Study of the formation of silver nanoparticles in mesoporous silica functionalized with 4,4-bipyridine

• Grant number: 12/01723-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): May 01, 2012
• Effective date (End): October 31, 2012
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Yoshitaka Gushikem
• Grantee: Bruno José dos Santos
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The main objective of the project is the preparation of silver nanoparticles (AgNPs) supported by organofunctionalized mesoporous silicas. Two different substrates will be explored: mesoporous silica with a highly ordered and uniform porous structure, consisting of cylindrical pores or channels arranged in parallel and packed in hexagonal arrangement (SBA-15), and a mesoporous silica characterized by an irregular porous structure with variable size and shape, and randomly distributed along with the porous structure (MDS). The two arrays will have their surfaces chemically modified with the functional group derived from 4,4 '-bipyridine, with different functionalization degrees. The modified matrix will be used as support for the preparation and stabilization of silver nanoparticles (AgNPs). The materials will be immersed in solutions containing Ag+ ions, which will be retained within the porous structure through interaction with the molecule 4,4 '-bipyridine. Studies presented in the literature describe the use of molecules containing basic sites for the reduction of Ag+ ions and consequent formation of silver nanoparticles. Therefore, the present project aims to explore the reducing properties of the molecule 4,4 '-bipyridine for preparing silver nanoparticles supported on these matrices. The objective is to evaluate the effect of different porous structures of the matrices and the different degrees of functionalization in the preparation and stabilization of silver nanoparticles. Properties such as shape, size, dispersion, and stability of AgNPs will be properly assessed on the basis of the synthesis conditions. (AU)