Fast purification of graphene oxide solution by continuous counter current hollow fibre dialysis: A step towards large scale production

Abstract

Continuous countercurrent hollow fibre based dialysis was used to purify a graphene oxide (GO) solution rapidly. A 12 kDa cutoff membrane was used for this purpose. The deposited layer of GO particles and flakes acted as a dynamic membrane that entrapped electrolytes, to some extent. This method took 17 h to purify 1 L of GO solution compared to several weeks by batch dialysis without compromising purification efficiency. A one-dimensional steady state model was used to estimate the overall mass transfer coefficient and predict the concentration profiles of feed and dialysate side. Thus, the demonstrated method was a step towards large scale production of GO.

High-Throughput Preparation of Uncontaminated Graphene-Oxide Aqueous Dispersions with Antioxidant Properties by Semi-Automated Diffusion Dialysis

“…We suggest a continuous signal registration approach. Previously, merely conductometry monitoring [ 91 ] or simultaneous conductivity and pH [ 27 ] were used for total online control of dialysis purification in scaling processes [ 34 ]. EC is the best option for signal registration because the primary contaminants of GO aqueous dispersions are charged particles.…”

“…Tunable reduction of Mn 4+ to Mn 2+ by oxalic acid effectively removes Mn species [ 25 ]. Secondly, purification from sulfur as anion contaminants is of importance [ 25 , 26 , 27 ]. Thirdly, the purification target is oxidative debris [ 28 ], also referred to as carbonaceous garbage [ 29 ] that consists of oxidized polyaromatic fragments adsorbed on GO nanoplatelets [ 30 ].…”