Polymer Skeleton Research Articles

Advances in Electrically Conductive Hydrogels: Performance and Applications

AbstractElectrically conductive hydrogels are highly hydrated 3D networks consisting of a hydrophilic polymer skeleton and electrically conductive materials. Conductive hydrogels have excellent mechanical and electrical properties and have further extensive application prospects in biomedical treatment and other fields. Whereas numerous electrically conductive hydrogels have been fabricated, a set of general principles, that can rationally guide the synthesis of conductive hydrogels using different substances and fabrication methods for various application scenarios, remain a central demand of electrically conductive hydrogels. This paper systematically summarizes the processing, performances, and applications of conductive hydrogels, and discusses the challenges and opportunities in this field. In view of the shortcomings of conductive hydrogels in high electrical conductivity, matchable mechanical properties, as well as integrated devices and machines, it is proposed to synergistically design and process conductive hydrogels with applications in complex surroundings. It is believed that this will present a fresh perspective for the research and development of conductive hydrogels, and further expand the application of conductive hydrogels.

Bioinspired Passive Cooling Hydrogel for Visualizing Hygroscopicity and Desorption Process

AbstractSelf‐hygroscopic hydrogels, characterized by high evaporation enthalpy, cooling efficiency, and self‐regulating properties, have garnered significant attention. However, most current research focuses on enhancing the hygroscopic and desorption performance, often overlooking the importance of monitoring the self‐regulation process, which limits its further application. Advanced visualization technologies, such as in situ electrical impedance tomography, low‐field nuclear magnetic resonance, and hyperspectral imaging, offer potential insights into this behavior, yet they often require additional devices, incur high costs, and involve complex sample preparation processes. Therefore, drawing inspiration from nature, humidity‐color‐sensitive hydrogels (HCSHs) strategy is proposed for visualized cooling. Benefiting from the strong polar responsiveness of the aggregation‐induced emission (AIE) molecules, the hydrogel's fluorescence significantly changes with varying interior water content, thereby its self‐regulation process is monitored easily. Further, the obtained hydrogel could be applied in the electronic device cooling owing to the polymer skeletons’ high swelling ratio, strong adhesion, and excellent self‐hygroscopic properties. This strategy overcomes current limitations in the visual technology of self‐hygroscopic materials and provides new insights into intelligent thermal management for electronic devices.

Multi-stimulus response AIE fluorescent hydrogel for “Blind box” multistage secure information encryption

Aggregation-induced emission (AIE) hydrogels have been widely applied in the field of information security due to their tunable optical properties and aggregation-induced emission properties. The introduction of spiropyranoid organic fluorescent dyes with multi-stimulus response into AIE hydrogels will endow them more functions. However, the traditional 2D anti-counterfeiting has the problem that the hidden information is easy to be copied. Therefore, it is urgent to develop a new anti-counterfeiting strategy to improve the level of information security. In this study, we present for the first time a new strategy of combining multi-stimulus response AIE fluorescent hydrogels with shape memory polyurethane to apply them in the field of information security. The polymer skeleton of fluorescent hydrogel (PCHS hydrogel) is composed of polyvinyl alcohol (PVA) and carboxymethyl chitosan (CMCS) through hydrogen bonding. Four [4-(3, 5-dicarboxyphenyl)] tetraphenyl ethylene (H8ETTB) and 1- (2-hydroxyethyl) −3, 3-dimethylindolin-6 ’-nitrobenzo spiropyrone (SP) are chosen as the fluorescent fillers. PCHS hydrogel is printed onto shape memory polyurethanes (SMPU) by a flexible electronic printer. As a result, the hidden information printed on the SMPU needs to be decrypted at temperatures (80 ℃) and under ultraviolet irradiation(365 nm). Moreover, the hidden information can be destroyed by adding H+ or applying external force after heating to 80 ℃. This effectively improves the security of the information and prevents its disclosure. Interestingly, we can choose the destruction method to make the destruction of information more flexible. This strategy has great potential in the field of information encryption and anti-counterfeiting.

Oxidation of alcohols to carbonyl compounds with H2O2 in water catalyzed by polyoxometalate-based hyper-crosslinked ionic polymer

The oxidation reaction involving hydrogen peroxide (H2O2) in water is of great attraction in fundamental research and industrial application, but there is still a long way to go. Herein, a new hybrid catalyst PW@Py-HIP was successfully synthesized by immobilization of phosphotungstic anions onto/into the pyridinium-based hyper-crosslinked ionic polymer using a post-synthetic strategy. This facile synthetic method afforded heterogeneous catalyst with a large specific surface area of 428.7 m2·g−1 and stable polymeric skeleton. The amphiphilic PW@Py-HIP exhibited remarkable catalytic activity and quantitative selectivity for the oxidation of alcohols into carbonyl compounds with H2O2 in water. The turnover frequency (TOF) and turnover number (TON) values reached 1088.9 h−1 and 4083.3, respectively. Owing to its good heterogeneous nature, PW@Py-HIP can be recycled for six times without significant loss of activity. The developed catalytic system confirmed to be beneficial toward the synthesis of related carbonyl compounds from various alcohols with appreciable conversions.

The influence of CuxS particles on the thermal decomposition of anion exchangers

AbstractDue to the versality, surface imperfections and diverse redox chemistry of CuxS, hybrid ion exchangers (HIXs) containing these particles are an interesting object of research, including thermal transformation. The composite materials used for testing were strongly basic anion exchangers, with macroreticular (M) and gel-type structure (G), containing in the poly (styrene/divinylbenzene) skeleton fine particles of covellite/brochantite (M1), covellite (M2), covellite/digenite/djurleite (G1) and covellite/digenite (G2). The prepared HIXs contained 12–16 mass% S + Cu. They were subjected to thermal analysis under air and N2 to identify the role of the inorganic phase in decomposition of the polymeric phase. The results were discussed on the basis of the TG/DTG curves and X-ray diffraction (XRD) patterns of the solid residues (CuO after combustion, carbon/Cu2S after pyrolysis). It was found that CuxS in the resin phase exhibited oxidative activity promoting the combustion process. The polymeric skeleton of HIXs decomposed in air at a much lower temperature compared to pure resins (400 vs 600 °C). The TG/DTG curves had a model shape, three separate conversions occurring in a narrow temperature range, which indicated sequential decomposition. The low consumption of hydrogen for the reduction of CuxS to Cu2S during pyrolysis was not conducive to condensation of alkyl radicals and increase of the mass of carbon matter. The results advance the understanding of the effect of copper/sulfur-containing fine particles on the thermal decomposition of anion exchanger and can be useful in preparation of multifunctional carbon-containing composite materials.

Dynamically Cross-linked Oligo[2]rotaxane Networks Mediated by Metal-Coordination.

Polyrotaxanes (PRs) have attracted significant research attention due to their unique topological structures and high degrees of conformational freedom. Herein, we take advantage of an oligo[2]rotaxane to construct a novel class of dynamically cross-linked rotaxane network (DCRN) mediated by metal-coordination. The oligo[2]rotaxane skeleton offers several distinct advantages: In addition to retaining the merits of traditional polymer backbones, the ordered intramolecular motion of the [2]rotaxane motifs introduced dangling chains into the network, thereby enhancing the stretchability of the DCRN. Additionally, the dissociation of host-guest recognition and subsequent sliding motion, along with the breakage of metal-coordination interactions, represented an integrated energy dissipation pathway to enhance mechanical properties. Moreover, the resulting DCRN demonstrated responsiveness to multiple stimuli and displayed exceptional self-healing capabilities in a gel state. Upon exposure to PPh3, which induced network deconstruction by breaking the coordinated cross-linking points, the oligo[2]rotaxane could be recovered, showcasing good recyclability. These findings demonstrate the untapped potential of the oligo[2]rotaxane as a polymer skeleton to develop DCRN and open the door to extend their advanced applications in intelligent mechanically interlocked materials.

An artificial layer enables in situ generation of a homogeneous inorganic/organic composite solid electrolyte interphase for stable lithium metal batteries.

Lithium (Li) metal anodes are considered one of the most promising anodes for high-performance batteries with ultra-high specific energy density. However, uncontrolled dendrite growth and the unsuitability of common systems for high voltage hinder the development of Li metal batteries with long cycle life. Herein, we report a rationally designed artificial solid electrolyte interphase (SEI) for Li metal anodes, incorporating LiNO3 and lithium difluoro(oxalato)borate (LiDFOB) as additives within a porous poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) polymer skeleton (referred to as PNF). LiNO3 and LiDFOB can release and synergistically react at the electrode surface, leading to the in situ generation of a homogeneously distributed inorganic/organic SEI during the electrochemical process. This SEI improves homogeneity, ionic conductivity and mechanical stability, contributing to the suppression of electrolyte side reactions and Li dendrite growth. Moreover, a uniform CEI with high Li+ conductivity can be constructed on the NCM811 particles, further enhancing the structural integrity of the NCM811 cathode. As a result, the artificial SEI layer on Li metal anodes enables stable cycling of Li-Cu half cells in an ester-based electrolyte and Li-LiNi0.8Mn0.1Co0.1O2 full cell even at a high voltage of 4.5 V. This work provides new insights into designing homogeneous SEIs for Li metal batteries.

Ladder‐Type Redox‐Active Polymer Achieves Ultra‐Stable and Fast Proton Storage in Aqueous Proton Batteries

AbstractA ladder‐type rigid‐coplanar polymer with highly ordered molecular arrangement has been designed via a covalent cycloconjugation conformational strategy. Benefitting from the extended π‐electron delocalization in the highly aromatic ladder‐type polymeric backbone, the prepared polymer exhibits fast intra‐chain charge transport along the polymeric chain, realizing extraordinary proton‐storage capability in aqueous proton batteries.Affordable and safe aqueous proton batteries (APBs) with unique “Grotthuss mechanism,” are very significant for advancing carbon neutrality initiatives. While organic polymers offer a robust and adaptable framework that is well‐suited for APB electrodes, the limited proton‐storage redox capacity has constrained their broader application. Herein, a ladder‐type polymer (PNMZ) has been designed via a covalent cycloconjugation conformational strategy that exhibits optimized electronic structure and fast intra‐chain charge transport within the high‐aromaticity polymeric skeleton. As a result, the polymer exhibits exceptional proton‐storage redox kinetics, which are evidenced by in‐operando monitoring techniques and theoretical calculations. It achieves a remarkable proton‐storage capacity of 189 mAh g−1 at 2 A g−1 and excellent long‐term cycling stability, with approximately 97.8 % capacity retention over 10,000 cycles. Finally, a high‐performance all‐polymer APB device has been successfully constructed with a desirable capacity retention of 99.7 % after 6,000 cycles and high energy density of 56.3 Wh kg−1.

Ladder-Type Redox-Active Polymer Achieves Ultra-stable and Fast Proton Storage in Aqueous Proton Batteries.

Affordable and safe aqueous proton batteries (APBs) with unique "Grotthuss mechanism," are very significant for advancing carbon neutrality initiatives. While organic polymers offer a robust and adaptable framework that is well-suited for APB electrodes, the limited proton-storage redox capacity has constrained their broader application. Herein, a ladder-type polymer (PNMZ) has been designed via a covalent cycloconjugation conformational strategy that exhibits optimized electronic structure and fast intra-chain charge transport within the high-aromaticity polymeric skeleton. As a result, the polymer exhibits exceptional proton-storage redox kinetics, which are evidenced by in-operando monitoring techniques and theoretical calculations. It achieves a remarkable proton-storage capacity of 189 mAh g-1 at 2 A g-1 and excellent long-term cycling stability, with approximately 97.8% capacity retention over 10,000 cycles. Finally, a high-performance all-polymer APB device has been successfully constructed with a desirable capacity retention of 99.7% after 6,000 cycles and high energy density of 56.3 Wh kg-1.

Mechanical and thermal stability properties improvement of polyethylene wax-coated tungsten carbide/high-density polyethylene γ-rays shielding composites through irradiation-induced crosslinking

It is well known that the properties of polyethylene can be improved by irradiation-induced crosslinking the formation of three-dimensional network structures. This paper investigated the effects of gamma irradiation on the mechanical, thermal stability, and γ-rays shielding properties of TAIC-containing γ-rays shielding composites (HDPE/WC-PEW/TAIC). As a result, SEM images showed that agglomerations are alleviated after polyethylene wax (PEW) coated tungsten carbide (WC). The tensile strength and hardness increased from 25.39 MPa to 94 HA to 29.49 MPa and 98 HA after 50 kGy irradiation in vacuum as compared with all composites, while the thermal stability was also improved. The XPS and gel content results showed that the more crosslinked structures generated after 50 kGy irradiated in vacuum between high-density polyethylene (HDPE) and PEW, but irradiation in air is accompanied by the destruction of polymer skeleton. Moreover, the shielding rates of HDPE/WC-PEW/TAIC with thickness of 2 mm and containing 50 wt% WC can exceed 50% and 25% for 137Cs and 60Co sources respectively. In summary, HDPE/WC-PEW/TAIC could be an alternative to lead as γ-rays shielding material with excellent mechanical, thermal, and γ-rays shielding properties after 50 kGy irradiation in vacuum.

Unlocking Spatial Surface Energy in Porous Skeletons: a Pathway to Bridging Electronic Circuits from 2D to 3D Architectures.

Conventional approaches to creating high-resolution electric circuits face challenges such as the requirement for skilled personnel and expensive equipment. In response, we propose an innovative strategy that leverages a photochemically modified porous polymer skeleton for in-situ circuit fabrication. By developing maskless surface energy manipulation that guides PEDOT:PSS-based conductive ink deposition, electric circuits with high precision, density, stability and adaptability are effortlessly engineered within or atop the porous skeleton, enabling transitions between 2D and 3D circuit configurations. This process simplifies prototyping while significantly reducing costs and maintaining efficiency, promising advancements across various technological sectors.

Study on the Polymer Morphology and Electro-Optical Performance of Acrylate/Epoxy Resin-Based Polymer-Stabilized Liquid Crystals Based on Stepwise Photopolymerization.

Stepwise photopolymerization is a miraculous strategy modulating the polymer skeleton and electro-optical properties of light modulators based on liquid crystal/polymer composites. However, owing to the indistinct polymerization mechanism and curing condition discrepancy, the required polymer structures and electro-optical properties are hard to be controlled precisely. Herein, a novel polymer-stabilized liquid crystal film based on acrylate/epoxy resin is proposed, fabricated and the relationships between preparation process, polymer content, polymer morphology and electro-optical properties are studied. The in-situ photopolymerization of acrylate/epoxy resin liquid crystalline polymer is fulfilled using cation photo-initiator UV 6976. The distinct photopolymerization speed between acrylate and epoxy resin benefits the polymer morphology control, and with accurate containment of the polymerization process and polymer composition, the superior electro-optical properties at a higher polymer content are acquired. The polymer morphology and electro-optical properties are influenced by the polymer content and mass ratio between acrylate and epoxy resin. The best electro-optical properties among samples are attained by controlling the mass ratio between acrylate and epoxy resin to 1:1, integrating higher densities of scattering centers and lower anchoring effect. With higher polymer content, the strategy of increasing the mass ratio of E6M benefits the improvement of E-O properties for alleviating polymer density. This work provides insights to stepwise polymerization of liquid crystalline monomers and offers a fancy strategy for the preparation of novel liquid crystal dimming films.

Isomers of n-Type Poly(thiophene-alt-co-thiazole) for Organic Thermoelectrics.

n-Type polythiophene represents a promising category of n-type polymer thermoelectric materials known for their straightforward structure and scalable synthesis. However, n-type polythiophene often suffers from a twisted backbone and poor stacking property when introducing high-density electron-withdrawing groups for a lower lowest unoccupied molecular orbital (LUMO) level, which is considered to be beneficial for n-doping efficiency. Herein, we developed two isomers of polythiophene derivatives, PTTz1 and PTTz2, by inserting thiazole units into the polythiophene backbone composed of thieno[3,4-c]pyrrole-4,6-dione (TPD) and thiophene-3,4-dicarbonitrile (2CNT). Although PTTz1 and PTTz2 share a similar polymer skeleton, they differ in thiazole configuration, with the nitrogen atoms of the thiazole units oriented toward TPD and 2CNT, respectively. The insertion of thiazole units significantly planarizes the polythiophene backbone while largely preserving low LUMO levels. Notably, PTTz2 exhibits a more coplanar backbone and closer π-stacking compared to PTTz1, resulting in a greatly enhanced electron mobility. Both PTTz1 and PTTz2 can be easily n-doped due to their deep LUMO levels. PTTz2 demonstrates superior thermoelectric performance, with an electrical conductivity of 50.3 S cm-1 and a power factor of 23.8 μW m-1 K-2, which is approximately double that of PTTz1. This study highlights the impact of the thiazole unit on n-type polythiophene derivatives and provides valuable guidelines for the design of high-performance n-type polymer thermoelectric materials.

Covalently linked molecular catalysts in conjugated polymer dots boost photocatalytic alcohol oxidation in neutral condition

As a new class of organic photocatalysts, polymer dots show a potential application in photocatalytic hydrogen peroxide production coupled with chemical oxidation such as methanol oxidation. However, the poor methanol oxidation ability by polymer dots still inhibits the overall photocatalytic reaction occurring in the neutral condition. In this work, an organic molecular catalyst 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl radical is covalently linked to a fluorene unit in a polymer skeleton, eventually enabling photocatalytic hydrogen peroxide production coupled with methanol oxidation in the neutral condition. By conducting various spectroscopic measurements, charge transfer between components in this molecular catalyst-immobilized polymer dots system is studied and found to be very efficient for hydrogen peroxide production coupled with alcohol oxidation. This work proves a strategy for designing polymer dots photocatalysts with molecular catalysts, facilitating their future development and potential applications in other fields such as water splitting, CO2 reduction, photoredox catalysis and photodynamic therapy.

Intelligent micelles for on-demand drug delivery targeting extracellular matrix of pancreatic cancer

As a key pathological feature of pancreatic ductal adenocarcinoma(PDAC), the dense extracellular matrix(ECM) limits the penetration of chemotherapy drugs and is involved in the formation of immunosuppressive microenvironment. Meanwhile, clinical practice has shown that the treatment strategy for ECM should consider its restriction of tumor cell metastasis, and the need for in-depth chemotherapy without destroying ECM is proposed. STAT3 inhibitors have been reported to regulate tumor microenvironment including interrupt the form of ECM. Therefore, we designed and established a micelle system MP@HA with in vivo targeting and responsive drug release function co-loading gemcitabine monophosphate and STAT3 inhibitor silibinin. The hyaluronic acid on the surface of the micelle can bind specifically to the CD44 molecule on the surface of tumor cells and help micelles accumulate at the tumor site. The nitroimidazole used to modify the polymeric skeleton can make the micellar structure collapse in response to hypoxia reduction conditions in the tumor environment, and release silibinin to widely regulate STAT3 molecules in the PDAC microenvironment. The polymer fragment attached with gemcitabine monophosphate can penetrate deep into PDAC tumors due to its small size and positive charge exposed, achieving deep chemotherapy. This research indicates a promising micelle system meeting complicated demands proposed in PDAC treatment to improve antitumor efficacy.

One-Pot synthesis of amino acid-based functional hyper-crosslinked ionic polymers as heterogeneous catalysts for efficient fixation of CO2 with epoxides

The exploitation of multifunctional heterogeneous catalysts for efficient CO2 fixation has been an urgent task in recent years. Herein, three novel amino acid-based hyper-crosslinked ionic polymers (HIPs) with different pendant groups have been constructed via simultaneously Friedel-Crafts alkylation and quaternization reactions in a one-pot manner. The obtained HIPs showed a luxuriant meso/microporous morphology and perfect thermal and chemical stability that are of great importance for practical application. Furthermore, they also showed an excellent CO2 uptake capacity up to 25.17 cm3/g that benefits from N-rich porphyrin units and the amino pendant in the polymer skeleton. Meanwhile, the obtained amino acid-based HIPs can efficiently catalyze the cycloaddition of various epoxides with CO2 under mild conditions without solvents, cocatalysts, and transition metals. Among them, the HIP-His-1 shows the best performance to achieve 99 % product yield with 99 % selectivity for pure CO2 and can also convert diluted CO2 (15 %CO2 and 85 %N2) with satisfactory performance. Moreover, it also shows an exciting reusability which can maintain 91 % of its catalytic yield and 99 % of the selectivity after 5 cycles. The cooperative effects of hydrogen-bond donors (HBDs) and nucleophilic anions during the catalytic process are proposed based on theoretical calculations and this will provide new inspiration for the design and application of HIPs on CO2 conversion.

Thermally stable modification of PEO‐based all‐solid‐state electrolytes via a stretching flow field: Constructing a supportive polymer skeleton

AbstractSince the advent of all‐solid‐state lithium‐ion batteries (ASSLIBs), they have been widely regarded as the ideal high‐temperature‐resistant energy storage devices. The solid‐state electrolyte, a crucial component, should possess high ionic conductivity, excellent flexibility, and significant mechanical strength. Poly(ethylene oxide)‐based all‐solid‐state polymer electrolytes (PEO‐ASSPE) appear to meet these criteria. However, PEO‐ASSPE exhibits poor stability at elevated temperatures, where localized overheating and internal thermal runaway can lead to battery short‐circuit failure. To address these issues, this study employs a ethylene‐methacrylic acid copolymer (EMAA) as a structural support polymer, blended via a eccentric rotor mixer. The homogeneously dispersed EMAA within the PEO matrix forms an interpenetrating network structure and interacts with other components, significantly enhancing the high‐temperature electrochemical stability of the composite polymer electrolytes (CPEs) while maintaining ionic conductivity. Research has demonstrated that when the EMAA content is 40 wt.%, the resulting CPE‐40EMAA exhibit high ionic conductivity (4.07 × 10−4 S cm−1), a high lithium‐ion transference number (0.564), a broad electrochemical stability window (5.1 V), and excellent high‐temperature lithium metal cycling stability (stable cycling for 800 h at current density of 0.1 mA cm−2), which sufficiently meets the electrochemical performance requirements for ASSPEs in high‐temperature energy storage batteries.

A novel functionalized CuTi hybrid nanocomposites: facile one-pot mycosynthesis, characterization, antimicrobial, antibiofilm, antifouling and wastewater disinfection performance

BackgroundThe continuous progress in nanotechnology is rapid and extensive with overwhelming futuristic aspects. Through modernizing inventive synthesis protocols, a paradigm leapfrogging in novelties and findings are channeled toward fostering human health and sustaining the surrounding environment. Owing to the overpricing and jeopardy of physicochemical synthesizing approaches, the quest for ecologically adequate schemes is incontestable. By developing environmentally friendly strategies, mycosynthesis of nanocomposites has been alluring.ResultsHerein, a novel architecture of binary CuO and TiO2 in nanocomposites form was fabricated using bionanofactory Candida sp., for the first time. For accentuating the structural properties of CuTi nanocomposites (CuTiNCs), various characterization techniques were employed. UV-Vis spectroscopy detected SPR at 350 nm, and XRD ascertained the crystalline nature of a hybrid system. However, absorption peaks at 8, 4.5, and 0.5 keV confirmed the presence of Cu, Ti and oxygen, respectively, in an undefined assemblage of polygonal-spheres of 15–75 nm aggregated in the fungal matrix of biomolecules as revealed by EDX, SEM and TEM. However, FTIR, ζ-potential and TGA reflected long-term stability (− 27.7 mV) of self-functionalized CuTiNCs. Interestingly, a considerable and significant biocide performance was detected at 50 µg/mL of CuTiNCs against some human and plant pathogens, compared to monometallic counterparts. Further, CuTiNCs (200 µg/mL) ceased significantly the development of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans biofilms by 80.3 ± 1.4, 68.7 ± 3.0 and 55.7 ± 3.0%, respectively. Whereas, 64.63 ± 3.5 and 89.82 ± 4.3% antimicrofouling potentiality was recorded for 100 and 200 µg/ml of CuTiNCs, respectively; highlighting their destructive effect against marine microfoulers cells and decaying of their extracellular polymeric skeleton as visualized by SEM. Moreover, CuTiNCs (100 and 200 µg/ml) exerted significantly outstanding disinfection potency within 2 h by reducing the microbial load (i.e., total plate count, mold & yeast, total coliforms and faecal Streptococcus) in domestic and agricultural effluents reached >50%.ConclusionThe synergistic efficiency provided by CuNPs and TiNPs in mycofunctionalized CuTiNCs boosted its recruitment as antiphytopathogenic, antibiofilm, antimicrofouling and disinfectant agent in various realms.

Bioinspired Colorimetric Double Inverse Opal Photonic Crystal Indicators for Ethanol Concentration Sensing in Fermentation Engineering.

Photonic crystal-based ethanol concentration indicators with rapid response and brilliant structural color output definitely take a place in colorimetric sensors. Here, based on the H-bond-regulated swelling of acrylate shape memory polymers (SMPs) and the solvent-induced structural color change of the double inverse opal photonic crystals (DIOPCs), new-type photonic crystals (PCs) colorimetric indicators were constructed, exhibiting a span of maximum reflection wavelength (λmax) up to ∼166 nm in response to alcohols with concentrations from 0 to 100 vol %. DIOPC indicators (DIOPCIs) show a rapid response to alcohols (<1.5 s) and output different structural colors (covering from blue to red). The colorimetric sensing mechanism includes the solvent-triggered recovery of the inverse opal skeleton, the cosolvency effect and H-bonds induced swelling/shrinkage of the polymer, the phase separation between polystyrene (PS) microsphere and polymer skeleton, and the light diffraction of DIOPCs. While ensuring a larger λmax span by regulating the H-bond interactions in polymer chains through acrylamide (AAm), AAm-modified DIOPCIs are sensitive to some specific ethanol concentrations. The real-time sensing of ethanol concentration during fermentation verified the practicability of DIOPCIs, thus establishing a visual model between structural color and corresponding fermentation kinetics. We envisage that the DIOPCIs will contribute to the intelligentization of the alcoholic fermentation and distillation industry.

Smart Building Material with Near‐Infrared‐Triggered Reversible Color Switching

Smart materials and devices play an increasingly important role in improving modern life due to their richer functions, enhanced controllability, and improved biocompatibility. Herein, calcium silicate hydration (C–S–H) is integrated with layered [Co(NCS)2(pyrazine)2]n metal–organic frameworks (Co–MOF) and polymeric skeleton to fabricate the smart building material (M–C–S–H). C–S–H was anchored on the polymeric skeleton to reinforce the network structure for enhanced mechanical strength and toughness. Simultaneously, the highly porous skeleton structure enables the uniform distribution of layered Co–MOF, which could maintain its molecular form to endow the M–C–S–H with the photoresponsive color‐switching performance. The M–C–S–H as a smart building material exhibits the color change between light blue and black blue upon near‐infrared illumination on/off within a wide temperature range to achieve personalized wall and building decoration. Taking advantage of the low cost, rapid response, outstanding reversibility, and good color stability, M–C–S–H could provide lively, dynamic, and changeable decorating effects for walls and buildings.