POS6-1361
Phosphorylated cellulose nanofiber Composite Membrane Containing Acid-Functionalized Fumed Silica for Polymer Electrolyte Membranes
When and Where
Nov 30, -0001
00:00 - 00:00
Room 301 (Grand Ballroom)
Presenter(s)
Hyuntaek Han (Seoul National University, Department of Agriculture, Forestry and Bioresources)
Co-Author(s)
Abstract
Phosphorylated cellulose nanofiber (PCNF) has attracted attention as a sustainable matrix for polymer electrolyte membranes because of its acidic phosphate groups, film-forming ability, and renewable origin. In this study, acid-functionalized fumed silica was incorporated into PCNF to regulate the physicochemical properties of cellulose-based composite membranes. Fumed silica was modified by two acid-treatment routes: sulfuric acid treatment to introduce surface sulfate groups and phosphoric acid treatment to introduce surface phosphate groups. The modified silica particles were dispersed in PCNF suspensions, followed by solution casting to prepare composite membranes.
The surface functionalization of silica was confirmed using Fourier-transform infrared spectroscopy (FTIR) and acid-base titration. The morphology of composite membranes was examined by scanning electron microscopy (SEM) to evaluate filler dispersion and cross-sectional structure. Water uptake and swelling ratio were measured to assess hydration behavior and dimensional stability. Sulfate-modified silica increased membrane swelling owing to its hydrophilic acidic groups, whereas phosphate-modified silica reduced swelling, which was attributed to crosslinking or strong interfacial interactions within the PCNF network. Thermal stability was analyzed by thermogravimetric analysis, and ion exchange capacity (IEC) was measured to evaluate the density of ion-conducting acidic sites.
The surface functionalization of silica was confirmed using Fourier-transform infrared spectroscopy (FTIR) and acid-base titration. The morphology of composite membranes was examined by scanning electron microscopy (SEM) to evaluate filler dispersion and cross-sectional structure. Water uptake and swelling ratio were measured to assess hydration behavior and dimensional stability. Sulfate-modified silica increased membrane swelling owing to its hydrophilic acidic groups, whereas phosphate-modified silica reduced swelling, which was attributed to crosslinking or strong interfacial interactions within the PCNF network. Thermal stability was analyzed by thermogravimetric analysis, and ion exchange capacity (IEC) was measured to evaluate the density of ion-conducting acidic sites.
