Study On Superhydrophobic Flexible Resistive Sensor Based On Carbon Material

Due to its unique moisture resistance and stability,the superhydrophobic material can be used in a variety of harsh external environments without affecting its performance and life.Therefore,the application of superhydrophobic materials to gas detection and simple motion detection can solve the problem of the use environment of the sensor.Based on the above reasons,the main work of this paper is based on the following points:1.A"conductive material+adhesive"method is proposed to prepare superhydrophobic flexible film.Graphene?Gr?or multi-walled carbon nanotubes?MWCNTs?are used as conductive materials,and hydrogenated styrene-ethylene/butylene-styrene block copolymer?SEBS?helps to glue graphene or MWCNTs,thereby a specific superhydrophobic surface is established on the flexible substrate.The materials were characterized by surface contact angle measuring instrument and scanning electron microscope?SEM?.The Gr/SEBS and MWCNT/SEBS films have excellent superhydrophobicity,and the apparent contact angles?CA?are 167.0°and 179.6°,respectively.The use of other conductive materials such as nitrogen-doped MWCNTs,nickel-coated MWCNTs,ZIF-67,etc.to prepare hydrophobic films shows that the original wettability of various conductive materials can be changed by a simple"conductive material+adhesive"method.This method builds an effective bridge between conductive materials and superhydrophobic systems,and provides a new and convenient way for developing sensor materials with high moisture resistance.2.A Gr/SEBS superhydrophobic flexible film is used to construct a superhydrophobic Gr/SEBS flexible polydimethylsiloxane resistive strain sensor.The prepared sensor has good superhydrophobicity and conductivity,and shows large tensile sensing range?-10%-30%?,bending torsion range?-150°-150°?and normalized relative resistance??R/R₀>1?,suggesting good tensile,bending and torsional response.3.A MWCNT/SEBS superhydrophobic flexible film is used to construct a flexible paperbased resistive gas sensor.The adsorption and desorption processes of chemical vapors such as acetone,toluene,ethanol are reflected by the resistance change,which is caused by the damage and recovery of the MWCNT/SEBS conductive network resulting from the swelling and deswelling of SEBS matrix.With the home-made device,the sensing of these chemical vapors can be achieved by monitoring the resistance change through the current-time curve?I-t?.The performance of the prepared sensor is investigated using acetone vapor as model analyte.The sensor shows low detection limit?0.052?mol?and two-stage linearity from 0.013 mmol to 0.68 mmol.In addition,the flexible sensor also displays good repeatability,long-term stability,as well as significant moisture and corrosion resistance.The superhydrophobic materials preparaed by"conductive material+adhesive"has potential application in wearable electronic,gas leakage monitoring,etc.