Direct synthesis of porous functionalised polysilsesqiuoxanes self-
bonded spheres
A. M. Torchia
a
, M. Teodoro
a
, S. Fiorilli
b
, B. Onida
b
, F. Testa
a
*, E. Garrone
b
and R.
Aiello
a
a
Dipartimento di Ingegneria Chimica e dei Materiali, Università della Calabria, Via Pietro
Bucci, Cubo 44A, I-87030 Rende (CS) Italy. Tel.: +39-0984496690; Fax: +39-0984496655;
E-mail: f.testa@unical.it
b
Dipartimento di Scienza dei Materiali e Ingegneria Chimica, Politecnico di Torino, Corso Duca
degli Abruzzi, 24, I-10129 Torino, Italy
ABSTRACT
Direct synthesis of functionalised hard spheres obtained starting from 1,2-
bis(triethoxysilyl)ethane (BTSE) as silica precursor is reported. –SH organic moiety comes
from 3-mercaptopropyltrimethoxysilane (MPTMS) and –CN is obtained from 3-
cyanopropyltriethoxysilane (CPTES) reagents, respectively. –CN group was hydrolysed in
order to obtain –COOH functional group. Syntheses follow S
+
X
-
I
+
assembly pathways.
1. INTRODUCTION
Silica based hybrid organic-inorganic mesoporous materials have recently found application
as scavenger, in gas-chromatography, water purification, adsorption-based separations,
electro-optical devices, etc. Because the control of the particle morphology and size of porous
silica could open new possibilities for its emerging applications in these areas, many efforts
have been devoted to the synthesis of porous spheres with controlled size. On the other hand,
from a technological point of view monodispersed porous silica spheres are very promising
because they can be easily packed into reactors, columns or fixed and fluidized beds.
The versatility of hybrid materials comes from all the properties that can be exploited
through a combination of organic and inorganic compositions. In particular, the suitable
choice of organic moieties allows tailoring the material for specific applications.
In this paper the synthesis of hard spheres made of silica tetrahedra with ethene moiety
bridge-bounded into the material [1, 2], is reported. The pore walls have been provided with
–SH, –CN and –COOH function envisaging application in the fields of removal and
separation of cationic and anionic species. For example, it is well-known that the thiol-
functionalized porous silica has strong binding affinities for selected heavy metal ions such as
Hg
2+
, or for precious metal ions [3-6]. Anchored thiol groups can be oxidized to provide
sulfonic acid moieties for applications in solid acid catalysis [7-9]. However, few papers have
been published on totally morphologically well-controlled products of thiol-functionalised
porous silica spheres. On the other hand, –CN function is the organic precursor necessary to
obtain –COOH function of cationic resins by acid hydrolysis.
1944
From Zeolites to Porous MOF Materials – the 40
th
Anniversary
of International Zeolite Conference
R. Xu, Z. Gao, J. Chen and W. Yan (Editors)
© 2007 Elsevier B.V. All rights reserved.