore, replacing perfluorosulfonic acid (PFSA) ionomers with environmentally friendly and less expensive hydrocarbon-based materials represents an attractive strategy for the development and optimization of polymer electrolyte membranes for energy conversion applications.
Semicrystalline syndiotactic polystyrene (sPS) exhibits complex polymorphic behavior including crystalline forms with polymer chains in either planar zigzag conformations (α and β forms) or TTGG helical conformations (γ, δ, and ε forms). In addition, sPS can form a variety of co-crystalline (clathrate) complexes with numerous small organic molecules, which can be incorporated as guest species within cavities located between the polymer helices in the δ and ε forms and can subsequently be exchanged without disrupting the crystalline framework. Exploiting this unique property, sPS membranes containing the δ crystalline form can be functionalized homogeneously through the so-called solid-state sulfonation method: sulfonation occurs selectively within the amorphous regions, which become hydrophilic and proton-conductive upon hydration, while the crystalline domains remain largely unaffected. Subsequent annealing at 180–200 °C promotes the conversion of the δ form into the thermodynamically stable α or β crystalline forms, yielding sulfonated sPS membranes with enhanced mechanical and chemical stability and properties suitable for fuel cell applications, as we recently have confirmed.
To understand and optimize the performance of sPS membranes, it is first necessary to establish correlations between their microscopic structural and dynamical properties and proton conductivity, as well as to gain insight into the water transport mechanisms operating over different length and time scales. Small-angle neutron scattering (SANS), performed over an extended Q range, and multi-resolution quasielastic neutron scattering (QENS), both benefiting from contrast variation achieved through the selective deuteration of components in the hydrated membranes, are particularly powerful and complementary techniques for investigating the structural organization and molecular dynamics of this material, as will be shown in this presentation.