A strategy for processing cellulose acetate into a uniform porous structure utilizing NaCl as additive

We present a novel method for processing high-molecular-weight cellulose acetate (CA) to create a uniformly porous membrane with enhanced thermal stability, using NaCl salt as an additive. Incorporating additives into high-molecular-weight polymers is challenging due to their long and rigid chains, which can prevent the uniform dispersion of the additive. For CA, achieving a homogeneous dispersion of additives is particularly challenging due to its inherent properties. NaCl, known for its high lattice energy, typically struggles to dissociate its ionic aggregates, complicating its even dispersion within the polymer matrix. To overcome this, we pre-hydrated the NaCl in water to disassemble these ionic aggregates before introducing it to the CA solution. Continuous stirring facilitated interactions between NaCl and CA, leading to a uniform dispersion of NaCl within the CA. The dispersion process was further enhanced by applying water pressure, which resulted in the formation of uniformly sized pores. We monitored the water flux continuously, establishing a reliable trend line with a coefficient of determination (R2) to validate our results. Additionally, the homogeneous dispersion of NaCl in the CA matrix was confirmed through measurements such as porosity and Gurley value, which yielded results of 19.55