Corresponding Author

Hou-yi MA(hyma@sdu.edu.cn)


Novel diethylene triamine penta(methylene phosphonic acid) (DTPMPA)-zinc ion (Zn2+) conversion coatings with uniform blue color and excellent corrosion protection were directly formed on the cold rolled steel (CRS) substrates by immersing a CRS plate into the film-forming solutions containing the appropriate concentrations of DTPMPA and Zn2+ ion at the proper pH. In this paper, surface morphologies and elemental compositions of DTPMPA-Zn2+ conversion coatings were characterized by SEM and EDS, respectivey. The surface functional groups, chemical constituents and binding modes to the substrates were investigated by means of FTIR and XPS methods. The influences of DTPMPA concentrations and pH values on the corrosion protection properties of the DTPMPA-Zn2+ conversion coatings were studied using electrochemical impedance spectroscopy (EIS) and polarization measurements. The results revealed that DTPMPA reacted with Zn2+ ions, forming the DTPMPA-Zn2+ chelate under the coexistence condition of both substances. Moreover, the chelate would be deposited onto the CRS substrate through the cross-linking of Zn2+ ions and form three-dimensional DTPMPA-Zn2+ thin films with uniform blue color and thickness. This kind of conversion coating exhibited the best corrosion resistance performance with the protection efficiency of 91.6% when the concentrations of DTPMPA and Zn2+ ion were 0.2wt% and 0.044wt%, respectively, in the film-forming solutions at pH = 3.0.

Graphical Abstract


DTPMPA, chemical conversion coating, chelation, corrosion protection, pH, zinc ion

Publication Date


Online Available Date


Revised Date


Received Date



[1] Rani B E, Basu B B J. Green inhibitors for corrosion protection of metals and alloys: an overview[J]. International Journal of Corrosion, 2012, 2012: 1-15.

[2] Gupta R K, Birbilis N. The influence of nanocrystalline structure and processing route on corrosion of stainless steel: A review[J]. Corrosion Science, 2015, 92: 1-15.

[3] Li J, Liang C, Huang N. Effect of B-Mo-W complex inhibitor on corrosion of mild steel in 55% LiBr solution[J]. Journal of Materials Engineering and Performance, 2015, 24(11): 4456-4461.

[4] Montemor M F. Functional and smart coatings for corrosion protection: a review of recent advances[J]. Surface and Coatings Technology, 2014, 258: 17-37.

[5] Bai X, Tran T H, Yu D, et al. Novel conducting polymer based composite coatings for corrosion protection of zinc[J]. Corrosion Science, 2015, 95: 110-116.

[6] Yu T, Lin C T. Performance of in-situ phosphatizing reagents in solvent-borne paints[J]. Industrial & Engineering Chemistry Research, 1997, 36(2): 368-374.

[7] Whitten M C, Lin C T. Coating performance of polyestermelamine enamels catalyzed by an in situ phosphatizing reagent on aluminum[J]. Industrial & Engineering Chemistry Research, 1999, 38(10): 3903-3910.

[8] Neuder H, Lin C T. Chrome-free single-step in-situ phosphatizing coatings on a Ti-6Al-4V titanium alloy[J]. Journal of Coatings Technology, 2002, 74(930): 37-42.

[9] Neuder H A, Sizemore C A, Whitten M C, et al. Enhanced paint adhesion to metals using in situ phosphatizing coatings[J]. Journal of Adhesion Science and Technology, 2004, 18(1): 123-140.

[10] Tang Y A(汤永安), Yan J W(颜佳伟), Zhu F(朱凤), et al. Electrochemical behaviors of nonionic fluorosurfactant zonyl FSN self-assembled monolayers on Au(111) and An(110)[J]. Journal of Electrochemistry(电化学), 2011, 17(1): 37-42.

[11] Ma Y H(马跃辉), Wang Y(王炜), Yu D(俞丹), et al. Application of self-assembly technique in the process of metallized fabric[J]. Journal of Electrochemistry(电化学), 2008, 14(4): 422-426.

[12] Hirotsu T, Higashi T, Motoyama K, et al. Cyclodextrinbased sustained and controllable release system of insulin utilizing the combination system of self-assembly PEGylation and polypseudorotaxane formation[J]. Carbohydrate Polymers, 2017, 164: 42-48.

[13] Yuan Y, Liu Z M, Liu Z Y, et al. Photoluminescence and self-assembly of cesium lead halide perovskite nanocrystals: Effects of chain length of organic amines and reaction temperature[J]. Applied Surface Science, 2017, 405: 280-288.

[14] Mokarian-Tabari P, Senthamaraikannan R, Glynn C, et al. Large block copolymer self-assembly for fabrication of subwavelength nanostructures for applications in optics[J]. Nano Letters, 2017, 17(5): 2973-2978.

[15] Cheng J K, Yao Y G, Zhang J, et al. A simultaneous redox, alkylation, self-assembly reaction under solvothermal conditions afforded a luminescent copper(I) chain polymer constructed of Cu3I4-and EtS-4-C5H4N+ Et Components (Et=CH3CH2)[J]. Journal of the American Chemical Society, 2004, 126(25): 7796-7797.

[16] Lan Y Q, Li S L, Wang X L, et al. Self-assembly of polyoxometalate-based metal organic frameworks based on octamolybdates and copper-organic units: from CuII, CuI, II to CuI via changing organic amine[J]. Inorganic Chemistry, 2008, 47(18): 8179-8187.

[17] Adamec J, Rusnak F, Owen W G, et al. Iron-dependent self-assembly of recombinant yeast frataxin: Implications for Friedreich ataxia[J]. The American Journal of Human Genetics, 2000, 67(3): 549-562.

[18] Hasenknopf B, Lehn J M, Boumediene N, et al. Selfassembly of tetra-and hexanuclear circular helicates[J]. Jorrnal of the American Chemical Society, 1997, 119(45): 10956-10962.

[19] Hasenknopf B, Lehn J M. Trinuclear double helicates of iron (II) and nickel (II): Self-assembly and resolution into helical enantiomers[J]. Helvetica Chimica Acta, 1996, 79(6): 1643-1650.

[20] Nakajima D, Kikuchi T, Natsui S, et al. Mirror-finished superhydrophobic aluminum surfaces modified by anodic alumina nanofibers and self-assembled monolayers[J]. Applied Surface Science, 2018, 440: 506-513.

[21] Thissen P, Valtiner M, Grundmeier G. Stability of phosphonic acid self-assembled monolayers on amorphous and single-crystalline aluminum oxide surfaces in aqueous solution[J]. Langmuir, 2009, 26(1): 156-164.

[22] Andres R P, Bielfeld J D, Henderson J I, et al. Self-assembly of a two-dimensional superlattice of molecularly linked metal clusters[J]. Science, 1996, 273(5282): 1690-1693.

[23] Debono R F, Loucks G D, Manna D D, et al. Self-assembly of short and long-chain n-alkyl thiols onto gold surfaces: A real-time study using surface plasmon resonance techniques[J]. Canadian Journal of Chemistry, 1996, 74(5): 677-688.

[24] Schneider T W, Buttry D A. Electrochemical quartz crystal microbalance studies of adsorption and desorption of self-assembled monolayers of alkyl thiols on gold[J]. Journal of the American Chemical Society, 1993, 115(26): 12391-12397.

[25] Fujita M, Oguro D, Miyazawa M, et al. Self-assembly of ten molecules into nanometre-sized organic host frameworks[J]. Nature, 1995, 378(6556): 469-471.

[26] Schmuck C, Wienand W. Highly stable self-assembly in water: ion pair driven dimerization of a guanidiniocarbonyl pyrrole carboxylate zwitterion[J]. Journal of the American Chemical Society, 2003, 125(2): 452-459.

[27] MacGillivray L R, Groeneman R H, Atwood J L. Design and self-assembly of cavity-containing rectangular grids[J]. Journal of the American Chemical Society, 1998, 120(11): 2676-2677.

[28] Kim D H, Han J T, Park Y D, et al. Single-crystal polythiophene microwires grown by self-assembly[J]. Advanced Materials, 2006, 18(6): 719-723.

[29] Liu N, Chen Z, Dunphy D R, et al. Photoresponsive nanocomposite formed by self-assembly of an azobenzene-modified silane[J]. Angewandte Chemie International Edition, 2003, 42(15): 1731-1734.

[30] Fan H, Chen Z, Brinker C J, et al. Synthesis of organosilane functionalized nanocrystal micelles and their self-assembly[J]. Journal of the American Chemical Society, 2005, 127(40): 13746-13747.

[31] Gao X, Liu S, Lu H, et al. Corrosion inhibition of iron in acidic solutions by monoalkyl phosphate esters with different chain lengths[J]. Industrial & Engineering Chemistry Research, 2015, 54(7): 1941-1952.

[32] Gao X, Zhao C, Lu H, et al. Influence of phytic acid on the corrosion behavior of iron under acidic and neutral conditions[J]. Electrochimica Acta, 2014, 150: 188-196.

[33] Kiaei Z, Haghtalab A. Experimental study of using Ca-DTPMP nanoparticles in inhibition of CaCO3 scaling in a bulk water process[J]. Desalination, 2014, 338: 84-92.

[34] Nassar M Y, El-Kolaly M T, Mahran M R H. Synthesis of a 188Re-DTPMP complex using carrier-free 188Re and study of its stability[J]. Journal of Radioanalytical and Nuclear Chemistry, 2011, 287(3): 779-785.

[35] Subhashini S, Rajalakshmi R, Safina A S. Biodegradable aquatic waste-fish scales as corrosion inhibitor for mild steel in acid medium[J]. Material Science Research India, 2008, 5(2): 375-382.

[36] Mobin M, Aslam J, Alam R. Corrosion protection of poly(aniline-co-N-ethylaniline)/ZnO nanocomposite coating on mild steel[J]. Arabian Journal for Science and Engineering, 2017, 42(1): 209-224.

[37] Tozar A, Karahan I H. Structural and corrosion protection properties of electrochemically deposited nano-sized Zn-Ni alloy coatings[J]. Applied Surface Science, 2014, 318: 15-23.

[38] Devi B S, Rajendran S. Influence of henna extract on the inhibition efficiency of diethylene triamine penta(methylenephosphonic acid) DTPMP-Zn2+ system[J]. International Journal of Advances in Engineering, Science and Technology, 2011, 1(2): 111-128.

[39] Jalili M, Rostami M, Ramezanzadeh B. An investigation of the electrochemical action of the epoxy zinc-rich coatings containing surface modified aluminum nanoparticle[J]. Applied Surface Science, 2015, 328: 95-108.

[40] Shabanova I N, Chausov F F, Naimushina E A, et al. XPS characterization of new corrosion inhibitor: zinc aminophosphonate coordination complex[J]. Surface and Interface Analysis, 2014, 46(10/11): 750-753.

[41] Gonzalez Y, Lafont M C, Pebere N, et al. A synergistic effect between zinc salt and phosphonic acid for corrosion inhibition of a carbon steel[J]. Journal of Applied Electrochemistry, 1996, 26(12): 1259-1265.

[42] Syed J A, Lu H, Tang S, et al. Enhanced corrosion protective PANI-PAA/PEI multilayer composite coatings for 316SS by spin coating technique[J]. Applied Surface Science, 2015, 325: 160-169.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.