Hydrogels exhibit potential applications in smart wearable devices because of their exceptional sensitivity to various external stimuli.However,their applications are limited by challenges in terms of issues in biocom...Hydrogels exhibit potential applications in smart wearable devices because of their exceptional sensitivity to various external stimuli.However,their applications are limited by challenges in terms of issues in biocompatibility,custom shape,and self-healing.Herein,a conductive,stretchable,adaptable,self-healing,and biocompatible liquid metal GaInSn/Ni-based composite hydrogel is developed by incorporating a magnetic liquid metal into the hydrogel framework through crosslinking polyvinyl alcohol(PVA)with sodium tetraborate.The excellent stretchability and fast self-healing capability of the PVA/liquid metal hydrogel are derived from its abundant hydrogen binding sites and liquid metal fusion.Significantly,owing to the magnetic constituent,the PVA/liquid metal hydrogel can be guided remotely using an external magnetic field to a specific position to repair the broken wires with no need for manual operation.The composite hydrogel also exhibits sensitive deformation responses and can be used as a strain sensor to monitor various body motions.Additionally,the multifunctional hydrogel displays absorption-dominated electromagnetic interference(EMI)shielding properties.The total shielding performance of the composite hydrogel increases to~62.5 dB from~31.8 dB of the pure PVA hydrogel at the thickness of 3.0 mm.The proposed bioinspired multifunctional magnetic hydrogel demonstrates substantial application potential in the field of intelligent wearable devices.展开更多
With the gradually increasing protection awareness about electromagnetic pollution,the demand for absorbing materials with renewability and environmental friendliness has attracted widespread attention.In this work,co...With the gradually increasing protection awareness about electromagnetic pollution,the demand for absorbing materials with renewability and environmental friendliness has attracted widespread attention.In this work,composites consisting of straw-derived biochar combined with NiCo alloy were successfully fabricated through high-temperature carbonization and subsequent hydrothermal reaction.The electromagnetic parameters of the porous biocarbon/NiCo composites can be effectively modified by altering their NiCo content,and their improved absorbing performance can be attributed to the synergy effect of magnetic-dielectric characteristics.An exceptional reflection loss of-27.0 dB at 2.2 mm thickness and an effective absorption bandwidth of 4.4 GHz(11.7-16.1 GHz)were achieved.These results revealed that the porous biocarbon/NiCo composites could be used as a new generation absorbing material because of their low density,light weight,excellent conductivity,and strong absorption.展开更多
电磁波在无线通信等领域的广泛应用导致了严重的电磁污染,迫切需要研发高性能电磁波吸收材料.本文针对吸波材料阻抗不匹配等关键问题,设计并成功制备了新型核壳LaOCl/LaFeO_(3)纳米纤维电磁波吸收剂.这种独特的一维多级结构由导电LaFeO_...电磁波在无线通信等领域的广泛应用导致了严重的电磁污染,迫切需要研发高性能电磁波吸收材料.本文针对吸波材料阻抗不匹配等关键问题,设计并成功制备了新型核壳LaOCl/LaFeO_(3)纳米纤维电磁波吸收剂.这种独特的一维多级结构由导电LaFeO_(3)磁性壳层和离子化合物LaOCl核层组成.基于介电-磁损耗耦合和阻抗匹配的协同作用,LaOCl/LaFeO_(3)纳米纤维在超低负载条件下(4 w t%),表现出-40.1 d B(2.0 mm)的反射损耗和6.4 GHz(2.4 mm)的有效吸收带宽.该工作提出了一种新型LaOCl/LaFeO_(3)纳米纤维吸波材料,并为阻抗匹配调控和电磁吸波性能优化开辟了新策略.展开更多
基金the financial supports from the National Natural Science Foundation of China(52231007,51725101,11727807,22088101,52271167)the Shanghai Excellent Academic/Technological Leaders Program(19XD1400400)+4 种基金the Ministry of Science and Technology of China(973 Project Nos.2018YFA0209100 and 2021YFA1200600)the Fundamental Research Funds for the Central Universities(2022JCCXHH09)the Foundation for University Youth Key Teachers of Henan Province(2020GGJS170)the Support Program for Scientific and Technological Innovation Talents of Higher Education in Henan Province(21HASTIT004)Key Research Project of Zhejiang Lab(No.2021PE0AC02)。
文摘Hydrogels exhibit potential applications in smart wearable devices because of their exceptional sensitivity to various external stimuli.However,their applications are limited by challenges in terms of issues in biocompatibility,custom shape,and self-healing.Herein,a conductive,stretchable,adaptable,self-healing,and biocompatible liquid metal GaInSn/Ni-based composite hydrogel is developed by incorporating a magnetic liquid metal into the hydrogel framework through crosslinking polyvinyl alcohol(PVA)with sodium tetraborate.The excellent stretchability and fast self-healing capability of the PVA/liquid metal hydrogel are derived from its abundant hydrogen binding sites and liquid metal fusion.Significantly,owing to the magnetic constituent,the PVA/liquid metal hydrogel can be guided remotely using an external magnetic field to a specific position to repair the broken wires with no need for manual operation.The composite hydrogel also exhibits sensitive deformation responses and can be used as a strain sensor to monitor various body motions.Additionally,the multifunctional hydrogel displays absorption-dominated electromagnetic interference(EMI)shielding properties.The total shielding performance of the composite hydrogel increases to~62.5 dB from~31.8 dB of the pure PVA hydrogel at the thickness of 3.0 mm.The proposed bioinspired multifunctional magnetic hydrogel demonstrates substantial application potential in the field of intelligent wearable devices.
基金supported by the National Natural Science Foundation of China(No.U2004177)the Henan Province Science and Technology Research and Development Project in 2020,China(No.202300410491)the Key Scientific Research Projects of Provincial Universities in 2021,China(No.21A430045)。
文摘With the gradually increasing protection awareness about electromagnetic pollution,the demand for absorbing materials with renewability and environmental friendliness has attracted widespread attention.In this work,composites consisting of straw-derived biochar combined with NiCo alloy were successfully fabricated through high-temperature carbonization and subsequent hydrothermal reaction.The electromagnetic parameters of the porous biocarbon/NiCo composites can be effectively modified by altering their NiCo content,and their improved absorbing performance can be attributed to the synergy effect of magnetic-dielectric characteristics.An exceptional reflection loss of-27.0 dB at 2.2 mm thickness and an effective absorption bandwidth of 4.4 GHz(11.7-16.1 GHz)were achieved.These results revealed that the porous biocarbon/NiCo composites could be used as a new generation absorbing material because of their low density,light weight,excellent conductivity,and strong absorption.
基金financially supported by the National Natural Science Foundation of China(52102068,52073156,and 52202058)the State Key Laboratory of New Ceramic and Fine Processing,Tsinghua University(KF202112)+5 种基金the Science and Technology on Advanced Functional Composite Laboratory(6142906200509)the Natural Science Foundation of Jiangsu Province(20KJB430017)NUPTSF(NY219162)the Key Science and Technology Program of Henan Province(212102210591)the Foundation for University Youth Key Teachers of Henan Province(2020GGJS170)the Support Program for Scientific and Technological Innovation Talents of Higher Education in Henan Province(21HASTIT004)。
文摘电磁波在无线通信等领域的广泛应用导致了严重的电磁污染,迫切需要研发高性能电磁波吸收材料.本文针对吸波材料阻抗不匹配等关键问题,设计并成功制备了新型核壳LaOCl/LaFeO_(3)纳米纤维电磁波吸收剂.这种独特的一维多级结构由导电LaFeO_(3)磁性壳层和离子化合物LaOCl核层组成.基于介电-磁损耗耦合和阻抗匹配的协同作用,LaOCl/LaFeO_(3)纳米纤维在超低负载条件下(4 w t%),表现出-40.1 d B(2.0 mm)的反射损耗和6.4 GHz(2.4 mm)的有效吸收带宽.该工作提出了一种新型LaOCl/LaFeO_(3)纳米纤维吸波材料,并为阻抗匹配调控和电磁吸波性能优化开辟了新策略.
