Study on the Preparation of Cellulose Acetate Separation Membrane and New Adjusting Method of Pore Size

Abstract

As a kind of eco-friendly (biodegradable) material and with a natural anti-fouling ability, cellulose acetate (CA) is more suitable for single-use membrane (especially in bioprocess). In this study, the method for preparing CA membrane by Vapor-assisted Nonsolvent Induced Phase Separation (VNIPS) was studied. The influences of ratio compositions (solid content, acetone/N,N-Dimethylacetamide ratio, glycerol/CA ratio) and membrane preparation conditions (evaporation time, evaporation temperature and humidity) on the microstructure and other properties were systematically evaluated. Results indicated that acetone/N,N-Dimethylacetamide ratio and glycerol/CA ratio had great influence on the cross-section structure of membranes. Additionally, the membrane with homogeneous sponge-like porous structure could be prepared stably within certain limits of ratios. Under the premise of keeping the content of other components fixed, the separation membrane with a full sponge pore structure can be obtained when the ratio of glycerol/CA is ≥2.5 or the acetone/solvent ratio is between 0.25 and 0.5. Evaporation time and temperature, humidity and other membrane preparation conditions mainly affected the surface morphology and the pore size. This kind of high-performance membrane with homogeneous sponge-like pore and controllable surface morphology could be potentially used for bioseparation processes.

Hydrophilic Scaffolds Containing Extracts of Stryphnodendron adstringens and Abarema cochliacarpa for Wound Healing: In Vivo Proofs of Concept

“…The mechanical properties and permeability indicate that the incorporation of the SA extract reduced the thickness of the GELSA biomembrane, indicating improved material compacting properties. Thickness is an important variable because it influences the uniformity of materials and homogeneity, and is strongly influenced by the casting-type production processes variations, mass/area ratio, and relative humidity of the air and drying [ 35 ]. Souza et al [ 36 ] developed bioactive collagen membranes containing red propolis, of similar thicknesses as reported in our study (i.e., 38.9 µm in membranes with collagen only, 22.2 µm for membranes with modified collagen, 28.1 µm for membranes with incorporated extracts).…”

Porous Microneedles for Therapy and Diagnosis: Fabrication and Challenges

“…The experiment demonstrates that the maximum pore size changes from 1.87 μm down to 0.79 μm as the concentration of CA increases from 7 wt % to 10 wt %. From 94.7 ± 3.2% to 87.5 ± 5.2%, the porosity decreased . When making polycarbonate sheets with different molecular weights (Mn = 1.6 × 10, 4 2.3 × 10, 4 2.8 × 10 4 ), the pore diameter changes from 1.3 to 0.4 μm as the molecular weight increases .…”

“…From 94.7 ± 3.2% to 87.5 ± 5.2%, the porosity decreased. 67 When making polycarbonate sheets with different molecular weights (Mn = 1.6 × 10, 4 2.3 × 10, 4 2.8 × 10 4 ), the pore diameter changes from 1.3 to 0.4 μm as the molecular weight increases. 68 Adding some hydrophilic polymers to raw materials, such as polyvinylpyrrolidone (PVP) 69−72 and polyethylene glycol (PEG), 72−74 can improve porosity and reduce macropore formation, and these additives can improve raw material hydrophilicity.…”

Polymer-modified regenerated cellulose membranes: following the atom transfer radical polymerization concepts consistent with the principles of green chemistry

“…Vapor-assisted nonsolvent induced phase separation (VNIPS) technique is also known, as being based on the dry-wet casting process, i.e. cellulose solution is exposed to a nonsolvent vapor (usual water), and then immersed in a coagulation bath (Wang et al 2022a).…”