Bin Jiang, Baoyu Wang, Luhong Zhang, Yongli Sun , Xiaoming Xiao , Na Yang , Haozhen Dou
School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, China
ABSTRACT
Poly(L‐lactic acid) (PLLA) ultrafiltration (UF) membrane was fabricated by immersion precipitation method using Tween 80 as an additive. Membrane structure was characterized by scanning electron microscopy (SEM), porosity and pore size measurement, and atomic force microscopy (AFM). Membrane performance was evaluated by pure water flux, molecular weight cut‐off, and tensile test. It was found that the addition of Tween 80 into the casting solution significantly increased the permeability and molecular weight cut‐off of membrane. Tensile test confirmed that the as‐prepared PLLA membranes exhibited acceptable mechanical properties for ultrafiltration. Further, the role of Tween 80 in the process of membrane formation was analyzed and proposed. The addition of Tween 80 favored the formation of larger pores by interrupting the polymer chain entanglement and improving the miscibility between solvent and coagulant.
Graphical abstract

KEYWORDS
biopolymers and renewable polymers; membranes; polyesters膜