Effect of polymer-solvent compatibility on polyamide hollow fiber membranes prepared via thermally induced phase separation

Preparation, Modification, and Application of Ethylene-Chlorotrifluoroethylene Copolymer Membranes

Ethylene-chlorotrifluoroethylene (ECTFE) was first commercialized by DuPont in 1974. Its unique chemical structure gives it high heat resistance, mechanical strength, and corrosion resistance. But also due to these properties, it is difficult to prepare a membrane from it by the nonsolvent-induced phase separation (NIPS) method. However, it can be prepared as a microfiltration membrane using the thermally induced phase separation (TIPS) method at certain temperatures and with the selection of suitable solvents, and the use of green solvents is receiving increasing attention from researchers. The surface wettability of ECTFE membranes usually needs to be modified before use to strengthen its performance to meet the application requirements, usually by graft modification and surface oxidation techniques. This paper provides an overview of the structure of ECTFE and its preparation and modification methods, as well as recent advances in its application areas and prospects for the future methods of preparing high-performance ECTFE membranes.

Nanofiber Scaffolds as Drug Delivery Systems Promoting Wound Healing

Nanofiber scaffolds have emerged as a revolutionary drug delivery platform for promoting wound healing, due to their unique properties, including high surface area, interconnected porosity, excellent breathability, and moisture absorption, as well as their spatial structure which mimics the extracellular matrix. However, the use of nanofibers to achieve controlled drug loading and release still presents many challenges, with ongoing research still exploring how to load drugs onto nanofiber scaffolds without loss of activity and how to control their release in a specific spatiotemporal manner. This comprehensive study systematically reviews the applications and recent advances related to drug-laden nanofiber scaffolds for skin-wound management. First, we introduce commonly used methods for nanofiber preparation, including electrostatic spinning, sol-gel, molecular self-assembly, thermally induced phase separation, and 3D-printing techniques. Next, we summarize the polymers used in the preparation of nanofibers and drug delivery methods utilizing nanofiber scaffolds. We then review the application of drug-loaded nanofiber scaffolds for wound healing, considering the different stages of wound healing in which the drug acts. Finally, we briefly describe stimulus-responsive drug delivery schemes for nanofiber scaffolds, as well as other exciting drug delivery systems.

ECTFE Membrane Fabrication Using Green Binary Diluents TEGDA/TOTM and Its Performance in Membrane Condenser

Poly(ethylene-chlorotrifluoroethylene) (ECTFE) membrane is a hydrophobic membrane material that can be used to recover water from high-humidity gases in the membrane condenser (MC) process. In this study, ECTFE membranes were prepared by the thermally induced phase separation (TIPS) method using the green binary diluents triglyceride diacetate (TEGDA) and trioctyl trimellitate (TOTM). Thermodynamic phase diagrams of the ECTFE/TEGDA: TOTM system were made. The effects of the diluent composition and cooling rate on the structure and properties of the ECTFE membranes were investigated by characterizing the SEM, contact angle, mechanical properties, pore size and porosity. The results showed that ECTFE membranes with cellular structure were successfully prepared and exhibit good mechanical properties. Moreover, increasing the TOTM content in the binary diluents and decreasing the cooling rate could effectively improve the mean pore size of the ECTFE membranes, but the increase in TOTM content reduced the mechanical properties. During the MC process, the water recovery performance of ECTFE membranes increased with the increase in the mean pore size of the membranes, and the condensation flow and water recovery of membrane prepared at 20% TOTM were 1.71 kg·m⁻²·h⁻¹ and 54.84%, respectively, which were better than the performance of commercial hydrophobic PVDF membranes in the MC. These results indicated that there is good potential for the application of ECTFE membranes during the MC process.