PREPARATION OF ELECTROSPUN SILICA NANOFIBERS WITH CONTROLLED MESOPOROUS STRUCTURE VIA SURFACTANT SELF-ASSEMBLY

Abstract

Silica electrospun nanofibers has been an interesting material for sensors or sorbents. Even though the electrospun nanofibers have high specific surface area, the researchers still improve their performance by creating porous structure in nanofibers. One of the methods is the use of surfactant micelle as a template for porous structure in nanofibers. However, the effect of surfactant micelle on porous structure in nanofibers is still a topic of discussion. Therefore, in this study various surfactants were examined for the effect on porous structure in electrospun silica nanofibers. Two types of surfactant were examined; cationic surfactant and non-ionic surfactant. Cationic surfactant with different non-ionic chain which are hexadecyl-trimethyl-ammonium bromide (CTAB), di-n-alkyl-dimethyl-ammonium chloride (DAAC), and n-octyl-trimethyl-ammonium bromide (OTAB) and non-ionic surfactant which is Pluronic F127 (PF) were studied. The characteristics of nanofibers were examined by FTIR, SEM, TEM, nitrogen physisorption and image analysis. The nanofibers with porous structure were observed. The concentration of some surfactants slightly impacted the morphology of nanofibers. In addition, the sol-gel process was interrupted when short alkyl chain surfactant was used at high concentration which prevents the formation of silica network structure. Moreover, the types and concentrations of surfactant affected the surface area, pore shape and uniformity of porous structure in silica nanofibers. Finally, the fabricated silica nanofibers were applied for a dye removal. The silica electrospun nanofibers showed a better efficiency in dye removal than the commercial silica gel.