Electrochemical Synthesis of Polycarbazole and ZnO Doped Polycarbazole on Stainless Steel Surface and Investigation of Corrosion Performances

Öz

In this study, ZnO doped polycarbazole (PCz-ZnO) films were obtained by electropolymerization of carbazole (Cz) monomer in the presence of different concentrations of ZnO on the surface of 304 stainless steel (304-SS). Electropolymerization process was carried out using cyclic voltammetry method in the potential range of 0.3 V to 1.4 V, at 50 mVs-1 scan rate by applying 10 cycles in acetonitrile (ACN) solution containing Cz, ZnO and tetra butyl ammonium perchlorate (TBAP). PCz films were doped with three different amounts of ZnO (0.01%, 0.05%, 0.10%). In order to determine the optimum ZnO amount, the potentiodynamic polarization curves recorded for PCz-ZnO films in 1 M H2SO4 medium were compared and it was determined that the 0.05% ZnO doped PCz films showed the best corrosion performance. The structures of the 0.05% ZnO doped PCz-ZnO films were characterized by ATR-FTIR and SEM, and the corrosion performances of these films were investigated via variation of the open circuit potential with time (Eocp-t) curves, potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) methods in 1 M H2SO4 solutions and compared with the data of undoped PCz. It was determined that the corrosion performance of polymer-coated stainless steels, which were monitored for 168 hours with EIS, started to decrease after 72 hours, but ZnO doped polycarbazole showed improvement at 120 hours.

Anahtar Kelimeler

• Corrosion
• Polycarbozale
• ZnO
• Steel
• Conducting polymer
• Electropolymerization.

Polikarbazol ve ZnO Katkılı Polikarbazolün Paslanmaz Çelik Yüzeyinde Elektrokimyasal Sentezi ve Korozyon Performanslarının Araştırılması

Öz

Bu çalışmada karbazol (Kz) monomerin farklı derişimlerde ZnO varlığında 304 paslanmaz çelik (304-PÇ) yüzeyinde elektropolimerizasyonu ile ZnO katkılı polikarbazol (PKz-ZnO) filmleri elde edilmiştir. Elektropolimerizasyon işlemi Kz, ZnO ve tetra bütil amonyum perklorat (TBAP) içeren asetonitril (ACN) çözeltisi içerisinde dönüşümlü voltametri yöntemi ile 0,3 V ile 1,4 V potansiyel aralığında, 50 mVs-1 tarama hızında 10 döngü alınarak gerçekleştirilmiştir. Üç farklı miktarda (%0,01, %0,05, %0,10) ZnO ile PKz filmleri katkılanmıştır. Optimum ZnO miktarını belirlemek amacıyla elde edilen PKz-ZnO filmlerinin 1 M H2SO4 ortamında kaydedilen potansiyodinamik polarizasyon eğrileri karşılaştırılmış ve %0,05 oranında ZnO katkılı PKz filmlerinin en iyi korozyon performansını gösterdiği belirlenmiştir. %0,05 ZnO katkılı PKz-ZnO filmlerinin yapıları ATR-FTIR ve SEM ile karakterize edilerek bu filmlerin korozyon performansları 1 M H2SO4 ortamında açık devre potansiyelinin zamanla değişimi (Eocp-t) eğrileri, potansiyodinamik polarizasyon (PP) ve elektrokimyasal empedans spektroskopisi (EIS) yöntemleri ile incelenerek katkılanmamış PKz’nin verileri ile karşılaştırılmıştır. EIS ile 168 saat izlenen polimer kaplı paslanmaz çeliklerin korozyon performanslarının 72. saatten sonra azalmaya başladığı ancak ZnO katkılı polikarbazolün 120. saatte tekrar iyileşme gösterdiği saptanmıştır.

Anahtar Kelimeler

• Korozyon
• Polikarbazol
• ZnO
• Çelik
• İletken Polimer
• Elektropolimerizasyon.

Kaynakça

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