Various synthesis and post-synthesis techniques are described in order to p
rovide some insights into the latest developments in pore size engineering.
Zeolites with tailor-made micropores can be the result of a controlled che
mical surface treatment or the use of structure-directing templates during
the synthesis. Various chemical modification methods, based on an ion excha
nge process, preadsorption of polar molecules and modification of the frame
work were discussed with respect to their mechanism. Furthermore, pillared
clays are proposed as a new class of porous materials with properties excee
ding those of zeolites. Depending on the synthesis procedure and conditions
the micro-and mesoporosity is evaluated. Moreover, the possibilities in po
re size engineering using structure-directing templates during the synthesi
s are illustrated by the mesoporous MCM and micro-/mesoporous clay heterost
ructure (PCH) materials. The pore size engineering in various oxides, such
as zeolites and clay minerals is emerging as a new area of great scientific
and technological interest. Materials with tailor-made pore sizes and shap
es an particular important in applications where molecular recognition is n
eeded, such as shape-selective-catalysis, molecular sieving, chemical sensi
ng and selective adsorption. In general, the pore size engineering of these
porous materials can be the result of: (1) a controlled chemical surface t
reatment; or (2) the use of structure-directing templates during the synthe
sis. (C) 2001 Elsevier Science B.V. All rights reserved.