Biomacromolecule-dispersed Carbon Nanotubes And Their Multifunctional Strain-sensing Fabrics

With the increasing progress of textile technology,fiber textiles are not limited to the original functions of heat preservation,beautification and comfort,but are developing towards intelligence.Smart textiles can sense and respond to external conditions while retaining textile materials,textile styles and technical characteristics,and integrate textile,electronics,chemistry,biology,medicine and other disciplines.Compared with traditional metal and semiconductor strain sensors,flexible strain sensors overcome their shortcomings such as brittleness,no ductility,and low sensitivity,and have great potential in the fields of flexible electronics,simulated robots,and smart wearables.At present,low cost,easy processing,and green environmental protection have become important factors for the design,development and practical application of flexible strain sensors.Carbon nanotubes(CNTs)are promising conductive materials for flexible strain sensors due to their good electrical conductivity,strength,stability,and light weight.However,the problems of easy agglomeration,difficult processing,and low biocompatibility of CNTs greatly limit the application.In this paper,the biomacromolecules sericin(SS),natural dyes Gallnut(Ga)and carboxymethylcellulose(CMC)were used to modify CNTs non-covalently.The nylon-spandex elastic fabrics were treated by the adhesive impregnation of sericin,the dyeable cotton fabrics of gall and the carboxymethylcellulose-impregnated nylon-spandex elastic fabrics were respectively used to prepare strains with high sensitivity,wide strain range and cyclic stability.Sensing smart fabrics for detection of human motion signals.Due to the versatility of CNTs,various functions such as electric heating and electromagnetic shielding can also be realized at the same time.The specific results are as follows:(1)With the aid of the small molecule surfactant of dodecylbenzene sulfonic acid(SDBS),a uniformly dispersed and stable sericin-dispersed CNT aqueous solution was prepared by ultrasonic dispersion,and then the adhesive property of sericin was utilized to impregnate the Nylon spandex elastic fabric.The prepared composite fabric not only retained the air permeability and flexibility of the original fabric,but also had excellent strain sensing,electrothermal and electromagnetic shielding properties,and could be used for the detection of human motion signals.The dispersion and stabilization mechanism of sericin-dispersed CNT,the strain sensing and cyclic stabilization mechanism of sericin-dispersed CNT-based composite elastic fabrics,and the synergy of structure-function integration were explored to provide a new design idea for multifunctional strain-sensing smart textiles.(2)CNT was modified by the covalent bond of the natural dye gallnut to form a uniformly dispersed and stable gallnut-dispersed CNT aqueous solution.Cotton fabric was dyed through the traditional dyeing process with natural dyes under the action of mordant.According to the short fiber structure characteristics,a strain sensing fabric with negative resistance change was prepared,which could be woven or sewn on clothing or directly attached to human skin to detect human motion signals.The dispersion and stabilization mechanism of gall-dispersed CNT,and the strain sensing and cyclic stabilization mechanism of gallnut-dispersed CNTbased composite cotton fabrics were explored to provide a new design mechanism for multifunctional strain-sensing smart textiles.(3)In this paper,a green and environmentally friendly way is used to disperse and prepare the strain sensing fabric.Firstly,carbon nanotubes were modified by non-covalent bonds with carboxymethyl cellulose,and a uniformly dispersed aqueous solution of carboxymethyl fiber dispersed carbon nanotubes(CMC@CNT)was prepared.The dispersion principle was analyzed and a flexible multifunctional strain sensor was prepared.The fabric has good friction and washability,as well as excellent strain sensing properties,electrothermal properties and electromagnetic shielding properties,and can be used for the detection of human motion signals.Combining CMC with CNT may yield excellent strain-sensing materials,which provides a promising strategy for fabricating flexible strain-sensing fabrics.