Application of acoustic levitation for the investigation of hydrogels

This thesis is written as a requirement of the “Mechanical Engineering” Bachelor program at Vietnamese-German University. It reports the content of my working progress at the Ruhr University Bochum and the Fraunhofer UMSICHT during the last exchange semester of the program in Germany.
A lot of research has been carried out to investigate the sol-gel processing of hydrogel, but most of them are conducted in ambient condition. Thus, the studies about the transition under pressurized carbon dioxide are not broadly accessible. Moreover, the effect of different factors such as temperature, pH value of the solution, and type of catalyst, etc on gelation time under mentioned environment is not widely available. This thesis provides a possible method for the investigation of the gelation time in the sol-gel processing under high temperature and pressure CO2 environment. The acoustic levitation technology can support the study; nonetheless, the investigation is unachievable with the current setup of the levitator at Ruhr University Bochum because of the gelation. To perform the determination of gelation point, a guideline is created to modify and improve the levitator. Then, this thesis creates a list of requirements and classifies the requirements according to the guideline. After that, possible solutions are generated with their disadvantages and advantages. Finally, the most optimal solution is chosen based on their pros and cons with explanation.