聚乙烯醇/纳米石墨片复合材料的制备及导电性能

Preparation of Poly(vinyl alcohol)/Graphite Nanosheets Composite and Its Conducting Properties

首先使用高压均质法在水溶液中制备纳米石墨片(GNS),然后用溶液法制备了不同浓度的聚乙烯醇/纳米石墨片(PVA/GNS)复合膜。使用扫描电镜、原子力显微镜对GNS的形貌进行了表征。结果表明,高压均质法可以在水溶液中有效地剥离石墨片,剥离得到的GNS的厚度范围在几纳米至几十纳米。通过与聚乙烯醇/石墨粉(PVA/Graphite)混合液的对比,发现GNS在PVA溶液中有更好的分散性。本文考察了室温下PVA/GNS复合膜在不同GNS添加量情况下的导电性。结果表明PVA/GNS复合膜具有比石墨粉更低的渗流阈值,其渗流阈值低至3.36%(体积分数),并用渗流理论验证并解释了复合物的导电特性。

Graphite nanosheets（GNS） were fabricated in water through assistance of high pressure homogenization（HPH）. Poly（vinyl alcohol）/graphite nanosheets（PVA/GNS） composites were prepared by varying the amount of GNS loading in the solution. The morphology of the GNS was characterized by the SEM and AFM. It is found that HPH can exfoliate graphite efficiently and the prepared GNS has better stability in PVA solution than graphite. The percolation threshold of PVA/GNS composite at room temperature is as low as 3.36%（volume fraction）,much lower than that of the composites filled with conventional graphite particles. The conducting behavior of the composites is interpreted by percolation theory.