Zhang Hong, Ma Chuan-Guo, Dai Pei-Bang, Zhang Jian
School of Material Science and Engineering, Guilin University of Electronic Technology Guilin 541004 China
Guangxi Key Laboratory of Information Materials Guilin 541004 China.
RSC Adv. 2019 May 8;9(25):14276-14285. doi: 10.1039/c9ra00734b. eCollection 2019 May 7.
Herein, at first, graphene oxide (GO) was prepared by a modified Hummers' method, compounded with borates and then loaded onto a melamine sponge (MS) skeleton by an impregnation-reduction method to obtain a reduced graphene oxide (rGO)-borate compound (rGB)-loaded MS. Then, MS/rGB/silicone rubber (SR) composites were prepared by a vacuum infusion process. Moreover, the microstructures, electrical conductivity, and dielectric properties of the composites were investigated. The results showed that rGO presented a sheet-like structure, compounding with borates produced during the reduction of GO by sodium borohydride. rGB was co-loaded onto the MS skeleton, and a three-dimensional percolation network was successfully constructed in the MS/rGB/SR composite. In addition, there was an efficient synergistic effect between rGO and borates, which significantly improved the dielectric constant of the composites. At the rGO volume fraction of 1.89 vol%, the composite had the volume resistivity of 6.57 × 10 Ω cm, the ultra-high dielectric constant of 2.71 × 10 with the dielectric loss of 1.36 at 1 kHz, and the relatively low percolation threshold of 0.815 vol%. Furthermore, the composite exhibited high compression sensitivity at low compressive strains.
在此，首先通过改进的Hummers法制备氧化石墨烯（GO），将其与硼酸盐复合，然后通过浸渍还原法负载到三聚氰胺海绵（MS）骨架上，以获得负载还原氧化石墨烯（rGO）-硼酸盐化合物（rGB）的MS。然后，通过真空灌注工艺制备MS/rGB/硅橡胶（SR）复合材料。此外，研究了复合材料的微观结构、电导率和介电性能。结果表明，rGO呈现片状结构，在硼氢化钠还原GO的过程中与生成的硼酸盐复合。rGB共负载在MS骨架上，并且在MS/rGB/SR复合材料中成功构建了三维渗流网络。此外，rGO和硼酸盐之间存在有效的协同效应，这显著提高了复合材料的介电常数。在rGO体积分数为1.89 vol%时，复合材料的体积电阻率为6.57×10Ω·cm，在1 kHz时具有2.71×10的超高介电常数且介电损耗为1.36，渗流阈值相对较低，为0.815 vol%。此外，该复合材料在低压缩应变下表现出高压缩敏感性。
