Titanium dioxide micro-nanocontainers, corrosion-resistant waterborne epoxy coating and preparation method thereof
A titanium dioxide micro-nanocontainers, corrosion-resistant waterborne epoxy coatings and preparation method thereof, including preparation steps as follows: TiO 2 micro-nano spheres are synthesized by applying hydrothermal method; a polyaniline layer doped with molybdate ions is deposited on the surface of TiO 2 micro-nano spheres by adopting the method of in-situ chemical polymerization, TiO 2 /PANI-MoO 4 2− micro-nano-spheres are obtained, then, polydopamine is encapsulated on the surface of TiO 2 /PANI-MoO 4 2− micro-nano spheres to obtain titanium dioxide micro-nanocontainers; next, antirust filler, defoamer, dispersant and thickener are added into waterborne epoxy emulsion, then titanium dioxide micro-nanocontainers are added in the waterborne epoxy emulsion for dispersing and grinding, filtering and encapsulating to obtain component A; the waterborne epoxy curing agent and deionized water are mixed in proportion to obtain component B; component A is stirred, then it is mixed with the component B in proportion, corrosion-resistant waterborne epoxy coatings is obtained. According to the invention, the titanium dioxide micro-nanocontainers is synthesized and added into the coating as an additive, which can not only improve the compatibility between the filler and the emulsion, but greatly improves the long-term corrosion resistance of the coating by prolonging the release time of the corrosion inhibitors.
1. A preparation method of titanium dioxide micro-nanocontainers doped with molybdate corrosion inhibitors, including three preparation steps as follows:
step 1, synthesizing TiO 2 micro-nano spheres by using the hydrothermal method, specifically comprising:
dissolving ammonium fluoride in ultrapure water to obtain an ammonium fluoride solution, next, using TiCL as titanium source, slowly dropping it into the ammonium fluoride solution, then pouring the mixture into a hydrothermal reactor, carrying out reaction at 150-170° C. for 4-8 h, centrifuging the reaction product after cooling it to room temperature, washing and drying the centrifuged product to obtain TiO 2 micro-nano spheres;
step 2, depositing a polyaniline layer doped with molybdate ions on the surface of TiO 2 micro-nano spheres by using the in-situ polymerization method, obtaining TiO 2 /PANI-MoO 4 2− micro-nano spheres, specifically comprising:
adding TiO 2 micro-nano spheres, sodium dodecyl sulfate, molybdate and aniline into water, mixing and dissolving the materials to obtain a mixed solution, then, slowly dripping ammonium persulfate into the mixed solution in an ice bath environment, and stirring the mixed solution while dripping until the color of the solution changes from white to dark green, completing in-situ polymerization of polyaniline and dope of MoO 4 2− on the surface of TiO 2 micro-nano spheres, carrying out complete reaction, washing and drying the reacted material to obtain TiO 2 /PANI-MoO 4 2− micro-nano spheres;
step 3, encapsulating polydopamine on the surface of TiO 2 /PANI-MoO 4 2− micro-nano spheres, obtaining titanium dioxide micro-nanocontainers doped with molybdate corrosion inhibitors, specifically comprising:
adding dopamine and TiO2/PANI-MoO42− micro-nano spheres into Tris-HCl buffer solution to obtain a mixture, stirring the mixture for reaction for 8-14 h, centrifugal washing and drying the reaction product to obtain polydopamine modified titanium dioxide micro-nanocontainers.