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Synergistic fluorescent hydrogel actuators with selective spatial shape/color-changing behaviors via interfacial supramolecular assembly

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SmartMat 2024年第2期5卷 93-102页

作者： Wei Lu Ruijia Wang Muqing Si Yi Zhang Shuangshuang Wu Ning Zhu Wenqin Wang Tao Chen Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingboChina School of Chemical Sciences University of Chinese Academy of SciencesBeijingChina Faculty of Materials Science and Chemical Engineering Ningbo UniversityNingboChina College of Biotechnology and Pharmaceutical Engineering Nanjing Tech UniversityNanjingJiangsuChina

Biomimetic intelligent polymeric hydrogel actuators with cooperative fluorescence-color switchable behaviors are expected to find great potential applications in soft robotics,visual detection/display,and camouflage applications.However,it remains challenging to realize the spatial manipulation of synergistic shape/color-changing behaviors.Herein,we report an interfacial supramolecular assembly(ISA)approach that enables the construction of robust fluorescent polymeric hydrogel actuators with spatially anisotropic structures.On the basis of this ISA approach,diverse 2D/3D soft fluorescent hydrogel actuators,including chameleon-and octopi-shaped ones with spatially anisotropic structures,were facilely assembled from two different fluorescent hydrogel building blocks sharing the same physically cross-linked agar network.Spatially control over synergistic shape/color-changing behaviors was then realized in one single anisotropic hydrogel actuator.The proposed ISA approach is universal and expected to open promising avenues for developing powerful bioinspired intelligent soft actuators/robotics with selective spatial shape/color-changing behaviors.

关键词： actuator anisotropic structure interfacial supramolecular assembly multicolor fluorescent hydrogels self-gluing

anisotropic phononic crystal structure with low-frequency bandgap and heat flux manipulation

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Science China(Physics,Mechanics & Astronomy) 2020年第2期63卷 93-103页

作者： Ting Guo XiongWei Yang Qian Geng Zhen Li YueMing Li Xian Wang Hu Zhang State Key Laboratory for Strength and Vibration of Mechanical structures Shaanxi Key Laboratory of Environment and Control for Flight Vehicle School of Aerospace Xi’an Jiaotong University

This study presents a two-dimensional phononic crystal with heat flux manipulation and wide bandgaps of out-of-plane modes within the low-frequency range. The anisotropic matrix made of spiral-multilayered materials with different thermal conductivities, and the coating layer inserted with metal are designed for heat flux manipulation. Rubber-coated metal cylinders are periodically embedded in the anisotropic matrix to obtain the low-frequency bandgaps of out-of-plane modes. Numerical simulation is carried out to validate the heat and elastic characteristics of the spiral-multilayered anisotropic structure and reveal the effects of the laying angle and temperature on the bandgaps. Subsequently, a spiral-multilayered plate with periodic structures is studied, which shows an obvious vibration attenuation in the frequency ranges of the bandgaps and a deflected heat flux from the initial propagation direction. In the experimental investigation, the multi-phase spiral-multilayered anisotropic plate is simplified to a single-phase anisotropic plate made of aluminum. The characteristics of this type of anisotropic phononic crystal structure may pave the way for the design of a new kind of thermo-acoustic metamaterial serving in combined thermal and acoustic environments.

关键词： heat flux manipulation bandgap anisotropic structure thermal stress spiral-multilayered structure

anisotropic hemp-stem-derived biochar supported phase change materials with efficient solar-thermal energy conversion and storage

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Biochar 2022年第1期4卷 546-560页

作者： Ruiying Yang Xiran Guo Haotian Wu Weizhi Kang Kun Song Yaqiong Li Xiubing Huang Ge Wang Beijing Key Laboratory of Function Materials for Molecule and structure Construction School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 10083People’s Republic of China

As cheap and renewable sources,the exploitation of biomass resources was of great value in phase change energy storage.In this study,hemp stems were converted into biochars with three-dimensional multi-level anisotropic pores through a temperature-controlled charring process,which were used as supports for polyethylene glycol(PEG6000)to form shape-stable composite phase change materials(ss-CPCMs).It is shown that the ss-CPCMs using anisotropic hemp-stem-derived biochar obtained at a carbonization temperature of 900℃as a support has high PEG6000 loading rate(88.62wt%),large latent heat(170.44 J/g)and favorable thermal stability owning to its high surface area and hierarchical pores.The biochar-based ss-CPCM also has good light absorption ability with a maximum solar-thermal conversion efficiency of 97.70%.In addition,the different thermal conductivities in the transverse and longitudinal directions of ss-CPCMs reflect the unique anisotropic structure.This work can not only improve the high-value utilization of biochars,but also provide the ss-CPCMs with excellent performance for solar-thermal conversion and storage systems.

关键词： Biochar Phase change materials anisotropic structure Solar-thermal conversion

In-situ polymerization for mechanical strong composite actuators based on anisotropic wood and thermoresponsive polymer

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Chinese Chemical Letters 2022年第5期33卷 2635-2638页

作者： Lian Chen Xianshuo Wei Feng Wang Shaoju Jian Weisen Yang Chunxin Ma Gaigai Duan Shaohua Jiang Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources International Innovation Center for Forest Chemicals and MaterialsCollege of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China Fujian Key Laboratory of Eco-Industrial Green Technology College of Ecology and Resources EngineeringWuyi UniversityWuyishan 354300China Shandong Key Laboratory of Biochemical Analysis College of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdao 266042China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou 570228China

Stimuli-responsive hydrogels hold an irreplaceable statue in intelligent actuation materials because of their reversible stretchability and excellent biocompatibility.However,the poor mechanical performance and complicated fabrication process of anisotropic structures severely limit their further applications.Herein,we report a high-strength thermoresponsive wood-PNIPAM composite hydrogel actuator with complex deformations,through a simple in-situ polymerization.In this composite hydrogel actuator,the anisotropic wood and the thermoresponsive PNIPAM hydrogel hydroel can work together to pro-vide bending and even other complex deformations.Owing to strong interfacial interaction,this actuator perfectly realized the combination of good mechanical properties(∼1.1 MPa)and fast actuation speed(∼0.9 s).In addition,by adjusting the orientation direction of wood,this actuator can achieve various complex deformations.Such composite hydrogel actuator could be a good candidate for intelligent appli-cations,such as intelligent actuators,smart valves,manipulators and even soft robots.

关键词： Actuator anisotropic structure Thermoresponsive Wood

anisotropic thermoelectric transport properties in polycrystalline SnSe_(2)

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Chinese Physics B 2021年第6期30卷 476-483页

作者：李彩云何文科王东洋赵立东 School of Materials Science and Engineering Beihang UniversityBeijing 100191China

It is reported that SnSe_(2) consisting of the same elements as SnSe, is a new promising thermoelectric material with advantageous layered structure. In this work, the thermoelectric performance of polycrystalline SnSe_(2) is improved through introducing SnSe phase and electron doping(Cl doped in Se sites). The anisotropic transport properties of SnSe_(2) are investigated. A great reduction of the thermal conductivity is achieved in SnSe_(2) through introducing SnSe phase, which mainly results from the strong SnSe_(2)–SnSe inter-phase scattering. Then the carrier concentration is optimized via Cl doping, leading to a great enhancement of the electrical transport properties, thus an extraordinary power factor of ^5.12 μW·cm^(-1)·K^(-2) is achieved along the direction parallel to the spark plasma sintering(SPS) pressure direction( P). Through the comprehensive consideration on the anisotropic thermoelectric transport properties, an enhanced figure of merit ZT is attained and reaches to ^ 0.6 at 773 K in SnSe_(2)-2% SnSe after 5% Cl doping along the P direction, which is much higher than ^ 0.13 and ^ 0.09 obtained in SnSe_(2)-2% SnSe and pristine SnSe_(2) samples, respectively.

关键词： thermoelectric SnSe_(2) anisotropic structure Cl-doping

Preparation of anisotropic MnO2 Nanocatalysts for Selective Oxidation of Benzyl Alcohol and 5-Hydroxymethylfurfural

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Transactions of Tianjin University 2020年第5期26卷 382-390页

作者： Huanlin Wang Yu Song Xuan Liu Shiyu Lu Chunmei Zhou Yuguang Jin Yanhui Yang School of Chemistry and Molecular Engineering(SCME) Institute of Advanced Synthesis(IAS)The Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing Tech UniversityNanjing 211816China State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

anisotropic MnO2 nanostructures,includingα-phase nanowire,α-phase nanorod,δ-phase nanosheet,α+δ-phase nanowire,and amorphous fl occule,were synthesized by a simple hydrothermal method through adjusting the pH of the precursor solution and using diff erent counterions.The catalytic properties of the as-synthesized MnO2 nanomaterials in the selective oxidation of benzyl alcohol(BA)and 5-hydroxymethylfurfural(HMF)were evaluated.The eff ects of micromorphology,phase structure,and redox state on the catalytic activity of MnO2 nanomaterials were investigated.The results showed that the intrinsic catalytic oxidation activity was mainly infl uenced by the unique anisotropic structure and surface chemical property of MnO2.With one-dimensional and 2D structures exposing highly active surfaces,unique crystal forms,and high oxidation state of Mn,the intrinsic activities for MnO2 catalysts synthesized in pH 1,5,and 10 solutions(denoted as MnO2-pH1,MnO2-pH5,and MnO2-pH10,respectively)were twice higher than those of other MnO2 catalysts in oxidation of BA and HMF.With a moderate aspect ratio,theα+δnanowire of MnO2-pH10 exhibited the highest average oxidation state,most abundant active sites,and the best catalytic oxidation activity.

关键词： Manganese dioxide anisotropic structure Catalytic oxidation Benzyl alcohol 5-hydroxymethylfurfural

BEM FOR MODAL ANALYSIS OF 3-D anisotropic structureS

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Acta Mechanica Solida Sinica 2001年第4期14卷 364-373页

作者： Du Sanhu Wu Dafang Li Zailiang Beijing Univ Aeronaut & Astronaut Solid Mech Res Ctr Beijing 100083 Peoples R China

The boundary element method for the modal analysis of freevibration for 3-D anisotropic structures using particular solutionshas been developed. The complete polynomials of order two are used toconstruct the particular solutions for general anisotropic materials.The numerical results for 3-D free vibra- tion analysis of anisotropic cantilever beam by the method presented is in goodagreement with the results us- ing the Ritz technique. Foranisotropic materials, the numerical results calculated form theproposed method are in good agreement with the results from MSC.NASTRAN.

关键词： boundary element method anisotropic structure particular solutions modalanalysis

The Prey Capture Mechanism of Micro structure on the Sarracenia Judith Hindle Inner Surface

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Journal of Bionic Engineering 2018年第1期15卷 34-41页

作者： Yang Gan Huawel Chen Tong Ran Pengfei Zhang Deyuan Zhang School of Mechanical Engineering and Automation Beihang University Beijing 1 O0191 China

Low friction surface has attracted considerable attention due to its potential application in various fields. As a typical carnivorous plant, Sarracenia Judith Hindle possesses unique slippery surface to capture prey especially in wet environment. In order to make clear the low friction mechanism, structural characterization was carried out and unique inclined micro-thorn structure was found on the inner wall surface. Micro-droplets harvest on the surface of the micro-thorn was discovered via the observation in wet environment. Friction force measurement was conducted by sliding the ants＇ footpad on the inner surface and polymer replica surfaces, which demonstrated that the friction force decreases on those surfaces in wet environment or inward direction. Further analysis manifested that the slippery inner surface grown with hierarchical micro-thorn structure leads to the friction decrease, and that is the fundamental mechanism for prey capture and retention in the pitcher of carnivorous plant Sarracenia Judith Hindle.

关键词： prey capture hierarchical microstructure Sarracenia low friction surface anisotropic structure