Improving the mechanical properties of clay/polymer aerogels by a simple dip-coating procedure

Clay aerogels have many advantages as one of the lowest density family of materials current technology can provide; they possess very low thermal conductivities, high porosities, and high surface areas. Although the mechanical properties of native clay aerogels are rather low, incorporating water-dispersible polymers into the clay gel before they are processed into aerogel forms can easily produce more robust, low-density composites. Various processing modifications and additives can be employed to strengthen the aerogel material, but currently, the materials have some notable weaknesses in abrasion resistance, water absorption, and flexural properties. In this study, we employed a low-cost rubber coating material to quickly and efficiently address all three of these problems. After coating, the aerogels gained significant mechanical reinforcement, a 20-fold increase in flexural modulus and a 15-fold increase in yield stress, while exhibiting an increase of only 8% in the thermal conductivity. Improvements such as these can improve the commercial applicability of clay/polymer aerogels as thermal insulation materials. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012