Preventing the corrosion of iron in inaccessible structures requires a coating method that reaches all surface areas and creates a uniform protective layer. An ages old practice to protect iron artefacts is to coat them with animal fat, that is, a mixture of lipids. This “method” is accidentally ingenious: some natural phospholipids found in animal fat have the potential to form a tightly packed self-assembled monolayer on metal oxide surfaces, similar to the surfactant monolayers that have attracted increasing attention lately. Thus, the most primitive corrosion prevention method may point at a way to coat complex iron structures in an industrial environment. Here the ability of phosphatidic acid, a natural lipid, to coat and protect iron surfaces was examined. Iron coated quartz crystal microbalance (QCM) sensors were used for the experiments, to monitor the deposition of the lipid as well as the acidic corrosion (dissolution) of iron in situ, in real time. The sensors were coated by self-assembled monolayers of di-myristoyl phosphatidic acid using the liposome deposition method. In this process, 50-100 nm vesicles formed by the lipid are delivered in an aqueous solution and spontaneously coat the iron surfaces upon contact. QCM and ellipsometry measurements confirmed that continuous bilayer and monolayer surface coatings can be achieved by this method. QCM measurements also confirmed that the layers were corrosion resistant in 0.01M acetic acid solution that would dissolve the thin iron layer in minutes in the absence of the protective coating. XPS results suggested a chemisorption-based mechanism of phosphatidic acid attachment to the iron surface. Hence, liposome deposition of phosphatidic acid offers a suitable solution to coat iron surfaces in inaccessible structures in situ.
If the inline PDF is not rendering correctly, you can download the PDF file here.
1. Jevremović I, Singer M, Nešić S and Mišković-Stanković V, Corrosion Science, 2013, 77, 265-272.
2. Raja PB and Sethuraman MG, Materials Letters, 2008, 62, 113-116.
3. Soliman SA, Metwally MS, Selim SR, Bedair MA and Abbas MA, Journal of Industrial and Engineering Chemistry, 2014, 20, 4311-4320.
4. Shpan’ko SP, Grigor’ev VP, Anisimova VA, Plekhanova EV and Tolpygin IE, Protection of Metals and Physical Chemistry of Surfaces, 2013, 49, 859-864.
5. El Bribri A, Tabyaoui M, Tabyaoui B, El Attari H and Bentiss F, Materials Chemistry and Physics, 2013, 141, 240-247.
6. Moussa M, El-Far A and El-Shafei A, Materials chemistry and physics, 2007, 105, 105-113.
7. Fuchs-Godec R and Dolecek V, Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2004, 244, 73-76.
8. Obot I and Obi-Egbedi N, Current Applied Physics, 2011, 11, 382-392.
9. Bouklah M, Benchat N, Aouniti A, Hammouti N, Benkaddour M, Lagrenée M, Vezin H and Bentiss F, Progress in organic coatings, 2004, 51, 118-124.
10. Babu BR and Thangavel K, Anti-Corrosion Methods and Materials, 2005, 52, 219-225.
11. Butler LN, Fellows CM and Gilbert RG, Progress in Organic Coatings, 2005, 53, 112-118.
12. Deyab MA, International Journal of Hydrogen Energy, 2013, 38, 13511-13519.
13. Qiu LG, Xie AJ and Shen YH, Corrosion science, 2005, 47, 273-278.
14. Starovoitova YV, Andreev NN, Gedvillo IA and Zhmakina AS, Protection of Metals and Physical Chemistry of Surfaces, 2009, 45, 792-795.
15. Tawfik SM and Zaky MF, Research on Chemical Intermediates, 2015, 41, 8747-8772.
16. Tamilarasan TR, Rajendran R, Rajagopal R and Sudagar J, Surface & Coatings Technology, 2015, 276, 320-326.
17. Murira CM, Punckt C, Schniepp HC, Khusid and Aksay IA, Langmuir, 2008, 24, 14269-14275.
18. Amalhay M and Ignatiadis I, Materials science forum, 1998.
19. Gao X, Liu ST, Lu HF, Gao F and Ma HY, Industrial & Engineering Chemistry Research, 2015, 54, 1941-1952.
20. Dettin M, Bagno A, Gambaretto R, Iucci G, Conconi MT, Tuccitto N, Menti AM, Grandi C, Di Bello C, Licciardello A and Polzonetti G, Journal of Biomedical Materials Research Part A, 2009, 90A, 35-45.