CINDECA   05422
CENTRO DE INVESTIGACION Y DESARROLLO EN CIENCIAS APLICADAS "DR. JORGE J. RONCO"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
STRUCTURE-PROPERTY BEHAVIOUR OF NEW HYBRID MATERIALS
Autor/es:
L. MUSANTE; J. SAMBETH; R. TORREGROSSA; P. VÁZQUEZ; J. M. MARTÍN-MARTÍNEZ
Lugar:
Zalakaros
Reunión:
Conferencia; Eurofillers 2007; 2007
Resumen:
Organic/inorganic hybrid
materials prepared by the sol-gel approach have rapidly become a fascinating
new field of research in materials science. The explosion of activity in this
area in the past decade has made tremendous progress in both the fundamental
understanding of the sol-gel process and the development and applications of
new organic/inorganic hybrid materials.
Basically, sol-gel reactions
can be viewed as a
two-step network-forming polymerization process. Most commonly, metal alkoxides
are hydrolyzed to generate intermediate species of metal hydroxides. These
species then undergo a stepwise polycondensation reaction to form a
three-dimensional network. This network structure imposes restrictions on the
molecular movement, thereby making it possible to obtain a multicomponent
system without crystallization.
Essentially all studies
on such systems have concentrated on a mixture of inorganic components, and the final products are usually
hard and brittle. In light of the success of making multicomponent sol-gel
glasses, it appeared to the authors that new hybrid materials could be made
through the incorporation of some organic-based species that have appropriate
functional groups to undergo the co-condensation reaction with inorganic-based
alkoxides. If this attempt was successful, it could provide a new way of
bridging organic and inorganic materials. In addition, the material obtained
should show some properties of the inorganic glassy matrix as well as possibly some characteristics of the incorporated
components. Therefore, materials with new or special application might be made
by choosing appropriate reacting components for this new sol-gel process. In
this process, the acidity of the environment and the water content of the
system have been proven to display a critical effect on the structure of the
final product. The combination of organic and inorganic components and the
synergism of their properties in one material is particularly useful and allows
the development of materials with totally new properties.
The objective of this work is the comparison of the different degree
from hydrofobicity of silica obtained by means of the sol-gel method, using two
modifiers for such aim: tris-hydroximetyl-aminometane (TRIS) and
1,1,1,3,3,3hexametyldisilane (HDMS), incorporated in separated form and its
comporting with pure silica. The obtained materials were characterized
by TEM-EDX, FT-IR, DRIFTS, DRX, DRS, SEM and pH measurements, extremely important for the future
use of these fillers on the adhesives in water-based formulations.