Preparation of poly(L-lactic acid) microfiltration membranes by a nonsolvent-induced phase separation method with the aid of surfactants

【Original Contribution】 Preparation of a Poly(L–Lactic Acid) Membrane Scaffold with Open Finger–Like Pores Prepared by a Nonsolvent–Induced Phase Separation Method with the Aid of a Surfactant

“…2(b)). Conversely, an were 10% and 20%, respectively, as expected from the phase diagram reported elsewhere 11) . Thus, the PLLA membranes with open finger-like pores and 500 µm thickness prepared from a 10% PLLA solution in 1,4-dioxane containing 15% Tween 80 were used in this study.…”

“…The cell density increased to 5000 6000 cells/mm 2 after 14 28 days of culture at which time the culture reached stationary phase. In comparison, the maximum cell density of Saos-2 cells has been reported to be 2000 3000 cells/mm 2 on culture flasks and dishes 11,15) . Therefore, the cells grew 2 3 times higher per unit apparent area in the PLLA membrane scaffold than in monolayer cultures.…”

“…PLLA membranes were prepared via the NIPS method similar to as reported elsewhere 11) . Typically, 5.00 g PLLA was dissolved in 38.25 g 1,4-dioxane con- …”

“…However, large cells such as human osteoblast-like cells (20 50 µm or larger) 10) are difficult to grow in these pores. Thus, the pore size on the inlet side should be larger than 100 µm to allow cells to grow in the pores and those on the opposite side should be smaller than 10 µm to retain the cells in the vent-induced phase separation (NIPS) method with the aid of surfactants 11) in a manner similar to that used for the preparation of poly(methyl methacrylate) membranes 12) . Surfactants, which exhibit hydrophiliclipophilic balance (HLB) values of 14.9 15.6, e.g.…”

Preparation of Poly(lactic acid) Flat Sheet Membranes by Liquid Induced Phase Separation

“…This phenomena is related to the velocity of precipitation of the system: the formation of macrovoids is mostly associated to instantaneous demixing, provided it allows the growth and coalescence of large nuclei of the polymer‐poor phase during liquid‐liquid demixing. The suppression of the formation of macrovoids in PLA systems due to delay in precipitation is also widely reported in the literature …”