Preparation Of High Strength Ionic Conductive Elastomers And Their Performance As Flexible Sensors

With the rapid development of soft electronics technology in the era of Internet of Things,the application of stretchable ionic conductors in flexible ionic electronics sensors has obtained new opportunities,but also faces challenges.Ionic elastomers(ionogels)based on ionic liquids show unique advantages in the construction of flexible ionic electronic devices due to their high ionic conductivity,thermal stability and non-volatility.However,ionic elastomers(ionogels)have limited their practical application as flexible ionic electronic devices due to their poor mechanical properties and lack of functionality.In this paper,multi-functional ionogels and ionic elastomers were designed and prepared by regulating the non-covalent bond interaction between ionic liquids and polymerization networks.Their mechanical properties and toughening mechanism were studied in detail,and their electrical conductivity,adhesion and environmental stability were evaluated.Its practical application as a multifunctional flexible ion electronics sensor is further explored.Firstly,the interaction between ionic liquid and polymer network is explored by using the different compatibility of different monomers in the same ionic liquid.A copolymer(P(AA-co-MEA)ionogel with phase separation structure was prepared by free radical copolymerization of 2-methoxy-ethyl acrylate(MEA)and hydrophilic acrylic acid(AA)in hydrophobic 1-ethyl-3-methylimidazoline bis(trifluoromethyl sulfonyl)imide([EMIM][TFSI]).The physical and chemical characterization,mechanical and electrical tests show that the polymer phase closely bonded by hydrogen bond improves the mechanical strength.The combination of the solvent-rich phase(ionic conductive phase)with the assembled conductive nanochannel facilitates ion migration.Based on the high mechanical properties(～716%,0.28 MPa),high ionic conductivity(2.0 m S/cm),environmental stability and self-adhesion of copolymer ionogels,wearable sensors with high sensitivity were prepared and applied in underwater environment to monitor motion signals.In order to further the polymerization of acrylic acid(AA)monomer in different ionic liquids(ILs),the influence of different ILs canalic and canalic ion structures on the prepared ionic elastomers was explored.The optimized PAA-BMIMCl ionic elastomer has strong adhesion(～20 N/m),high self-healing efficiency(> 80%),high Young’s modulus(～2.91 MPa),excellent tensile property(> 1200%)and fracture strength(2.16 MPa).Based on the excellent mechanical properties,ionic conductivity,self-adhesion and self-healing properties of ionic elastomers,as well as the ability of ionic elastomers to sensitive temperature sensing,high sensitivity resistance/capacitance temperature sensors based on ionic elastomers were explored and applied to monitor motion signals in a variety of complex environments.