Preparation And Properties Of Self-assembled Films On Copper Alloy Surface

Copper alloy is one of the most commonly used metal structural materials.Because of its excellent performance,it is widely used in various industries.However,because it is easily corroded in the atmosphere or in an acidic aqueous solution,it is of great significance to seek efficient and reasonable technology to prevent corrosion of copper alloys.Self-assembly technology has developed rapidly due to its simple preparation process,environmental protection and low cost.In this paper,?-aminotrimethoxysilane(?-APS),benzotriazole(BTA)and laboratory-made N-alkylbenzotriazole were used to prepare self-assembled molecular films on the surface of copper alloys.The effects of single factor influencing conditions on corrosion resistance were studied by electrochemical tests(potentiostatic scanning,AC impedance method),contact angle test,and scanning electron microscope(SEM).The main conclusions of the paper are as follows:(1)The optimal process conditions for self-assembly of ?-aminotrimethoxysilane on the surface of copper alloys are at pH = 12,the optimal hydrolysis temperature is 30 ° C,and the optimal hydrolysis time is 8 hours.3ml of?-aminotrimethoxysilane in 100 ml solution,the ratio of ethanol to deionized water is 20:77,the best dip coating time is 15 min,the curing temperature is 100 ° C,and the optimal curing time is 30 min.By examining the effect of single factor conditions on the corrosion resistance of the silane film,it is known that the dip coating time has the greatest effect on the corrosion resistance of the silane film within the range of the optimal process conditions.(2)Through contact angle measurement,it was found that the existence of ?-APS self-assembled film changed the surface of the copper alloy from 73 °,which was originally hydrophilic to 113 °,which was hydrophobic,thereby protecting the copper alloy.The Tafel curve and AC impedance method test showed that the corrosion resistance of copper alloy surface increased.The surface of different copper alloys was artificially corroded.The SEM observation revealed that the copper alloy surface with assembled molecular films had little effect.(3)The corrosion resistance of benzotriazole and its derivatives to copper alloys has been studied by electrochemical methods.The results show that in the same concentration of self-assemblysolution,the comparative experiment shows that benzotriazole is self-assembled for 24 hours.Both azole and N-alkylbenzotriazole are the best corrosion inhibitors for copper alloy surfaces.At the same assembly time,when the concentration of the self-assembly solution was 50 mM,benzotriazole and N-alkylbenzotriazole were most effective in protecting the surface of copper alloys.By comparing three monoalkyl organics,it is found that the longer the alkyl chain,the better the corrosion resistance.