Synergistic Induction Of Long Silver Nanowires By Halogen Anions And Its Multifunctional Strain Sensing Core-spun Yarn/Fabric

Traditional electronic devices are generally rigid devices that are prone to breakage and failure when twisted or other large deformations.In contrast,smart textiles are an integrated assembly of sensors and textiles,composed of stable fibers and woven structures,with the advantages of being flexible and wearable,capable of adapting to complex deformations,and meeting applications in fields such as healthcare,security,and sports and health need.Wearable smart textiles can sense different stimuli such as pressure,strain,temperature,pH value,etc.,and convert them into electrical signals for corresponding information processing,which can be used to measure human physiological parameters and adapt to the development trend of technology of the times.Conductive materials,flexible substrates,and structural design are the key to the formation of wearable smart textiles.The selection of conductive materials and flexible substrates determines the basic performance of wearable smart textiles.The structural design determines the structural stability and practical applications of wearable smart textiles.sex.However,the current wearable smart textiles still have problems such as poor structural stability,single function,and low sensitivity.Therefore,this topic has carried on the research and exploration of multi-functional strain sensing fabric from three aspects:conductive material,flexible substrate and structural design.Long silver nanowires（AgNWs）were prepared by polyol synthesis.Using waterborne polyurethane（WPU）as dispersant and adhesive of AgNWs,elastic cotton core-spun yarn and cotton elastic bandage as flexible substrate,AgNWs multi-function strain sensing core-spun yarn/fabric was prepared by pre-stretching process design.In the process of synthesizing AgNWs,through the calculation of precipitation solubility product and experimental characterization of AgCl and AgBr,the growth mechanism of AgNWs induced by halogen anions was studied,and AgNWs with an aspect ratio of 1000 was prepared.In the process of preparing AgNWs multi-function strain sensing core-spun yarn/fabric,through pre-stretching process design and WPU modification,it is combined with elastic cotton core-spun yarn and cotton elastic bandage,focusing on the optimum load of AgNWs and the optimum elongation of pre-stretching process,so that a stable and uniform AgNWs conductive network can be formed under low AgNWs load.Furthermore,it gives the core-spun yarn/fabric excellent electrical conductivity,thermal conductivity,antibacterial,serviceability and other functions.Research indicates:（1）AgNO₃ is used as the precursor of silver,ethylene glycol（EG）is used as the solvent and reducing agent,polyvinylpyrrolidone（PVP）with a molecular weight of 1.3 million is used as the end-capping agent,and halogen sodium salt is used as the nucleating agent.When the total amount remains unchanged at 37.5μM,when NaBr/NaCl+NaBr=5%,the synergistic effect of NaBr and NaCl is the strongest,and the aspect ratio of synergistically induced AgNWs can reach 1000;（2）When the elastic cotton core-spun yarn was used as the flexible substrate,the prepared core-spun yarn with AgNWs loading of 12wt%was in the strain range of 0-80%,and the sensitivity was as high as 16.5,and the performance was stable after a hundred strain cycles;at5 V Under voltage,within the strain range of 0-30%,the maximum temperature range is 44-86℃,and the response time is about 30 s;within 18-24 h,the AgNWs core-spun yarn can not only inhibit the growth of Escherichia coli,but also inhibit the golden yellow Staphylococcus growth,good antibacterial effect;（3）when cotton elastic bandage is used as flexible substrate,the sensitivity of the fabric with 5wt%AgNWs load is 5.3,the strain range is 0-50%,and the hundred strain cycles still show good stability;under 3 V voltage and 0-50%strain range,the maximum temperature range is 45-88℃,and the electrothermal performance is good.Within 18-24 hours,AgNWs fabric can not only inhibit the growth of Escherichia coli,but also inhibit the growth of Staphylococcus aureus.AgNWs multi-function strain sensing core-spun yarn/fabric not only has excellent strain sensing,electrothermal and cyclic stability,but also has good air permeability and excellent fastness,which reflects the practical application prospect of AgNWs multi-function strain sensing core-spun yarn/fabric in the field of wearable smart textiles.