Synthesis of amorphous silica and sulfonic acid functionalized silica used as reinforced phase for polymer electrolyte membrane

• Published in: Advances in natural sciences. Nanoscience and nanotechnology 2013-12, Vol.4 (4), p.45007-6
• Main Authors: Tran, Thanh Nhan, Anh Pham, Thi Van, Phung Le, My Loan, Thoa Nguyen, Thi Phuong, Tran, Van Man
• Format: Article
• Language: English
• Subjects: amorphous silica; Electrolytes; Electronics; fuel cell; functionalized silica; Membranes; nanoparticle; Nanostructure; Particle size; Polyvinylidene fluorides; Silicon dioxide; Specific surface
• ISSN: 2043-6262; 2043-6254; 2043-6254; 2043-6262
• DOI: 10.1088/2043-6262/4/4/045007

In this work silica (SiO2) and sulfonic acid-functionalized silica (sul-SiO2) were synthesized by sol-gel method from tetraethoxysilane (TEOS) and 3-mercatopropyltrimethoxysilane (MPTMS) with various ratios between them. The synthesized materials were characterized by x-ray diffraction (XRD) for crystalline structure, Brunauer-Emmet-Teller (BET) specific surface area analysis, transmission electronic microscopy (TEM) and dynamic light scattering (DLS) for particle size analysis, and ion exchange capacity (IEC) for determining sulfur content in Sul-SiO2 materials. The initial results showed that the average particle size of amorphous SiO2 and Sul-SiO2 at different TEOS: MPTMS ratios are in narrow distribution with average diameter about 20-30 nm. The particle size of Sul-SiO2 is almost unaffected by the content of MPTMS while IEC depends strongly on it. Composite membranes of 60 μm thickness were successfully prepared from blending of poly(vinylidene fluoride) (PVDF) and synthesized amorphous SiO2. It was shown that the latter may be used as a reinforced phase for composite membrane electrolytes based on PVDF.