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Wang Z.,CAS Shenyang Institute of Metal Research | Han E.,CAS Shenyang Institute of Metal Research | Liu F.,CAS Shenyang Institute of Metal Research | Shi H.,CAS Shenyang Institute of Metal Research | And 2 more authors.
Materials China

The aim of this paper is to investigate the effect of SiO2 nano-concentrate and ZnO nano-concentrate on properties of epoxy and polyurethane marine coating. The corrosion-inhibiting and anti-aging properties of composite nano-coatings used in marine environment were investigated by the salt spray test, xenon lamp aging test, ocean accelerated cycle aging test. The stable well-dispersed nano-concentrates were prepared by three-step method, and epoxy and polyurethane marine nano-coatings were modified by SiO2 nano-concentrate and ZnO nano-concentrate. The work has investigated corrosion resistance, weathering resistance and antifouling property of marine nano-coating by use of transmission electron microscopy (TEM), fourier transform infrared spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS), gloss meter and measuring instrument of surface contact angle. The FTIR analysis and viscosity measurement of SiO2 nano-concentrates and TEM observation of ZnO nano-concentrates demonstrate that the well-dispersed state of nanoparticles can be attributed to the strong steric effect of long carbon chains of polymer dispersing agent. The bonding strength of epoxy nano-coating with 1.0% SiO2 nano-concentrate increases from 4.4 MPa of epoxy coating without nano-concentrate to 5.6 MPa. The analytic results of salt spray test demonstrate that 1.0% SiO2 nano-concentrates improve the resistance of epoxy nano-coating to salt spray. The gloss measurement in the xenon lamp aging test demonstrates that gloss of polyurethane nano-coating is higher than that of polyurethane coating without nanoparticles. The C/O ratio of polyurethane coating without nano-concentrate after accelerated cycle aging test dramatically decreases 20.1% while the C/O ratio of polyurethane nano-coating with 1.2% ZnO nano-concentrate after aging test only decreases 10.7%. The measurements of gloss and surface contact angle during ocean accelerated cycle aging test indicate that 1.2% ZnO nano-concentrations greatly enhance the anti-aging and surface contact angle of polyurethane coating. In conclusion, the nano-concentrates can improve corrosion resistance and weathering resistance of nano-coatings in marine heavy corrosion environment. Source

Shi H.,Chinese Academy of Sciences | Liu F.,Chinese Academy of Sciences | Han E.,Chinese Academy of Sciences | Hao Q.,Dalian Yuxiang Science and Technology Corporation | Qiu Z.,Dalian Yuxiang Science and Technology Corporation
Materials China

Antifouling coating with low surface energy is an important branch of marine coatings. In the present work, an organosilicone modified acrylic resin was used as coating matrix and nano SiO2 was used as filler to prepare an antifouling coating with low surface energy. The effect of silicone monomer content on the properties of the modified acrylic resin was investigated. It was found that with the increase of silicone monomer content, the viscosity of the modified acrylic resin decreases, while the water contact angle of the modified acrylic resin increases. The effect of nano SiO2 content on the coating morphology and water contact angle was studied. The results show that the addition of small amount of nano SiO2 (1% and 3%) that was treated by fluorosilane can significantly increase water contact angle and improve the anti-fouling property of the coatings. The water contact angle of polyurethane coating with addition of nano SiO2 paste is higher than that of polyurethane coating with addition of fluorosilane modified SiO2, while the later is higher than that of polyurethane coating with addition of unmodified SiO2. When the contents of nano SiO2 are 1% and 3%, the water contact angles of the coatings reach 101.8°and 103°, respectively. The dispersed nano SiO2 in concentrated paste contributes to the micro-nano structure of coating surface, which benefits the anti-fouling property. Source

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