Porous silica prepared by SOL-GEL with P123 and oil/water emulsions

• Grant number: 11/22702-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): March 01, 2012
• Effective date (End): October 31, 2012
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Dimas Roberto Vollet
• Grantee: Carlos Miranda Awano
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

The copolymer Pluronic P123 has been used as a surfactant in templates for preparation of mesoporous silicas with high specific surface area and uniform pore structure, often ordered, so making them of great scientific and technological interest for many applications in several knowledge areas, such as in catalysis, separation, adsorption, enzyme immobilization, drug drive and release, and in the nanotechnology, working as good matrix for nanoparticle preparation of advanced materials. The combination of oil in water emulsions with surfactants aiming their use as templates has attracted the attention of workers for obtaining of hierarchically structured materials, constituted by a multimodal pore size distribution, normally by a mesopore structure combined with a macropore one. The aim of present proposal is to prepare silicas with multimodal pore size distribution, through combining the earlier experience acquired by the student in his master study in preparing mesoporous silica with P123 and the large possibilities to get hierarchical structure using oil in water emulsions. The conditions yielding silicas with ordered mesoporous structure (typically in the silica precipitation) or with a mesopore size distribution (typically in the gelation process), in conjunction with a macropore structure, will be studied as a function of the oil quantity in the oil/water emulsions. The structure and thermal stability of the resulting calcined materials will be studied by the techniques of small-angle X-ray scattering (SAXS), nitrogen adsorption, mercury porosimetry, thermal analysis (TG and DTA), and transmission (TEM) and scanning (SEM) electron microscopy.