Development of nanostructure membrane from regenerated bacterial cellulose

Abstract

In this research study, bacterial cellulose (BC) and alginate were used as raw materials for the frabrication of a new regenerated cellulose membrane. The environmental friendly procedure for regenerated bacterial cellulose (RBC) was developed. The optimum conditions involved swelling BC in 4% wt NaOH/ 3% wt urea solution, followed by freeze thaw process and blending with alginate at various rations. Supercritical CO[subscript 2] drying method was then applied for porous preparation of the membrane. Afterward, the fabricated membranes were characterized for nonstructure and physical properties. The mechanical properties of the pure RBC membrane were better than the blend membranes. However, the water vapor permeability and the percent water absorption of the pure RBC membrane were lower. The tensile strength, the elongation at break and the percent water absorption of the pure RBC membrane were 4.32 MPa, 35.20% and 49.67%, respectively. The water vapor transmission rate of the RBC was 2,504 g/m[superscript 2] day and its pore size was 1.26 nm. The RBC blend membrane with 20% wt alginate exhibited the most orderly alignment of fibers on its surface with the tensile strength, the elongation at break and the percent water absorption at 3.38 MPa, 31.6% and 52.25%, respectively. The water vapor transmission rate was 5,609 g/m[superscript 2] day and the pore size was 1.06nm.