| In recent years,textile materials are very popular in the field of high-performance flexible wearable electronics due to their unique light-weight,flexibility and versatility.Polyester fabric has attracted wide attention because of its flexibility,strength and environmental stability,but its insulation limits its application in flexible electronic devices.Among many conductive materials,carbon nanotubes（CNTs）,with their high electrical conductivity,large surface area and low density properties,can serve as an ideal architecture for high-performance flexible electronics applications.Currently,conductive composites based on polyester fabrics have been extensively studied,but they have poor interaction and low bonding fastness.In this paper,the polyester fabric was used as a flexible substrate material,and carbon nanotube/polyester conductive fabric was prepared by loading the conductive material onto the surface of polyester fabric through CNTs surface micro-dissolution modification.To this end,the following three works have been carried out:（1）Phenol/ethanol was selected as the dissolution system for polyester.By regulating the concentration of phenol in the system and heat treatment temperature,the best dissolution process parameters were characterized by SEM,XRD,strength,stiffness and whiteness tests.The test results showed that when the volume ratio of phenol to ethanol in the system was 1:1 and the heat treatment temperature was 90 oC,it can achieve effective dissolution of the surface layer of polyester fabric without damaging the internal structure of the fabric.FTIR,TG and DSC were tested before and after micro-dissolution,and the phenol/ethanol system was found to be a good solvent for polyester,and the thermal stability and wettability of m-PET were improved.（2）A CNTs conductive network structure was constructed on the surface of polyester fabric using the coating/micro-dissolution method under the condition of v（phenol）:v（ethanol）=1:1.The effects of CNTs coating layers and heat treatment conditions during the coating process on the electrical conductivity of P-CCPF were investigated.The continuity of the CNTs conductive network on the fabric surface gradually became better with the increase of the number of coating layers,and the resistance of P-CCPF was decreased.The best conductivity of P-CCPF（244.34Ω/cm2）was achieved when the coating layers were 5,and the loading mass of CNTs was 0.46 mg/cm2.The P-CCPF showed excellent electrical conductivity at a heat treatment temperature of 110 oC,a hot pressing time of 10min and a heat treatment pressure of 10 MPa.Due to the inherent flexibility of the polyester fabric,the minimum radius of curvature of CCPF was 0.2 mm during the bending process.When the folding angle increased from 0o to 180o,the fabric resistance value decreased gradually and the change rate of resistance was 15.89%when the CCPF was folded toward the load side of CNTs.While the CCPF was folded toward the load side of non-CNTs,the fabric resistance value increased and the change rate of resistance was 10.50%.After the introduction of CNTs on the surface of polyester fabric,the wettability of the two sides of CCPF was different.The contact angles of F-CCPF and B-CCPF were maintained at 143o and 102o,respectively,where the side loaded with CNTs became hydrophobic.After micro-dissolution treatment,CCPF has high scratch fastness（200 times scratches）,washing fastness（30times washing）,abrasion fastness（500 times wears）and UV stability（after 4h UV irradiation）,showing good electrical conductivity stability.In addition,the change rate of sheet resistance of CCPF was kept below 1%in air,water,high temperature and high humidity environments.After CCPF was soaked in H2SO4,Na OH,Na Cl,C2H5OH and C3H6O solutions for 5 h,the change rate of sheet resistance was 0.48%,0.21%,0.33%,0.10%and 0.44%,respectively,showing excellent environmental stability and conductive durability.（3）Based on the excellent electrical stability and durability of CCPF,its applications in sensors,electrothermal materials and energy storage devices were analyzed and studied.The structural stability of CCPF in high temperature,high humidity,acid,alkali,salt and organic solution environments,the sensor assembled with CCPF can monitor changes in environmental conditions,including the temperature,moisture,weight and vibration.The current signal intensity of CCPFS under different bending angles was affected by the degree of bending,with good sensitivity of 1.48 deg-1 to bending deformation,and the response performance was stable after 200 bending strains.The responsiveness of CCPFS to the human motion was verified with mechanical movements of CCPF itself（such as bending,folding,twisting,pressing and squeezing）.In addition,CCPFS can effectively monitor large（such as fingers,wrists,elbows and knees）and small（blinking,swallowing,puffing,breathing）human movements as well as pulses.The CCPF was connected to a DC power supply through wires at both ends.When the applied voltage was 25 V,the steady-state temperature of CCPF was 85.3 oC after heating for 30 s,which was about 60 oC higher than the ambient temperature,and the power density can reach 345.07 m W/cm2.In addition,repeated on-off cycle tests under applied voltage at 5 V and10 V,and 100 repeated bending tests,showed the stable electrothermal performance and repeatability of CCPF for dynamic thermal response.The D-CCPF electrode was prepared by coating CNTs layers on both sides of the polyester fabric surface,exhibiting a high specific capacitance of 117.61 m F/cm2,which was 1.45 times higher than that of the S-CCPF electrode（81.04 m F/cm2）prepared by coating CNTs on one side.When the current density was 0.025 m A/cm2,the D-CCPF could provide an energy density of 10.45μWh/cm2 and a power density of 42.52μW/cm2.In summary,CCPF’s outstanding sensing responsiveness,electrothermal effect and supercapacitor performance broaden the potential application in the field of flexible sensors and energy storage electro-heating materials. |
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