This Is AuburnElectronic Theses and Dissertations

Surface engineering of multi-functional coatings to enhance the electrochemical performance




Lin, Mao-Chia

Type of Degree

PhD Dissertation


Chemical Engineering


The electrochemical behavior of functionalized composite for surface engineering and its application is described in this dissertation. The research work includes electropolymerization, microwave synthesis, characterization, and examination of prepared materials. Corrosion is a spontaneous procedure and unpreventable. The hexavalent chromate Cr6+ had been a promising corrosion inhibitor and the very first application can be tracked back to 1915. However, due to the negative impact on the environment and health, the use of the chromate compound had been limited. Therefore, searching for alternative materials to replace the hexavalent chromate Cr6+ becomes very important. Among the abundance of potential materials, conducting polymer attracts attention because of its unique characteristics. The electrodeposition of polypyrrole onto copper and aluminum alloy was achieved by potentiostatic electropolymerization in the first section. In the first project, the passivation ability of oxalic acid and sodium salicylate for copper was studied, and then the corrosion protection efficiency. In addition, in order to improve the binding ability of the polypyrrole film, tannic acid was introduced as the adhesion promoter into the electropolymerization process. The effect of tannic acid was demonstrated by promoting adhesion from 0B to 3B and improving the corrosion protection efficiency by 30 %. A coating with good adhesion can prevent the delamination of the protective layer and restrict the spread of the corrosive ions. The best result from each dopant was incorporated with tannic acid for improving the adhesion and anti-corrosion performance. For the second project, the aluminum alloy was investigated by the same process and intended to investigate the effect of dopants that contains the sulfonate group for electropolymerization of polypyrrole. The results illustrated that surfactant-liked dopants facilitated electrodeposition. In addition, the dopant with a larger chemical structure provided better protection efficiency. The application of a spray paint topcoat to the entire system can result in even better protection performance. This is because the topcoat acts as a barrier, effectively preventing the penetration of aggressive ions. In 2020, the outbreak of COVID-19 blows the whole world heavily. While people are taking measures to protect themselves from getting infected by a virus, it is also essential to improve the ability to detect the virus in people who may already be infected but are not showing symptoms. Early detection of the virus can help to prevent the further spread of the virus by allowing infected individuals to receive proper medical care and quarantine measures. This can also help identify potential outbreaks and take appropriate measures to prevent them from spreading further. So, improving the ability to detect the virus is an important aspect of managing and controlling the spread of infectious diseases. The third project focused on the development of a DNA biosensor for the detection of COVID-19. We utilized a hybrid material made from ZnS and graphene, which was prepared using a non-equilibrium heating approach based on microwave technology. The biosensor was then tested using synthetic DNA samples as well as standard samples of the SARS-CoV-2 virus. The results of the study showed that the ZnS/G hybrid material was highly effective in detecting low concentrations of the virus. The biosensor was also found to be highly sensitive, meaning it could accurately detect even small amounts of the virus. The use of microwave-based synthesis techniques allowed for the creation of a highly efficient biosensor that could be used for early and accurate detection of COVID-19. This research has potential implications for the development of improved methods for diagnosing and monitoring infectious diseases.