Ultrafast Graphene Oxide-Lignin Biopolymer Nanocomposite Membranes for Separation of Biomolecules, Dyes, and Salts

Abstract

Graphene oxide offers a promising opportunity to fabricate highly efficient and pressure-endurable membranes in terms of water permeability while demonstrating a high level of solute rejection. However, achieving higher permeance with an excellent separation capability is still challenging. Herein, we report a class of graphene oxide-lignin biopolymer (GOLB) membranes for the first time prepared by functionalizing GO nanosheets with lignin biopolymer extracted from plant pulp. Lignin biopolymer is the most abundant, green, low-cost, and environmentally friendly material with a variety of oxygen functional groups. The asprepared GOLB membranes have a unique laminated structure that provides an excellent rejection (>99%) for several organic dyes, proteins, and biomolecules with variable molecular weight and exhibits ultrawater permeance ∼1300 L m −2 h −1 bar −1 , more than that of reported GO-based membranes. It is interesting that due to larger interlayer spacing, such membranes show less rejection (<10%) for salts, i.e., NaCl, MgCl 2 , Na 2 SO 4 , etc. Furthermore, these membranes are highly stable up to 37 days in an aqueous environment and 28 days in acidic and basic solutions compared to pristine GO-based membranes.

Highly efficient mica-incorporated graphene oxide-based membranes for water purification and desalination

“…These groups facilitate the easy fabrication and modification of GO membranes through the stacking of nanosheets onto a porous substrate by chemical methods. 28 Zhang et al have prepared isophorone diisocyanate (IPDI)-intercalated GO-based membranes for the separation of heavy metal ions and dye molecules. The prepared IPDI-GO-based membranes show a rejection of 40–70% for heavy metal ions and dye molecules in an aqueous medium.…”