Adsorption and protective properties of substituted sodium malonates on nickel in neutral aqueous solutions

The adsorption and protective action of sodium malonate and its alkyl derivatives (C2 and C9) on the surface of nickel in a neutral buffer solution was studied. Adsorption isotherms of malonate and its alkylderivatives on the oxidized surface of nickel were obtained and the values of free energy of adsorption 0 -DGa were determined, which lie in the range from 51 to 79 kJ/mol. The dependence of the protective effect on the hydrophobicity of alkylmalonates was revealed. The higher the hydrophobicity of the compound, the higher the protective effect. A composition of sodium malonate and laurate in a ratio of 4:1 has been developed, which has a higher protective effect than sodium malonate and laurate alone.