Functionalized graphene oxide/carboxymethyl chitosan composite aerogels with strong compressive strength for water purification

Abstract

A new type of polydopamine functionalized graphene oxide/carboxymethyl chitosan (DGO/CMC) composite aerogels was synthesized via sol–gel once‐forming self‐assembly and lyophilization. Polydopamine (PDA) on the surface of GO nanosheets replaced those traditional crosslinking agents to connect CMC chains via hydrogen bonding for the establishment of 3D porous aerogels. With the increasing proportion of CMC, the microstructure of aerogels changed from small pores to large plate‐bridge‐like pores. In addition, their maximum compressive strengths were 6.767, 11.94, and 16.98 MPa under 90% compressions, respectively, which increased in accordance with CMC content. Furthermore, the adsorption system of the aerogels was simulated well by the pseudo second‐order kinetic model and the Langmuir isotherm model, with maximum mass adsorption capacities of 170.3, 186.8, and 312.8 mg/g for Cu2+, Ni2+, and Pb2+ ions, respectively. These composite materials have potential applications for water purification because of their simple and efficient synthesis and excellent recyclability and reusability.

On the Sorbent Ability and Reusability of Graphene-Oxide–Chitosan Aerogels for the Removal of Dyes from Wastewater

“…This phenomenon was much more evident for CBY; this can be explained by considering that the regeneration procedure is probably more effective with IC due to its higher affinity for the solvent employed for the regeneration. Moreover, some loss of the sample in the form of small fragments was observed during each adsorption and regeneration cycles due to the mechanical and physical stress to which the gel was subjected during the adsorption and regeneration [44]. This occurrence more significant with CBY.…”