| With the global environment becoming more and more serious,water-based inorganic coating has become a development trend in the future.Silicate zinc rich coating is a kind of water-based inorganic coating,which has the characteristics of green,environmental protection,low toxicity and good corrosion resistance.However,compared with organic coatings,silicate zinc rich coatings have poor comprehensive performance,such as poor water resistance and adhesion.Moreover,the high content of zinc powder in silicate zinc rich coatings will affect the health of construction personnel and increase the cost of coating preparation.In order to improve the corrosion resistance of silicate zinc rich coatings and reduce the zinc content,graphene(Gr)/silicate zinc rich anticorrosive coatings and nano ZnO/graphene(Nano-ZnO/Gr)silicate zinc rich anticorrosive coatings were prepared,and their properties were characterized..The main contents of this paper are as follows:1.Composite of graphene was prepared by C VD method and Nano-ZnO/Gr was prepared by hydrothermal method.The morphology and structure of graphene and Nano-ZnO/Gr(Nanometer zinc oxide)were characterized by SEM,physical adsorption instrument,XRD and IR.The results show that the number of graphene layers is about 8-10,the specific surface area is 312.12 m2 g-1,The average aperture is 19.79 nm,and the micropore area is 49.45 m2 g-1;the Nano-ZnO/Gr is the physical composite of Nano-ZnO and graphene.2.Graphene/silicate zinc rich anticorrosive coating and Nano-ZnO/Gr silicate zinc rich anticorrosive coating were prepared by adding graphene and Nano-ZnO/Gr complex into silicate zinc rich coating respectively.The morphology and corrosion resistance of the coating were characterized by SEM,electrochemical test and salt spray test.The results show that the coating with zinc content of 30wt%and graphene content of 0.05wt%has best corrosion resistance in the prepared graphene/silicate zinc rich coating,the water resistance of the coating is up to 12 days,the self corrosion potential(Ecorr)is-0.577 V,the self corrosion current density(icorr)is 1.325×10-6 A/cm2,and the modulus in the low frequency region(|Z|0.01Hz)is 2.62×104 Ω·cm2,coating charge transfer resistance(Rct)is 2.91×104 Ω·cm2,the salt spray test is over 240 h.Among the Nano-ZnO/Gr salt zinc rich coatings,the coatings with 30wt%zinc and 1wt%Nano-ZnO have best corrosion resistance,the water resistance of the coating is up to 17 days,Ecorr is-0.589 V,icorr is 7.82×10-7 A/cm2,|Z|0.01Hz is 3.069×104 Ω·cm2,Rct is 3.045×104 Ω·cm2,the salt spray test is over 360 h.It can be concluded that the corrosion resistance of Nano-ZnO/Gr composite is better than that of graphene silicate zinc rich coating,and Nano-ZnO/Gr silicate zinc rich coating has good application value. |
