Sol–gel-derived corrosion-protective coatings with controllable release of incorporated organic corrosion inhibitors

Khramov, A.N.; Voevodin, N.N.; Balbyshev, V.N.; Mantz, Robert A.

doi:10.1016/j.tsf.2004.12.021

Cited by 162 publications

(81 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Some United States Air Force studies investigated various routes towards improving coating performance including the use of rare-earth metal salts [18], amine cross-linkers [19][20][21], supramolecular inclusion and organic corrosion inhibitors [22,23].…”

Section: Introductionmentioning

confidence: 99%

Corrosion protection of AA 2024-T3 aluminium alloys using 3, 4-diaminobenzoic acid chelated zirconium–silane hybrid sol–gels

Varma

Colreavy

Cassidy³

et al. 2010

Thin Solid Films

View full text Add to dashboard Cite

Organic-inorganic polymers formed by hydrolysis/condensation reactions of alkoxide precursors, such as organically modified silanes (Ormosils) are used for several industrial applications such as electronic, optical and protective anticorrosion coatings. Such materials possess superior chemical stability, physical strength and scratch resistance characteristics when compared to organic polymers. Further performance improvement can be achieved through the incorporation of zirconium and titanium based nanoparticles, also formed through from precursors via the sol-gel process. However due to the inherent reactivity differences of the above precursors, they must be hydrolysed separately before being combined for final condensation. Zirconium precursors are commonly chelated using acetic acid or acetyl acetonate prior to hydrolysis, to lower the hydrolysis rate. In this body of work, 3,4-diaminobenzoic acid (DABA) and acetyl acetonate (acac) were compared as chelating ligands for controlling the hydrolysis reactions of zirconium n-propoxide to form nanoparticles within a silane sol matrix. The sols were applied as coatings on aerospace grade aluminium alloy AA 2024-T3 and characterised by physical, spectroscopical, microscopical, electrochemical and calorimetric techniques. The electrochemical properties of the coatings, as characterised by EIS and PDS, correlated with neutral salt spray evaluations confirming that the use of DABA as a chelating ligand significantly improved the coating performance when compared to the traditional diketone ligand. The data indicates the anticorrosion properties of the nitrogen rich chelate have a key role in protecting the alloy through the formation of smaller zirconium nanoparticles, thus improving the polymer network stability.

show abstract

Section: Introductionmentioning

confidence: 99%

Corrosion protection of AA 2024-T3 aluminium alloys using 3, 4-diaminobenzoic acid chelated zirconium–silane hybrid sol–gels

Varma

Colreavy

Cassidy³

et al. 2010

Thin Solid Films

View full text Add to dashboard Cite

show abstract

“…Such smart systems include pH permeable polyelectrolyte-based coatings, conjugated (or conducting) polymers and organic coatings coupled with encapsulated inhibitors encapsulated in nano/micro containers. 102 Khramov et al immobilized organic inhibitors in cyclodextrin cavities, within sol-gel coatings that were applied onto AA2024-T3 substrates and were found to offer better protection, than those systems in which the inhibitors were directly dispersed into the sol-gel matrix. 95 Buchheit et al 103 used Zn-Al layered double hydroxides (LDHs) as containers for inhibiting decavanadate ions (V 10 O 28 6-), within epoxy coatings upon AA2024-T3.…”

Section: Lithium-containing Coatingsmentioning

confidence: 99%

Chromate replacement: what does the future hold?

Gharbi

Thomas

Smith³

et al. 2018

npj Mater Degrad

177

View full text Add to dashboard Cite

The ubiquitous use of chromium and its derivatives as corrosion preventative compounds accelerated rapidly after the second industrial revolution, with such compounds now integral to modern society. However, the detrimental impact of chromium compounds on the environment and human health has prompted the need to revisit the majority of current industrial corrosion protection measures. This review retraces the origins of chromium replacement motivations, introducing the various legislative actions aimed at diminishing the use of chromium compounds, and critically reviews alternative corrosion preventative technologies developed in the recent decades to now. The review, herein, is intended for a broad audience in order to provide a concise update to an increasingly timely issue.

show abstract

“…Harrison's solution (3.5 wt % (NH 4 ) 2 SO 4 and 0.5 % NaCl) was used as electrolyte as it closely emulates the atmospheric environment for aircraft [21]. EIS electrochemical cells were made by mounting bottom-less plastic vials to the exposed surface of the coated panel (4.9 cm 2 ) with amine hardened epoxy glue (Araldite ® ) .…”

Section: Coating Characterisationmentioning

confidence: 99%

Influence of magnesium nitrate on the corrosion performance of sol–gel coated AA2024-T3 aluminium alloy

Varma¹,

Duffy

Cassidy³

2009

Surface and Coatings Technology

View full text Add to dashboard Cite

Traditional anti-corrosion technology has relied heavily on using reducible metal species, predominantly hexavalent chromium (Cr(VI)), for protecting reactive metal alloys such as aluminium which is extensively used in the aerospace sector. However, the impending changes in the use of Cr(VI) in Europe and the United States have forced aerospace manufacturers to examine alternative materials for protecting aluminium. One of the most promising alternatives being investigated are organosilane based sol-gels containing anticorrosion additives. In this work the anti-corrosion properties of magnesium (II) nitrate (Mg(NO 3 ) 2 ) as a inhibitor was investigated at different concentrations (0.1% -1.0 wt %) in a methyltriethoxysilane (MTEOS) sol-gel on the aluminium alloy AA 2024-T3 and compared to Alodine TM 1200 (the established Cr(VI) pre-treatment). Electrochemical evaluation of the coating system by electrochemical impedance spectroscopy (EIS) and potentiodynamic scanning (PDS) measurements correlated strongly with results obtained from Neutral Salt Spray (NSS) exposure data. The surface morphology of the coating was studied using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results indicated the optimum performance was achieved using a Mg (NO 3 ) 2 . level of 0.7% w/w. It is proposed that the superior anticorrosion properties of the Mg 2+ rich sol-gel is due to the pore blocking mechanism of insoluble Mg(OH) 2 formed during the hydrolysis process.

show abstract

Sol–gel-derived corrosion-protective coatings with controllable release of incorporated organic corrosion inhibitors

Cited by 162 publications

References 8 publications

Corrosion protection of AA 2024-T3 aluminium alloys using 3, 4-diaminobenzoic acid chelated zirconium–silane hybrid sol–gels

Corrosion protection of AA 2024-T3 aluminium alloys using 3, 4-diaminobenzoic acid chelated zirconium–silane hybrid sol–gels

Chromate replacement: what does the future hold?

Influence of magnesium nitrate on the corrosion performance of sol–gel coated AA2024-T3 aluminium alloy

Contact Info

Product

Resources

About