ساخت و مشخصه يابي پوشش نانوكامپوزيتي PDMS-SiO2-CuO بر فولاد زنگ نزن و ارزيابي رفتار آبگريزي آن

Preparation and Characterization of PDMS-SiO2-CuO Nanocomposite Coating on Stainless Steel and Its Super-hydrophobicity Property

براي افزايش مقاومت به اكسيداسيون و خوردگي داغ فولاد ها مي توان عناصر مختلفي از جمله آلومينيوم، كروم، سيليسيم، تيتانيوم و يا تركيبي از آنها را روي سطح نفوذ داد. در اين تحقيق با استفاده از فرايند سمانتاسيون فشرده پوشش هم زمان آلومينيوم- تيتانيوم روي زيرلايه فولاد زنگ نزن فريتي 430 AISI ايجاد شد. پوشش توسط ميكروسكوپ الكتروني روبشي (SEM) و پراش پرتو ايكس (XRD) مورد بررسي قرار گرفت. پوشش حاصل شامل دو لايه به ضخامت حدود 14 ميكرومتر بود. نتايج آزمون پراش پرتو ايكس وجود فازهاي FeTi، 2TiO، AlTi، Ti3Al و Ti5Al را نشان داد. اكسيداسيون هم دما و اكسيداسيون سيكلي در دماي 1000 درجه سانتي گراد روي نمونه هاي بدون پوشش و پوشش دار انجام شد. نتايج اكسيداسيون هم دما و سيكلي نشان داد پوشش نفوذي آلومينيوم- تيتانيوم باعث بهبود مقاومت به اكسيداسيون فولاد زنگ نزن فريتي 430 AISI شد.

With the advances in the development of biomaterials for tissue replacement, the attention of scientists has been focused on the improvement of clinical implant properties. In this regard, despite the appropriate properties of the stainless steel, the application of stainless steel as implants has been limited due to the weak corrosion resistivity. The purpose of this paper was preparation and characterization of hydrophobic polydimethylsiloxane (PDMS)-SiO2-CuO nanocomposite coating on the 316L stainless steel surface. The 316L stainless steel was coated by SiO2 nanoparticles (20 wt. %), CuO nanoparticles (0.5, 1 and 2 wt. %) and biocompatible PDMS. In this research, x-ray diffraction (XRD) and scanning electron microscopy (SEM) were applied to characterize the coating. Moreover, the roughness and water contact angle of the coatings consisting of various amounts of CuO nanopowder were estimated. Finally, the effects of various amounts of the CuO nanopowder on the corrosion resistivity of nanocomposite coatings were investigated. XRD patterns confirmed the presence of crystalline CuO nanoparticles on the substrate. Due to the non-crystalline nature of silica nanoparticles and the semi-crystalline PDMS polymer, no peak confirming the presence of these phases was detected on the XRD pattern of the nanocomposite coating. SEM images showed the formation of a lotus leaf-like layer on the surface of the nanocomposite coating containing 1 and 2 wt. % CuO. Moreover, water contact angle evolution revealed that while contact angle was 81 degree without CuO nanoparticles, it was enhanced to 146 degree in the presence of 1 wt. % CuO. Moreover, the corrosion study showed the nanocomposite containing 2 wt.% CuO had the best corrosion resistance, the corrosion current density of 2.1E-7 A.cm-2, and the corrosion potential of 0.22 V.