Dutch Polymer Institute

Hyperuricemia (HUA), a metabolic disorder associated with inflammatory and gut microbiota dysbiosis, demands effective intestinal-targeted therapies. Herein, a novel intestinal-targeted delivery system was designed based on quercetin nanorods coated Lactobacillus paracasei MC1 encapsulated within manganese-crosslinked Mesona chinensis polysaccharide microgels (MCPM-QUE-MC1). The MC1 strain, isolated from the traditional fermented food "Jiangshui", exhibits potent uric acid-degrading activity. The quercetin nanocoating enhances mucosal adhesion and antioxidative capacity through a prebiotic nanointerface, while manganese ions impart nanozyme-like catalytic activity, scavenging hydrogen peroxide (H2O2) and modulating the intestinal microenvironment. This synergistic assembly protects probiotics from gastric acidity and promotes intestinal colonization, as validated in mouse and pig models. In HUA mice, oral administration of MCPM-QUE-MC1 significantly reduced serum uric acid levels to 101.83 ± 6.88µmol L-1, increased MC1 abundance by 8.37-fold, improved renal function, suppressed inflammatory cytokines, and restored gut microbial homeostasis by notably enriching short-chain fatty acid-producing bacteria. Mechanistically, the therapeutic effect arises from enhanced uric acid degradation, inhibition of hepatic xanthine oxidase, reduction of intestinal permeability, and systemic endotoxemia. Overall, this study establishes a promising probiotic-polyphenol prebiotic-microgel composite platform for HUA alleviation, offering a new insight into gut microbiota-targeted therapies for metabolic diseases.

Stimuli-responsive luminescent polymeric materials which combine afterglow emission with mechanical flexibility and adaptability to external stimuli are well-suited for dynamic optical devices, encoding, anticounterfeiting, and soft robotics. However, current systems rely on static matrices and organic phosphors, which limit their afterglow duration, flexibility, processability, and responsiveness to various stimuli. Here, an active glow luminescent system for encoding, signaling, and tracking in dark environments by integrating inorganic ultralong afterglow phosphors with adaptive liquid crystal elastomer actuators is demonstrated. The resulting material exhibits ultralong emission (up to 1200 s) in the dark, enabling reprogrammable information encryption and reversible scattering-to-transparent transition upon mechanical, thermal, or light stimuli, allowing for multimodal decoding. A bicolor, spatially encoded phosphorescent soft actuator is fabricated that appears plain and unmarked under daylight, but reveals structured emission in the dark while simultaneously exhibiting shape change under heat or light. Incorporation of an additional fluorescent dye further endows the system with light-environment sensitivity, enabling luminescent rolling wheels and fiber actuators capable of self-signaling and recovery tracking. This work not only demonstrates constructing active luminescent materials but also provides valuable insights toward adaptive and interactive glowing optical devices.

Recently, we have shown that alkyl substituents destabilize the carbon radical center of organic radicals. However, seemingly in contradiction with this earlier finding, the series of isomeric n-butyl, s-butyl, and t-butyl radicals shows an increasingly stable (less positive) heat of formation ∆Hf, despite an increasing number of alkyl substituents at the radical center. Herein, we provide a solution to this apparent paradox of contradicting pictures. The crux of the matter is that ∆Hf not only comprises the substituent effect on the radical center but also the intrinsic stability of the substituents. Furthermore, we provide a generalizable framework for extracting the actual intrinsic substituent effects from experimental and computational data, an approach with broad applicability to radical chemistry, thermochemistry, and beyond.

ABSTRACT Pickering stabilization has gained scientific interest over the past few decades, yet its practical application remains restricted. This is likely due to the challenges in characterizing particle behavior at interfaces, making it difficult to relate findings from model systems to practical applications. Here, we applied several explorative techniques such as x‐ray powder diffraction, thermal analysis, and quasi‐elastic neutron scattering to obtain a better insight into the role of interfacial hydration in the stabilization of Pickering‐stabilized systems. As Pickering‐stabilized systems, we used bubbles and the so‐called antibubbles that were obtained by freeze‐drying an emulsion or double emulsion, respectively, template. Silica particles with different hydrophobicities were used to stabilize these (anti)bubbles. Our results demonstrate that increasing particle hydrophobicity enhances silica–water–maltodextrin interactions, modifying the water structure, and significantly influencing the thermal degradation profiles. Practical applications : Pickering‐stabilized bubbles are promising for encapsulating probiotics and delivering antioxidants in food systems by forming gas‐shell capsules. To scale these systems for commercial use, it is crucial to understand interfacial hydration and particle wettability, as tuning particle hydrophobicity can significantly enhance edible coatings and extend shelf life. Our results show that neutron spectroscopy provides an effective in situ method for assessing the hydrophobicity of silica particles. This approach offers a novel method for investigating wetting behavior.

4D microstructured actuators are micro-objects made of stimuli-responsive materials capable of induced shape deformations, with applications ranging from microrobotics to smart micropatterned haptic surfaces. The novel technology dual-wavelength volumetric microlithography (DWVML) realizes rapid printing of high-resolution 3D microstructures and so has the potential to pave the way to feasible manufacturing of 4D microdevices. In this work, DWVML is applied for the first time to printing stimuli-responsive materials, namely, liquid crystal networks (LCNs). An LCN photoresist is developed and characterized, and large arrays of up to 5625 LCN micropillars with programmable shape changes are produced by means of DWVML in the time span of seconds, over areas as large as ∼5.4 mm2. The production rate of 0.24 mm3 h-1 is achieved, exceeding speeds previously reported for additive manufacturing of LCNs by 2 orders of magnitude. Finally, a membrane with tunable, micrometer-sized pores is fabricated to illustrate the potential DWVML holds for real-world applications.

Vitrimers are a promising class of polymer networks that feature thermally activated dynamic covalent bonds. Although promising for many applications in material science, vitrimers tend to be difficult to process because of high viscosity. Processability is commonly enhanced at the expense of mechanical performance at service temperature, and thus this trade-off remains an important challenge in the development of these materials. Herein, we report a new approach based on thermoreversible organic nanofillers (TRONs), which we define as low molar mass molecules that act as reinforcing fillers at the service temperature and plasticizers at the processing temperature. This concept is exemplified in the context of an elastomeric dioxaborolane-based polybutadiene vitrimer as a model matrix, and two different dibenzylidene sorbitol derivatives are evaluated as TRONs. We find that vitrimers loaded with TRONs exhibit improved creep resistance and tensile properties at service temperatures while also exhibiting lower viscosity at processing temperatures.

During processing of fiber composites, the fiber-induced stresses influence the local flow fields, which, in turn, influence the stress distribution and the fiber orientation. Therefore, it is crucial to be able to predict the rheology of fiber-filled polymer composites. In this study, we investigate the fiber orientation kinetics and rheological properties of fiber composites in uniaxial extensional flow by comparing direct numerical finite element simulations to experimental results from our previous study [Egelmeers et al., “In-situ experimental investigation of fiber orientation kinetics during uniaxial extensional flow of polymer composites,” J. Rheol. 68, 171–185 (2023)]. In the simulations, fiber–fiber interactions only occur hydrodynamically and lubrication stresses are fully resolved by using adaptive meshing. We employed a 7-mode and a 5-mode viscoelastic Giesekus material model to describe the behavior of, respectively, a strain hardening low-density polyethylene (LDPE) matrix and a non-strain hardening linear LDPE matrix, and investigated the influence of the Weissenberg number, strain hardening, and fiber volume fraction on the fiber orientation kinetics. We found that none of these parameters influence the fiber orientation kinetics, which agrees with our experimental data. The transient uniaxial extensional viscosity of a fiber-filled polymer suspension is investigated by comparing finite element simulations to a constitutive model proposed by Hinch and Leal [“Time-dependent shear flows of a suspension of particles with weak Brownian rotations,” J. Fluid Mech. 57(4), 753–767 (1973)] and to experimental results obtained in our previous study [Egelmeers et al., “In-situ experimental investigation of fiber orientation kinetics during uniaxial extensional flow of polymer composites,” J. Rheol. 68, 171–185 (2023)]. The simulations describe the experimental data well. Moreover, high agreement is found for the transient viscosity as a function of fiber orientation between the model and the simulations. At high strains for high fiber volume fractions, however, the simulations show additional strain hardening, which we attribute to local changes in microstructure.

The demand for fiber-filled polymers has witnessed a significant upswing in recent years. A comprehensive understanding of the local fiber orientation is imperative to accurately predict the mechanical properties of fiber-filled products. In this study, we experimentally investigated the fiber orientation kinetics in uniaxial extensional flows. For this, we equipped a rheometer with a Sentmanat extensional measurement device and with an optical train that allows us to measure the fiber orientation in situ during uniaxial extension using small angle light scattering. We investigated an experimental system with glass fibers for the suspended phase (L/D=8−15), and for the matrix either low density polyethylene, which shows strain hardening in extension, or linear low density polyethylene, which shows no strain hardening. For these two polymer matrices, the fiber orientation kinetics were investigated as a function of fiber volume fraction (ϕ=1%, 5%, and 10%) and Weissenberg number (by varying the Hencky strain rate, ϵ˙H=0.01−1s−1). We found that all these parameters did not influence the fiber orientation kinetics in uniaxial extension and that these kinetics can be described by a multiparticle model, based on Jeffery’s equation for single particles. Our results show that, in uniaxial extension, fiber orientation is solely determined by the applied strain and that, up to the concentrated regime (ϕ≈D/L), fiber-fiber interactions do not influence the fiber orientation. The extensional stress growth coefficient of these composites, which is measured simultaneously with the orientation, shows high agreement with Batchelor’s equation for rodlike suspensions.

Abstract Shaping a sustainable future is closely tied to the development of advanced plastic recycling technologies. As global recycling rates remain low, the lion's share of post‐consumer plastics is either incinerated or disposed of in landfills. This unbalanced plastic waste management not only poses severe environmental risks, but also entails an irrevocable loss of chemical resources that are embedded in synthetic polymers. To give plastic waste a new life, a series of photocatalytic methods has recently been reported that convert polymers directly into value‐added organic molecules. These approaches operate at ambient temperature, show high reactivity/selectivity, and provide alternative reaction pathways as compared to thermal depolymerizations. This Minireview highlights the scientific breakthroughs in upcycling polymers through state‐of‐the‐art photocatalysis under environmentally benign conditions.

A novel series membranes based on non-linear all-aromatic polyimides (PIs) was investigated with the aim to understand how the PI backbone geometry and local electrostatics govern gas transport and the ability to separate CO2/CH4 mixtures. Non-linear 3-ring aromatic diamines, with exocyclic bond angles varying between 120 and 134°, enable the design of high Tg (>276 °C) PIs. A polar 1,3,4-oxadiazole diamine (ODD) (μ = 3D) monomer and a non-polar m-terphenyl diamine (TPD) reference monomer were synthesized and coupled with 3 dianhydrides, i.e. ODPA, ODDA, and 6FDA. In 6FDA-based membranes CO2 permeabilities (PCO2) are the highest of the series. The 6FDA-ODD membrane shows excellent membrane performance with high PCO2 values at all feed pressures. Up to 12 bar (6 bar CO2) none of the membranes reached their plasticization pressure. The non-linear backbone geometry promotes CO2 permeability, whereas the presence of an electrostatic dipole moment associated with the 1,3,4-oxadiazole heterocycle governs CO2/CH4 separation selectivity.