Xu Yi-Tao, Li Joyce, MacLachlan Mark J
Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
Stewart Blusson Quantum Matter Institute, University of British Columbia, 2355 East Mall, Vancouver, British Columbia V6T 1Z1, Canada.
Nanoscale Horiz. 2022 Jan 31;7(2):185-191. doi: 10.1039/d1nh00523e.
Graphene oxide (GO) is an important nanomaterial for producing photonic liquids due to its ability to display full-color reflections in water. However, the poor stability of GO photonic liquids and unsatisfactory dispersibility of GO nanosheets in hydrophobic liquid media have been significant drawbacks to developing photonic materials based on GO. Here, stable GO hydrophobic photonic liquids are demonstrated for the first time. GO nanosheets are directed into different hydrophobic liquid media, including reactive liquid precursors like tetraethoxysilane and ethyl acrylate, in the presence of phase transfer additives. These liquids exhibit tunable reflection wavelength up to ∼1300 nm with improved stability relative to aqueous GO photonic suspensions at elevated temperatures or under ambient conditions. Supported by an entropy-driven depletion mechanism, hydrophobic additives can effectively mediate the self-assembly of GO to produce tunable photonic liquids without the need to adjust GO concentrations. Furthermore, simultaneous infrared and visible light reflection can be achieved, enabling infrared photonic GO liquids to display visible colors. The improved stability and tunable photonic properties of hydrophobic GO liquids will open a way for developing GO-based optical materials and devices.
氧化石墨烯（GO）是一种重要的纳米材料，因其能够在水中呈现全彩反射而可用于制备光子液体。然而，GO光子液体稳定性差以及GO纳米片在疏水液体介质中的分散性不理想，一直是开发基于GO的光子材料的重大缺陷。在此，首次展示了稳定的GO疏水光子液体。在相转移添加剂存在的情况下，将GO纳米片引入不同的疏水液体介质中，包括反应性液体前驱体如四乙氧基硅烷和丙烯酸乙酯。这些液体在高温或环境条件下相对于水性GO光子悬浮液具有更高的稳定性，其反射波长可调至约1300 nm。在熵驱动的耗尽机制支持下，疏水添加剂可有效介导GO的自组装，从而产生可调谐的光子液体，而无需调整GO的浓度。此外，还可实现红外和可见光的同时反射，使红外光子GO液体呈现可见颜色。疏水GO液体稳定性的提高和可调谐的光子特性将为开发基于GO的光学材料和器件开辟道路。
