رسائل دكتوراة
English
2021
Development of Functionalized Graphene Oxide Based Corrosion Inhibitors for Oil Field Applications
Tawfik A. Saleh, هارونا كبيرو
كلية الكيميائيات والمواد-جامعة الملك فهد للبترول والمعادن · السعودية
In this study we have synthesized a series of functionalized graphene oxide-based composites with carboxylates, amines, hydroxyls, etc. attached to graphene nanosheets. The proposed functionalized graphene-based composites were characterized using different techniques including FTIR, Raman, TGA, and TEM techniques. The materials were investigated for use as corrosion inhibitors for carbon steel corrosion in oil field (Acidizing & CO2 saturated NaCl) corrosive environments using the weight loss (gravimetric), electrochemical experimental techniques combined with surface analytical techniques such as FTIR, SEM, AFM and XPS. The effect of concentration, temperature and time on the performance of the inhibitor was investigated in this study. Surface enhanced Raman scattering (SERS) using silver nanoparticles was also utilized to investigate the adsorption and adsorption behaviour of some of the studied compounds with concentration. And computational tools were utilized to estimate the relative stability of functionalized GOs to GO and to further understand the nature of the inhibitors interactions with the steel surface so as to gain more insight into the adsorption mechanism of the studied compounds onto the steel surface. All the studied compounds showed excellent efficiency at all the studied temperatures and immersion time. Most of the compounds acted as mixed-type inhibitors, according to the PDP measurement. The studied compounds were observed to obey the Langmuir adsorption isotherm. SEM/EDS, AFM, FTIR and XPS examinations of the steel surface after 24 hours’ immersion in the blank and inhibited solutions confirmed the adsorption of the compounds to the steel surface, forming protective layers that protected the steel surface from the corrosive media aggressive attack. The TGA analysis reveals the functionalized GOs to exhibit a greater stability than GO. SERS intensity showed excellent correlation with the weight loss and electrochemical results. Results from computational analysis indicates that the molecules get adsorbed to the steel surface majorly via an interaction between the steel surface and aromatic rings of the GO moiety. The theoretical results affirm the results obtained from the experimental study, especially the TGA, TEM and PDP results. Because the GO was made from waste graphite powder, this research is important in addressing two major environmental issues: corrosion and waste disposal.