Express Method of Preparation of Hollow Fiber Membrane Samples for Spinning Solution Optimization: Polysulfone as Example

Abstract

This article describes a new technique for the preparation of hollow fiber (HF) membrane samples using an automatic manipulator unit. The manipulator uses a syringe needle to form a HF of a given geometry. The needle in automatic mode is sequentially immersed, first into the polymer solution and then into the coagulation bath. The possibility of using a manipulator to obtain HF samples was studied on the known polysulfone (PSf)/N-methylpyrrolidone (NMP)/pore-forming additive system. A series of HF membrane samples were made within 29 h from twelve 1 mL PSf casting solutions. This was 15 times faster than obtaining samples of HF membranes at the multifunctional research laboratory facility. From the point of view of the consumption of the components of the casting solution, the use of the manipulator was 30 times more economical, and the consumption of water for precipitation and washing was 8000 times less. The developed method made it possible to study samples of HF by scanning electron microscopy (SEM), ultrafiltration, and evaluate its mechanical properties without spinning the membranes. Using the new technique, the optimal composition of the casting solution for the wet spinning of HF PSf membranes was selected during two weeks. Thus, the manipulator makes it possible to significantly reduce the time of the new membrane preparation, reduce the volume of used polymer, and thus makes it promising to study expensive or new membrane materials.

Spinning of Polysulfone Hollow Fiber Membranes Using Constant Dope Solution Composition: Viscosity Control via Temperature

“…Usually, the dope solution viscosity can be changed by the following ways: varying of the polymer concentration [11][12][13][14][15][16][17][18][19][20][21] and molecular weight [11,12,18]; the quantitative ratio of polymers [19,21,22] (if a polymer mixture is used); the composition and monomer unit ratio of copolymers [11]; the types of solvents [11]; the types [12,23], concentrations [12,20,[24][25][26] and molecular weight [27] of the additives in the dope solution, etc. Table 1 presents a literature data analysis from the standpoint of the main ways to change the dope solution viscosity and the effect of the viscosity change on the properties of the resulting hollow fiber membranes.…”

Characterisation and modelling the mechanics of cellulose nanofibril added polyethersulfone ultrafiltration membranes

“…excessively increase the viscosity of the membrane casting solution. The high PES-PVP-CNF1 casting solution lowers the rate of change during phase inversion, delaying the liquid-liquid separation and forming a less porous, denser membrane [ 35 , 74 , 75 ]. Similarly, the structure of PES-PVP-CNF1 is denser than PES-PVP-CNF0.5 due to the high loading of CNF increasing the membrane viscosity.…”

Polyvinyl alcohol‐based membranes for filtration of aqueous solutions: A comprehensive review

“…[229] • Wet-spinning Wet-spinning method is mainly applied for preparation of hollow fiber membranes. [230,231] In this technique, a polymer solution is deposited via a syringe pump in a controlled manner and extruded through a nozzle. [232] The generated fibers are then deposited inside a coagulation bath followed by the polymer precipitation.…”