Characterization and Formation of Porous Hydroxyethyl Cellulose Membranes via Gas-Based Permeation: A Structural and Thermal Analysis

This research explores the fabrication of porous Hydroxyethyl Cellulose (HEC) membranes, characterized by their inherent mechanical strength and freedom from additional additives. Employing a gas-based method, a 200-µm HEC film was cast and its permeance was examined under varying gas pressures. The experimental process involved systematic pressure increments, revealing the formation of pores due to solvent evaporation during the drying phase and the subsequent weakening of intermolecular bonds. As gas pressure increased, both the number and size of pores exhibited significant growth, establishing pressure as a critical factor influencing pore characteristics. Structural analysis through Fourier Transform Infrared (FT-IR) spectroscopy demonstrated no chemical alterations during gas permeation, confirming that pore formation was purely a physical phenomenon. FT-IR further identified specific peaks corresponding to the molecular structure of HEC. Deconvolution analysis of the FT-IR data highlighted the absence of chemical changes in the ether and hydroxyl functional groups, reaffirming the physical nature of pore formation. Thermogravimetric Analysis (TGA) was employed to assess thermal stability, revealing that HEC films remained stable even at temperatures exceeding 300 °C. Notably, films subjected to the gas permeation process exhibited more rapid degradation, signifying alterations in their physical properties due to pore formation.