Hydrophilicity and flux properties improvement of high performance polysulfone membranes via sulfonation and blending with Poly(lactic acid)

Abstract

To achieve increased flow and reduce fouling, polymeric membranes can be functionalized with hydrophilic groups such as sulfone, amines, and others. This research has aimed at the sulfonation of Polysulfone (PSU) with various agents and at varying substitution degrees to change its hydrophobic character. PSU was also blended with Poly(lactic acid) (PLA), which is a more hydrophilic polymer. The phase inversion method was used to make PSU, PLA, sulfonated PSU, and PSU/PLA blend-based membranes. Sulfonation degrees of sulfonated PSU membranes were assessed using FT-IR, mechanical characteristics of membranes were determined, and thermal properties of membranes were clarified using DSC and TGA techniques. Hydrophilic natures and membrane alterations were investigated, as well as contact angle and water uptake measures. Among three distinct sulfonation agents (trimethylsilyl chlorosulfonate (TMSCS), sulfuric acid, and chlorosulfonic acid) employed to produce a 20% sulfonation degree of polysulfone, TMSCS was chosen as having the highest sulfonation efficiency (91.5%). With increasing sulfonation degree, a drop in molecular weight was seen in all sulfonated polysulfone samples. The mechanical strength values of polysulfone after sulfonation with TMSCS rose from 35.23 MPa to 63.35 MPa, while the contact angle value decreased from 85.58° to 71°. The contact angle value reduced from 85.58° to 64.68° while the mechanical strength of the PSU and PSU/PLA (50:50) blend increased from 35.23 MPa to 39.3 MPa. Membranes were also tested for pure water flux, hydrostability, and biostability. In terms of application requirements, it was determined that sulfonated PSU-based membranes manufactured with TMSCS with a 20% sulfonation degree and PSU/PLA blend-based membranes with a 50:50 (w:w) ratio have the optimum compositions with high flux quantities.

Immunomodulatory poly(L-lactic acid) nanofibrous membranes promote diabetic wound healing by inhibiting inflammation, oxidation and bacterial infection

“…Enhancing the water affinity of PLLA membranes promotes the attachment, development and multiplication of dermal cells on the membranes [ 59 ]. To enhance the hydrophilicity of PLLA-based nanofibrous membranes, the surface of the membrane is typically subjected to chemical grafting or hydrolysis, which introduces new substances or damages the structure of the membrane to a certain extent [ 60 , 61 ]. However, ammonia plasma treatment offers a convenient and inexpensive approach that allows for the prompt introduction of hydrophilic groups without compromising the structure of the material [ 62 , 63 ].…”

Development of polyethersulfone/polylactic acid‐blended nanocellulose membranes for enhanced removal of methylene blue dye

“…Aseri et al 25 fabricated polyvinylidene fluoride/polylactic acid (PVDF/PLA) hollow fiber ultrafiltration membranes and found that the addition of PLA led to increased water flux, antifouling, and reduction in decomposition temperatures in the synthesized membranes which they report minimizes the membrane's environmental impact. Tasci et al 26 blended sulfonated polysulfone (PSU) with PLA to improve the properties of PSU as a membrane material. The resultant PSU/PLA blend‐based membranes showed optimum compositions with high flux quantities.…”