This research focuses on the development of a sustainable approach for the generation of free-standing, highly transparent and flexible films of chitin nanocrystals (ChNCs) from shrimp shells. ChNCs were extracted by acid hydrolysis and subsequently treated in an alkaline environment to produce surface-deacetylated chitin nanocrystals (CsNCs). The effects of deacetylation on the size, morphology and colloidal stability of the nanocrystals were systematically investigated using scanning electron microscopy, dynamic light scattering and zeta potential analysis. The reaction time was optimized to improve the degree of deacetylation and thus particle interactions, which in turn had a direct impact on the structural and mechanical properties of the films. To further enhance the functional properties of the films, natural polyphenols (epigallocatechin gallate, tannic acid and the methanol-insoluble fraction of hardwood lignosulfonate) of different chain length and content of hydroxyl groups were incorporated as crosslinkers, strengthening the hydrogen bonding network and significantly improving mechanical strength, water resistance, and bioactivity.[1] The resulting films exhibited no dissolution observed up to 7 days of soaking in water, strong antioxidant and antimicrobial properties, including bactericidal activity against both Gram-negative (E. coli) and Gram-positive (S. aureus) bacterial strains as high as 99.99%. Additionally, glycerol was explored as a plasticizer to optimize flexibility and mechanical performance while maintaining the films’ hierarchically ordered structures. This work provides critical insights into the self-assembly of chitin-based films and demonstrates the potential of utilizing seafood byproducts for the development of high-performance, biobased materials with high applicability potential.

Porous polymers have been used for various applications like catalysis, absorption, drug delivery, tissue engineering, and more on. For these applications, thermal behaviour of a material plays a crucial role affecting the material properties. However, the effect of porosity on the thermal properties of porous polymers has scantly been reported. Addressing this, polymeric constructs with varying levels of porosity were fabricated by utilizing Pickering emulsion templating. Stable emulsions of ε-caprolactone (CL) were prepared using silica nanoparticles (SiNP) as stabilizers and silicone oil as dispersed phase, which were further in-situ polymerized and crosslinked. The extent of porosity was controlled by changing the dispersed phase volume percentage of these emulsions. The crystallization behaviour of the polymer present at the interface between two droplets was investigated under non-isothermal conditions due to its better relevance during real-time application. It was observed that inclusion of SiNP and porosity led to extremely diminished crystallization temperature and kinetics. Various models, namely Jeziorny, Ozawa, and Mo models, were utilized to explain the crystallization behaviour of substrates under non-isothermal conditions. While a 3-regime crystallization was demonstrated by non-crosslinked and crosslinked PCL, presence of SiNP and porosity led to 2-regime crystallization. This change in crystallization kinetics of the material was further prominent in materials with higher extent of porosity. Additionally, the changes in crystal structure of various polymer materials were observed using x-ray diffractometer explaining the crystallization behaviour of the porous constructs.

Conjugated polymer networks (CPN), which are member of porous organic polymer family, have recently attained tremendous research attention due to their multifaceted applications including energy storage[1], catalysis[2] and separation[3] that originated from their unique combinations of properties like extended conjugation, microporosity and high surface area. CPN with higher dimensional structure and interconnected pores favoring electrolyte percolation will show better electrochromic property compared to linear polymer. CPN containing heteroarmatic monomers in their backbone can be considered as carbon skeleton with doped heteroatom and ideal as electrocatalyst. Herein, we have developed two triazine-based donor-acceptor conjugated polymer networks by coupling 3-substituted thiophene (donor) unit with a triazine ring (acceptor) through a phenyl ring spacer (Figure 1). Two different sidechains, alkyl (CPN1) and oligoethylene glycol (CPN2), were rationally introduced into the 3-position of thiophene in the CPN to investigate the effect of side-chain functionality on the electrochromic and electrocatalytic property. Both CPN exhibited reversible yellow-to-deep brown Vis-to-NIR electrochromism with moderate response times and a high coloration efficiency (CE) in the organic polymer category. Whereas, both CPN demonstrated superior electrocatalytic oxygen evolution reaction (OER) activity in basic medium with long-term durability. The electrocatalytic performance of CPN2, which achieved a current density of 10 mA/cm2 at an overpotential (η) of 328 mV, is much superior to CPN1, which reached the same current density at an overpotential of 488 mV.

Poly-/Oligo(phenylene ethynylene)s (PPE/OPE) display conjugated, rigid scaffolds and are of particular interest for their photophysical and electronic properties. Herein, we introduce a photoswitchable azobenzene group into sequence-defined OPE backbones. The resulting photo-responsiveness was investigated and, for the first time, quantified using size-exclusion chromatography. This study provides new insights into stimuli-responsive materials and extends the analytical techniques used to investigate these dynamic molecular systems.

The deployment of safe and efficient Carbon Capture, transport and Storage systems is crucial to reducing atmospheric CO2 concentrations and achieving a net-zero carbon footprint in the short to medium term [1,2]. As part of the ECCSELLENT project, Alma Mater Studiorum-University of Bologna is leading efforts to enhance Italy's CCUS research infrastructure by developing advanced polymeric materials for use as membranes in carbon capture processes and as liners or gaskets for CO2 transport. Polymers, thanks to their lightweight nature, adaptability, and chemical resistance, are ideal for handling extreme conditions of pressure and temperature typical of CO2 transport chains, essential for controlling leakage and failure [3,4].
To this aim, UniBo proposed innovative preparation techniques for hollow fiber and thin-films membranes whose mechanical properties and nanoscale morphologies are determined using techniques such as Dielectric spectroscopy and Atomic Force Microscopy (AFM) (Fig. 1b) enabling a deeper understanding of the relationship between material properties and their strength and durability. Moreover, polymers are being investigated as potential liners and sealants for CO2 transport. Their CO2 sorption (Fig.1a) and permeation behaviour under high-pressure and low-temperature conditions is assessed using BET instruments and custom-built permeation test rigs. This characterization evaluates the effects of dense-phase CO2 on material properties, including energy storage, glass transition temperature (Tg), swelling, and plasticization. This project is paving the way for innovative CCUS applications and long-term sustainability in CO₂ management technologies.

The charge transport properties of conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) layer-by-layer (LbL) thin films were systematically investigated using different substrates, including glass, indium tin oxide (ITO), and GaAs:Si. The use of an ITO substrate significantly enhanced the electrical conductivity of the films, reaching up to 8004.52 S/cm. This improvement is attributed to enhanced charge transfer at the interface, which may promote better alignment of polymer chains near the surface, thereby increasing overall conductivity. Figure 1 presents the temperature-dependent electrical conductivity of films coated on ITO.
For PEDOT:PSS films deposited on glass, temperature-dependent electrical conductivity was measured using a low-temperature Hall system. The experimental data were fitted with two charge transport models: (a) tunneling and (b) variable range hopping (VRH). The results indicate that the tunneling model provides a better fit, suggesting that charge transport in PEDOT:PSS primarily occurs through carrier tunneling between polar and bipolar regions within the polymer chains. Figure 2 compares the experimental data with both models, while Table 1 summarizes the effects of different substrates on electrical conductivity.
This study provides valuable insights into the charge transport mechanisms of PEDOT:PSS and highlights its potential for future applications in energy conversion and storage devices.

Thermoplastic polymers have gained prominence in individual ballistic armor owing to their advantageous properties. Its lightweight and flexible nature, along with its high impact resistance, makes it a feasible option as an alternative to metals and ceramics. They are mainly employed as fibers (para-aramid fibers and polyethylene) or matrices (epoxy, phenolic, polyethylene, polyurethane) in ballistic composites¹.
A ballistic impact creates a shock wave front on the bullet/armor interface travelling through the material². The propagation of a shock wave front in a solid medium is characterized by an abrupt discontinuity in the thermodynamic properties of the material, notably pressure, internal energy and specific volume³. The balance of mass, momentum and energy that governs this phenomenon can be mathematically treated by the Hankine-Hugoniot equations. For polymeric materials, the application of high pressures at high strain rates, with increase of temperatures above the melting temperature, leads to significant morphological changes.
In this communication, high density polyethylene (HDPE) samples were subjected to shock wave compression tests (flyer plate) of different values. The estimated thermodynamic responses were calculated and compared with existent values in the literature⁴⁵ , obtaining consistent results. Synchrotron Scanning SAXS/WAXS measurements were performed on the different samples in the Normal (ND) and Transversal direction (TD) to the shock wave. The results allow the morphological characterization of the system at the atomic and nanometric scale.

Conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) layer-by-layer (LbL) thin films deposited on different substrates (glass, ITO and GaAs:Si). The in-plane thermal conductivity was measured using thermoflectance method, while cross – plane thermal conductivity using photothermal infrared radiometry [1]. In –plane electrical conductivity obtained using 4-probe method. The cross-plane electrical conductivity was measured using modified 4-probe method. The measurements were done in temperature range between -50 C to 50 C. Better understanding of thermoelectrical properties of PEDOT:PSS. The linear relation between was found and shown on Figure 1, while in-plane conductivity shown in Figure 2.

Lignin is an abundant renewable resource with interesting properties, e.g., its natural antioxidant activity. As a complex crosslinked copolymer, it is difficult to fully understand the relationship between its structure and properties. Comprehensive knowledge of its structure though is essential for future applications such as being an additive for food packaging materials. [1]
A frequently used strategy to characterize lignin’s antioxidant activity is by bulk-type assays. Those assays include, e.g., DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), FRAP (ferric ion reducing antioxidant potential), and FC (Folin-Ciocalteu). [2]
In the case of the 3D biopolymer lignin (mixture of different molecular mass fractions, different functional group contents, different monomer compositions) bulk-type assays only give a single average value for the investigated property. As different fractions may influence each other in an additive, synergistic, or inhibitory way it is important to know the individual contribution of those fractions. [3]
In this study, both size-exclusion chromatography (SEC) and reversed-phase liquid chromatography (RP-LC) were used in a two-dimensional setup combined with post-column ABTS assay to qualitatively map and assess the antioxidant profile of softwood Kraft lignin. The results show that each of the chromatographic techniques alone are unable to sufficiently resolve the sample’s complexity presented by lignin. Two-dimensional chromatography reveals that both polymeric lignin and oligomeric lignin have antioxidant activity, though smaller fractions show higher specific antioxidant activity.

Nowadays, ultrasound (US) is widely used in industry and research in various applications, including controlled drug release, and viscosity control of formulations. To investigate the rheological properties of such formulations upon an ultrasonic trigger, a new setup was developed, allowing in situ rheological measurements during ultrasonication. Our Sonorheometer consists of a rheometer in a plate-plate geometry with a custom-made bottom plate, allowing the fixture of an ultrasonic transducer (28 kHz or 1 MHz) and introduction of a corresponding trigger into the sample. Ultrasound in the low kHz-range has shown promising effects regarding a decrease in viscosity in numerous thixotropic systems in literature. [1,2] To efficiently drive the US transducer a continuous sine signal is applied with a waveform generator in combination with a power amplifier, custom-made for the low kHz-range. Further implementation of a PTFE stamp in place of a common metal stamp provides the necessary damping properties while exhibiting chemical and thermal stability. The presented work will focus on the impact of US on the rheological behavior of different samples highlighting industrially relevant showcase examples as well as potential applications for this new device.

The study of membrane proteins (MP) remains a challenge, especially in a native membrane environment. The use of amphipathic copolymers serves as an alternative to the traditional detergent-based methods. In recent years, poly(styrene-co-maleic acid) (SMA) with a 2:1 styrene (hydrophobic) to maleic acid (hydrophilic) ratio has been deemed the “industry standard” for MP research.1 A novel series of poly(styrene-co-maleic acid-co-(N-benzyl)maleimide) (BzAM) terpolymers have been developed, in which the hydrophilic/hydrophobic balance has been progressively changed, for the isolation of membrane proteins.2 The BzAM series was designed to imitate SMA2:1 while incorporating the benefits of a well-defined molecular architecture. This will allow researchers to select the BzAM polymer with hydrophilic/hydrophobic characteristics best suited to encapsulating their specific MP of interest. It is of considerable interest to conduct in-depth characterization of these polymers and their nanodisks utilizing advanced separation techniques such as asymmetric flow field-flow fractionation (AF4) with multiple detection to better understand their membrane solubilization properties.3–5 The influence of factors such as backbone flexibility and charge density on the morphology of the nanodisk may be better understood. Understanding BzAM and their nanodisk morphologies and assembly processes under different conditions will aid in developing better strategies for solubilizing membranes.

Functional polyolefins (FPO), prepared by catalysis, reveal enhanced properties such as adhesion, compatibility, and mechanical strength in comparison with commercially available non-functionalized counterparts. By incorporation of diverse functional groups in polyolefins, a few highly interesting markets have been identified and the new applications of FPO have been explored. Due to the complexity of the FPO structure, morphology and micromechanical characterization is essential to provide insights on the material microstructure and to correlate it with material bulk properties to support development of FPO for diverse applications.

Here we present several advanced microscopy and microanalysis techniques that we developed for different FPO applications. For example, morphology analysis by atomic force microscopy (AFM) and scanning electron microscopy (SEM) have been used for the characterization of microphase separation in the self-assembled FPO-based block/grafted copolymers [1]. The study provided a better understanding of the relationship between the polymer composition and the materials microphase separation behavior and helped us to identify potential FPO applications as filtration films and compatibilizers for polymer blends. We also demonstrated that the microanalysis by AFM-based quantitative nano-mechanical mapping and fluorescence microscopy was crucial to support the development of FPO as bitumen modifiers enabling better performance and increased lifetime of the final asphalt [2]. Microanalysis revealed that the surface morphology and mechanical properties such as modulus and adhesion changed upon addition of FPO to bitumen. These findings further explained the observed changes in the bulk rheological behavior and adhesion properties for FPO modified bitumen.

KWS-2 is a pinhole SANS diffractometer optimized for the investigation of complex morphologies and rapid structural changes in soft-matter and biophysical systems. The instrument enables the exploration of a broad Q range between 1.0x10-4 and 2.0 Å-1 offering high neutron intensities and adjustable experimental resolution in continuous or TOF mode based on the instrument's optimized neutron guide system, versatile velocity selector, and main double-disk chopper. The wide Q range is covered by the combination of pinhole mode with the main 3He tubes MHZ detector, high-resolution (low Q) focusing mode with MgF2 lenses and secondary HRD (scintillation), and wide-angle detection mode with additional WANS-3He tube detectors that collect neutrons scattered up to a scattering angleθ = 53° in either continuous or TOF acquisition mode to bridge the atomic and mesoscale at the instrument. Up to twelve-fold enhancement of the intensity on the sample by the MgF2 focusing lenses and the large sample size while maintaining the same resolution (low Q) as in pinhole mode enables reliable measurements under unfavorable contrast or sample stability conditions. A dedicated suite of sample environments is available, for in-beam purification (SEC), shear (rheometer), rapid mixing (stopped-flow), deformation (stretching device), low-temperature (cryostat with sapphire windows), hydration (versatile SANS-specific dew point generator and humidity chamber) and ion transport (conductivity cell). In-situ light absorption complementarities (IR spectroscopy and UV-Vis spectroscopy) are also available for simultaneous analysis of the sample with SANS. The performance and special capabilities of the instrument for research on polymer systems under different conditions is presented.

We use large-scale computer simulations of star polymer gels to analyze which structural features can be assessed from scattering data of polymer networks. We separate static and dynamic contributions of the scattering intensity I(q), allowing us to determine the correlation length ξ of the corresponding polymer solution and the static correlation length Ξ of network inhomogeneities, combining several properties of the denser cross-link blobs. The dynamic contribution, I_dyn, is related to the correlation length ξ, incorporating parts of the form factor of the star polymer for polymer volume fractions around the overlap condition. At swelling equilibrium, the cross-link motion is confined within a volume comparable to the size of the somewhat denser cross-link blob. Since the cross-link blob size scales ∝ ξ, we measure Ξ ∝ ξ for our nearly ideal model networks. The motion of the cross-links in a harmonic confining potential implies a Gaussian shape of the static density inhomogeneities, a dependence confirmed by the static contribution to the scattering data of all samples in our study. At swelling equilibrium, dynamic scattering I_dyn(0) from thermal fluctuations is almost identical to the scattering intensity I_stat(0) from static inhomogeneities. At preparation conditions, I_stat(0)/I_dyn(0) decays with a power law following the polymer fraction of the cross-link blobs. Here, the larger volume available for cross-link motion stands out for increasing polymer volume fraction ϕ, reducing the concentration dependence of Ξ.

Polysaccharides, abundant biopolymers, hold promise for sustainable materials and potential synthetic polymer replacements. Their molecular structure and solvent type critically influence polymer chain interactions, affecting macroscopic rheological behavior. Thus, tailoring the solvent enables materials with tunable properties.

In this study, we explore the sol-gel transitions of two biopolymers—native cellulose and agar—exhibiting different levels of hydrophobicity. When dissolved in 1-ethyl-3-methylimidazolium acetate (EMImAc), they behave as viscoelastic liquids, with their shear modulus scaling with polymer concentration (c) with power of 2.3, consistent with the behavior of semiflexible polymer solutions. However, cellulose in EMImAc demonstrates a scaling law of 4 for specific viscosity (ηsp) vs c, indicative of entangled neutral polymers in θ-solvent conditions. In contrast, agar in EMImAc exhibits scaling of 7.6, suggesting intermolecular chain associations.

Remarkably, adding water to cellulose/EMImAc results in gel formation, with gel strength adjustable by varying water content. The modulus follows a power-law relationship surpassing conventional crosslinked networks. Wide-angle X-ray scattering (WAXS) analysis confirms the absence of crystallinity, indicating the formation of heterogeneous and amorphous gels. Furthermore, WAXS and Raman spectroscopy suggest that gelation occurs via solvent exchange, while photon correlation imaging reveals that the sol-gel transition in cellulose/EMImAc is entirely diffusive.

In contrast, adding water to agar/EMImAc leads to a nonmonotonic variation in complex viscosity with increasing water content before the sol-gel transition occurs. These findings highlight a straightforward approach to designing gels for diverse applications by modulating intermolecular interactions in natural polysaccharides through simple solvent modifications.

Carbon nanocomposites are materials of great interest. These materials have generally been processed using conventional techniques such as injection and compression moulding. Various studies have shown that, depending on the processing technique used, electrical properties are affected since there is hardly any shear in techniques such as compression moulding, but high shear in injection moulding. However, recently, they are starting to be processed using more advanced techniques, such as additive manufacturing that has shown great potential for processing highly complex customised structures with electrical conductivity. In this work, the influence of shear on the electrical properties of poly(butylene succinate-co-adipate) (PBSA) nanocomposites with multi-walled carbon nanotubes (MWCNT) was studied. For this purpose, mixtures with various MWCNT concentrations were prepared and processed by injection, compresion and 3D printing, evaluating the resulting conductivity. The results show that the higher the shear applied in the processing, the higher the MWCNT concentration is needed to achieve the percolation threshold. To understand the effect of shear and to replicate what happens in processing, rheological measurements have been performed on the molten material at small amplitude oscillatory shear (SAOS) and large amplitude oscillatory shear (LAOS) using a dielectric spectroscopy coupling set up to simultaneously measure the electrical and rheological behaviour. Thus, it has been determined that the rheological threshold differs from the electrical percolation threshold.

To improve the mechanical and physical properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), this study investigated the dynamic mechanical properties, warping, and shrinkage behavior of 3D printed and injection molded samples from biopolymer blends of PHBV/poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (PX).
These copolymers belong to the PHA family of biopolyesters, which are synthesized by several prokaryotic microorganisms1. The blends’ viscoelastic properties were investigated through dynamic mechanical analysis (DMA) through the storage modulus (G') and tan delta (tan(δ)). The results showed that increasing the PX content in the blend reduced the storage modulus, indicating a decrease in stiffness as PX was added 2. The tan delta curves revealed a greater damping capacity in blends with a higher PX content, indicating improved energy dissipation. The warping coefficient analysis revealed that blends with a higher PX content had significantly lower warpages than pure PHBV did, indicating that PX blends have the potential to reduce warping during additive manufacturing 3. Shrinkage analyses revealed that a higher PX content was associated with less shrinkage, which was specifically evident in the injection flow direction. This study clearly showed that the amorphous nature of PX plays a role in shrinkage reduction 4.
Our research shows how to tailor the mechanical performance of PHA-based materials for applications requiring different stiffnesses and characteristics, thereby reducing shrinkage and warping. The results suggest an improved quality of 3D printed objects, leading to a wider range of applications.