Ultrasonic Liquid Phase Exfoliation (LPE) has gathered attention from both scientific and industrial communities for its accessibility and cost-effectiveness in producing graphene. However, this technique has faced challenges such as low yield and long production time. In this study, we developed a cyclic ultrasonication system to exfoliate expanded graphite (EG) by applying static pressure to a flow chamber to address these challenges. Using deionized water (DIW) as solvent and polyvinylpyrrolidone (PVP) as dispersion, we obtained graphene slurries with an average lateral size of 7 μm and averaged number of layers of 3.5 layers, after 40 min of ultrasonication. After centrifugation, the yield of single and bilayer graphene was approximately 16 %. The findings showed that regulating hydrostatic pressure can effectively affect the lateral size and number of layers of few-layer graphene. The proposed method is of good potential for scaled-up production of few-layer graphene.

中文翻译：

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静压对少层石墨烯超声液相剥离的影响

超声波液相剥离（LPE）因其生产石墨烯的便利性和成本效益而引起了科学界和工业界的关注。然而，该技术面临着产量低、生产时间长等挑战。在这项研究中，我们开发了一种循环超声处理系统，通过向流动室施加静压来剥离膨胀石墨 (EG)，以应对这些挑战。以去离子水（DIW）为溶剂，聚乙烯吡咯烷酮（PVP）为分散液，超声处理40分钟后得到平均横向尺寸为7μm、平均层数为3.5层的石墨烯浆料。离心后，单层和双层石墨烯的产率约为16%。研究结果表明，调节静水压力可以有效影响少层石墨烯的横向尺寸和层数。该方法对于大规模生产少层石墨烯具有良好的潜力。