EFISIENSI INHIBITOR PADA KOROSI Cu-37Zn

Abstrak : Salah satu upaya pencegahan korosi pada logam dapat dilakukan dengan penambahan inhibitor ke dalam larutan uji. Inhibitor korosi yang dicoba adalah benzotriazol (BTAH) dan sistein (Cys). Penentuan laju korosi Cu-37Zn tanpa dan dengan adanya inhibitor korosi dilakukan secara elektrokimia dengan menggunakan teknik Electrochemical Impedance Spectroscopy (EIS). Hasil penelitian ini menunjukkan bahwa pada larutan uji dengan komposisi : 5,3 ppm Ca(NO3)2, 78 ppm NaCl dan ion sulfida sebesar 15 ppm diperoleh bahwa efisiensi benzotriazol (80 ppm) dan sistein (25 ppm) pada suhu kamar berturut-turut sebesar 40,74% dan 68,16%. Inhibitor yang di uji dalam penelitian ini teradsorpsi secara fisik pada permukaan logam Cu-37Zn dengan energi bebas adsorpsi (ΔGads) benzotriazol dan sistein berturut-turut adalah –18,53 dan –23,03 kJ/mol. Kata kunci : Inhibitor, EIS, Benzotriazol, Sistein Abstract : An effort to prevent of the corrosion can be performed by mean of inhibitor corrosion addition into the sample of water. We also investigated benzotriazole (BTAH) and cysteine (CYS) as inhibitor. The rates of corrosion Cu-37Zn in absence and presence of the corrosion inhibitor were determined by using Electrochemical Impedance Spectroscopy (EIS) technique. The obtained results were indicated that at sample of water with composition of 5.3 ppm Ca(NO3)2, 78 ppm NaCl and 15 ppm sulfide ion,  the inhibitor efficiency of benzotriazole (80 ppm) and cysteine (25 ppm) at room temperature were 40.74% and 68.16% respectively. Since both inhibitors were physicaly adsorbed on Cu-37Zn with adsorption free energy (ΔGads)of benzotriazole and cysteine is –18.53 kJ/mol and –23.03 kJ/mol respectively. Keywords : Inhibitor, EIS, Benzotriazole, cysteine.