Shape-morphing hydrogels can be widely used to develop artificial muscles,reconfigurable biodevices,and soft robotics.However,conventional approaches for developing shape-morphing hydrogels highly rely on composite ma...Shape-morphing hydrogels can be widely used to develop artificial muscles,reconfigurable biodevices,and soft robotics.However,conventional approaches for developing shape-morphing hydrogels highly rely on composite materials or complex manufacturing techniques,which limit their practical applications.Herein,we develop an unprecedented strategy to edit the shape morphing of monocomponent natural polysaccharide hydrogel films via integrating gradient cross-linking density and geometry effect.Owing to the synergistic effect,the shape morphing of chitosan(CS)hydrogel films with gradient cross-linking density can be facilely edited by changing their geometries(length-to-width ratios or thicknesses).Therefore,helix,short-side rolling,and longside rolling can be easily customized.Furthermore,various complex artificial 3D deformations such as artificial claw,horn,and flower can also be obtained by combining various flat CS hydrogel films with different geometries into one system,which can further demonstrate various shape transformations as triggered by pH.This work offers a simple strategy to construct a monocomponent hydrogel with geometry-directing programmable deformations,which provides universal insights into the design of shape-morphing polymers and will promote their applications in biodevices and soft robotics.展开更多
Modulation of the surface electron distribution is a challenging problem that determines the adsorption ability of catalytic process.Here,we address this challenge by bridging the inner and outer layers of the core–s...Modulation of the surface electron distribution is a challenging problem that determines the adsorption ability of catalytic process.Here,we address this challenge by bridging the inner and outer layers of the core–shell structure through the bridge Br atom.Carbon shell wrapped copper bromide nanorods(CuBr@C)are constructed for the first time by chemical vapour deposition with hexabromobenzene(HBB).HBB pyrolysis provides both bridge Br atom and C shells.The C shell protects the stability of the internal halide structure,while the bridge Br atom triggers the rearrangement of the surface electrons and exhibits excellent electrocatalytic activity.Impressively,the hydrogen evolution reaction(HER)activity of CuBr@C is significantly better than that of commercial N-doped carbon nanotubes,surpassing commercial Pt/C at over 200 mA·cm^(−2).Density functional theory(DFT)calculations reveal that bridge Br atoms inspire aggregation of delocalized electrons on C-shell surfaces,leading to optimization of hydrogen adsorption energy.展开更多
基金supported by the National Key R&D Program of China(2017YFA0701303,2017YFC0111202)the National Natural Science Foundation of China(52022102,52003287)+3 种基金the Youth Innovation Promotion Association of CAS(2019353)the CAS Key Laboratory of Health Informatics,Shenzhen Institutes of Advanced Technology,Chinese Academy of Sciences(2011DP173015)the Foundation of Hunan Educational Committee(18K030)the Shenzhen Science and Technology Innovation Committee(JCYJ20180507182051636,KQJSCX20180330170232019).
文摘Shape-morphing hydrogels can be widely used to develop artificial muscles,reconfigurable biodevices,and soft robotics.However,conventional approaches for developing shape-morphing hydrogels highly rely on composite materials or complex manufacturing techniques,which limit their practical applications.Herein,we develop an unprecedented strategy to edit the shape morphing of monocomponent natural polysaccharide hydrogel films via integrating gradient cross-linking density and geometry effect.Owing to the synergistic effect,the shape morphing of chitosan(CS)hydrogel films with gradient cross-linking density can be facilely edited by changing their geometries(length-to-width ratios or thicknesses).Therefore,helix,short-side rolling,and longside rolling can be easily customized.Furthermore,various complex artificial 3D deformations such as artificial claw,horn,and flower can also be obtained by combining various flat CS hydrogel films with different geometries into one system,which can further demonstrate various shape transformations as triggered by pH.This work offers a simple strategy to construct a monocomponent hydrogel with geometry-directing programmable deformations,which provides universal insights into the design of shape-morphing polymers and will promote their applications in biodevices and soft robotics.
基金the National Natural Science Foundation of China(Nos.51872116 and 12034002)Jilin Province Science and Technology Development Program(No.20210301009GX)+3 种基金Project for Self-innovation Capability Construction of Jilin Province Development and Reform Commission(No.2021C026)the Program for JLU Science and Technology Innovative Research Team(JLUSTIRT,No.2017TD-09)Jilin Province Science and Technology Development Program(No.20190201233JC)the Fundamental Research Funds for the Central Universities.
文摘Modulation of the surface electron distribution is a challenging problem that determines the adsorption ability of catalytic process.Here,we address this challenge by bridging the inner and outer layers of the core–shell structure through the bridge Br atom.Carbon shell wrapped copper bromide nanorods(CuBr@C)are constructed for the first time by chemical vapour deposition with hexabromobenzene(HBB).HBB pyrolysis provides both bridge Br atom and C shells.The C shell protects the stability of the internal halide structure,while the bridge Br atom triggers the rearrangement of the surface electrons and exhibits excellent electrocatalytic activity.Impressively,the hydrogen evolution reaction(HER)activity of CuBr@C is significantly better than that of commercial N-doped carbon nanotubes,surpassing commercial Pt/C at over 200 mA·cm^(−2).Density functional theory(DFT)calculations reveal that bridge Br atoms inspire aggregation of delocalized electrons on C-shell surfaces,leading to optimization of hydrogen adsorption energy.
