Micro and nano celluloses and their composites with cellulose, silica gel and gypsum

• Grant number: 06/57117-3
• Support Opportunities: Research Projects - Thematic Grants
• Start date: July 01, 2007
• End date: June 30, 2011
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Milton Ferreira de Souza
• Grantee: Milton Ferreira de Souza
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Pesquisadores principais: Máximo Siu Li ; Tito José Bonagamba

Abstract

Cellulose, calcium sulphate dihydrate and silica gel, all of them hydrophilic, are naturally abundant in Brazil and, in addition, find a great number of applications. Silica is used in the tire industry, dentifrice, paints and inks, medicines, Portland cement concrete, etc. Gypsum, or calcium sulphate dihydrate, is been extensively used as a building material because of its recyclable and nonflammable characteristics. The investment of €6bi recently made by Saint Gobain, a French company, in the production of dry wall, is a clear indication for the potential growth of gypsum industry. On the other hand, cellulose is a polymer naturally synthesized by plants and the most important component of their cell walls. Cellulose, which has Brazil as one of its biggest world manufacturers, owes its importance to the mechanical strength of their fibrils (in particular due to the high level of intermolecular hydrogen bonding), as well as to its chemical properties that allows for a great amount of chemicals to derive there from. Those three substances commonly share the hydrophilic character, what gives rise to opportunities for composites preparation among them having water as the only adhesive, and, thus, suitably fit the requisites for sustainability. Bearing in mind that cellulose is a thermoplastic polymer, silica gel a thermosetting one and gypsum an aggregate of crystals, composites can be tailored through hydrogen bonds. The resulting materials will be characterized by an interdisciplinary group and evaluated from scientific and technological standpoint: 1) the "confined water" and the hydrogen bonding, an up-to-date scientific theme; 2) the preparation of micro and nano cellulose fibrils by mechanical or enzymatic means; and 3) the development of composites with technological, economical and social relevance. (AU)