Exploring Sodium Carboxymethyl Cellulose as a Substitute for Cellulose Acetate: Fabrication and Potential Applications of a Porous Membrane

Cellulose, abundantly available on earth, offers numerous advantages that have spurred extensive research. Porous cellulose acetate is notably widely applied in diverse industries. Despite its benefits, cellulose acetate is limited by its relatively lower thermal stability and solubility restricted to organic solvents. This study presents a porous membrane composed of sodium carboxymethyl cellulose (SCMC) as an alternative to cellulose acetate. SCMC, characterized by its remarkable thermal stability, facile film-forming capability, sustained dispersibility in aqueous solutions, and emulsion-forming ability, was utilized. The manufacturing process of the SCMC membrane employed a free-standing technique with lactic acid as an additive, yielding a film that generated unobstructed pores aided by nitrogen gas. Gas permeation began at 2.5 bar and achieved a peak performance of 1.5 GPU at 3 bar. The interaction between SCMC and lactic acid was confirmed through shifts in Fourier transform infrared spectral peaks, and the thermal stability was validated via thermogravimetric analysis. Thus, the development of a porous SCMC membrane heralds a range of potential applications, extending beyond lithium-ion batteries to various industrial sectors.