Han Lijing, Wang Hairui, Tang Qi, Lang Xiurui, Wang Xuemeng, Zong Yingxia, Zong Chengzhong
School of Polymer Science and Engineering, Qingdao University of Science and Technology Qingdao 266042 China.
College of Chemical and Molecular Engineering, Qingdao University of Science and Technology Qingdao 266042 China
RSC Adv. 2021 Nov 29;11(60):38264-38272. doi: 10.1039/d1ra06138k. eCollection 2021 Nov 23.
In this paper, a reduced graphene oxide/polypropylene (rGO/PP) dielectric composite with high dielectric constant and low dielectric loss at a low filler content was prepared constructing a segregated moderately-reduced graphene network by encapsulation of GO on PP latex particles and subsequent reduction of GO by hydrazine hydrate. GO/PP latex was prepared through artificial PP latex preparation in the presence of GO based on the solution-emulsification technique. As the emulsification proceeded, GO could self-assemble to become encapsulated on the surface of PP latex particles composed of PP and maleic-anhydride-grafted-PP because of the hydrogen bonding interaction between maleic-anhydride-grafted-PP and GO nanosheets. After reduction, the rGO encapsulated PP latex particles were obtained, and after coagulation and hot pressing, a segregated graphene network was achieved at a low content of rGO, demonstrated by TEM images. The dielectric constant at 1 kHz obviously increased from 3.28 for PP to 55.8 for the composite with 1.5 wt% rGO. The dielectric loss of the composite was retained at a low value (1.04). This study provides a new simple and effective strategy for preparing high-performance dielectric composites with high dielectric constant and low dielectric loss, facilitating the wide application of dielectric materials.
本文通过在聚丙烯（PP）胶乳颗粒上包覆氧化石墨烯（GO）并随后用水合肼还原GO，构建了一种隔离的适度还原石墨烯网络，制备了一种在低填料含量下具有高介电常数和低介电损耗的还原氧化石墨烯/聚丙烯（rGO/PP）介电复合材料。基于溶液乳化技术，在GO存在下通过人工制备PP胶乳来制备GO/PP胶乳。随着乳化过程的进行，由于马来酸酐接枝PP与GO纳米片之间的氢键相互作用，GO能够自组装并被包覆在由PP和马来酸酐接枝PP组成的PP胶乳颗粒表面。还原后，得到了包覆rGO的PP胶乳颗粒，经过凝聚和热压后，在低rGO含量下实现了隔离的石墨烯网络，透射电子显微镜（TEM）图像证明了这一点。1 kHz时的介电常数从PP的3.28显著增加到含1.5 wt% rGO的复合材料的55.8。该复合材料的介电损耗保持在较低值（1.04）。本研究为制备具有高介电常数和低介电损耗的高性能介电复合材料提供了一种新的简单有效的策略，有利于介电材料的广泛应用。
