氧化石墨烯核-壳杂化粒子/硅橡胶介电弹性体复合材料的制备与性能

摘要

采用阳离子聚电解质聚二烯丙基二甲基氯化铵(PDDA)改性 SiO2,再通过静电自组装制备了 SiO2-PD-DA-氧化石墨烯(GO)核-壳杂化粒子。采用溶液共混法将 SiO2-PDDA-GO引入到高温硫化硅橡胶(SR)中,制备了SiO2-PDDA-GO/SR介电弹性体复合材料。结果表明：该方法能实现 GO 在 SiO2表面大面积的包覆,解决了 GO容易自聚集的问题,且PDDA具有还原 GO的作用,无需再对 GO核-壳杂化粒子/SR复合材料进行原位热还原,简化了实验方案,节能环保。SiO2-PDDA-GO填充量为60wt%时,在100 Hz 频率下,SiO2-PDDA-GO/SR 介电弹性体复合材料的介电常数为21.53,是 SR的11.6倍,介电损耗保持较低值,同时,复合材料的模量保持在较低水平。在电场强度为2.48 kV/mm时,60wt%的SiO2-PDDA-GO/SR介电弹性体复合材料横向电致形变在同一电场强度下与 SR相比增加了15倍。%Cationic polyelectrolyte poly(diallyldimethylammonium chloride)(PDDA)was used to modify SiO2 ,and SiO2-PDDA-graphite oxide (GO)core-shell hybrid particles were prepared by electrostatic self-assembly.By intro-ducing SiO2-PDDA-GO into high-temperature vulcanization silicone rubber (SR)with solution blending method, SiO2-PDDA-GO/SR dielectric elastomer composites were prepared.Results show that this method can realize GO large surface coating on surface of SiO2 to prevent GO from self-agglomerating.GO core-shell hybrid particles/SR composites were obtained without in-situ thermal reduction because PDDA can reduce GO,made experimental scheme simple and environmental protection.The dielectric constant of SiO2-PDDA-GO/SR dielectric composite at 100 Hz increases to 21.53 with 60wt% SiO2-PDDA-GO which is 11.6 times than SR,and dielectric loss remains at low level.Meanwhile,modulus of composites remains low level.The lateral actuation strain of SiO2-PDDA-GO/SR dielectric elastomer composites with 60wt% SiO2-PDDA-GO at 2.48 kV/mm compared with pure SR increases 15 fold under same electric field intensity.