Lee Yong Bok, Jang Heejun, Ahn Chi Won
J Nanosci Nanotechnol. 2016 Feb;16(2):1810-3. doi: 10.1166/jnn.2016.11954.
We report a formvar assisted transfer method to make graphene TEM grids having single layer graphene. Our method uses formvar instead of PMMA as the polymer support and produces clean graphene. Formvar was easily removed by dissolving in chloroform and did not leave residues after removal because of the lower the molecular weight. Our transfer method achieved the higher average coverage (about 55%) than direct transfer method (about 5%). Since mesh grids were not exposed to a metal etchant solution during our transfer process, the mesh grid material for graphene transfer was not limited. Our graphene transfer method produces high quality and single layer graphene for a graphene TEM grid. Consequently, the formvar assisted graphene transfer method solves disadvantages of polymer support method and direct transfer.
我们报告了一种用于制备具有单层石墨烯的石墨烯透射电子显微镜（TEM）网格的福尔马弗辅助转移方法。我们的方法使用福尔马弗而非聚甲基丙烯酸甲酯（PMMA）作为聚合物支撑体，并能制备出洁净的石墨烯。福尔马弗通过溶解于氯仿中易于去除，且由于分子量较低，去除后不会留下残留物。我们的转移方法实现了比直接转移方法更高的平均覆盖率（约55%），而直接转移方法的平均覆盖率约为5%。由于在我们的转移过程中网孔网格未暴露于金属蚀刻剂溶液中，用于石墨烯转移的网孔网格材料不受限制。我们的石墨烯转移方法可为石墨烯TEM网格制备高质量的单层石墨烯。因此，福尔马弗辅助石墨烯转移方法解决了聚合物支撑法和直接转移法的缺点。
