Design and Fabrication of High-Performance Ultrafiltration Membranes for Low-Temperature Conditions

Abstract

The influence of cold weather conditions on ultrafiltration (UF) membrane performance is noteworthy. Investigating alterations in UF membrane fouling behavior under low-temperature conditions and developing strategies to enhance their performance holds significant importance for advancing membrane separation technology in cold regions. We initiate an exploration into how low-temperature conditions impact the permeation and separation capabilities of unmodified PES UF membranes, concurrently scrutinizing the associated influencing mechanisms. Employing molecular design, we strategically incorporate hydrophilic carboxyl-functionalized groups into the molecular structure of poly (aryl ether sulfone) materials. This method facilitates the development of a series of PAES-modified UF membranes (LTM-x%), exhibiting exceptional performance in low-temperature conditions, grounded in the principles of the hydration layer theory. In a low-temperature condition (5±1oC), the BSA solution flux and SA solution flux of the LTM-80 membrane surpass the pristine PES membrane flux by 187.38% and 171.82%, respectively. Notably, compared to the solution flux at room temperature (22±1oC), the LTM-80 membrane shows only a slight decrease in the 5±1oC temperature (flux decline rates of 18.52% for BSA solution and 15.12% for SA solution), in contrast to the pronounced decline observed in the pristine PES membrane (49.24% for BSA and 47.67% for SA). This investigation unveils an effective and viable strategy for designing and developing high-performance UF membranes suitable for cold regions.

Keywords: Low-temperature condition, Ultrafiltration membrane, membrane fouling, Flux decline rate