Superhydrophilic alkynyl carbon composite nanofiltration membrane for water purification

Abstract

Alkynyl carbon material (ACM) is a type of graphite derivative that is mainly composed of sp2 and sp1 hybrid carbons. It has a uniform distribution pore of 3–5 nm. Given its extreme thinness, high porosity and superhydrophilic surface, it is ideal for highly permeable and selective membranes. In this paper, a novel alkynyl carbon composite nanofiltration membrane was first prepared based on the coprecipitation of PDA, PEI and ACM. XPS, FTIR, SEM confirmed that the ACM was effectively compounded on the surface of the PAN substrate. CA and Zeta potential analyses show that the membrane surface is superhydrophilic due to itself superhydrophility and pore structures. The nanofiltration experiments showed that the water flux of the membrane is as high as 366 L m−2 h−1 MPa−1, which also provides a good rejetion of organic dyes and natural organic matter (NOM) in water. For example, the permeation flux and rejection of methyl blue and humic acid are 360 L m−2 h−1 MPa−1 and 96% and 285 L m−2 h−1 MPa−1 and 94%, respectively. In addition, the membrane also showed strong running stability. This new membrane separation material has great potential application prospects in water purification and wastewater treatment.