Nanocomposites were produced from cotton with montmorillonite clay used as the nanofiller material. Three exfoliation and intercalation methods with different solvents and clay pretreatment techniques were tested for the production of these organic-inorganic hybrids. The method that resulted in superior clay-cotton nanocomposites used a clay pretreatment with 4-methylmorpholine-N-oxide as the cotton solvent. The nanocomposites showed significant improvements in the thermal properties in comparison with unbleached cotton and cotton processed under the conditions for nanocomposite preparation. The degradation temperature of the nanocomposites increased by 45 degreesC, and the char yields for some compositions were twice those of unbleached cotton. The crystalline melt of the materials decreased by 15 degreesC. Future research will include the development of textiles based on these cotton-clay materials and testing for flame-retardant properties and product strength. 2004 Wiley Periodicals, Inc.