氧化石墨烯墨水的制备及直写图案化

Fabrication and patterning of graphene oxide ink with direct ink writing

采用改进的Hummers法制备宽度分布范围为30-70μm的大尺寸氧化石墨烯及其墨水,并通过直写打印实验,研究了最佳打印条件和氧化石墨烯墨水直写图案化。结果表明,当氧化石墨烯浓度为15 mg/mL、打印压力为70 kPa、线速度为3 mm/s时,打印线条流畅,形貌精细可控;还原剂为15%氢碘酸、还原时间为3 h时,打印线条的还原程度最高,且电性能最佳,电导率可达4.40×10^4S/m,远超过现有打印技术的石墨烯图案电导率;实现了氧化石墨烯墨水在亲水聚对苯二甲酸乙二醇酯（PET）、聚二甲基硅氧烷（PDMS）、玻璃、硅片等多种柔性和非柔性基底上的图案化直写打印,且经还原处理的氧化石墨烯图案可作为连接导线实现发光二极管的集成,对于石墨烯基印刷电子器件的发展具有重要意义。

Giant graphene oxide（GGO） with radial size distribution of 30-70 μm is fabricated using the modified Hummers method, and graphene oxide ink is prepared. Through direct ink writing, the optimal printing parameters and patterning of graphene oxide ink are realized. When graphene oxide with a concentration of 15 mg/m L is printed at 70 k Pa and 3 mm/s, the printing line is smooth and its morphology is fine and controllable. When the printing line is reduced by 15% hydroiodic acid for 3 h, its reduction degree is the highest and has the best electrical performance, with a conductivity up to 4.40×10^4 S/m, which is much higher than that of the graphene patterned by the existing printing technology. Patterning of graphene oxide ink on various flexible and non-flexible substrates, such as PET, PDMS,glass and silicon wafers is alao successfully achieved. Reduced graphene oxide pattern can be used as a connecting conductor to realize the integration of LED, which is of great significance for the development of graphene based printed electronic devices.