Functional clay aerogel composites through hydrophobic modification and architecture of layered clays

Abstract This paper implements hydrophobic modified clay layers with ammonia salts (Organoclay) using ultra-sonication and water as a solvent to develop functional clay/Poly vinyl alcohol (PVA) aerogel composites through an environmentally friendly freeze drying process. Various compositions have been designed aiming at the high effectiveness of reducing moisture absorption while increasing the structural integrity and overall compressive modulus but reducing the thermal conductivity of the aerogel composites. The results showed significant enhancement to both physical and mechanical properties of the aerogel composites. The microstructure systems of the aerogel composites could be tailored to result in multifunctional performance for the targeted applications. The moisture absorption could be reduced five folds compared to that of normal clay aerogels depending on the exposure relative humidity. While the modulus of the aerogel composites was doubled from an initial modulus of 0.39 to 0.82 MPa, the thermal conductivity was reduced by up 20% reaching values as low as 0.0315 w/mk. These aerogel composites could be an effective and efficient thermal insulation material to be implemented in the construction industry.