Preparation and properties of nanostructured ceramic foam from kaolinite

The effective method for preparation and stabilization of nanostructured ceramic foam from kaolinite is described in this work. The technique is based on the redistribution of particles from original kaolinite aggregates and on the formation of solid framework of aqueous foams stabilized by surfactants. This process is spontaneous and highly effective as the surface energy of the system decreases and provides the driving force for rearrangement of solid phase in foam. The stability of these structures is time-limited, as water flowing from the bubble walls reduces their thickness. Therefore the structure of foam must be stabilized by the materials absorbing water physically or by formation of hydrates. The following high-temperature treatment provides solid foam prepared by sintering and having certain mechanical strength. The foams of bubble walls thickness within the nanometers scale can be prepared by this method hence the thickness of wall is considerably smaller than the median of particle size of original kaolinite.