Observations on the dynamics of nonsolvent-induced phase inversion

Preparation and characterization of polyethersulfone microfiltration membranes by a 2-methoxyethanol additive

“…Barton et al [18] and Strathmann et al [19] showed that the addition of solvent in the coagulation bath can delay the occurrence of liquidliquid demixing in the casting solution and thus results in the generation of a sponge structure. In this study some different methods were used such as the addition of 2-ME to the casting solution.…”

“…The different pore sizes of membranes were obtained, depending on the rate of diffusion. Low diffusion rates produced membranes with large pores, while high diffusion rates produced membranes with small pores [18,19,21]. At the same composition of casting solution, as the temperature increased, the viscosity of casting solution decreased and the diffusivity increased.…”

Morphology of cellulose objects regenerated from cellulose–N-methylmorpholine N-oxide–water solutions

“…Polar liquids, like water or alcohol, are used as coagulation bath because they are miscible with NMMO and cause NMMO removal from the cellulose solution. It is expected that the regeneration of cellulose-NMMOwater solutions follows the well known principles of phase separation in polymer solutions valid in membrane formation, Koenhen et al (1977), Broens et al (1980), Shen and Cabasso (1982), Radovanovic et al (1992), Pereira Nunes and Inoue (1996), Tsay and McHugh (1992), Barton et al (1997).…”

“…Finger-like morphologies are formed when the non-solvent enters into a polymer solution faster than the solvent diffuses out. Sponge-like structures are formed when the solvent diffuses out faster than the non-solvent diffuses in (Shen and Cabasso 1982;Barton et al 1997).…”

Studies of semi-permeable membranes deposited on a cellulose support

“…In this method, initially a single-phase homogeneous polymer solution is cast onto a suitable substrate to form a thin film or hollow fiber and is then immersed in a coagulation bath, which results in diffusive exchanges of solvent and non-solvent and solidification of the polymer. The transport properties and the morphology of the membrane strongly depend on both the thermodynamics and kinetics of the phase separation process [7][8][9][10][11][12][13][14]. Properties of obtained membranes depend on relative humidity of air and temperature of gelation [12][13][14][15][16][17].…”