Preparation Of Silicone-based Nano-composite Coating And Their Anti-corrosion And Anti-fouling Properties

The marine environment is a very complicated and severe natural balance system.Therefore,the marine environment puts forward higher requirements on the surface protection and durability of metal materials.Marine corrosion and biofouling are two key ocean problems.Silicone polymer materials are widely used as protective coating materials for anticorrosion and antifouling due to their excellent properties of high and low temperature resistance,weathering resistance,aging resistance and physiological inertia.However,the application of organosilicon coatings in the field of anti-corrosion and anti-fouling still has some problems,including insufficient protection effect and limited fuctions.Therefore,we have developed a series of composited organosilicon coatings with improved anti-corrosion and anti-fouling performance by adding nano fillers.The main research contents and conclusions are summarized as follows:(1)Silanized graphene f-GNs were successfully prepared by grafting3-aminopropyl triethoxysilane(APTES)onto graphene oxide(GO).The f-GNs was added to the sulfhydryl functionalized organosilicon sol to prepare silanized graphene synergistic organosilicon sol-gel anticorrosive coating.The f-GNs were well-dispersed into the sol by dehydration and condensation with the precursor.Electrochemical and salt spray tests showed the addition of f-GNs increased the corrosion resistance of the sulfhydryl functionalized organosilicon sol-gel coating on the surface of the copper alloy effectively.The impedance modulus of the sol-gel coating doped 0.1 wt%f-GNs was 2.45×10~6 ohm cm~2,larger than that of the raw sol-gel coating.(2)A kind of hydrophilic polymer PNIPAM containing thiol group was synthesized.The nanocomposite hydrogel system consisting of the hydrophilic polymer PNIPAM and nano-silver was incorporated into the organosilicone elastomer system to obtain the organosilicon coatings with good antifouling property.The anti-fouling performance of silicone elastomer coatings is effectively improved.The anti-bacterial rate of the nanocomposited silicone coating was up to 100%.Compared with organosilicon elastomers,the adhesion of chlorella,navicular algae and phaeodactylum on the surface decreased 70%,94%and 4%,respectively.The coatings also showed better removal ability and inhibited the attachment of large marine fouling organism ability in the real sea.(3)The graphene loaded with nanoparticles silver(rGO-Ag)was prepared by solid phase reaction.The rGO-Ag and low molecular weight PDMS-OH were added to the sulfhydryl functionalized organosilicon sol to prepare nanocomposited sol-gel with anti-corrosion and anti-fouling properties.The rGO-Ag was well dispersed in organosilicon sol.PDMS-OH was crosslinked in organosilicon sol by dehydration and condensation with precursors.Electrochemical,antibacterial and anti-algal tests,the addition of rGO-Ag showed the anti-corrosion and anti-fouling properties of the organosilicon composite sol-gel coating.The impedance modulus of rGO-Ag doped PDMS/sol-gel composite coating was 1.82×10~6 ohm cm~2,which was 2 times higher than that of raw sol-gel coating.The bactericidal rate of the nanocomposited coating was 96%,and also has better resistance to bacteria/alga adhesion abilities compared with pure sol-gel coating.