Electrochemical investigations on the corrosion protection effect of poly(vinyl carbazole)-silica hybrid sol-gel materials

In this paper, a series of organic–inorganic hybrid materials consisting of epoxy resin frameworks and dispersed nanoparticles of amino-modified silica (AMS) were successfully prepared. First of all, the AMS nanoparticles were synthesized by carrying out the conventional acid-catalyzed sol–gel reactions of tetraethyl orthosilicate (TEOS) in the presence of (3-aminopropyl)-trimethoxysilane (APTES) molecules. The as-prepared AMS nanoparticles were then characterized by FTIR, 13C-NMR and 29Si-NMR spectroscopy. Subsequently, a series of hybrid materials were prepared by performing in-situ thermal ring-opening polymerization reactions of epoxy resin in the presence of as-prepared AMS nanoparticles and raw silica (RS) particles. The as-prepared epoxy-silica hybrid materials with AMS nanoparticles were found to show better dispersion capability than that of RS particles existed in hybrid materials based on the morphological observation of transmission electron microscopy (TEM). The hybrid materials containing AMS nanoparticles in the form of coating on cold-rolled steel (CRS) were found to be much superior in corrosion protection over those of hybrid materials with RS particles when tested by a series of electrochemical measurements of potentiodynamic and impedance spectroscopy in 5 wt% aqueous NaCl electrolyte. The increase of corrosion protection effect of hybrid coatings may have probably resulted from the enhancement of the adhesion strength of the hybrid coatings on CRS coupons, which may be attributed to the formation of Fe—O—Si covalent bond at the interface of coating/CRS system based on the FTIR-RAS (reflection absorption spectroscopy) studies. The better dispersion capability of AMS nanoparticles in hybrid materials were found to lead more effectively enhanced molecular barrier property, mechanical strength, surface hydrophobicity and optical clarity as compared to that of RS particles, in the form of coating and membrane, based on the measurements of molecular permeability analysis, dynamic mechanical analysis, contact angle measurements and ultraviolet-visible transmission spectra, respectively.

Download Full-text

Electroactive Epoxy-Titania Hybrid Anti-Corrosive Coatings Prepared by Small Basic Molecule-Catalyzed Sol-Gel Route

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.747.35 ◽

2013 ◽

Vol 747 ◽

pp. 35-38 ◽

Cited By ~ 2

Author(s):

Cheng Ming Chang ◽

Jui Ming Yeh

Keyword(s):

Titanium Dioxide ◽

Corrosion Protection ◽

Sol Gel ◽

Electrochemical Corrosion ◽

Oxygen Barrier ◽

Protection Effect ◽

Barrier Coating ◽

Cold Rolled ◽

Passive Metal ◽

Oxygen Barrier Property

This article, the preparation and corrosion protection studies of a series of electroactive epoxy titanium dioxide (EET) hybrid materials containing conjugated segments of electroactive amino-capped aniline trimer (ACAT) and titanium dioxide (TiO2) nanoparticles of ~100 nm in diameter was first presented. It should be noted that EET at higher concentration of TiO2 was found to reveal better corrosion protection effect as compared to neat electroactive epoxy coating on cold-rolled steel (CRS) electrode based on electrochemical corrosion measurements in 3.5 wt% NaCl electrolyte. Effective enhancement of corrosion protection of EET coatings could be interpreted by electroactive epoxy as a densely physical barrier coating and the redox catalytic capabilities of ACAT units existed in EET may induce the formation of passive metal oxide layers on CRS electrode. Further the well-dispersed TiO2 nanoparticles in EET matrix could act as effective hinder to enhance the oxygen barrier property of EET.

Download Full-text