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The mechanical properties of black thin film on glass substrates and metallic, obtained
from the synthesis of organic-inorganic silica hybrids via sol-gel are described. Hybrid silica-based
coatings with tetraethoxysilane (TEOS), methyltrietoxysilane (MTES), polyurethane (PU) and
commercial silica colloidal solution (Ludox HS30) as precursors, were used. The procedure is
divided in the following three steps: 1) obtaining homogenous and stable solutions of different
organic silica-polymer composition, 2) aggregation of the black pigment with the formulate
FeMnO
x
, 3) Coating substrates by both dip-coating and aerograph airbrush, at room temperature.
The films obtained were characterized by SEM, AFM and nano-indentation. The coatings of the
Ludox-MTES-PU/FeMnO
x
system showed the better characteristics concerning the morphology and
the adhesion to the glass and metallic copper substrates
The superficial protection of materials by means of coverings can be the solution of many practical
problems, especially in adverse working conditions. Many procedures for the manufacture of the
coverings exist (CVD, PVD, Sol-Gel, etc), the suitability of each method depending on the type of
substrate, as well as on the coating desired.
The sol-gel process is one of the most interesting alternatives to obtain thin films [1].
Additionally, sol-gel coatings can be deposited simply by using an airbrush tool.
In general, technical specifications of the coatings include a good mechanical characterization to
assurance its protective effectiveness in working conditions. Between all the possible methodologies
available for studying the mechanical properties of the materials, the indentation tests have
numerous advantages, being non destructive and needing only a small portion of material to
accomplish the experiments.
In this work, we have analysed the films morphology by SEM and AFM techniques before
studying the mechanical properties by means nanoindentation. This one has demonstrated to be a
powerful tool to characterize mechanical properties such as the hardness and the Young´s modulus
of different coatings [2]. However, until now, nanoindentation had only found limited application to
organic-inorganic polymers [3, 4].
The study has taken place on the two following systems: tetraethoxysilane (TEOS)-
methyltriethoxy silane (MTES)- polyurethane (PU) /FeMnO
x
and Ludox®-MTES-PU/FeMnO
x
.
Finally we have studied the optical properties of the system which behaves optimal mechanical
properties.
Key Engineering Materials Vol. 423 (2010) pp 161-165
© (2010) Trans Tech Publications, Switzerland
doi:10.4028/www.scientific.net/KEM.423.161
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of the
publisher: Trans Tech Publications Ltd, Switzerland, www.ttp.net. (ID: 83.46.15.231-05/09/09,07:33:57)