Although electrically conductive and hydrophilic MXene sheets are promising for multifunctional fibers and electronic textiles,it is still a challenge to simultaneously enhance both conductivity and mechanical propert...Although electrically conductive and hydrophilic MXene sheets are promising for multifunctional fibers and electronic textiles,it is still a challenge to simultaneously enhance both conductivity and mechanical properties of MXene fibers because of the high rigidity of MXene sheets and insufficient inter-sheet interactions.Herein,we demonstrate a core-shell wet-spinning methodology for fabricating highly conductive,super-tough,ultra-strong,and environmentally stable Ti_(3)C_(2)T_(x) MXene-based core-shell fibers with conductive MXene cores and tough aramid nanofiber(ANF)shells.The highly orientated and low-defect structure endows the ANF@MXene core-shell fiber with supertoughness of~48.1 MJ m^(-3),high strength of~502.9 MPa,and high conductivity of~3.0×10^(5)S m^(-1).The super-tough and conductive ANF@MXene fibers can be woven into textiles,exhibiting an excellent electromagnetic interference(EMI)shielding efficiency of 83.4 dB at a small thickness of 213μm.Importantly,the protection of the ANF shells provides the fibers with satisfactory cyclic stability under dynamic stretching and bending,and excellent resistance to acid,alkali,seawater,cryogenic and high temperatures,and fire.The oxidation resistance of the fibers is demonstrated by their wellmaintained EMI shielding performances.The multifunctional core-shell fibers would be highly promising in the fields of EMI shielding textiles,wearable electronics and aerospace.展开更多
Lightweight,flexible,and electrically conductive porous films are promising for efficient electromagnetic interference(EMI)shielding.However,the mechanical and electrical properties of porous films are far from optimu...Lightweight,flexible,and electrically conductive porous films are promising for efficient electromagnetic interference(EMI)shielding.However,the mechanical and electrical properties of porous films are far from optimum.Herein,we fabricate mechanically flexible and electrically conductive reduced graphene oxide(rGO)-Ti_(3)C_(2)T_(x)MXene(rG-M)porous films with optimized continuous cellular morphology by a controlled hydrazine foaming process.The presence of MXene prevents excessive expansion of the rG-M film,improves the electron conduction paths,and enhances the mechanical properties.The resultant rG-M porous film has superior mechanical and electric performances compared to its rGO counterpart,giving one of the highest tensile strengths(24.5 MPa)among the porous films,a high electrical conductivity of 74.4 S·cm^(−1),and an excellent broadband EMI shielding from 8 to 26.5 GHz.A high EMI shielding effectiveness of 52.6 dB is achieved for the porous film by adjusting its thickness and treatment procedure,providing a feasible fabrication route for lightweight and high-performance EMI shielding materials.展开更多
基金Financial support from the National Natural Science Foundation of China(51922020,52090034)the Fundamental Research Funds for the Central Universities(BHYC1707B,XK1802-2)。
文摘Although electrically conductive and hydrophilic MXene sheets are promising for multifunctional fibers and electronic textiles,it is still a challenge to simultaneously enhance both conductivity and mechanical properties of MXene fibers because of the high rigidity of MXene sheets and insufficient inter-sheet interactions.Herein,we demonstrate a core-shell wet-spinning methodology for fabricating highly conductive,super-tough,ultra-strong,and environmentally stable Ti_(3)C_(2)T_(x) MXene-based core-shell fibers with conductive MXene cores and tough aramid nanofiber(ANF)shells.The highly orientated and low-defect structure endows the ANF@MXene core-shell fiber with supertoughness of~48.1 MJ m^(-3),high strength of~502.9 MPa,and high conductivity of~3.0×10^(5)S m^(-1).The super-tough and conductive ANF@MXene fibers can be woven into textiles,exhibiting an excellent electromagnetic interference(EMI)shielding efficiency of 83.4 dB at a small thickness of 213μm.Importantly,the protection of the ANF shells provides the fibers with satisfactory cyclic stability under dynamic stretching and bending,and excellent resistance to acid,alkali,seawater,cryogenic and high temperatures,and fire.The oxidation resistance of the fibers is demonstrated by their wellmaintained EMI shielding performances.The multifunctional core-shell fibers would be highly promising in the fields of EMI shielding textiles,wearable electronics and aerospace.
基金supported by the National Natural Science Foundation of China(Nos.51922020 and U1905217)the Fundamental Research Funds for the Central Universities(Nos.BHYC1707B and XK1802-2).
文摘Lightweight,flexible,and electrically conductive porous films are promising for efficient electromagnetic interference(EMI)shielding.However,the mechanical and electrical properties of porous films are far from optimum.Herein,we fabricate mechanically flexible and electrically conductive reduced graphene oxide(rGO)-Ti_(3)C_(2)T_(x)MXene(rG-M)porous films with optimized continuous cellular morphology by a controlled hydrazine foaming process.The presence of MXene prevents excessive expansion of the rG-M film,improves the electron conduction paths,and enhances the mechanical properties.The resultant rG-M porous film has superior mechanical and electric performances compared to its rGO counterpart,giving one of the highest tensile strengths(24.5 MPa)among the porous films,a high electrical conductivity of 74.4 S·cm^(−1),and an excellent broadband EMI shielding from 8 to 26.5 GHz.A high EMI shielding effectiveness of 52.6 dB is achieved for the porous film by adjusting its thickness and treatment procedure,providing a feasible fabrication route for lightweight and high-performance EMI shielding materials.
