Fabrication Of Organic Compound Membrane On Copper And Research On Corrosion Properties In Seawater

Matal can be applied in industrial production widely, but economic loss caused bymetal corrosion over a hundred million every year reaches up to4%in GDP. Copper ismore stable and anticorrosive than common metal, and copper ion librative can sterilize.Therefore, copper can be widely used in ocean, shipping, petrochemical industry.However, its low anticorrosion properties cause damage to production and life. In order tolighten or prevent corrosion between copper and environment interface, it is prettyimportant to treat surface of copper.In this paper, octadecylamine (ODA) film has been obtained on copper substrates. Atthe same time, the surface structure of the film was characterized by scanning electronmicroscopy (SEM), energy dispersive X-ray analysis (EDX) and water contact anglemeasurement. The results show that ODA organic membrane is loose and porous, and thecontact angle slightly improved. Moreover, the potentiodynamic polarization andelectrochemical impedance spectroscopy test are used to research the anticorrosionproperties, anticorrosion theories of films are proved by equivalent circuit. The resultsshow that, ODA organic membrane improved electric capacity. The EIS results show that,the impedance of copper coated by ODA reaches to3,3000·cm2from4000·cm2, whichhints a nice anticorrosion property. The flaw of which is, the film is not tight enough tocombine to copper surface.Recent years, the discovery of DOPA provides wide field for modifing materialsueface. There are amino and catechol which may bond on many matrix. In addition, theDOPA like materials coating layers could be further modified by the strong covalentinteraction between thiol-or amine-containing molecules, which provide chance foradsorpting next film. Based on the above disadvantage of ODA, the ODA film wassteadily absorbed on copper substrate via the easily-absorbed DOPA like materials. Theformation and surface structure of the film were characterized by contact angle, SEM, andEDX. The result shows that a compact organic film was formed on copper surface. The contect angle reaches to110°,improving the hydrophobic property. The potentiodynamicpolarization and electrochemical impedance spectroscopy tests found two timeconstants,which proved that, there are twe kinds of films, one of which is poly-DOPAagents film, the other is ODA grafted. DOPA agents indeed improve adhesive propertyand condensing of the complex film. And the impedance reaches to106·cm2,improving3orders of magnitude. Therefore Cl-was inhibited so as to lighten corrosion of copper.In order to protect the matrix copper from fouling, we explore to prepare layeredpolymer membrane by ATRP method. On account of the amino contained by ATPS,which can used to be a platform to graft other group, we import monomer containingtertiary amino which have bacteriostasis. SEM and EDX are used to observe the surfacetopography, and the polymer membrane was proved to graft successfully. Anti-bacteriatexts prove that, copper with layered polymer membrane could sterilize obviously in60hours. If this method imply in seawater, metal could avoid adhesion of microorganism.And the method provides guiding significance.