PNIPAM-based thermoresponsive materials have garnered significant attention in the fields of biomedicine and smart materials due to their temperature-sensitive properties. The ability to regulate their lower critical solution temperature (LCST) allows for precise control over the phase behavior of the polymer, facilitating reversible phase transitions at specific temperatures. This capability is crucial for expanding applications in various contexts, such as drug release at different environmental temperatures and color-changing windows. This review comprehensively summarizes the strategies for regulating the LCST of PNIPAM and explores its potential applications. The manuscript discusses key factors influencing phase transition from two perspectives: chain regulation and molecular incorporation, including polymer chain structure, cross-linking density, solvent properties, and the role of additives. Additionally, the impact of different preparation conditions on LCST is also introduced. Recent advancements in various regulatory mechanisms are reviewed, highlighting the advantages and disadvantages of each strategy, as well as future development directions. This review provides a systematic theoretical foundation and practical guidance for the design and development of PNIPAM with tunable LCST.

Electrical stimulation has been shown to enhance tissue regeneration, which is why piezoelectric-polymer-based scaffolds are on the rise for advanced tissue-engineering approaches. Recent studies have shown that electrical cues can modulate cell function in vitro and in vivo and that these cues can be delivered through the application of an external noninvasive ultrasound (US) source to actuate a piezoelectric polymer. However, poly(l-lactide) (PLLA) possesses a shear piezoelectric coefficient and therefore requires different strategies of US stimulation relative to other well-established piezoelectric materials such as poly(vinylidene fluoride-trifluoroethylene) P(VDF-TrFE). Thus, this work compares three different stimulation methods ranging from 1 to 500 kHz (a nanokicking bioreactor, an US transducer, and an US bath) to actuate a PLLA diaphragm with the aim of creating a bioelectrical cell culture device. The US bath stimulated PLLA films (37 kHz) generated an output voltage of 548 ± 16 mV, the highest of all tested systems. The nanokicker stimulated PLLA films (1.3 kHz) were associated with a voltage output of 4.8 ± 0.7 mV, and the US probe (500 kHz) actuated films generated an output voltage of 9.1 ± 0.8 mV, which is still high enough for electrical cell stimulation. Moreover, the influence of the film tension on the voltage output was examined, and reduced tension was observed to increase the piezoelectric response of the PLLA films by 118% and reduce the piezoelectric response of P(VDF-TrFE) films by 24%. This shows that piezoelectric PLLA-based scaffolds can be designed in a manner to take advantage of the shear piezoelectric effect of PLLA, when applying external US stimulation.

Much attention has been paid to nonspherical polymer particles, which have hidden and intriguing properties compared to those of conventional spherical particles. Polymeric nanofibers are one type of nonspherical nanomaterial, but fabricating such nanofibers stably suspended in water and controlling their aggregation and dispersion properties remain a challenge. Herein, we propose a top-down method to fabricate nonspherical and fragmented nanofibers stably suspended in water. We use a simple procedure: (i) electrospinning of the polystyrene nanofibers, (ii) fragmentation by homogenizer, and (iii) surface modification of the fragmented nanofibers. Intriguingly, the fragmented nanofibers after precipitation were bulkily packed together, compared to spherical particles, due to their nonspherical shape and the stiffness derived from polystyrene. Using this unique property, we demonstrate that fragmented nanofibers with a bulky aggregation property can provide specific, visual, and highly sensitive detection of antigen. The fragmented nanofibers may be a candidate carrier for an alternative to a conventional latex turbidimetric immunoassay.

An area of research in organic electronics focuses on sustainable approaches using biomass-derived materials to reduce dependence on fossil fuels. In this work, forest biomass is explored for synthesizing biobased heterocyclic monomers. More specifically, using vanillin from lignin and precursor sugars from cellulose and hemicellulose, partially biobased conjugated polymers were synthesized. These monomers in combination with functionalized diketopyrrolopyrrole (DPP) were copolymerized via eco-friendly direct (hetero)arylation polymerization (DHAP). The resulting materials exhibited promising properties for applications in organic field-effect transistors (OFETs), achieving hole mobilities up to 6.14 × 10^–3 cm² V^–1 s^–1. This research highlights the potential of biomass as a sustainable feedstock and DHAP as one of the eco-friendly polymerization methods contributing to the advancement of more environmentally responsible organic electronics.

Pharmaceuticals’ pervasive contamination of aquatic ecosystems underscores the urgent need for efficacious and innovative remediation strategies. This study introduces a highly selective and efficient approach for recovering Ibuprofen using molecularly imprinted polymers (MIPs). The cross-linked polymer was synthesized by reacting poly(2-oxazoline) with amino side chains and hexamethylene diisocyanate in the presence of Ibuprofen. Key parameters affecting Ibuprofen adsorption, including initial concentration, contact time, and MIP reusability, were thoroughly examined. The developed MIP exhibits a remarkable adsorption capacity, achieving a maximum Ibuprofen binding capacity of 92 mg g^–1 and significantly outperforming the non-imprinted polymer’s 30 mg g^–1. Moreover, kinetic studies reveal a rapid adsorption process predominantly following pseudo-first-order kinetics, indicating chemisorption as the primary mechanism. The MIPs demonstrate excellent reusability and maintain their efficacy in real-world scenarios, as evidenced by the successful recovery of Ibuprofen from lake water samples with significant removal percentages, instilling confidence in its potential application.

Owing to the increasing global emphasis on the eco-friendliness of materials, significant progress has been made toward the development of polymer blends containing biodegradable polylactic acid (PLA). Over the past few decades, research on PLA has primarily focused on enhancing its physical properties and processability for advantageous industrial applications. In this study, we leveraged the unique rheological properties of bottlebrush polymers (BBPs) to improve the processability of PLA and verified their applicability as processing aids. Cellulose acetate butyrate (CAB)-based PLA-grafted polymers (CAB-g-PLA) were designed to mimic the characteristics of BBPs. Moreover CAB-g-PLAs were synthesized by grafting PLA onto cellulose-based biodegradable polymers to produce blends with PLA without compromising their biodegradability. The biodegradable CAB-g-PLAs were characterized through GPC, FT-IR spectroscopy, and SEM. The rheological and mechanical properties of the PLA blends with the CAB-g-PLAs were compared by adjusting the molecular weights of the backbone and side-chains of the CAB-g-PLAs. The role of CAB-g-PLAs as processing aids was analyzed by examining the melt tension and drawing resonance phenomena during the extrusion process, demonstrating the improved processability of the PLA blends. Our results facilitate the broader industrial adoption of biodegradable polymers, enabling industries to achieve eco-friendly goals without compromising material performance.

The regulation of pore structure and its impact on the properties of microporous polyurethane elastomers (MPUEs) are crucial for various applications. This study investigated how different chain extenders, including diethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol, influenced the microphase separation, hydrogen bonding, pore morphology, and properties of MPUEs. The experimental results demonstrated that increasing the chain extender length enhanced hydrogen bonding and promoted microphase separation within the MPUEs. Concurrently, the gel reaction rate slowed, leading to corresponding changes in pore structure, which, in turn, affected the material’s damping and mechanical properties. Nonisothermal DSC and infrared expansion methods were employed to study the kinetics of polyurethane gel and foaming reactions. The kinetic analysis revealed that the pore structure could be effectively controlled by manipulating the gel reaction system. This study highlights the importance of achieving an optimal balance between gel and foaming reactions to produce MPUEs with desirable properties. The findings provide valuable insights into tailoring the microstructure of MPUEs for specific applications through the choice of chain extenders.

The present study reports a facile method for gluing chemically different materials without pretreatment of their surfaces by in situ simultaneous formation of multiple interfacial adhesions and cohesion based on the concept of reversibly interlocked polymer networks (RILNs). As a demonstration of the design, the cross-linked polyacrylate containing reversible boronic ester bonds (SN-PA) and cross-linked polyurethane containing reversible disulfide bonds (SN-PU) are stacked and then sandwiched between the target adherends, glass, and fluoropolymer encapsulated polyethylene terephthalate (TPT). Besides, zirconium ions are incorporated into SN-PU in advance. Under hot compression, the two types of reversible covalent bonds are triggered and the temporarily de-cross-linked hydrophilic SN-PA and hydrophobic SN-PU are able to well wet glass and TPT, respectively, and interdiffuse across the SN-PA/SN-PU boundary. During the subsequent cooling, hydrogen bonds and coordination bonds are built up at the polymer/adherend interfaces, while RILNs are produced between SN-PA and SN-PU so that the peeling strength of the bonded glass/TPT assembly achieves 38.94 N/cm, which is higher than the values reported so far.

The development of novel fluorescent probes for Fe³⁺ ions that exhibit high selectivity, sensitivity, and biocompatibility presents a significant challenge in the field. In response to this challenge, we have designed and synthesized a green fluorescent polycarbonate (PPCF) by utilizing carbon dioxide and epoxides, incorporating fluorescent functional groups. This polymeric fluorescent probe demonstrates a high degree of selectivity for detecting Fe³⁺, with minimal interference from other prevalent ions. The fluorescence intensity displays robust linear correlation with Fe³⁺ concentration over the span of 20–200 μM, thereby enabling quantitative analysis. Furthermore, the fluorescence quenching effect induced by Fe³⁺ results in a detection limit of 262 nM, which is competitive with existing fluorescent probes for Fe³⁺ detection. Additionally, CCK-8 assays indicate that PPCF4 possesses a high safety threshold at elevated concentrations and exhibits favorable biocompatibility, essential for in vivo Fe³⁺ detection. Successful fluorescent imaging of Fe³⁺ within HeLa cells has also been accomplished. This research presents an environmentally sustainable and effective strategy for the detection of Fe³⁺ and for fluorescent imaging within cellular contexts using fluorescent probes.

Nitrogen dioxide (NO₂) is a tremendously toxic environmental pollutant that can be lethal to humans and extremely dangerous to the environment. NO₂, being a highly volatile gas, undergoes photochemical reactions that can cause acid rain or generate ozone. Exposure to extremely low concentrations of NO₂ can severely impact human health, primarily damaging lung tissues. Thus, fabricating highly sensitive and portable sensors for room-temperature detection of NO₂ gas with a very low response/recovery time is extremely important for environmental monitoring and human safety. To address the above challenges, we have fabricated an extremely sensitive and highly selective NO₂ gas sensor based on a glycerol-cross-linked PEDOT:PSS/MoS₂ nanocomposite using two-dimensional MoS₂ nanosheets. The deposition of the gas sensor over the substrate was facilitated by increasing the roughness of the substrate and the adhesion of the conducting polymeric films. Increased roughness facilitated better gas adsorption, which in turn increased the gas sensing capacity of the sensor. Three different nanocomposites were prepared using different concentrations of MoS₂ nanosheets, and the sensor with the greatest responsivity to NO₂ gas was optimized. The sensor material showed an N-type semiconducting behavior in the presence of NO₂ gas with swift response and recovery times of 10.2 and 5.5 s in the presence of 100 ppb NO₂ gas. The fabricated gas sensor gave a superior response to extremely low concentrations of NO₂ gas even at room temperature. The sensor showed a response of 500.3% to 50 ppm of NO₂ and 22.1% to 100 ppb of NO₂ gas, and the detection limit was 40.02 ppb. The highly selective sensor shows a zero or very low response toward other oxidizing/reducing gases. Moreover, room-temperature gas sensing is an additional advantage because it reduces the power consumption of the device. The large surface area of the polymeric nanofilms is proposed to help enhance the charge transfer phenomenon between the N-type electron-rich semiconductor and the electron-accepting oxidizing gas, resulting in their excellent gas-sensing performance. This study proposes potential semiconducting nanostructured sensor materials with prospects for real-time NO₂ detection for human protection and environmental safety.

Transparent rigid packaging traditionally relies on fossil fuel-based polymers such as polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP), which contribute to the production of nonbiodegradable waste, landfills, and environmental pollution. Although they exhibit favorable light transmission, their nonbiodegradability raises significant sustainability concerns. In contrast, cellulosic plant fibers are biodegradable. We aim to utilize biomass waste to produce functional, transparent packaging material, thereby lowering the overall carbon footprint. This study explores transparent high-modulus rigid packaging materials using jute fibers. Transparent jute/thiol–ene composites were developed by using ultraviolet (UV) polymerization techniques, achieving light transmission as high as 80% at 550 nm with a 20% fiber content at 1 mm thickness. These composites showed almost a doubling in tensile modulus compared with commercial PET films. Copper nanoparticles were successfully added to provide antimicrobial properties. Hydrolytic degradation analysis confirmed composite biodegradability and its potential as sustainable solutions for packaging applications.

Poly(ether ether ketone) (PEEK) is a semicrystalline engineering plastic with excellent characteristics. However, its modulus and dimensional stability decrease significantly above the glass transition temperature (T_g). In this paper, cross-linkable PAEK (DBPEEKs) with carbon–carbon double bonds was synthesized, and the majority of cross-linkable synthesis methods were determined by using the curing kinetics. By the introduction of biphenyl bisphenol (BP) as a rigid monomer unit, a series of cross-linkable crystalline PAEK (DPEDEKs) with strong cross-linking and crystallinity after curing were generated. DPEDEK-25% after the curing process (DPEDEK-25%-gradient curing) still maintained 24% crystallinity (X_c) at a gel content (f) of 96%. This coexistence of crystallization and cross-linking broadens the application range of PEEK at high temperatures. At 250 °C, DPEDEK-25%-gradient curing had a tensile strength of 42 MPa, which was higher than that of the PEEK composite material 450GL30 at 275 °C and similar to that of 450CA30 (VICTREX official website). DPEDEK-25%-gradient curing remained applicable at 300 °C, with a wear rate of 7.69 × 10^–7 mm³ N^–1 m^–1 and an average friction coefficient (COF) of 0.41. Whether at ambient or elevated temperatures, DPEDEK-25%-gradient curing had the same solvent resistance as PEEK. This work provides important guidance for expanding the application scope of PEEK at high temperatures.

Stretchable conductive hydrogels exhibit promising potential as portable electronic devices and strain sensors. However, they suffer from intricate preparation procedures and inadequate mechanical properties for constructing triboelectric nanogenerators (TENGs). Herein, we propose a borax-cross-linked poly(vinyl alcohol) (PVA)/polyethylene glycol (PEG)/Chinese ink (C) carbon nanoparticle composite hydrogel, which boasts a simple fabrication method and environmental friendliness. The dispersion of carbon nanoparticles throughout the polymer network bolsters the mechanical strength of the hydrogel and also imparts good electrical conductivity. The incorporation of PEG improves the mechanical properties of the hydrogel, while the dynamic bonding between borate ions and PVA confers excellent self-recovery properties. Upon cutting and reuniting the fractured surfaces for 30 s, the two segments of the hydrogel underwent spontaneous healing without external stimuli. The mended incisions of the hydrogel nearly vanished and withstood stretching to three times their original length without fracturing, showing a remarkable self-healing capability and stretchability. Finally, TENGs were prepared using the PVA/PEG/C hydrogel, and the output voltage was approximately 2.9 V across all frequencies. The PVA/PEG/C-TENG demonstrated a rapid response at 180° of bending, reacting to the stimulation in a mere 0.256 s and returning to its original state within 0.511 s after the stimulus was removed. The PVA/PEG/C hydrogel shows versatility in applications such as wearable motion monitoring, precise stroke recognition, and efficient mechanical energy harvesting.

Direct air capture (DAC) of CO₂ via solvent-based absorption is considered a promising negative-emission technology. However, the low concentration of CO₂ in the air and slow transport into the solvent make DAC notoriously challenging to implement without costly investments. In this study, we explore the fundamental role that the bulk and surface properties of CO₂-permeable polymer membranes play in enhancing the efficiency of the solution sorption process in passive DAC of CO₂. This work leverages various spectroscopic and computational studies to demonstrate that a hybrid system, comprising a reusable CO₂-permeable polymer layer placed atop an aqueous amino acid (AA) solution, can outperform a pure aqueous AA system by 2-fold. We show how the enhanced solubility of CO₂ in the polymer layer can improve the transport of CO₂ into the aqueous phase, while the chemistry of the polymer can control the interfacial barrier for CO₂ permeation and the interfacial concentration of reactive AAs. The derived knowledge of the material properties achieved here can aid in the design of DAC systems with improved performance.

The latest innovations in gas separation technologies reveal that including amine-functionalized carriers with embedding two-dimensional (2D) nanosheets in polymer membranes substantially augments the efficacy of CO₂ separation. This study presents an approach wherein UiO-66 (a Zr terephthalate) is modified with Cloisite Na-MMT, an organically modified montmorillonite (MMT) clay, via a postsynthesis modification (PSM) process. The MMT-modified UiO-66 (Cloisite@UiO-66), along with the amino-functionalized UiO-66 (UiO-66-NH₂) blended with graphene oxide (GO) with filler loading between 2.5–5.0 wt %, are then subsequently integrated into the polysulfone (PSf) polymer matrix to fabricate mixed matrix membranes (MMMs) for applications in gas separation. Fourier-transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM) analysis were employed to analyze chemical interactions and surface morphology of synthesized nanofillers and the prepared membranes. Gas separation experiments were performed using a CO₂:N₂ and CO₂:CH₄ mixture (10:90 vol %) under the absolute temperature of 25 ± 2 °C and 2 bar pressure. Incorporating the blending of GO with UiO-66-NH₂ and hybrid Cloisite@UiO-66 into the MMM led to substantial improvements in CO₂ permeance and significantly increased the CO₂/N₂ and CO₂/CH₄ selectivity of the fabricated membranes. The Cloisite@UiO-66@MMM exhibited a remarkable CO₂ permeance of 89.02 GPU and optimal selectivity of 76.09 for CO₂/N₂ and 50.86 for CO₂/CH₄ among all the tested MMMs. These findings suggest that composite fillers, which combine the functionalities of MOFs, GO, and MMT-modified MOFs, hold considerable potential for tuning and improving the performance characteristics of polymer-based membranes. Such membranes have significant potential for the efficient separation of CO₂ from industrial emissions, natural gas, and various complex gas mixtures, thereby facilitating the development of more efficient and sustainable solutions for gas capture and purification in various applications in the future.

Fabric coatings, offering a range of benefits to personal health and the environment and addressing other specific needs, present a promising application in various fields. However, ensuring their long-term reliability, durability, and recyclability remains crucial to meet the demands of practical applications and sustainable development. To address this problem, we have developed a self-healing polyurethane (BPU) that integrates phenylboronic acid groups into the polyurethane chains and cross-links them to form dynamic boroxine bonds. This unique structure endows the BPU with a healing efficiency of 94%, a recycling efficiency of 93%, and an adhesion strength to cotton fabric of 1.42 MPa due to the high mobility of polymer chains and dynamic boroxine bonds. Leveraging these exceptional properties, we successfully prepared a multifunctional coating fabric (BPU/APD) by incorporating an azobenzene–polyurethane polymeric dye (APD) with BPU as a binder. This BPU/APD-coated fabric shows reversible photoisomeric behavior, remarkable ultraviolet protection function (UPF = 85.8), and excellent durability against washing and adhesion. Notably, the coated fabric can fully heal tiny scratches at 60 °C under 3 MPa for 5 min. After undergoing four healing cycles, the fractured coating fabric retains over 85% of its initial strength following the first healing, indicating its multiple healing capabilities. Moreover, the BPU/APD coatings on the waste fabrics can be recycled and reused repeatedly, maintaining a similar color strength and adhesion strength. This research paves the way for the development of multifunctional coating fabrics through the creation of self-healing polyurethane coatings, proving its great potential in smart textiles.

As a high-performance polymer material, conductive hydrogels are widely employed in the fields of motion monitoring, electronic skin, and energy storage devices, which rely on flexible materials, including hydrogel, elastomer, and composite hydrogel. However, preparing a composite hydrogel with excellent mechanical properties is a great challenge. Inspired by the structure of crocodile skin, a trilayer structure conductive composite hydrogel was prepared. The three layers were Ecoflex elastomer, poly(acrylamide-2-hydroxyethyl methacrylate) (PAAm-HEMA) hydrogel, and graphene/2-hydroxyethyl methacrylate (G/PHEMA) hydrogel, respectively. Covalent bonds were generated by a photochemical reaction between elastomer Eco and the P(AAm-HEMA) hydrogel. Covalent bonds were also formed between the P(AAm-HEMA) hydrogel and G/PHEMA hydrogel by the chemical reaction of N,N′-methylenebis(2-propenamide), which worked as cross-linking agent; hydrogen bonding between these two hydrogels also formed. These physical and chemical interactions provided firm bonding between the layers and prevented interlayer slippage under an external force. The G/PHEMA-P(AAm-HEMA)-Eco composite hydrogel possessed high fracture stress and elongation at break of up to 2.1 MPa and 1305%, respectively. The conductivity of 0.028 S/m was attributed to the incorporation of graphene in the network of the G/PHEMA hydrogel. Based on the excellent mechanical properties and electrical conductivity, this composite hydrogel was applied as a flexible sensor to detect human motion signals. These results indicate that the trilayer G/PHEMA-P(AAm-HEMA)-Eco composite hydrogel represents a promising material, paving the way for innovative applications in next-generation flexible electronic devices.

Polymeric coatings are known to enhance the processing and performance of multiwalled carbon nanotubes (MWCNTs) in composites. Sequential admicellar polymerization (s-AP) was applied to facilitate aqueous dispersion of MWCNTs and enhance their electrical conductivity for fillers in hydrophilic composites. The process involved double AP to create two functional polymer layers on the MWCNT surfaces. Initially, polyindole (PIn) was formed, followed by the formation of poly(vinyl acetate) (PVAc) as the second layer with thicknesses as thin as 3–4 nm for PIn and 5 nm for PVAc by FESEM image analysis. Optimal properties were achieved at 30 mM indole and 20 mM vinyl acetate monomer concentrations, yielding a 57% increase in electrical conductivity (8.23 × 10⁴ S/cm) and a stable MWCNT suspension in water. HPLC was used to analyze and investigate the monomer adsorption inside admicelles of SDS on the MWCNT surface. FTIR, FESEM, and TGA were applied for further characterization.

Impregnated decorative paper is an important and high-value wood-based panel decorative material. However, traditional melamine–urea–formaldehyde impregnated decorative paper (MUFP) suffers from formaldehyde emission and brittleness. Therefore, it is crucial to develop high-performance, formaldehyde-free, flexible impregnated decorative paper as an alternative to MUFP. Here, a layer-by-layer self-assembly strategy is adopted to prepare high-performance, formaldehyde-free polyamide epichlorohydrin (PAE)/poly(vinyl alcohol) (PVA)/melamine (MA) impregnated decorative paper (PMPP). The first PAE resin layer acts as a wet strength agent, while the second PVA/MA resin layer acts as a toughening agent, forming a dual network structure through chemical and hydrogen bonding. Due to the unique layer-by-layer self-assembled dual-network structure, the elongation at break and work of fracture of PMPP is 4.4% and 265.50 mJ, respectively. These values are nine- and eight-times higher than those of MUFP, respectively, demonstrating the excellent toughness of PMPP. Additionally, PMPP is subjected to water activation and hot pressing, and its surface properties meet the GB/T15102–2017 Chinese national standard. In addition, the formaldehyde emission of PMPP is only 0.01 mg/L, which meets the environmental standards of China’s GB/T 28995–2022 (≤1.5 mg/L), Europe’s EN 717–1 (≤0.5 mg/L), and Japan’s JAS 234:2003 (<0.3 mg/L). Thus, this work offers a novel approach to achieve high-performance, formaldehyde-free, flexible impregnated decorative paper.

Aiming at a polymeric porous membrane applied in the field of electrochemistry, especially alkaline water electrolysis, this paper combines polymer network microstructure prediction, characterization, high-throughput computation, and artificial neural networks to predict the performance of the membrane by material intrinsic characteristics and manufacturing parameters. Through the joint use of principal component analysis, fully connected neural networks, and convolutional neural networks, the microstructure tortuosity and maximum pore size can be predicted at the accuracy of R² = 0.746 and R² = 0.886, respectively. The influence of input parameters on performances is further analyzed, and several algorithms are utilized for parameter optimization of membrane manufacturing. The optimal parameters are implemented to a hand-cast membrane, which surpasses a commercialized membrane in certain aspects.

Heterogeneous catalysis is significantly enhanced by the use of highly porous polymers with specific functionalities, such as basic groups, which accelerate reaction rates. Polymers of intrinsic microporosity (PIMs) provide a unique platform for catalytic reactions owing to their high surface areas and customizable pore structures. We herein report a series of Tröger’s base polymers (TB-PIMs) with enhanced basicity, achieved through the incorporation of nitrogen-containing groups into their repeat units, such as triazine and triphenylamine. These polymers offer a perfect balance between the pore “swellability”, which allows the use of substrates of various dimensions, and the basicity of their repeat units, which facilitates the use of reactants with diverse acidity. The catalytic activity is evaluated through the Knoevenagel condensation of benzaldehydes and various methylene species, conducted in the presence of ethanol as a green solvent and using a 1:1 ratio of the two reagents. The results highlight a significant improvement, with reactions reaching completion using just a 1% molar ratio of catalysts and achieving a 3-fold enhancement over previous results with 4-tert-butyl-benzaldehyde. Computational modeling confirms that the enhanced basicity of the repeat units is attributable to the polymer design. Additionally, preliminary studies are undertaken to assess the kinetics of the catalyzed condensation reaction.

A multifunctional alumina-based filler, Al₂O₃@APTES-Zn, has been synthesized by functionalizing Al₂O₃ nanoparticles with aminopropyl triethoxysilane (APTES) and subsequently anchoring Zn²⁺ centers. This multifunctional nanofiller acts simultaneously as a reinforcing agent, cross-linking promoter, and thermal conductivity enhancer in carboxylated nitrile rubber (XNBR) composites. The anchored Zn(II) sites also provide ionic interactions with XNBR terminations, enabling dynamic reversible bonds for self-healing properties. The comprehensive characterization of XNBR/Al₂O₃@APTES-Zn composites unveils enhanced cross-linking, improved tensile strength and strain at break (up to 17 MPa and 1416% at 24 phr filler), increased thermal conductivity (+11.4% compared to neat Al₂O₃ at the same loading), and superior self-repairing efficiency (up to 120%). These results demonstrate that the tailored surface and interfacial properties of Al₂O₃@APTES-Zn represent a promising benchmark for resilient and sustainable composites in applications, such as hoses, seals, gaskets, and automotive components.

In order to develop polypropylene (PP) based dielectric materials with high dielectric and energy storage properties, PP grafted polystyrene films (PP-g-PS) with different grafting content have been prepared by electron beam irradiation grafting method. Free radicals were generated in the PP chains during irradiation and also enhanced the polarity of PP due to the oxidation reaction. The results have shown that the presence of grafted PS introduced smaller spherical crystals, which led to more interfacial regions and increased the interfacial polarization. DFT simulations and TSDC proved that the grafted PS introduced deeper traps, which could effectively trap carriers at high speeds and reduce the carrier mobility. When the content of PS was 8 wt %, the PP-g-PS film achieved 600 MV/m breakdown strength, 5.43 J/cm³ discharge energy density, and more than 96% charge–discharge efficiency. What’s more, the grafting of PS significantly improved the high-temperature energy storage properties of PP. At 110 °C, the discharge energy density of the PP-g-PS (8%) film is 3.44 J/cm³, which is 93% higher than that of the PP film (1.78 J/cm³). And at the electric field strength of 440 MV/m, the efficiency still exceeds 96%. This study provides a simple and feasible strategy for the development of high-performance PP-based dielectric films.

Diabetic wounds are extremely difficult to heal due to the long duration and high recurrence rate. The bacterial infection caused by elevated blood glucose negatively affects the speed of wound healing. In this article, radially oriented nanofibers containing the natural antimicrobial agent purslane were prepared by electrostatic spinning. Subsequently, asiaticoside was loaded onto the surface of the fibers by electrostatic spraying. The experimental results indicated that radial nanofiber membranes exhibited uniform diameter distribution, suitable water vapor permeability, and good hydrophilicity as well as excellent antibacterial performance and biocompatibility. Due to the ordered arrangement, the radial nanofibers exhibited good wound healing ability, regular granulation tissue growth, and high collagen deposition. More importantly, the radially oriented fiber structure significantly promoted cell proliferation and adhesion. Based on these results, nanofiber membranes with a radially oriented structure have potential application prospects in the field of chronic diabetic wound healing.

Spider silk is recognized as one of the strongest naturally occurring materials due to its unique biphasic structure. Taking inspiration from natural spider silk, an ultrastrong, low-temperature-resistant, reusable thermoplastic silicon-containing polyamide (Si-PA) hot-melt adhesive (HMA) has been synthesized for the first time by melt polycondensation. The obtained Si-PA adhesive possesses a reliable bond strength of up to 20.6 MPa at ambient temperature and 9.5 MPa at −196 °C on stainless steel, notably outperforming comparable polyamide HMAs. These extraordinary performances mainly originate from the meticulously engineered microphase separation structure, wherein nanoscale crystalline regions (20–200 nm) disperse throughout the amorphous regions formed by organosilicon chain segments. Moreover, high-density hydrogen-bond-induced emission of the amide cluster leads to strong blue fluorescence. The Si-PAs show potential in the fields of cold-resistant adhesive devices and tamper-resistant displays. Furthermore, this design provides an idea for mimicking spider silk materials.

Polyimides (PIs) are used as binders in lithium-ion batteries (LIBs) owing to their excellent mechanical properties. Nevertheless, the impact of their fatigue-resistant properties on battery performance is still unclear. Herein, a series of PIs have been synthesized and used as the binders for SiO_x/C anode materials. PIs based on 3,3′,4,4′-biphenyl dianhydride (BPDA) and 4,4′-diaminodiphenyl ether (ODA), or p-phenylenediamine (PDA) retained more than 90% of their initial strengths after 100 cycles of stress load-release at 30% strain stretching, while the strength retention rate of PI based on pyromellitic dianhydride (PMDA) and ODA was only ∼85%. Consequently, the specific capacity retention rates of batteries using BPDA-ODA and BPDA-PDA binders exceeded 95% at 0.2C after 100 cycles, achieving about 1400 mA h g^–1 and 2.8 mA h cm^–2. By contrast, the batteries using PMDA-ODA binder retained only 56% of their original specific capacity after 100 cycles due to their inferior fatigue-resistance. In addition, the PMDA-based electrodes also showed more severe swelling after 100 cycles than those based on BPDA binders (110% vs 40%–60%). Overall, the fatigue-resistance of PI binders is crucial for keeping reversible volume changes of SiO_x/C materials for enhanced cycle life of LIBs.

The redox-active dendrimers consisting of a rigid, wholly aromatic polyphenylene interior and elongated flexible ferrocenyl-terminated spacers were synthesized for ion sensing purposes. The resulting compounds were characterized by NMR spectroscopy, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, and gel permeation chromatography. The electrochemical properties of the dendrimers and corresponding modified electrodes were studied using cyclic voltammetry, which exhibited a single chemically and electrochemically reversible wave for each system. An electrochemical response to the presence of transition metal cations (Pd²⁺, Cu⁺) and oxo anions ([H₂PO₄]⁻, [HSO₄]⁻) was observed. The fundamental origins of these phenomena were studied using DFT computations. It was also shown that the synthesized dendrimers were able to stabilize palladium nanoparticles, which were tested in a model reaction of 4-nitrophenol reduction.

In this paper, a fluorescent functionalized polyacrylamide material (P) was prepared by free radical precipitation polymerization based on a coumarin derivative (COMN) and acrylamide (AM). The chemical structure and composition of P were analyzed by ¹H NMR, UV–vis, and FT-IR spectra. The results of fluorescence spectra of common cations illustrate that P can realize the sensitive detection of copper (Cu²⁺) within 30 s in the pure water system, and the fluorescence quenching rate is as high as 95.47%, the limit of detection is 7.2 nM. It is worth noting that the above system rapidly changed from green to orange within 0.5 s. In addition, the fluorescence spectra of common anions reveal that P/Cu²⁺ had a strong interaction with cyanide (CN^–) (0–180 μM), and the limit of detection was 39.12 nM. The results of the cell imaging test show that P still manifests a good fluorescence response to Cu²⁺ and CN^– in HeLa cells, which provides a new method for the detection of these ions in vivo.

Since the discovery of 6PPD quinone and its severe toxicity to aquatic organisms, the development of safer rubber antiozonants (AO3s) has become imperative. Rubber AO3s must, by definition, protect rubber compounds against degradation due to ozone (O₃), a function that is critical to long-term performance of commercial rubber products, most notably in the tire industry. Identification of candidate AO3s is a challenging problem owing to both the susceptibility of virgin rubber compounds to ozonolysis and the stringent performance requirements for tires. While AO3s are known to protect rubber compounds through combined mechanisms of kinetic scavenging and film formation, aspects of each of these are underexplored. Herein, we develop the use of various experimental and computational metrics─gel permeation chromatography and solution viscometry as well as ground-state density functional theory─for the quantitative determination of kinetic scavenging ability across a benchmark data set of 35 rubber antidegradants. We demonstrate an efficient screening protocol for kinetic scavengers and discuss the implications for design of 6PPD alternatives, particularly those that have been proposed in recent literature.

A series of phenolphthalein-based polyimide membranes with kinked spirobisindane and sterically bulky durene diamine (DDA) moieties were synthesized and then cross-linked via controlled thermal heating. The gas permeability and diffusivity of the copolymer membranes increased with an increasing DDA content, and the thermally treated cross-linked membranes showed further enhancements in these parameters. The cross-linked membrane with a DDA loading of 75 mol % exhibited a CO₂ permeability of 1366.3 Barrer and CO₂/N₂ and CO₂/CH₄ selectivities of 20 and 14.5, respectively, approaching the 2008 Robeson upper bound and surpassing the separation performance of most phenolphthalein-based polyimide polymers. Furthermore, this membrane demonstrated strong resistance to physical aging up to 41 days and displayed stability against plasticization up to 20 atm.

The poly(lactic acid)/glycerol–poly(ε-caprolactone)–poly(d-lactic acid) (PLLA/GLY–PCL–PDLA) foam, which exhibits the integrated properties of high porosity, oil–water separation, and hydrophobic–oleophilic wettability, is successfully prepared by thermally induced phase separation methods. The star-shaped GLY–PCL–PDLA copolymer is synthesized by stepwise ring-opening polymerization. The special three-arm structure can form a three-dimensional physical cross-linked network structure with linear PLLA. The intersections of the arms of the star-shaped polymer can act as heterogeneous nucleating agents to promote linear polymer crystallization. The plasticizing effect of PCL reduces the folding energy of PLA chains and enhances their movement ability, which in turn induces the formation of stereocomposite crystals and results in a reduction in the glass transition temperature. The PDLA chain length in star polymers is closely related to the formation of stereocomposite crystals, and the stereocomposite crystals cannot form when the PDLA chain length in the copolymer is 30. The small pore structure traps air and forms an air cushion underneath the water droplets, significantly increasing the foam’s water contact angle to 146°. The porosity can grow up to 94% by expanding the volume of the polymer-lean phase. In addition, the resultant foam exhibits an excellent oil absorption performance (16 g/g) and does not decrease significantly after 10 cycles, which has great potential for application in oil–water separation.

Mixed matrix membranes (MMMs) have been widely studied as the most promising gas separation membrane materials. However, the heterogeneous distribution of fillers within the membrane has not been fully explored. Herein, a series of asymmetric MMMs with selective, intermediate, and diffusion layers were constructed from top to bottom by gravity-induced deposition behavior of the fillers. MMMs exhibit extremely high CO₂ separation performance for a particular asymmetric structure, changing the uniform permeability behavior of the gas. This also realizes the synergistic improvement of CO₂ permeability and selectivity. In particular, the CO₂ permeability of the UiO-H₂O-27/Pebax-60 wt % MMM was up to 909.14 Barrer, which is 4.1 times higher than that of the homogeneous membrane (P_CO2 = 223.64 Barrer). Compared to the pure Pebax membrane, the CO₂ permeability of the optimized membrane increased 8.2 times (from 110.87 to 909.14 Barrer), and the CO₂/N₂ selectivity increased from 42.6 to 68, successfully surpassing the upper bound of 2019.

It remains a challenge to balance the trade-off between toughness, stiffness, and shape memory properties in shape memory epoxy resins (SMEP). In this study, we employed molecular engineering to synthesize stiff–flexible SMEP, by reacting furan-containing epoxy monomers 2,5-bis[(2-epoxymethoxy)methyl]furan (BOF), derived from biomass, with amines containing imine-amine (IA) and 4,4′-dithiodiphenylamine (4-DTDA). The results indicate that the sacrificial hydrogen bonding and the necessary flexible segments confer BOF/4-DTDA/IA (BDI) with a toughness of up to 13.9 MJ/m³ and a stiffness of 3.5 GPa. Furthermore, the introduction of hyperbranched epoxy resin (HER) yields BOF/4-DTDA/IA/HER (BDIH), which maintains a stiffness exceeding 2 GPa while retaining a toughness of 11.2 MJ/m³. Additionally, BDIH exhibits enhanced tensile strength with an increasing strain rate, which we rationalize based on the loss modulus and scanning electron microscopy morphology analyses. The collaborative motion of the rigid–flexible chain segments and the hydrogen bonding contributes to BDI’s excellent shape memory performance (shape fixation ratio (R_f = 99.00%) and shape recovery ratio (R_r = 99.15%). The physical barrier effect and flexibility of the HER further enhance the shape memory properties. In conclusion, the mechanical features and shape memory performance of BDI and BDIH demonstrate the significant potential for applications in smart molds, smart devices, and other advanced technologies.

Pretreatment of anion-exchange membranes (AEMs) prior to their use in AEM fuel cells (AEMFCs) and AEM water electrolyzers (AEMWEs) is typically required to replace the anions with hydroxide (OH^–). Herein, hexamethyl-p-terphenyl poly(benzimidazolium) iodide (HMT-PMBI) (I^–) was used as a model AEM to investigate the exchange process. The exchanging solution (containing I^–, released from AEMs) was first examined by silver ions, where we found that no more precipitates can be visually observed after 3 exchanges. Moreover, we developed a quantitative method based on UV–vis spectroscopy, which is able to show that ∼61, 84, and 87% of the original I^– was removed after 1, 2, and 3 exchanges in 3 M KOH. In operando electrochemical studies revealed that current–voltage characteristics of AEMFCs are sensitive to residual iodide within the membrane, requiring at least three exchange cycles (>90% removal of iodide) to reach maximum performance. In contrast, AEMWEs are less sensitive to the exchange process, with trace iodide being effectively flushed during electrolysis.

Polydicyclopentadiene (PDCPD) is a thermosetting material used to produce body panels for industrial equipment and vehicles. PDCPD and other important thermosets are produced by direct transformation of neat monomer (dicyclopentadiene) to solid polymer using a catalyst in a process called reaction injection molding. As polymerization and cross-linking are competitive, the polymerization process is therefore inherently challenging to study. In this work, we develop a laboratory-scale method that is rapid and low cost, and which enables the comparison of initiators for ring-opening metathesis polymerization. Additionally, the method enables prediction of both the mechanical and thermal properties of the final material.

MOFs-filled mixed matrix membranes (MMMs) have great potential to break the trade-off effects of traditional gas separation membranes. However, achieving good interfacial compatibility and adequate dispersion of the MOF is not straightforward. In this study, a continuous postmodification was developed for advanced CO₂/N₂ MMMs. UiO-66-NH₂ was easily modified with trimesoyl chloride (UiO-66-TMC) and polyethylene glycol (UiO-66-PEG) sequentially, which was utilized as fillers to construct polyimide (PI) mixed matrix membranes (MMMs). Rich interactions between modified UiO-66-NH₂ and the PI polymer contribute to efficient CO₂ and N₂ separation. At 25 °C and 0.1 MPa, UiO-66-TMC/PI MMMs showed a CO₂/N₂ selectivity of 55.3, and a CO₂ permeability of 616.17 Barrer, and those are 56.7 and 686 Barrer for UiO-66-PEG200/PI MMMs. Both of their CO₂/N₂ separation performances exceed the 2008 Robeson upper bound. The ether bonds in PEG exhibit strong interactions with the CO₂ molecules and improve the CO₂ dissolution selectivity. Meanwhile, the introduction of organic ingredients realized good dispersion and interfacial compatibility within the PI matrix. This work lays the groundwork for the further fabrication of highly selective CO₂ separation materials with specific microscopic interface structures and properties.

Self-polishing antifouling coatings epitomize the foremost and most widely adopted approach within the realm of marine antifouling technology. However, their effectiveness under static conditions remains a significant limitation. Inspired by the highly hydrated interface of coral structures and their remarkable static antifouling capabilities, subsurface-initiated atom-transfer radical polymerization (sSI-ATRP) was employed to obtain the waterborne self-polishing antifouling coatings with a highly hydrated polymer interface (HHPI-m-WSPC). The pronounced polymer brush modification of these waterborne self-polishing coatings was confirmed by FT-IR, XPS, and SEM characterization. Particularly, the stable hydrated interface was investigated by incorporating typical polymer brushes of potassium 3-sulfopropyl methacrylate (SPMA). The synergistic effect between the self-polishing antifouling coatings and the hydrated interface exhibited an outstanding antifouling performance under static conditions. Moreover, even subsequent to abrasion or degradation of the surface polymer brushes, the underlying self-polishing coating can initiate fresh polymerization reactions, thereby restoring static antifouling properties to the interface and enabling the recyclable modification of the substrate. This study therefore proposes a promising avenue for advancing antifouling technology in marine environments.

The shrinkage of UV-curable polymers is directly related to the structural changes in the monomer behavior of the system. The issue of shrinkage in these systems can be mitigated by leveraging the dynamic behavior of disulfide bonds. However, it remains unclear how light induction affects the contraction of the system through processes such as bond cleavage, migration, and recombination of disulfide bonds. In this study, we modified the polyurethane core of a UV-curable system by incorporating three different topologies of disulfide bonds. We examined the impact of these different arrangements and their dynamic adjustment on reducing shrinkage using scanning electron microscopy, shrinkage rate tests, and theoretical analysis based on the Gauss-type radial distribution probability density function. Our findings show that the modified sample exhibited lower curing shrinkage and a smoother surface compared to unmodified polyurethane. Specifically, while the shrinkage rate before modification (PU) was 5.16%, after modification (DSBT-PU, DSBP-PU, DSBE-PU) it decreased to 1.24% for DSBT-PU, 0.67% for DSBP-PU, and 0.95% for DSBE-PU. We also observed that longer chain lengths in disulfide-containing fragments aided in dynamically adjusting the system structure. However, the increase in the molecular fragment length makes it more difficult to migrate dynamic disulfide bonds. Furthermore, our synthetic sample demonstrated high transmittance levels, exceeding 98%. Additionally, we conducted comprehensive examinations including testing 180° peel strength, differential scanning calorimetry, thermogravimetric analysis, tensile characteristics, and transmittance properties, among others. This work not only sheds light on how dynamic bonds influence system structure but also holds practical implications for applications in liquid optical clear adhesive (LOCA) and unique pressure-sensitive adhesives.

The time-dependent properties of polymer materials for packaging applications, whether for recycling or durability purposes, are the subject of several experimental and predictive studies. Amorphous polymers in the glassy state are known to undergo physical aging by structural relaxation, and it is proposed that this phenomenon be investigated in manufactured pieces. This study examines an injection blow molded polylactide bottle stored for 20 years under ambient conditions. Fast scanning calorimetry is used to determine the impact of the manufacturing process on the relaxation kinetics. By comparing the physical aging kinetics of samples that retain their thermomechanical history with those that have it erased, it is observed that the manufacturing process decelerates the structural relaxation by about 2 orders of magnitude. Therefore, the average relaxation advancement, calculated from standard calorimetric measurements, is almost negligible after 20 years of aging. Furthermore, the material demonstrates a diverse array of responses that vary depending on the specific spatial scale under scrutiny. This finding underscores that the overall signal from the PLA bottle can be dissected into the cumulative contributions of discrete regions, each possessing its own relaxation rate. It is hypothesized that the amorphous phase comprises microdomains with high mobility embedded within a slow matrix. In the fast regions, structural relaxation proceeds entirely, suggesting that these areas should continue their thermodynamic equilibration by crystallization.

We focused on clarifying the structure, thermal and electric conducting properties, and thermoelectric (TE) properties of an authentic aerogel comprising poly(3,4-ethyrenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) that was fabricated via supercritical CO₂ drying of an alcogel of cross-linked PEDOT:PSS. Most studies on porous organic TE materials have focused on cryogels with macroporous structures; few reports exist on authentic aerogels with mesoporous structures that exhibit TE effects. The fabricated PEDOT:PSS aerogel had a large surface area (300 m² g^–1) and mesopores (20–30 nm), which effectively restricted gas molecule convection, resulting in a low thermal conductivity of approximately 0.05 W m^–1 K^–1. Moreover, this unique structural integrity was retained up to nearly 300 °C. The conductivity was significantly enhanced by cross-linking treatment with divinyl sulfone (DVS) and methanol replacement prior to supercritical CO₂ drying, yielding an effect similar to that of secondary doping. The treated PEDOT:PSS aerogel exhibited a negative temperature dependence on conductivity, which can be attributed to the band-like carrier conduction typically observed in degenerate semiconductors. The relationship between the conductivity and Seebeck coefficient as a function of the temperature is also consistent with the behavior of degenerate semiconductors. Consequently, the PEDOT:PSS aerogel can be regarded as a mesoporous TE material with low thermal conductivity and the characteristic properties of a degenerate semiconductor.

In the realm of environmental protection and sustainable development, polylactic acid (PLA) materials have garnered significant attention due to their biodegradability. Moreover, PLA is more widely used in the clothing and home textile industries. However, the application of PLA in the textile industry is constrained by hydrolysis issues during conventional aqueous dyeing processes. This paper investigates a waterless dyeing technique utilizing linear silicone (LS) as a nonaqueous dyeing medium. Because PLA fibers are dyed in a nonaqueous environment, the breaking strength of PLA fabrics in the LS waterless dyeing system increased by 4% to 10%, and the breaking elongation improved by 7% to 20% at dyeing temperatures of 110 and 120 °C. However, it showed a reduction of 23.4% at 120 °C in water-bathed dyeing. The LS waterless dyeing system facilitates high-temperature dyeing of PLA fibers, ensuring that the fibers remain intact at temperatures below 140 °C. In contrast, when subjected to traditional water bath dyeing at 120 °C, the fibers exhibit significant breakage. The hydrolysis concerns are mitigated in the LS waterless dyeing bath, resulting in enhanced thermal stability and mechanical properties compared to that in fibers dyed in a conventional water-bathed dyeing system. At equivalent temperatures, the K/S value of dyed PLA fabric can be improved when a small dosage of acetic acid is employed in a waterless dyeing bath, while color fastness to washing, rubbing, and light remain uninfluenced. The selected dyeing medium can be recycled and reused, which not only significantly improves the resource utilization efficiency of the dyeing process but also effectively reduces the generation and emission of waste. This study provides a promising approach for waterless dyeing of PLA fiber, facilitating their practical application and marking an important milestone toward sustainability in the textile industry.

Substantial interest in producing thermosets and photoresponsive chemicals from bioresources is garnering, yet moderate performance drastically confines their applicability in electronic packaging material. Herein, several thermosetting epoxy building blocks from lignin-derived monomers (vanillyl alcohol and eugenol) were constructed, and a range of lignin-based enhanced photocurable resins were further developed using acrylic acid and tetrahydrophthalic anhydride as modifiers by an one-pot synthesis method. The comprehensive performance of lignin-based functionalized photocurable resins was systematically investigated, such as their photopolymerization behavior, thermal–mechanical properties, and electrical breakdown properties. As a result, the biobased thermosetting resin stemming from vanillyl alcohol monomers fulfilled fascinating heat resistance (T_g ≈ 103.9 °C) and tensile strength (28.89 ± 4.39 MPa). Additionally, inspired by a tunable chain-extending tactic, the toughness and electrical breakdown strength of the biobased photo-cross-linked films were further intensified by the insertion of flexible alkyl chain segments between cross-linked sites. As proof of concept, the formulated EAAT green ink, consisting of photocurable resin and inorganic, demonstrated a superior patterning ability after alkali development. The rationally designed lignin-derived photo-cross-linked network strengthening mechanism reported here offers an important and universal strategy for significantly enhancing the comprehensive properties of biobased photocurable materials.

Three-dimensional bioprinting has emerged as a promising technique for creating personalized scaffolds. However, traditional extrusion-based methods face challenges with resolution and structural fidelity. This study aims to introduce a hybrid bioink, combining N-acryloylglycinamide (NAGA) with a rheology modifier to enhance both the stability and precision of printed designs. Additionally, we implemented a controlled immersion shrinkage process to further enhance the resolution. Immersing the printed structures in a 55% w/v tannic acid (TA) solution, the average grid area was reduced to 35.21% of its original size, significantly improving resolution. This treatment also boosted the antioxidant properties of the hydrogel, achieving a 90.5% ABTS removal rate. The hydrogel demonstrated excellent cytocompatibility, enhanced cell proliferation, and maintained high-resolution printability and antioxidant properties, making it a promising biomaterial for soft tissue regeneration.

Vat polymerization (VP), an additive manufacturing technique, has emerged as a promising tool for the fabrication of controlled drug delivery devices. Drugs can easily be incorporated into photopolymerizable liquid resins without concerns of thermal degradation associated with traditional additive manufacturing techniques. Furthermore, these drug-loaded resins can be three-dimensional (3D) printed into devices with an improved speed and resolution not afforded by traditional additive manufacturing techniques. However, the effect of different drug physicochemical properties on the fabrication of these devices and subsequent drug release behavior have not been thoroughly investigated. In this work, we systematically investigate the influence of physicochemical parameters, such as water solubility, resin solubility, and light absorption, on the resulting fabrication and release performance of biodegradable drug delivery devices. We evaluated four model drugs, rhodamine B (RhB), 2-(4-hydroxyphenylazo)benzoic acid (HABA), Allura red AC (AR), and riboflavin, and determined their effects on photopolymerization and printing parameters using photorheology and working curve measurements. Their effects on drug release behavior or performance were also characterized using in vitro release studies. It was shown that the light absorption characteristics of the drug had a significant effect on the printability of the resulting devices. The solubility of the drugs in the resin also had an impact on their release and the release mechanism. This study serves to deepen the current understanding of how to utilize VP to fabricate controlled drug delivery devices with different drug types.

Biovitrimer pads with high flame retardancy and high thermal conductivity were developed using tannic acid (TA), phosphoric acid (PA), and poly(vinyl alcohol) (PVA). For the first time, it was discovered that this type of thermal pad is formed through dynamic bonding of P–O–C covalent bonds. The vitrimer transition temperature (T_v), which indicates dynamic covalent bonding, was controlled within the 74–91 °C range by adjusting the TA, PA, and PVA composition ratio. Below T_v, the vitrimer exhibited excellent elastic recovery properties, with a recovery rate of over 90% when subjected to 100% strain. The material demonstrated a tensile strength of 8 MPa and 430% elongation at break. Interestingly, samples deformed at 100 °C (above T_v) and then rapidly cooled showed a shape memory effect, returning to their original form when reheated above T_v. Thanks to the phosphoric acid in the vitrimer, these materials achieved high limiting oxygen index values exceeding 55% and the highest V-0 rating in the UL-94 test, demonstrating excellent flame retardancy not seen in existing vitrimers. Combining biovitrimer and hexagonal boron nitride (h-BN) produced a composite film with a thermal conductivity of up to 3.8 W/m·K, proving its effectiveness as a heat dissipation pad. Additionally, the vitrimer’s properties allowed for the complete recovery of both h-BN and biovitrimer through recycling. A closed-loop recycling process demonstrated that a composite film with the same heat dissipation performance could be remanufactured using reclaimed biovitrimer and h-BN.

Epoxy-amine polymerization was investigated as a synthetic method for developing poly(β-hydroxyl amine)s with active tertiary amino pendant groups. Primary amines bearing pyridinyl, imidazolyl, dimethylamino, diethylamino, and dibutylamino groups, along with controls bearing mild groups, were used in the polymerization with diglycidyl ether of bisphenol A. While optimized solution polymerization was established by using the primary amines substituted with mild groups, only dibutylamino groups were incorporated as active tertiary amino pendant groups into thermoplastic polymer without gelation. In bulk polymerization, the presence of all additional tertiary amino groups led to cross-linking. Model reactions showed two pathways where the tertiary amino groups involve cross-linking, which varied depending on the nucleophilicity and steric effects of the tertiary amino groups. The choice of tertiary amino group and stoichiometric imbalance between epoxy and amino monomers affected the physical properties of the resulting thermosetting polymers, which possess partially quaternized backbones with β-hydroxyl and active tertiary amino pendant groups.

Fully renewable hydrophobic materials offer a promising solution to addressing environmental challenges. Lignin, a relatively underutilized renewable polymer that naturally exhibits hydrophobicity, shows potential as a blend material in various applications. However, current approaches using technical lignin as a primary component or additive in renewable film manufacturing often rely on nonrenewable, external hydrophobic agents. Here, we developed a tandem strategy to create a fully renewable, hydrophobic lignin-based film. First, lignin was esterified by incorporating long-chain palmitic groups to enhance its hydrophobicity. A poly[(R)-3-hydroxybutyrate] (PHB) film containing 20% palmitoylated lignin demonstrated improved hydrophobicity, with the water contact angle (WCA) increasing from 75.4 to 106.7°. To further enhance hydrophobicity, the film underwent oxygen plasma treatment, which introduced macroscopic surface roughness in the form of “nanoforests.” This treatment significantly increased the WCA to 139°, confirming the effectiveness of the tandem strategy for producing hydrophobic 2D materials. Molecular dynamics simulations revealed that the C16 chain in palmitoylated lignin created a more compact complex with PHB through strong van der Waals interactions and optimized hydrogen bonding, suggesting potential for developing high-lignin-content films. This work demonstrates a facile approach for fabricating fully renewable, hydrophobic composite films without the need for external materials.

Polyamide 6 (PA6) is an eminent engineering plastic renowned for its exceptional mechanical attributes, yet its flammability restricts its application scope. Aluminum diethylphosphinate (ADP) has exhibited an ability to significantly reduce the flammability of PA6, yet it is incapable of enhancing the char-forming capacity of PA6. More importantly, ADP causes serious damage to the mechanical properties of PA6. Here, a boron-containing polymer (PDBD) was prepared and added to PA6 together with ADP to prepare flame-retardant PA6 composites. Compared with PA6/13ADP, the PA6/10ADP/3PDBD sample with 3 wt % PDBD replacing the ADP not only can pass a UL-94 V-0 rating, but also, the peak of heat release rate (PHRR) and the total heat release (THR) were reduced by 35.6% and 16.5%, respectively. Simultaneously, the incorporation of PDBD significantly enhanced the char-forming potential of PA6, signifying a robust synergism between PDBD and ADP in catalyzing and facilitating the char-forming procedure of PA6. Significantly, compared to those of PA6/13ADP, the elongation at break and notch impact strengths of PA6/10ADP/3PDBD composites are notably increased by 174.3% and 45.8% due to the robust hydrogen bond between PDBD and PA6. These results illustrate that PDBD can effectively augment the charring propensity of PA6/ADP and mitigate the detrimental effects of ADP on the mechanical properties of PA6. Therefore, this work provides a simple and feasible method for preparing high-performance PA6 composites.

The surface of films of poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] (PHBH), a biodegradable polyester, was oxidized using photoactivated chlorine dioxide radical gas, generating carboxyl groups for the introduction of quaternary ammonium cations, namely crystal violet. Crystal violet was stable in deionized water but was desorbed through cation exchange in high-salinity media. In soil, the antimicrobial activity of crystal violet inhibited the biodegradation of PHBH films. In seawater, crystal violet was immediately desorbed from the film, which triggered the biodegradation of PHBH films, and biodegradation was also observed in freshwater. Therefore, by introducing crystal violet to the surface of PHBH films, we have developed a material that is stable in soil but degrades when released into aqueous environments, expanding the potential applications of PHBH in our daily lives such as agricultural equipment and outdoor gear.

The unique fluorescent properties resulting from the distinctive electronic structure of rare earth elements (RE) in polymer materials are well-documented, yet these materials often exhibit insufficient mechanical strength. Considering this challenge, two RE cation-π interactions are introduced in this study to bestow exceptional mechanical properties (the stress of indole-based epoxy resins has been enhanced from 60 to 90 MPa, accompanied by an increase in strain from 6% to 11%) and excellent reprocessing and self-healing capabilities upon the polymers through dynamic weak cross-linking. Additionally, through capitalizing on the indole blue fluorescence of the substrate combined with the red fluorescence of Eu³⁺ and the green fluorescence of Tb³⁺, a wide color gamut of light-color tunability is achieved in the fluorescent polymer materials. The mechanical and fluorescent characteristics of RE-IERs are integrated, combining with the computer programming system to introduce a strategy for multi-information encryption and anticounterfeiting applications.

With the popularization of the concept of sustainable development, biobased precursors are attracting increasing attention in the production of UV-curable adhesives. In this study, a straightforward solvent-free approach to prepare biobased adhesives was employed to synthesize methacrylic acid-modified epoxy soybean oil (AESO), which was subsequently blended with flexible hyperbranched siloxane (HPSI-HS) and hydrophobic 2,2,2-trifluoroethyl methacrylate (TFEMA) monomers. The resultant adhesive can be effectively adhered to the substrates through in situ UV curing with the help of initiators. The introduction of HPSI-HS and TFEMA not only reduced the viscosity of the adhesive, achieving a solvent-free adhesion process, but also improved the adhesion strength, flexibility, and thermal stability of the adhesives. The adhesive exhibits exceptional bonding strength to a variety of substrates, including glass, PVDF, copper, and aluminum. The adhesive is insoluble in water and can be bonded in various liquid environments including dimethyl silicone oil, artificial sweat (pH 4.7), seawater, deionized water, hydrochloric acid aqueous solution, and sodium chloride aqueous solutions. The adhesive is prone to degradation in a concentrated alkaline solution. Both the adhesion strength and degradation performance can be effectively modulated by adjusting the formulation meticulously. The multifunctional, degradable, and biobased fluorosilicone adhesive that is suitable for diverse application scenarios presents a practical approach to the advancement of green adhesives.