Effects of air‐cooling on skin cells of hollow‐fiber membranes prepared via thermally induced phase separation

Abstract

A new coarsening model was established to describe the growth of skin droplets on a hollow-fiber membrane prepared by liquid-liquid thermally induced phase separation. Forced air-cooling was performed to trigger the phase separation. The heat and mass transfer processes of the skin layer are considered simultaneously. With the aid of a transfer model and data from the phase diagram, the skin cell sizes could be calculated. The effects of air velocity, air temperature, and dimensions of the hollow fiber on the skin cell sizes of the isotactic polypropylenedi-n-butyl phthalate-dioctyl phthalate system were investigated. The growth of the skin droplets follows an exponential relationship with time, and the exponent increases with the decrease in the polymer content.

Microwave foaming of carbon dioxide saturated poly lactic acid

“…Polymer foams with micro‐ and nano‐sized pores have gained significant attention in the recent past as they find numerous applications such as in filtration, energy absorption, thermal insulation, catalysis, and tissue engineering scaffolds. [ 1–7 ] The current techniques to fabricate polymer foams include particulate leaching, [ 8,9 ] thermal induced phase transition, [ 10,11 ] gas foaming, [ 12 ] block co‐polymers, [ 13 ] immiscible polymer blending, [ 14 ] and solid‐state foaming. [ 15,16 ] However, majority of these techniques result in thin films with low porosity and do not offer control over the resulting pore morphology.…”

Optimization of electro‐blown polysulfone nanofiber mats for air filtration applications

“…[16,18] Nanofibers, versatile materials which have been exploited in diverse application areas such as protective clothing and equipment, energy storage, electromagnetic sensors, functional materials, microwave absorbing materials, and tissue engineering can be manufactured by various techniques including melt blowing (MB), wet spinning, electrospinning, template synthesis, self-assembly, direct drawing, and phase separation. [10,14,[21][22][23][24][25][26][27][28][29][30] Furthermore, alternative emerging methods can be listed as centrifugal jet spinning, plasma-induced synthesis, and solution blow spinning (SBS). [14,23] Despite electrospinning (ES) has been the most prevailing one among the aforementioned techniques, it is inadequate to obtain nanofibers with high efficiency, and to be used for mass production.…”