Current thermochromic materials for smart windows suffer from poor environmental stability,lack of self-healing and recyclability,and susceptibility to contamination.In this study,thermochromic supramolecular ionogels...Current thermochromic materials for smart windows suffer from poor environmental stability,lack of self-healing and recyclability,and susceptibility to contamination.In this study,thermochromic supramolecular ionogels with excellent environmental stability,efficient room-temperature self-healing and recyclability properties,as well as amphiphobic slippery surfaces,are fabricated by incorporating binary ionic liquids into a rationally designed self-healing polyurethane with perfluoroalkyl side chains.The outstanding and stable thermochromic performance of the resulting ionogels stems from the hydrogen bond-mediated,confined,and reversible phase separation of ionic liquids within the polyurethane network,enabling the ionogels to effectively reduce indoor temperatures and enhance the comfort of occupants.The surface-enriched perfluoroalkyl side chains enable various liquids,including water,alkanes,and edible oils,to easily slide off the ionogel surface without leaving any residue,preventing the transmittance decrease and thermochromic performance degradation caused by contaminations.The dynamic hydrogen bonds within the polyurethane network enable the ionogels to repeatedly heal physical and chemical damages,as well as to be recycled multiple times without performance loss,thereby reducing maintenance costs and minimizing material waste.This study provides a novel approach to developing advanced thermochromic materials for smart windows,potentially improving the building energy efficiency and sustainability.展开更多
Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent resea...Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent research has significantly improved the performance of lignin-based hydrogels,suggesting their substantial potential in fields such as biomedicine,environmental science,and agriculture.This paper reviews the process of lignin extraction,systematically introduces synthesis strategies for preparing lignin-based hydrogels,and discusses the current state of research on these hydrogels in biomedical and environmental protection fields.It concludes by identifying the existing challenges in lignin hydrogel research and envisioning future prospects and development trends.展开更多
Aerogels are ultra-lightweight,porous materials defined by a complex network of interconnected pores and nanostructures,which effectively suppress heat transfer,making them exceptional for thermal insulation.Furthermo...Aerogels are ultra-lightweight,porous materials defined by a complex network of interconnected pores and nanostructures,which effectively suppress heat transfer,making them exceptional for thermal insulation.Furthermore,their porous architecture can trap and scatter light via multiple internal reflections,extending the optical path within the material.When combined with suitable light-absorbing materials,this feature significantly enhances light absorption(darkness).To validate this concept,mesoporous silica aerogel particles were incorporated into a resorcinol-formaldehyde(RF)sol,and the silica-to-RF ratio was optimized to achieve uniform carbon compound coatings on the silica pore walls.Notably,increasing silica loading raised the sol viscosity,enabling formulations ideal for direct ink writing processes with excellent shape fidelity for super-black topographical designs.The printed silica-RF green bodies exhibited remarkable mechanical strength and ultra-low thermal conductivity(15.8 m W m^(-1) K^(-1))prior to pyrolysis.Following pyrolysis,the composites maintained structural integrity and printed microcellular geometries while achieving super-black coloration(abs.99.56%in the 280-2500 nm range)and high photothermal conversion efficiency(94.2%).Additionally,these silica-carbon aerogel microcellulars demonstrated stable electrical conductivity and low electrochemical impedance.The synergistic combination of 3D printability and super-black photothermal features makes these composites highly versatile for multifunctional applications,including on-demand thermal management,and efficient solar-driven water production.展开更多
By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,t...By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,the interior heating power would increase the working temperature and fire risk,which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties.In this work,we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy.Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk,REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload,indicating a 12.0℃lower temperature than the RC film under the same conditions in the outdoor experiment.In the nighttime with a low workload,RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime.In addition,our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise,thus mitigating fire risks.Thus,our design shows a promising solution for the thermal management of outdoor devices,delivering outstanding performance in both heat dissipation and flame retardancy.展开更多
Thermochromic soft materials are flexible functional materials that adaptively tune optical properties(transmittance,reflectance,or scattering)with temperature for thermal modulation.Herein,a laminated thermochromic g...Thermochromic soft materials are flexible functional materials that adaptively tune optical properties(transmittance,reflectance,or scattering)with temperature for thermal modulation.Herein,a laminated thermochromic gel(DEE-DA)is synthesized by encapsulating a thermochromic hydrogel(DA)between two hydrophobic ionogels(DEE)in a stacked configuration.The synergy of multiple dynamic bonds endows the DEE-DA gel with exceptional mechanical properties and remarkable self-healing capability(98.8%at 30℃).More importantly,attributed to the temperature-responsive reversible cleavage and recombination of hydrogen bonds and borate ester bonds,DEE-DA gel demonstrates tunable transmittance with a light modulation efficiency of 85.45%.In response to the various external conditions,the gel can auto-adjust the optical properties to avoid sun irradiation or heat loss.Accordingly,the gel enables efficient dual-mode thermal modulation across a broad temperature range to realize thermal management.The research proposes gel thermochromism and laminated durability enhancement for adaptive materials in smart buildings and wearables.展开更多
While biomaterials are endowed with sophisticated functions by the temporal dynamics and autonomy derived from non-equilibrium assemblies in biological systems,fabricating advanced materials counterparts with these fe...While biomaterials are endowed with sophisticated functions by the temporal dynamics and autonomy derived from non-equilibrium assemblies in biological systems,fabricating advanced materials counterparts with these features through kinetic control remains rare.Herein,we report a non-equilibrium hydrogel that exhibits autonomous time-dependent ultrabright fluorescence(quantum yield 0.90),achieved through the kinetically controlled incorporation of thermodynamic equilibrium host-vip complexes into a poly(2-hydroxyethyl methacrylate)(PHEMA)network.Transient complexes are programmed by coupling rapid assembly kinetics with the slow competitive binding of the polymer matrix.This kinetic mismatch converts a thermodynamic equilibrium supramolecular system into a non-equilibrium state,generating temporally dynamic fluorescence that cyclically shifts from yellow to green and self-reverts.The programmed temporal dynamics endow the hydrogel with high potential for information encryption applications.展开更多
基金supported by the National Natural Science Foundation of China(22475082,21971083)。
文摘Current thermochromic materials for smart windows suffer from poor environmental stability,lack of self-healing and recyclability,and susceptibility to contamination.In this study,thermochromic supramolecular ionogels with excellent environmental stability,efficient room-temperature self-healing and recyclability properties,as well as amphiphobic slippery surfaces,are fabricated by incorporating binary ionic liquids into a rationally designed self-healing polyurethane with perfluoroalkyl side chains.The outstanding and stable thermochromic performance of the resulting ionogels stems from the hydrogen bond-mediated,confined,and reversible phase separation of ionic liquids within the polyurethane network,enabling the ionogels to effectively reduce indoor temperatures and enhance the comfort of occupants.The surface-enriched perfluoroalkyl side chains enable various liquids,including water,alkanes,and edible oils,to easily slide off the ionogel surface without leaving any residue,preventing the transmittance decrease and thermochromic performance degradation caused by contaminations.The dynamic hydrogen bonds within the polyurethane network enable the ionogels to repeatedly heal physical and chemical damages,as well as to be recycled multiple times without performance loss,thereby reducing maintenance costs and minimizing material waste.This study provides a novel approach to developing advanced thermochromic materials for smart windows,potentially improving the building energy efficiency and sustainability.
基金supported by the National Natural Science Foundation of China(21706052,22278114)Natural Science Foundation of Henan Province(242300421575).
文摘Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent research has significantly improved the performance of lignin-based hydrogels,suggesting their substantial potential in fields such as biomedicine,environmental science,and agriculture.This paper reviews the process of lignin extraction,systematically introduces synthesis strategies for preparing lignin-based hydrogels,and discusses the current state of research on these hydrogels in biomedical and environmental protection fields.It concludes by identifying the existing challenges in lignin hydrogel research and envisioning future prospects and development trends.
基金financially supported by the Swiss National Science Foundation(grant number IZLRZ2_164058)the China Scholarship Council Ph.D.student exchange programthe Priority Academic Program Development of Jiangsu Higher Education Institution(PAPD)。
文摘Aerogels are ultra-lightweight,porous materials defined by a complex network of interconnected pores and nanostructures,which effectively suppress heat transfer,making them exceptional for thermal insulation.Furthermore,their porous architecture can trap and scatter light via multiple internal reflections,extending the optical path within the material.When combined with suitable light-absorbing materials,this feature significantly enhances light absorption(darkness).To validate this concept,mesoporous silica aerogel particles were incorporated into a resorcinol-formaldehyde(RF)sol,and the silica-to-RF ratio was optimized to achieve uniform carbon compound coatings on the silica pore walls.Notably,increasing silica loading raised the sol viscosity,enabling formulations ideal for direct ink writing processes with excellent shape fidelity for super-black topographical designs.The printed silica-RF green bodies exhibited remarkable mechanical strength and ultra-low thermal conductivity(15.8 m W m^(-1) K^(-1))prior to pyrolysis.Following pyrolysis,the composites maintained structural integrity and printed microcellular geometries while achieving super-black coloration(abs.99.56%in the 280-2500 nm range)and high photothermal conversion efficiency(94.2%).Additionally,these silica-carbon aerogel microcellulars demonstrated stable electrical conductivity and low electrochemical impedance.The synergistic combination of 3D printability and super-black photothermal features makes these composites highly versatile for multifunctional applications,including on-demand thermal management,and efficient solar-driven water production.
基金financially supported by the Science and Technology Innovation Program of Hunan Province(2024RC3003)the Central South University Innovation-Driven Research Programme(2023CXQD012)the Initiative for Sustainable Energy for its financial support。
文摘By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,the interior heating power would increase the working temperature and fire risk,which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties.In this work,we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy.Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk,REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload,indicating a 12.0℃lower temperature than the RC film under the same conditions in the outdoor experiment.In the nighttime with a low workload,RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime.In addition,our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise,thus mitigating fire risks.Thus,our design shows a promising solution for the thermal management of outdoor devices,delivering outstanding performance in both heat dissipation and flame retardancy.
基金supported by the Yunlong Lake Laboratory of Deep Underground Science and Engineering Project(104024004)the National Natural Science Foundation of China(62288102)+2 种基金the Key Project of Basic Research Program of Jiangsu Province(BK20243036)the State Key Laboratory of Mechanics and Control for Aerospace Structures(Nanjing University of Aeronautics and astronautics)(MCAS-E-0124K01)the Cultivation Program for the Excellent Doctoral Dissertation of Nanjing Tech University(2023-06)。
文摘Thermochromic soft materials are flexible functional materials that adaptively tune optical properties(transmittance,reflectance,or scattering)with temperature for thermal modulation.Herein,a laminated thermochromic gel(DEE-DA)is synthesized by encapsulating a thermochromic hydrogel(DA)between two hydrophobic ionogels(DEE)in a stacked configuration.The synergy of multiple dynamic bonds endows the DEE-DA gel with exceptional mechanical properties and remarkable self-healing capability(98.8%at 30℃).More importantly,attributed to the temperature-responsive reversible cleavage and recombination of hydrogen bonds and borate ester bonds,DEE-DA gel demonstrates tunable transmittance with a light modulation efficiency of 85.45%.In response to the various external conditions,the gel can auto-adjust the optical properties to avoid sun irradiation or heat loss.Accordingly,the gel enables efficient dual-mode thermal modulation across a broad temperature range to realize thermal management.The research proposes gel thermochromism and laminated durability enhancement for adaptive materials in smart buildings and wearables.
基金supported by the National Natural Science Foundation of China(22025503,22220102004,22401093)the Science and Technology Commission of Shanghai Municipality(24DX1400200)+2 种基金the Innovation Program of Shanghai Municipal Education Commission(2023ZKZD40)the Programme of Introducing Talents of Discipline to Universities(B16017)the China Postdoctoral Science Foundation(2023M741167,GZB20230211,2024T170273)。
文摘While biomaterials are endowed with sophisticated functions by the temporal dynamics and autonomy derived from non-equilibrium assemblies in biological systems,fabricating advanced materials counterparts with these features through kinetic control remains rare.Herein,we report a non-equilibrium hydrogel that exhibits autonomous time-dependent ultrabright fluorescence(quantum yield 0.90),achieved through the kinetically controlled incorporation of thermodynamic equilibrium host-vip complexes into a poly(2-hydroxyethyl methacrylate)(PHEMA)network.Transient complexes are programmed by coupling rapid assembly kinetics with the slow competitive binding of the polymer matrix.This kinetic mismatch converts a thermodynamic equilibrium supramolecular system into a non-equilibrium state,generating temporally dynamic fluorescence that cyclically shifts from yellow to green and self-reverts.The programmed temporal dynamics endow the hydrogel with high potential for information encryption applications.
