Preparation, Properties And Application Of Magnetic Nanospheres

Magnetic nanomaterial is promising in many fields such as data storage,biomedicine and environmental improvement, owing to its surface which can be functionalized easily and its unique properties as magnetic material and nanomaterial.In this work, we loaded different corrosion inhibitors on the magnetic nanosphere, so that we prepared a kind of magnetic nanospheres with the ability of releasing inhibitors gradually. And then we dispersed it in the organic coating not only to protect metal from corrosion by releasing the corrosion inhibitors when stimulated by environmental situations, but also to achieve antifouling effect with the hydrophobic and nanoroughed surface by filling the magnetic nanospheres into polymer coating.By using the solvothermal method, we prepared Co Fe2O4 nanospheres with the size of about 100 nm, which had a loosen structure. BTA was loaded on Co Fe2O4 nanospheres through covalent bonds to achieve Co Fe2O4/BTA nanospheres. Then we adopted PEI to modify the surface of Co Fe2O4 nanospheres and then loaded PASP on the Co Fe2O4/PEI nanpspheres through the electrostatic reaction to get Co Fe2O4/PEI/PASP nanospheres. Using the same method, PAAS and IQAS were successively loaded on Co Fe2O4/PEI nanospheres and then we achieved Co Fe2O4/PEI/PAAS/IQAS nanospheres. The four kinds of nanospheres we obtained were all superparamagnetic and their saturation magnetization was respectively 70.0 emu/g, 65.0 emu/g, 59.5emu/g and 45.4 emu/g.Mixing Co Fe2O4/BTA, Co Fe2O4/PEI/PASP and Co Fe2O4/PEI/PAAS/IQAS nanospheres with SBS, we obtained a smooth and dense organic coating. The test results showed that, the coating doped with magnetic nanospheres were able to inhibit the anodic polarization of Cu, increase its impedance, reduce the corrosion current and then inhibit the corrosion on the copper sheet effectively. Among the three kinds of magnetic nanospheres loading the different corrosion inhibitors,Co Fe2O4/PEI/PAAS/IQAS nanospheres had the best performance in anticorrosion owing to its dual inhibitors. Mixed the Co Fe2O4/PEI/PAAS/IQAS nanospheres with SBS coating and scratched it with a knife to test the self-healing performance of the coating. The results showed that the corrosion inhibitors on or in the nanospherescould only be released by breaking down the electrostatic force with the nanospheres when stimulated by environmental situations, and then inhibited further corrosion of the metal, which showed that the nanospheres were able to repair the coating to a certain extent.By treating the glass with piranha solution and silane, the SEBS base layer and structure layer were tightly coated on the surface of glass, and then the PS-PDMS-PVMS coating doped with Co Fe2O4/PEI/PAAS/IQAS magnetic nanospheres was coated on the top, obtaining a hydrophobic and nanoroughed surface.The test results showed that the antifouling coating was nanoroughed and the water contact angle of the coating was 114.5°, which showed good performance in hydrophobicity. Compared with SEBS coating, which absorbed the protein continuously during immersing in the BSA-FITC protein solution, the PS-PDMS-PVMS coating doped with Co Fe2O4/PEI/PAAS/IQAS nanospheres didn't absorb any proteins, which showed that the coating had a good performance in antifouling obviously.