Synthesis of Lithium-exchange Silica Particles for Corrosion Protection of Aluminum Alloys

• Published in: E-journal of surface science and nanotechnology 2020/07/23, Vol.18, pp.239-248
• Main Authors: Thai, Thu Thuy, Trinh, Anh Truc, Pham, Thi Thanh Tam, Nguyen, Xuan Hoan, Pham, Gia Vu, To, Thi Xuan Hang
• Format: Article
• Language: English
• Subjects: Aluminum alloy; EIS; Inhibitor; Ion-exchange silica; Lithium
• ISSN: 1348-0391; 1348-0391
• DOI: 10.1380/ejssnt.2020.239

This study focuses on the synthesis of lithium-exchange silica (Si/Li) particles and their corrosion protection for aluminum alloy substrates. Silica is synthesized via a sol-gel method as a raw material to prepare Si/Li in a saturated lithium nitrate solution. The obtained samples are characterized by X-ray diffraction, field emission scanning electron microscopy, zeta potential measurements, Fourier transform infrared spectroscopy, and inductively coupled plasma mass spectroscopy. Inhibition properties of synthesized Si/Li are investigated by electrochemical impedance spectroscopy (EIS). The results show that Si/Li prepared in the saturated lithium nitrate solution has a high content of loaded lithium. This amount relates to a high and stable corrosion protection of Si/Li in the electrolyte solution for the aluminum alloy substrate. After 96 h of immersion in the electrolyte solution, electrochemical results show a high value of an inhibition efficiency up to 98%. Water-based epoxy coatings containing Si/Li are also prepared to highlight their corrosion protection efficiency for the aluminum alloy substrate. Concerning the EIS measurement results, the coating containing 5 wt% Si/Li shows high and stable barrier properties for a long immersion time in the protection of the aluminum alloy substrate.