The purpose of this independent study is to continue the research on the wettability of graphene. Since all previous research were done in ambient conditions and in short period, this research filled the gaps by analyzing how the contact angle of graphene varies with respect to temperature and environment over long term. In this experiment, Wilhelmy plate method was used. A glass sample was inserted into five liquids: water, glycerol, hexadecane, diiodomethane, and ethanol glycol; the interfacial tension of each liquid was calculated from 25-85 degree celsius and a temperature-interfacial tension relationship for each liquid was derived. Afterwards, the graphene sample was inserted into liquids using the same method, and a temperature-contact angle relationship was derived for each liquid. Since experimental interfacial tensions in water at different temperature corresponds to theoretical values, we assumed our experimental method was accurate. The results showed that contact angles of graphene in water and glycerol did not vary too much with time. Contact angles of graphene in hexadecane were zero, but the advancing contact angles in diiodomethane were in a decreasing tendency. Due to the time constraints, the experiment on ethanol glycol has not been finished. Our next steps will be finishing all experiments and deriving a surface energy equation for graphene.
Mechanical Engineering and Material Sciences Independent Study
Date of Submission
Zhang, Shuhan and Weisensee, Patricia, "Characterize the Wettability of Graphene" (2019). Mechanical Engineering and Materials Science Independent Study. 101.