Electrospun nanofibrous cellulose diacetate nitrate membrane for protein separation

This contribution describes the preparation and characterization of cellulose diacetate nitrate (CDNA) nanofibrous membranes for bovine serum albumin (BSA) purification. CDNA was synthesized by nitration of cellulose diacetate (CDA), using HNO₃/CH₂Cl₂ as nitration agent. The chemical and morphological structures of CDNA were investigated by Fourier-transform infrared spectroscopy (FTIR), Elemental analysis, X-ray diffraction (XRD) and Scanning electron microscopy (SEM). Five solvents, that is, acetone, dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), chloroform, and acetic acid were used to generate co-solvents for electrospinning CDNA. Long uniform CDNA nanofibers with an average diameter of 240±80nm were electrospun from a 15wt% CDNA solution in DMSO/chloroform (2/1, v/v). The presence of nitrate groups on the surface of CDNA nanofiber membrane was confirmed by X-ray photoelectron spectroscopy (XPS). The prepared CDNA-DMSO/chloroform nanofibers were applied to adsorbing BSA, and the maximum equilibrium adsorption capacity (from Langmuir isotherm data) for BSA was 300.11mg/g, which was higher than CDA nanofibers (18.63mg/g). The membrane showed reusability after regeneration with elution buffer. In conclusion, the CDNA nanofibrous membrane is a promising material for protein purification.