Basu Rajratan
Department of Physics, Soft Matter and Nanomaterials Laboratory, The United States Naval Academy, Annapolis, Maryland 21402, USA.
Phys Rev E. 2017 Jul;96(1-1):012707. doi: 10.1103/PhysRevE.96.012707. Epub 2017 Jul 27.
A small quantity of monolayer graphene flakes is doped in a nematic liquid crystal (LC), and the effective polar anchoring strength coefficient between the LC and the alignment substrate is found to increase by an order of magnitude. The hexagonal pattern of graphene can interact with the LC's benzene rings via π-π electron stacking, enabling the LC to anchor to the graphene surface homogeneously (i.e., planar anchoring). When the LC cell is filled with the graphene-doped LC, some graphene flakes are preferentially attached to the alignment layer and modify the substrate's anchoring property. These spontaneously deposited graphene flakes promote planar anchoring at the substrate and the polar anchoring energy at alignment layer is enhanced significantly. The enhanced anchoring energy is found to impact favorably on the electro-optic response of the LC. Additional studies reveal that the nematic electro-optic switching is significantly faster in the LC-graphene hybrid than that of the pure LC.
将少量单层石墨烯薄片掺杂到向列型液晶（LC）中，发现LC与取向基板之间的有效极性锚定强度系数增加了一个数量级。石墨烯的六边形图案可以通过π-π电子堆积与LC的苯环相互作用，使LC能够均匀地锚定在石墨烯表面（即平面锚定）。当LC盒填充有掺杂石墨烯的LC时，一些石墨烯薄片优先附着在取向层上并改变基板的锚定特性。这些自发沉积的石墨烯薄片促进了基板处的平面锚定，并且取向层处的极性锚定能量显著增强。发现增强的锚定能量对LC的电光响应有有利影响。进一步的研究表明，LC-石墨烯混合物中的向列型电光开关比纯LC的电光开关快得多。
