Self-Assembly of a Graphene Oxide Liquid Crystal for Water Treatment.

Abstract

Adsorbents, especially those with high removal efficiency, long life, and multi-purpose capabilities, are the most crucial components in an adsorption system. By taking advantage of the liquid-like mobility and crystal-like ordering of liquid crystal materials, a liquid crystal induction method is developed and applied to construct three-dimensional graphene-based adsorbents featuring excellent shape adaptability, a distinctive pore structure, and abundant surface functional groups. When the monoliths are used for water restoration, the large amount of residual oxygen-containing groups is more susceptible to electrophilic attack, thus contributing to cation adsorption (up to 705.4 mg g-1 for methylene blue), while the connected microvoids between the aligned graphene oxide sheets facilitate mass transfer, e.g., the high adsorption capacity for organic pollutants (196.2 g g-1 for ethylene glycol) and the high evaporation rate for water (4.01 kg m-2 h-1). This work gives a practical method for producing high-performance graphene-based functional materials for those applications that are sensitive to surface and mass transfer properties.