A Study On The Synthesis Of Porous Clays

Porous clays (PCs) prepared by the reactions of clay minerals with pillared agents base on the surface activity, interlayer ions exchangeable of clay minerals is an area of clays science which has received ever-increasing attention over recent year. Due to PCs possesses the 2D pore gallery or pore channel structure, large cavity, uniform of pore size, and especially its pore size can be controlled by artificial selection, this material is expected to find applications in the area of petroleum catalysis, environmental engineering and fine chemical industry etc.The properties and characteristics of the PCs is closely related to the prepared conditions such as clay matrix starting materials, pillared agents, reaction temperature and the fashion of.drying etc. In this thesis, the author has carried out a study on the impact factors of preparation on PCs properties by use of materials chemistry. Two series of the PCs prepared by the interlayed crosslinking of a 2:1 layer montmorillonite and a 1:1 interstratified rectorite with the pillared agent of Al polyoxocations are investigated by means of XRD, IR, TGA, MAS 27A1-NMR, and TEM instruments etc. The results show that the thermal stability of rectorite-PCs is higher than that of montmorillite-PCs, implying the clay matrix materials have an obvious influence on the PCs. The consumption of pillared agent is very important for preparing PCs which has large pore structure and high stability. The activatory PVA (polyvinyl alcohol) can expand the pore or cavity of PCs, so presence of suitable PVA consumption is benefit to get large pore structure of PCs. Drying fashion cannot be use to expand the PCs pore structure, however, it can be find to influent the PCs surface areas. The PCs with delaminated phenomena possesses very large pore and cavity structure. The acidity measurement indicates that solid acidity composition of PCs are mainly of Lewis acidity type, few of the Bronsted acidity type, sensitive to temperature, and ease to lost in the higher temperature environment.