A Novel Green Diluent for the Preparation of Poly(4-methyl-1-pentene) Membranes via a Thermally-Induced Phase Separation Method

Abstract

The use of green solvents satisfies safer chemical engineering practices and environmental security. Herein, myristic acid (MA)—a green diluent—was selected to prepare poly- (4-methyl-1-pentene) (PMP) membranes with bicontinuous porous structure via a thermally induced phase separation (TIPS) process to maintain a high gas permeability. Firstly, based on the Hansen solubility parameter ‘distance’, Ra, the effect of four natural fatty acids on the PMP membrane structure was compared and studied to determine the optimal green diluent, MA. The thermodynamic phase diagram of the PMP-MA system was calculated and presented to show that a liquid-liquid phase separation region could be found during the TIPS process and the monotectic point was around 34.89 wt%. Then, the effect of the PMP concentration on the morphologies and crystallization behavior was systematically investigated to determine a proper PMP concentration for the membrane preparation. Finally, PMP hollow fiber (HF) membranes were fabricated with a PMP concentration of 30 wt% for the membrane performance characterization. The resultant PMP HF membranes possessed good performances that the porosity was 70%, the tensile strength was 96 cN, and the nitrogen flux was 8.20 ± 0.10 mL·(bar·cm2·min)−1. We believe that this work can be a beneficial reference for people interested in the preparation of PMP membranes for medical applications.

Phosphorylcholine/Heparin Composite Coatings on Artificial Lung Membrane for Enhanced Hemo-compatibility

“…It possessed a bicontinuous pore structure and dense surface layer (1 μm), as shown in Figure S3­(b)–Figure S3­(e), and the outer surface depth varied from 0 to 70 nm, as shown from the AFM topography in Figure S3­(f). These data were comparable to literature results, − which suggested that the surface dense layer was thin enough to maintain high gas permeability. Also due to the bicontinuous pore structure and porosity as high as 63% of the membrane, the nitrogen permeance was 1.0 mL·(bar·cm 2 ·min) −1 .…”

Recent advances in polymer membranes employing non-toxic solvents and materials

“…220 Recently, four different fatty acids have been employed as green solvents for poly-(4-methyl-1-pentene) (PMP) membranes via TIPS process, including lauric acid (LA), myristic acid (MA), palmitic acid (PA), and stearic acid (SA). 221 The PMP membrane was employed for extracorporeal membrane oxygenation (ECMO) system, which is an extracorporeal device that can provide long-term cardiac and respiratory support for people whose heart and lungs cannot provide sufficient gas exchange or perfusion to sustain their life. For example, ECMO can be used as an effective approach to cure these patients who caught a COVID-19 virus at the moment.…”

Mutual Solubilities between Ethylene Glycol and Organic Diluents: Gas Chromatography and NMR

“…Nowadays, one important aspect of scientific efforts to develop greener separations is the application and evaluation of innovative solvent systems, usually with no drawbacks associated with their conventional organic counterparts [ 1 , 2 , 3 , 4 ]. Among various separation methods, somehow, liquid–liquid extraction should always clearly focus more attention on environmental “friendliness”; it suffers from one very significant weakness, i.e., the need for water-immiscible organic diluents [ 5 , 6 , 7 , 8 ].…”