Thermally conductive papers with electrical insulation and mechanical robustness are essential for efficient thermal management in modern electronics.In this study,we introduced a metal ion-assisted interfacial crossl...Thermally conductive papers with electrical insulation and mechanical robustness are essential for efficient thermal management in modern electronics.In this study,we introduced a metal ion-assisted interfacial crosslinking strategy to strengthen sugarfunctionalized graphene fluoride(SGF)and cellulose nanofibers(CNF)by hydrogen bonding and metal ion crosslinking that leads to simultaneous enhancements in thermal conductivity and mechanical properties.The facile sugarassisted ball-milling exfoliation method was developed to achieve the exfoliation of graphite fluoride and hydroxyl group functionalization on the surface of graphene fluoride.Thanks to the good dispersibility of the SGF sheets in water,the flexible SGF/CNF composite papers with hydrogen bonding were prepared via vacuum-assisted filtration.We introduced hydrogen bonding and metal ion crosslinking into SGF/CNF papers to obtain densely packed composite papers.Ca^(2+)or Al^(3+)ion-crosslinked SGF/CNF papers exhibited superior thermal and mechanical properties owing to hydrogen bonding and metal ion crosslinking.SGF/CNF-Ca^(2+)and SGF/CNF-Al^(3+)papers at 50 wt%of SGF yield in-plane thermal conductivities of 72.93 and 75.02 W m^(-1) K^(-1),and tensile strengths of 121.5 and 135.7 MPa,respectively.A thermal percolation value was observed at 12.6 vol%of SGF filler content.In addition,the SGF/CNF papers exhibited electrical insulation properties.These remarkable characteristics of the metal ion-crosslinked SGF/CNF papers are attributed to the densely packed structures caused by the strong interfacial interactions from hydrogen bonding as well as metal ion-crosslinking that could promote phonon transport.High-performance metal ion-crosslinked SGF/CNF papers with these fascinating advantages offer great potential for the thermal management of flexible electronics.展开更多
基金supported by the Basic Science Program(No.2022R1A2C2009700)through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICTthe Basic Science Research Capacity Enhancement Project(National Research Facilities and Equipment Center)through the Korea Ba-sic Science Institute funded by the Ministry of Education(No.2019R1A6C1010047)the Industrial Strategic Technology Development Program(No.20013248)through Korea Evaluation In-stitute of Industrial Technology funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘Thermally conductive papers with electrical insulation and mechanical robustness are essential for efficient thermal management in modern electronics.In this study,we introduced a metal ion-assisted interfacial crosslinking strategy to strengthen sugarfunctionalized graphene fluoride(SGF)and cellulose nanofibers(CNF)by hydrogen bonding and metal ion crosslinking that leads to simultaneous enhancements in thermal conductivity and mechanical properties.The facile sugarassisted ball-milling exfoliation method was developed to achieve the exfoliation of graphite fluoride and hydroxyl group functionalization on the surface of graphene fluoride.Thanks to the good dispersibility of the SGF sheets in water,the flexible SGF/CNF composite papers with hydrogen bonding were prepared via vacuum-assisted filtration.We introduced hydrogen bonding and metal ion crosslinking into SGF/CNF papers to obtain densely packed composite papers.Ca^(2+)or Al^(3+)ion-crosslinked SGF/CNF papers exhibited superior thermal and mechanical properties owing to hydrogen bonding and metal ion crosslinking.SGF/CNF-Ca^(2+)and SGF/CNF-Al^(3+)papers at 50 wt%of SGF yield in-plane thermal conductivities of 72.93 and 75.02 W m^(-1) K^(-1),and tensile strengths of 121.5 and 135.7 MPa,respectively.A thermal percolation value was observed at 12.6 vol%of SGF filler content.In addition,the SGF/CNF papers exhibited electrical insulation properties.These remarkable characteristics of the metal ion-crosslinked SGF/CNF papers are attributed to the densely packed structures caused by the strong interfacial interactions from hydrogen bonding as well as metal ion-crosslinking that could promote phonon transport.High-performance metal ion-crosslinked SGF/CNF papers with these fascinating advantages offer great potential for the thermal management of flexible electronics.
