文档介绍：Preface to Volume 3
For many purposes, zeolites and related materials are not utilized in the as-syn-
thesized form. Rather, they are only employed after an appropriate post-synthe-
sis modification.
Undoubtedly, the classic procedure of zeolite treatment after synthesis is that
of ion exchange achieved through treatment of a suspension of the as-synthe-
sized (or natural) zeolite powder (usually in the sodium or potassium form) in
an aqueous solution of a salt containing the cations to be introduced. Starting in
the 1930s, this type of ion exchange has been extensively studied, not only as a
method of preparation, but also with respect to thermodynamics and ics.
Application on an industrial scale is well developed and, because of its im-
portance, ion exchange in zeolites has been reviewed several times. Thus, the
first chapter of Volume 3 of the series “Molecular Sieves – Science and Techno-
logy”, which was contributed by and R. Harjula, was able to focus
on the developments and advances made during the last decade. It emphasizes
the need for improvement of theoretical approaches, utilization of the rapidly
putational power, and the importance of acquiring reliable data as
the bases for progress in fundamental studies on conventional ion exchange.
The more recent development of solid-state ion exchange and related modi-
fication techniques such as reactive ion exchange between solid zeolite powders
and solid or pounds containing the cations we wish to introduce is
rather exhaustively dealt with in the subsequent chapter written by . Karge
and . Beyer. The concept of solid-state ion exchange is explained and con-
trasted to the conventional exchange process. Experimental procedures as well
as techniques for monitoring the solid-state modification of zeolites are de-
scribed in great detail and illustrated by a large number of investigated systems.
Related methods of post-synthesis modification, possible mechanisms, an