Application of anti fouling graphene oxide membrane modified with gallic acid and ethylenediamine in emulsified oil separation

Abstract

This study investigates the modification of graphene oxide (GO) with ethylenediamine (EDA) to enhance its interlayer spacing to 1.04 nm and increase water flux to 879.2 L m⁻² h⁻¹. Subsequently, gallic acid (GA) was employed for secondary modification of the ethylenediamine-modified graphene oxide (EGO). Cellulose acetate (CA) served as the substrate for membrane fabrication, with the GA–EGO membrane prepared via a vacuum filtration method. The fundamental properties of the GA–EGO membrane were characterized using various analytical techniques, including water contact angle measurements and Fourier transform infrared spectroscopy (FTIR). The results indicated that the optimal concentration of GA in the GA–EGO membrane was 1 mg. Under these conditions, significant alterations to the membrane surface were observed, achieving a water contact angle of 0°, which corresponds to a superhydrophilic state. The GA–EGO membrane demonstrated an increased water flux of 1058.2 L m⁻² h⁻¹ and exhibited excellent emulsion separation capabilities, achieving a separation efficiency of 95.3% for coal–oil emulsions. Notably, after ten cycles of use, the GA–EGO membrane retained its operational efficiency. Furthermore, it maintained a separation efficiency exceeding 90% for emulsions derived from various oils, underscoring its promising potential for practical applications.