This research work reports on development and characterization of polyvinylidene fluoride (PVDF) thin films by intercalation of graphene during direct ink writing process with auxiliary electric potential (voltage). The effects of graphene additive on the crystallinity and β-phase transformation in PVDF thin films are studied. The results show that small amount of graphene additive in the writing ink promotes the crystalline nucleation, and the micro electric fields among graphene sheets also promote the formation of the folded β-PVDF chains and prevent the spherulite growth. When 0.05 wt% amount of graphene was added in the writing ink, the crystallinity of the thin film was about twice higher than that of the pure PVDF thin film, and the β-phase content in the thin film reached 67.30%. The sensitivity of the PVDF/graphene composite film is also much higher than that of the pure PVDF piezoelectric film.

中文翻译：

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石墨烯插层增强直接喷墨书写PVDF薄膜中的β相

这项研究工作报道了在直接墨水书写过程中，在辅助电位（电压）作用下，通过石墨烯的插层，聚偏二氟乙烯（PVDF）薄膜的开发和表征。研究了石墨烯添加剂对PVDF薄膜结晶度和β相变的影响。结果表明，书写墨水中少量的石墨烯添加剂可促进晶体成核，石墨烯片之间的微电场也可促进折叠的β-PVDF链的形成并防止球晶的生长。当在书写油墨中添加0.05重量％的石墨烯时，薄膜的结晶度比纯PVDF薄膜的结晶度高约两倍，并且薄膜中的β相含量达到67.30％。