To access the full text documents, please follow this link: http://hdl.handle.net/2117/76981

Title:	Improving the corrosion performance of hybrid sol-gel matrix by modification with phosphonic acid
Author:	Dalmoro, Viviane; Dos Santos, J.H.Z.; baibich, Lone M; Butler, Ian S; Armelín Diggroc, Elaine Aparecida; Alemán Llansó, Carlos; Azambuja, Denise S.
Other authors:	Universitat Politècnica de Catalunya. Departament d'Enginyeria Química; Universitat Politècnica de Catalunya. IMEM - Innovació, Modelització i Enginyeria en (BIO) Materials
Abstract:	Sol-gel films were prepared using different ratios of two silica precursors, vinyltrimethoxysilane (VTMS) and tetraethylorthosilicate (TEOS), targeting the anticorrosion treatment of aluminum alloy 2024-T3. The electrochemical behavior of the alloy coated with such films, which was studied in a 0.05 mol L-1 NaCI solution, revealed that the VTMS/TEOS ratio drastically affects the anticorrosion performance. Electrochemical impedance spectroscopy (EIS) results provided evidences that the best anticorrosive response occurs with the films prepared from 50% (v/v) ethanol, 46% (v/v) water, 3% (v/v) VTMS and 1% (v/v) TEOS. Moreover, the effects of the addition of ethylenediamine tetra(methylene phosphonic acid) (EDTPO) to a hybrid sol-gel matrix were examined. The corrosion resistance was considerably improved when the concentration of added phosphonic acid was 3.75 x 10(-5) mol L-1. Scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy analyses revealed that EDTPO-containing films provide a more uniform coverage. Results evidenced the formation of S-O-Al linkages in the VTMS/TEOS and VTMS/TEOS/EDTPO systems and that the VTMS/TEOS/EDTPO system contained P-O-Al linkages. The P-O-Al bonds, combined with the modified silica network action, may be responsible for the good anticorrosive behavior of the VTMS/TEOS/EDTPO films. (C) 2014 Published by Elsevier B.V.
Abstract:	Peer Reviewed
Subject(s):	-Àrees temàtiques de la UPC::Enginyeria química -Aluminum alloys -Corrosion and anti-corrosives -Surface modification -Corrosion resistance -Silane -aluminum-alloy -magnesium alloy -infrared-spectroscopy -phenylphosphonic acid -resistance properties -silane films -protection -coatings -silica -2024-t3 -Corrosió i anticorrosius -Revestiments protectors -Alumini -- Aliatges
Rights:	http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Document type:	Article - Submitted version Article
Share:

Show full item record