Pillaring Phyllosilicates and comparison with 2:1 HI isolated from soil.

• Grant number: 08/08315-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2008
• End date: May 31, 2009
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Antonio Carlos de Azevedo
• Grantee: Paula Gianesella Casarini
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The project aims to apply the knowledge about the clay pillaring process to sinthesize Hydroxy interlayered 2:1 (HI2:1), usually found in small amount in tropical soils. These minerals show variable intercalation degree (ID), and the reasons for that are not yet well known. Phyllosilicates 2:1 HI will be sinthesized in controled conditions using standards from the Clay and Clay Minerals Society Repository, a montmorillonite (octahedral substitution) and a beidellite (tetrahedral substitution). Measurements on the mineral peaks in the X-ray diffractogram will allow to learn about some of the factors influencing the ID and the resistance of the hydroxy polimers to extraction, such as the "locus" of isomorphous substitution (octahedral vs tetrahedral)