Preparation and Characterization of Sulfated Cellulose Nanocrystalline and its Composite Membrane for Removal of Tetracycline Hydrochloride in Water

Abstract

The removal of antibiotic pollutants remaining in the environmental media has been a big challenge nowadays. Herein, we report a facile and green approach to fabricate an eco‐friendly composite membrane without addition of any toxic polymers or chemical cross‐linking agents to effectively remove the tetracycline hydrochloride in Water. Firstly, the sulfated cellulose nanocrystalline (CNC) was obtained via hydrolysis of sulfuric acid by using microcrystalline cellulose (MCC) as raw material under ultrasonic condition. The as‐prepared CNC has a nanowhisker dimension with 200.2 ± 110.2 nm in length, 15.7 ± 9.3 nm in width, and 7.2 ± 3.1 nm in height. The obtained CNC is cellulose type I as determined by X‐ray diffraction (XRD), while its crystallinity index (CrI) can reach 82.3%. Then, the composite membrane derived from the obtained CNC and commercial mixed cellulose ester (MCE) membrane was facilely prepared through vacuum dewatering process, which is applied to remove tetracycline hydrochloride (Th) in solution. The results showed that the removal efficiency of Th through the neat MCE was only 28 ± 4%, while it could be improved to 58 ± 5% and 89 ± 1%, respectively, by filtering through composite membranes with different contents of CNC deposition. Such effect is derived from the combine factors based on both steric hindrance (sieving) and electrostatic interaction (Donnan) effect of the composite membranes. The development of related CNC materials and composite fabrication processes is in favor of cost‐effective and “green” polymer composites for the remediation of increasing antibiotic pollution and the purification of contaminated water nowadays.