Introduction - Mesoporous Organic-Inorganic Non-Siliceous Hybrid Materials - page 2

area, thus exhibiting broad applications in chemical, petrochemical, gas separation
industries, and other fields. For example, they can be employed to separate
molecules based on the pore size by selectively adsorbing smaller molecules from
a mixed system containing molecules too large to enter into the pores. However,
the pore sizes of zeolites are in the microporous region, usually less than 1.3 nm,
prohibiting the further applications that involve transfer and conversion of mac-
romolecules. Accordingly, the exploration and rational design of porous materials
with considerable porosity has become an important branch of materials science.
In comparison with microporous and macroporous materials, mesoporous
materials have attracted more and more research interest and have shown great
potentials in many areas due to their outstanding properties, such as approximate
pore diameters, high surface areas, tunable porosity, alternative pore shape, and
abundant compositions [ 3 - 5 ]. Mesoporous materials became a hot research topic in
1992, when Mobil Oil Corporation (Mobil) scientists first reported the M41S series
of mesoporous silica materials [ 6 , 7 ]. Cationic surfactants with long-chain alkyl were
utilized as a structure-directing agent to prepare ordered mesoporous (alumino-)
silicate materials. Furthermore, Mobil researchers not only developed a family of
mesoporous materials with ordered pore arrangements, but also proposed a general
“liquid-crystal templating” mechanism with detailed synthesis rules, thereby a new
research area of inorganic synthetic chemistry began to rise. Scientific workers have
witnessed a rapid development in mesoporous materials with new mesostructures
and compositions. If we refer to ISI Web of Knowledge and use “mesoporous” as
the subject, a predominantly increasing number of publications can be obviously
observed (Fig. 1.1 ), exhibiting the emerging development trends in this field.
Fig. 1.1 Statistics of the published papers related to “mesoporous” according to ISI Web of
Knowledge