Nanopesticides: Syntheses of Well-ordered Porous Silicas byUsing Anionic Surfactants and Basic Amino Acids

The term nanopesticide covers a wide variety of products and cannot be considered to represent a single category. Many nanoformulations combine several surfactants, polymers, and metal nanoparticles in the nanometer size range. The aims of nanoformulations are generally common to other pesticide formulations, these being to increase the apparent solubility of poorly soluble active ingredients, torelease the active ingredient in as low/targeted manner and/or to protect against premature degradation. Well-ordered mesoporous materials have attracted a great deal of attention because of their controllable structures and compositions, which make them suitable for a wide range of applications in pesticides, environmental clean-up. In general, the mesoporous materials can be synthesized based on the selfassemblyof surfactants and inorganic precursors. In addition to the use of the surfactants including cationic and nonionic surfactants, a synthesis route for preparing mesoporous silicas using anionic surfactants has been developed by using aminosilane or quaternized aminosilane as a co-structuredirecting agent. Furthermore, a novel and simple liquid-phase method for forming uniform-sized silicananospheres (SNSs) has been developed by using and basic amino acid as a base catalyst for hydrolysis of tetraethyl orthosilicate Si(OC2H5)4. These kinds of the mesoporous silicais synthetically interesting not only for their structural diversity but also for the opportunity to functionalize the pore surface. The removal of the surfactant by solvent extraction results in the mesoporous silica with aminopropyl groupsintact, which can be applied to pesticides adsorption

Keywords:

Nanopesticides , Mesoporous silica , Anionic surfactant , Silica nanosphere , Basic amino acid