2-hydroxyethyl Acrylate Research Articles

Photochromic ionogel with a wide temperature range and fatigue resistance for high-resolution rewritable information record

Recently, photochromic hydrogels have received significant attention and hold substantial promise for rewritable information record. However, the intrinsic instability of hydrogels has restricted their applications. Herein, a photochromic ionogel aiming at extending service life for long-term use is presented by embedding photochromic ammonium molybdate tetrahydrate [(NH4)6Mo7O24·4H2O] (Mo7) in engineered double networks. Covalently cross-linked 2-hydroxyethyl acrylate (HEA) and self-assembled cationic cellulose (JR-400) constitute the networks, and a protic ionic liquid of ethylammonium nitrate (EAN) is immobilized therein. Such a design affords the ionogel comprehensive properties, including high optical transparency (>97%), good adhesion, anti-dehydration, wide operating temperature range (–60 to 150 °C) as well as the sensitive and stable UV-light responsiveness (within 30 s). Besides, the ionogel exhibits admirable mechanical properties of high toughness (over 180 kJ/m3), excellent resilience and a high fatigue threshold (over 1000 cycles with negligible hysteresis). The photochromic process is typically accomplished by photoreduction of Mo7, which is combined with network through electrostatic interaction with quaternized JR-400. The distinctive feature is that EAN serving as both proton donor and electron donor, plays a dominant role in coloration process and formation of charge-transfer complex. The photochromic mechanism which is less well understood in ionic liquid medium, has been revealed. Remarkably, the ionogel used as an information carrier exhibits outstanding stability in a wide operating temperature range. The superiorities of the photochromic ionogel including accurate information recording capacity and application in harsh environments have greatly boosted the high-quality information dissemination and expanded applications of photochromic soft materials.

Study on the properties of slump-retaining polycarboxylate superplasticizer synthesized by EPEG at different pH

Abstract The application of EPEG-type polycarboxylate water reducer in concrete is gradually widespread and studying its preparation process and performance comparison will help promote the EPEG market. In this study, ethylene glycol nonvinyl polyoxymethylene ether (EPEG-2400), acrylic acid (AA) and hydroxyethyl acrylate (HEA) were used as the main synthetic monomers. Under the redox initiation system of hydrogen peroxide-formaldehyde sodium bisulfite, EPEG-type water-retaining polycarboxylate water reducer was synthesized by free radical copolymerization in aqueous solution. The influence of different pH values on the dispersibility of the synthesized polycarboxylate water reducer was studied. The results show that different pH values have little influence on the molecular weight of EPEG water-retaining polycarboxylate water reducer and the work performance of EPEG-synthesized water-retaining polycarboxylate water reducer is better under neutral conditions.

A non-spherical nanoparticles system for the delivery of peptides using polymer grafted nanocellulose

AbstractPeptide drugs are increasingly used to treat a variety of diseases ranging from cancer, and infections to cardiovascular diseases. However, peptides can suffer from low stability in the bloodstream. Entrapment of peptides into nano-sized carriers of various types has widely been explored, but all of them have spherical shapes. Nanocellulose can in contrast serve as a non-spherical nanoparticle with a high aspect ratio. After the isolation of nanocellulose by TEMPO-mediated oxidation, the material needs to be modified with polymers to generate nanoparticles with high water-solubility that can also favourably interact with peptide drugs. We have here chosen insulin as the model drug, which can strongly interact with cationic polymers. As it is known that cationic polymer may retain charged drugs too tightly, we have selected poly(2-(dimethylamino)ethyl acrylate) PDMAEA as a degradable polymer that undergoes self-hydrolysis to poly(acrylic acid) in water. This polymer was compared to poly(N-(3-(dimethylamino)propyl) acrylamide) PDMAPAA, which is a stable cationic polymer. The cationic polymer was co-grafted with poly(2-hydroxyethyl acrylate) PHEA as a water-soluble neutral polymer using the three-component Passerini reaction. A combination of fluorescence and UV-Vis techniques were used to quantify the amount of polymer that was conjugated to the surface. The polymer-coated nanocellulose was labelled with the fluorescent cyanine dye Cy5 while insulin was labelled with Cy3 creating a FRET system that allows monitoring of the interaction between insulin and polymer in cell growth media. We observed that despite the self-hydrolysis of PDMAEA into a negatively charged polymer, the negatively charged insulin was not released in buffer solution according to the FRET studies. Only the addition of serum-supplemented cell growth media led to insulin release. The limited release was explained with the fact that insulin, as well as other peptides, have a mixture of negative and positive charges, with the pH value and the isoelectric point determining the balance between both. Negative-charged polymers can therefore still interact favourably with negatively charged peptides by interacting with cationic amino acids. Graphical Abstract

Lithium-Ion-Doped Eutectogel for Surface-Capacitive Sensing Touch Panel.

Touch panels are deemed as a critical platform for the future of human--computer interaction. Recently, flexible touch panels have attracted much attention due to their superior adhesivity and integratability to the human body. However, hydrogel- or organogel-based devices suffer from instability due to liquid evaporation or low-conductivity substrates. It demands an alternative functional touch panel featuring temperature tolerance, high conductivity, and stretchability. Here, we introduce an eutectogel by immobilizing a novel deep eutectic solvent (DES) within 2-hydroxyethyl acrylate (HEA) covalently cross-linked polymer scaffolds. In this DES (ethylene carbonate(EC)-LiTFSI), the C═O group of EC is unique as an electron donor exhibiting strong coordination interactions with Li+, promoting the dissociation of Li+ from LiTFSI to achieve excellent conductivity. Benefiting from their traits, eutectogel presents high conductivity, transmittance, antifreezing, and mechanical strength. In addition, using the surface-capacitive sensing mechanism, the eutectogel can be designed as a 1D strip and 2D rectangular touch panel which can achieve high-resolution touching tracks, even in a low-temperature environment and pressure-then-recovered state. This eutectogel strategy is envisioned to facilitate the development of next-generation intelligent devices, especially in extreme stretching and low-temperature application scenarios.

Effect of Block Copolymer Self-Assembly on Phase Separation in Photopolymerizable Epoxy Blends.

Directing self-assembly of photopolymerizable systems is advantageous for controlling polymer nanostructure and material properties, but developing techniques for inducing ordered structure remains challenging. In this work, well-defined diblock or random copolymers were incorporated into cationic photopolymerizable epoxy systems to investigate the impact of copolymer architecture on self-assembly and phase separated nanostructures. Copolymers consisting of poly(hydroxyethyl acrylate)-x-(butyl acrylate) were prepared using photoiniferter polymerization to control functional group placement and molecular weight/polydispersity. Prepolymer configuration and concentration induced distinctly different effects on the resin flow and photopolymerization kinetics. The diblock copolymer self-assembled into nanostructured phases within the resin matrix, whereas the random copolymer formed an isotropic mixture. Rapid photopolymerization and ambient temperature conditions during cure facilitated retention of the self-assembled phases, leading to considerably different composite morphology and thermomechanical behavior. Increased loading of the diblock copolymer induced long-range ordered cocontinuous structures. Even with nearly identical prepolymer composition, controlled nanophase separation resulted in significantly enhanced tensile properties relative to those of the isotropic system. This work demonstrates that controlling phase separation with a block copolymer architecture allows access to nanostructured photopolymers with unique and enhanced properties.

Migration of polydimethylsiloxane chain segments toward the surface of UV-cured waterborne poly(urethane-acrylate) films

Waterborne polyurethane (WPU) has poor water resistance and low surface hydrophobicity due to the incorporation of hydrophilic chain-extender. The water resistance and the surface hydrophobicity can be improved by incorporation of polydimethylsiloxane (PDMS), which is attributed to the migration of PDMS chain segments toward the surface of WPU film. However, whether the PDMS chain segments can migrate toward the surface of WPU film after UV-curing, resulting in higher hydrophobicity, needs further investigation? We prepared the different WPUA films by changing the molar ratio of aminopropyl-terminated polydimethylsiloxane (APT-PDMS) to hydroxyethyl acrylate (HEA), to deeply understand the migrating phenomenon of PDMS chain segments toward the surface of WPUA films. The migration cause of PDMS chain segments and the influence of chemical cross-linking on the migration were investigated by thermal annealing and solvent immersion of WPUA films. In addition, the migration activation energy and the relaxation time were studied by the migration rate of PDMS chain segments in the thermal annealing and the rheological behavior of WPUA film, aiming to elucidate the migration of PDMS chain segments depending on the chain motion and the fractional free volume. This investigation provides a simple and feasible strategy for improving the hydrophobicity of waterborne polyurethane.

Solvent-free synthesis of pendant crosslinked polyurethane hot melt adhesive via dynamic Diels-Alder reaction

Pendant cross-linked polyurethane hot melt adhesive was synthesized without any solvents via Diels-Alder reaction (DA reaction) and was coded as DAPU. Firstly, a chain extender containing furan ring was synthesized via Michale addition reaction between hydroxyethyl acrylate (HEA) and furfuryl amine (FA). Secondly, the polyurethane prepolymer with pendant furan rings was synthesized from the reaction between the chain extender and isocyanate-terminated polyurethane prepolymer. Finally, the hot melt adhesive was cross-linked via DA reaction between furan rings and bismaleimide (BMI) without organic solvents due to the viscosity inhibition at higher temperature. DAPU exhibited a higher bonding performance (11.2 MPa) than the commercial reactive polyurethane hot melt adhesive (PUR-Ausbond 3550) and can reach 10.2 MPa after three times break as thermoplastic polyurethane hot melt adhesive (TPU-XJU83), due to the higher cross-linked density and the thermal reversibility of DA adducts. This confirmed that DAPU combined the merits of the two kinds of polyurethane hot melt adhesives successfully without involving solvents.

Engineering Sulfur-Containing Polymeric Fire-Retardant Coatings for Fire-Safe Rigid Polyurethane Foam.

With the advantages of lightweight and low thermal conductivity properties, polymeric foams are widely employed as thermal insulation materials for energy-saving buildings but suffer from inherent flammability. Flame-retardant coatings hold great promise for improving the fire safety of these foams without deteriorating the mechanical-physical properties of the foam. In this work, four kinds of sulfur-based flame-retardant copolymers are synthesized via a facile radical copolymerization. The sulfur-containing monomers serve as flame-retardant agents including vinyl sulfonic acid sodium (SPS), ethylene sulfonic acid sodium (VS), and sodium p-styrene sulfonate (VSS). Additionally, 2-hydroxyethyl acrylate (HEA) and 4-hydroxybutyl acrylate are employed to enable a strong interface adhesion with polymeric foams through interfacial H-bonding. By using as-synthesized waterborne flame-retardant polymeric coating with a thickness of 600µm, the coated polyurethane foam (PUF) can achieve a desired V-0 rating during the vertical burning test with a high limiting oxygen index (LOI) of >31.5vol%. By comparing these sulfur-containing polymeric fire-retardant coatings, poly(VS-co-HEA) coated PUF demonstrates the best interface adhesion capability and flame-retardant performance, with the lowest peak heat release rate of 166kW m-2 and the highest LOI of 36.4vol%. This work provides new avenues for the design and performance optimization of advanced fire-retardant polymeric coatings.

Preparation of a functional monomer containing polymerisable double bonds and chain transfer sulfhydryl groups

ABSTRACT Methacrylate functional monomers containing polymerisable double bonds and sulphhydryl group were synthesised using (methyl) hydroxyethyl (propyl) acrylate and mercaptopropionic acid as precursors with benzene (toluene, ethyl acetate, ether) as solvent and aqueous agent, p-toluene sulphonic acid as catalyst, hydroquinone as polymerisation inhibitor. The yield of methacrylate functional monomers was more than 90%. The structure and purity of methacrylate functional monomers was characterised by proton nuclear magnetic resonance (1H-NMR) and liquid chromatography–mass spectrometry (LC-MS). The precursor material source is of low cost and widely available, and the product did not need to be purified by a special method, which means that it can be directly used for the synthesis of vinyl branched polymer. Therefore, the price of vinyl branched polymer can be greatly reduced and the application range of vinyl branched polymer can be greatly expanded.

High-strength self-healing hydrogels based on boronate-diol complexation cross-linking with good bioavailability

In this report, new self-healing hydrogels were obtained through simple one-pot free radical polymerization of acrylamide, phenylboronic acid, and 2-hydroxyethyl acrylate as copolymer monomers, potassium persulfate (KPS) as initiator, and tetramethylethylenediamine (TEMED) as promoter under low-temperature alkaline (pH = 9) conditions. The boronic acid group of phenylboronic acid (PBA) can interact with the hydroxyl group of hydroxyethyl acrylate (HEA) to form dynamic boronic ester bonds instead of the conventional bis acrylate crosslinkers. The effect of PBA content on the mechanical strength of the hydrogels was systematically investigated. The hydrogels exhibited higher stress, elongation, and self-healing properties due to the synergistic effect of H-bonds and boronate-diol complexation. Further studies revealed that the A–H–0.2–P–0.08 hydrogels exhibited excellent resistance to compression fatigue and also showed good biocompatibility through in vitro cytotoxicity tests.

Synthesis and study of the effect of the structure of HPEG-type polycarboxylate plasticizers on the properties of low-strength concrete

Polycarboxylate superplasticizers have been synthesized as copolymers of acrylamide with polyethylene glycol metallyl ether (HPEG), acrylic acid, and 2-hydroxyethylacrylate, with a molecular weight of 25–33 kDa. The copolymers were characterized using GPC and NMR, revealing that during copolymerization, the copolymer includes up to 10 mol.% HPEG 3500 Da. Copolymers at a dosage of 0.12 wt% provide significant retention time of the concrete mix. When considering the same mole ratios of HPEG/(other monomers) in the initial mixture, copolymers containing the carboxylate and hydroxyethyl acrylate group are the most effective. In terms of concrete strength, the use of quaternary copolymers (AA/AM/HPEG/2-HEA) results in a slowdown in strength gain at the ages of 1–3 days, while the strength at the age of 28 days exceeds that of double (AM/HPEG) and triple (AA/AM/HPEG) copolymers.

Influence of Polymer Side Chain Size and Backbone Length on the Self-Assembly of Supramolecular Polymer Bottlebrushes.

Hydrogen bonds are a versatile tool for creating fibrous, bottlebrush-like assemblies of polymeric building blocks. However, a delicate balance of forces exists between the steric repulsion of the polymer chains and these directed supramolecular forces. In this work we have systematically investigated the influence of structural parameters of the attached polymers on the assembly behaviour of benzene trisurea (BTU) and benzene tris(phenylalanine) (BTP) conjugates in water. Polymers with increasing main chain lengths and different side chain sizes were prepared by reversible addition-fragmentation chain-transfer (RAFT) polymerization of hydroxyethyl acrylate (HEA), tri(ethylene glycol) methyl ether acrylate (TEGA) and oligo(ethylene glycol) methyl ether acrylate (OEGA). The resulting structures were analyzed using small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Both BTU and BTP formed fibres with PHEA attached, but a transition to spherical morphologies was observed at degrees of polymerisation (DP) of 70 and above. Overall, the main chain length appeared to be a dominating factor in inducing morphology transitions. Increasing the side chain size generally had a similar effect but mainly impeded any aggregation as is the case of POEGA. Interestingly, BTP conjugates still formed fibres, suggesting that the stronger intermolecular interactions can compensate partially for the steric repulsion.

Lamellar Microphase Separation and Phase Transition of Hydrogen-Bonding/Crystalline Statistical Copolymers: Amide Functionalization at the Interface.

Microphase separation of random copolymers, as well as that of high χ-low N block copolymers, is promising to construct sub-10-nm structures into materials. Herein, we designed statistical copolymers consisting of 2-hydroxyethyl acrylate (HEA) and N-octadecylacrylamide (ODAAm) to produce crystallization and hydrogen bond-assisted lamellar structure materials. The copolymers not only formed a crystalline lamellar structure with 3-4 nm domain spacing but also maintained an amorphous lamellar structure via phase transition above the melting temperature up to approximately 100 °C. The key is to introduce hydrogen-bonding amide junctions between the octadecyl groups and the polymer backbones, by which the polymer chains are physically fixed at the interface of lamellar structures even above the melting temperature. The stabilization of the lamellar structure by the amide units is also supported by the fact that the lamellar structure of all-acrylate random copolymers bearing hydroxyethyl and crystalline octadecyl groups is disordered above the melting temperature. By spin-coating on a silicon substrate, the HEA/ODAAm copolymer formed a multilayered lamellar thin film consisting of a hydrophilic hydroxyethyl/main chain phase and a hydrophobic octadecyl phase. The structure and order-disorder transition were analyzed by neutron reflectivity.

Highly Stretchable, Low‐Hysteresis, and Adhesive TA@MXene‐Composited Organohydrogels for Durable Wearable Sensors

AbstractAs wearable sensors advance rapidly, demands for multifunctional conductive soft materials are ever higher, including high stretchability, resilience, adhesiveness and stability, simultaneously in one material, for stable long‐term use. Nanocomposite hydrogels incorporating conductive two‐dimensional (2D) nanofillers, such as MXene‐composited gels, emerge as promising candidates. Yet, fulfilling all above requirements, particularly large stretchability with low hysteresis, remains a challenge, owing to the easy oxidation and weak interactions of MXene nanosheets with polymer chains. Herein, an interfacial engineering strategy is proposed, where tannic acid (TA) with high‐density hydroxyl groups is introduced to encapsulate MXene into a stable TA@MXene nano‐motif and meanwhile increase the hydrogen‐bonding interactions between TA@MXene and polymer network. By incorporating TA@MXene into poly(hydroxyethyl acrylate) (PHEA) network in a glycerol/water binary solvent, the obtained organohydrogel exhibits integrated properties of high stretchability (>500%) with low hysteresis (<3%), superior fatigue resistance (consistent hysteresis over 500 cycles at 300% strain), good adhesiveness, along with long‐term stability (>7 days) and antifreezing abilities (−40 °C). Such organohydrogels demonstrate superior strain‐sensitivity and thermosensitive capacities, enabling accurate and reliable detection of human movements, electrocardiogram signals, and body temperature. This general approach of stabilizing nanomaterials while effectively enhancing nanomaterial‐polymer bonding is applicable for synthesizing diverse high‐performance nanocomposited gels.

Characterization of Fluoroacrylate Palm Oil Polyurethane (FPOPU) with Different Synthesis Methods Using Fourier-Transform Infra-Red (FTIR)

In this study, fluoroacrylate palm oil polyurethane (FPOPU) was synthesized with different synthesis methods. FPOPU was synthesized stepwise starting with the synthesis of acrylated epoxidized palm oil (AEPO) by a reaction of acrylic acid (AA) and triethylamine (TEA) as the catalyst. Then, palm oil polyurethane (POPU) was formed by the reaction of AEPO with isophorone diisocyanate (IPDI) and hydroxyethyl acrylate (HEA) as an end cap agent. POPU was further added with 1,6 hexanediol diacrylate (HDDA), trimethyloltripropane triacrylate (TMPTA), and heptafluorodecyl methyl-metacrylate (HDFDMA) monomers to form FPOPU. FPOPU synthesis methods were studied by manipulating the sequence of chemicals added, temperature, and mixing time of POPU. The FPOPU mixture was finally cast onto a silicone mold with 1 mm thickness and cured under UV radiation at 120 seconds. Based on the analysis, pre-mixed IPDI with HEA at 60°C for 15 min followed by the addition of AEPO at 60°C and further mixed for 3 hours (Method 2) shows the complete formation of the urethane chain. It is proven by the existence of NH peak at 3500 cm-1 and the disappearance of NCO peak at the range of 2200-2500 cm-1 indicating the NCO functional group has completely reacted with OH group in AEPO. The addition of fluorination also can be proved by the existence of CF stretching at 1012 cm-1. This study provides information regarding comparison between the synthesis method of FPOPU.

Design of near-infrared responsive self-healing photocured polyurethane materials with thiourethane bonds

In this work, a photopolymerizable polyurethane oligomer (PETU) with thiourethane bonds was designed and synthesized. Afterwards, the near-infrared responsive self-healing polyurethane films (PETU-HI-X) were fabricated by photopolymerization using homemade PETU, polydopamine (PDA), and commercially available isobornyl acrylate (IBOA) and 2-hydroxyethyl acrylate (HEA). PETU-HI-X have good photopolymerization and photothermal conversion performance. The as-prepared near-infrared responsive self-healing polyurethane polymer PETU-HI-1.0 exhibited a tensile stress of 1.06 MPa, strain of 1021 %, initial decomposition temperature of 290 °C. In addition, the temperature of the material can rise to more than 100 °C after irradiation with near-infrared light for 3 min, showing excellent photothermal conversion performance, based on which the material shows more than 90 % self-healing efficiency after irradiation with near-infrared light for 30 min. More importantly, the near-infrared responsive self-healing polyurethane polymer PETU-HI-1.0 also has an excellent degradation property. The self-healing polyurethane films have also been used to prepare the flexible electronic device that can be healed and fully restored their conductivity after getting damaged.

Study of Synthesis of Dual-Curing Thermoplastic Polyurethane Hot-Melt Adhesive and Optimization by Using Gray Relational Analysis to Apply in Fabric Industry to Solve Seamless Bonding Issues.

People wear clothes for warmth, survival and necessity in modern life, but in the modern era, eco-friendliness, shortened production times, design and intelligence also matter. To determine the relationship between data series and verify the proximity of each data series, a gray relational analysis, or GRA, is applied to textiles, where seamless bonding technology enhances the bond between components. In this study, a polyurethane prepolymer, 2-hydroxyethyl acrylate (2-HEA) as an end-capping agent and n-octyl acrylate (ODA) as a photoinitiator were used to synthesize a dual-curing polyurethane hot-melt adhesive. Taguchi quality engineering and a gray relational analysis were used to discuss the influence of different mole ratios of NCO:OH and the effect of the molar ratio of the addition of octyl decyl acrylate on the mechanical strength. The Fourier transform infrared spectroscopy (FTIR) results showed the termination of the prepolymer's polymerization reaction and the C=O peak intensity at 1730 cm-1, indicating efficient bonding to the main chain. Advanced Polymer Chromatography (APC) was used to investigate the high-molecular-weight (20,000-30,000) polyurethane polymer bonded with octyl decyl acrylate to achieve a photothermosetting effect. The thermogravimetric analysis (TGA) results showed that the thermal decomposition temperature of the polyurethane hot-melt adhesive also increased, and they showed the highest pyrolysis temperature (349.89 °C) for the polyhydric alcohols. Furthermore, high peel strength (1.68 kg/cm) and shear strength (34.94 kg/cm2) values were detected with the dual-cure photothermosetting polyurethane hot-melt adhesive. The signal-to-noise ratio was also used to generate the gray relational degree. It was observed that the best parameter ratio of NCO:OH was 4:1 with five moles of monomer. The Taguchi quality engineering method was used to find the parameters of single-quality optimization, and then the gray relation calculation was used to obtain the parameter combination of multi-quality optimization for thermosetting the polyurethane hot-melt adhesive. The study aims to meet the requirements of seamless bonding in textile factories and optimize experimental parameter design by setting target values that can effectively increase production speed and reduce processing time and costs as well.

Ionic Conductive Cellulose-Based Hydrogels with Superior Long-Lasting Moisture and Antifreezing Features for Flexible Strain Sensor Applications.

Nowadays, wearable devices derived from flexible conductive hydrogels have attracted enormous attention. Nevertheless, the utilization of conductive hydrogels in practical applications under extreme conditions remains a significant challenge. Herein, a series of inorganic salt-ion-enhanced conductive hydrogels (HPE-LiCl) consisting of hydroxyethyl cellulose, hydroxyethyl acrylate, lithium chloride, and ethylene glycol/water binary solvent were fabricated via a facile one-pot method. Apart from outstanding self-adhesion, high stretchability, and remarkable fatigue resistance, the HPE-LiCl hydrogels possessed especially excellent antifreezing and long-lasting moisture performances, which could maintain satisfactory flexibility and electric conductivity over extended periods of time, even in challenging conditions such as extremely low temperatures (as low as -40 °C) and high temperatures (as high as 80 °C). Consequently, the HPE-LiCl-based sensor could timely and accurately monitor various human motion signals even in adverse environments and after long-term storage. Hence, this work presents a facile strategy for the design of long-term reliable hydrogels as smart strain sensors, especially used in extreme environments.

A Universal Approach Toward Intrinsically Flexible All-Inorganic Perovskite-Gel Composites with Full-Color Luminescence.

The combination of all-inorganic perovskites (PVSKs) and polymers allows for free-standing flexible optoelectronic devices. However, solubility difference of the PVSK precursors and concerns over the compatibility between polymer carriers and PVSKs imply a great challenge to incorporate different kinds of PVSKs into polymer matrices by the same manufacturing process. In this work, PVSK precursors are introduced into poly(2-hydroxyethyl acrylate) (PHEA) hydrogels in sequence, in which the PVSK-gel composites are achieved with full-color emissions by simply varying the precursor species. Moreover, it is found that CsBr has a higher interaction energy with the (111) plane of CsPbBr3 than the (110) plane; thus, the CsPbBr3 crystals with a shape of truncated cube and tetragon are observed during the CsPbBr3-Cs4PbBr6 phase transition over time. The PVSK-gel composites feature excellent bendability, elasticity, and stretchable deformation (tensile strain > 500%), which allows for 3D printing emissive customized stereoscopic architectures with shape-memory features.

Thiol-selective native grafting from polymerization for the generation of protein-polymer conjugates.

Protein-polymer conjugates combine properties of biopolymers and synthetic polymers, such as specific bioactivity and increased stability, with great benefits for various applications from catalysis to biomedicine. Furthermore, polymer conjugation can mimic important posttranslational modifications of proteins such as glycosylation. There are typically two approaches to create protein-polymer conjugates: the protein is functionalized in advance with an initiator for a grafting-from method or a previously produced polymer is conjugated to the protein via a grafting-to method. In this study, we present a new approach that uses native proteins and allows for direct grafting-from using a thiol-induced, light-activated controlled radical polymerization (TIRP) that is initiated at thiols from specific cysteine residues of the protein. This straightforward method is employed to introduce polymers onto proteins and enzymes without any prior protein modifications, it works in aqueous buffer and maintains the protein's native structure and activity. The resulting protein-polymer conjugates exhibit high molar masses and low dispersities. We demonstrate the versatility of this approach by introducing different types of polymers such as hydrophilic poly(2-hydroxyethyl acrylate) (pHEAA), temperature-responsive poly(N-isopropylacrylamide) (pNIPAM) as well as glycopolymers mimicking the natural protein glycosylation and enabling selective interactions. We present successful combinations of the protein and polymer functions e.g., temperature-induced aggregation leading to an increase in enzyme activity and the introduction of artificial glycosylation inducing specific protein-protein cluster formation and giving straightforward access to glycosurfaces. Based on this straightforward, potentially scalable yet highly controlled synthesis of protein-polymer conjugates, various areas of applications are envisioned ranging from biomedicine to material sciences.