Preparation And Properties Of Multiple Stimuli-Responsive Aramid Aerogel Fibers/Fabrics

With the emergence and development of intelligent wearable electronic devices and medical care systems,the strong demand for energy saving and effective personal thermoregulation has attracted great attention.In order to prevent thermal runaway and achieve thermal comfort during long-term wear of electronic devices in close contact with the skin,personal thermal management is becoming an important strategy for regulating and balancing heat exchange between the human body and the surrounding environment.In the healthcare applications of wearable electronic products,there is an urgent need for intelligent fibers and textiles with lightweight,mechanical flexibility,multiple responsiveness,and excellent thermal regulation capabilities for effective personal thermal management.However,achieving wearable intelligent textiles with functions such as human health management and thermal comfort management remains a huge challenge.Therefore,in this paper,the aerogel fiber/non-woven fabric with porous structure is prepared with aramid nanofibers(ANFs)as the basic unit,combined with conductive materials,and uses the characteristics of high latent heat of phase change materials to achieve different applications in the intelligent wearable field.The main work of this paper is as follows:(1)In order to obtain conductive materials with good performance and improve the application performance of wearable electronic devices.This article uses a solvothermal method to prepare silver nanowires(AgNWs)as conductive fillers,and obtains MXene(Ti3C2Tx)by selectively etching the Al layer in the MAX phase using lithium fluoride(Li F)and hydrochloric acid(HCl).Determine the preparation effect and size of conductive materials through characterization analysis.(2)The lightweight ANFs based aerogel fiber with 3D interconnected porous structure was fabricated by continuous wet spinning,sol gel and freeze drying processes.The porous structure inside the aerogel fiber is used as the 3D layered permeation framework of AgNWs interwoven MXene conductive network and the sealing body of phase change material polyethylene glycol(PEG).At the same time,the conductive network confined inside the aerogel fiber is interwoven with PEG,providing high conductivity and thermal conductivity.The stable intelligent fiber encapsulated with transparent FSi resin also has waterproof and oil resistant functions.The flexible braided aerogel fabric is combined with the thermoelectric device to realize efficient solar thermal power generation,so as to realize the all-weather stable operation of self powered wearable electronic devices and car models.Intelligent aromatic polyamide aerogel fibers and fabrics have great prospects in the next generation of wearable systems,such as self powered outdoor travel and lunar exploration(3)Through the use of deprotonation technology,a 1wt% concentration of aramid nanofiber dispersion was prepared,and then the aramid nano aerogel nonwoven fabric was constructed.Firstly,dissolve the abandoned aramid fibers from the factory in a mixed solvent system of dimethyl sulfoxide and potassium tert butanol.Secondly,the ANFs based aerogel non-woven fabric was obtained from the aramid nanofiber dispersion through scraper coating,sol gel,freeze drying and other processes.The layered porous structure inside non-woven fabrics is a good permeable framework for conductive materials such as AgNWs,MXene,and carbon nanotubes(CNTs).Polymer conductive material PEDOT can effectively prevent the oxidation of nano conductive materials and increase their conductivity.Phase change materials are confined within porous conductive networks,improving their conductivity and thermal conductivity,and achieving rapid transfer of latent heat in phase change materials.The intelligent aerogel non-woven fabric has good electrical conductivity and thermal properties,and has a good response in light and heat and electricity.