During her undergraduate studies in the Department of Chemical and Biological Engineering at UBC, Mirkvakili worked on superhydrophobic nano-patterned metallic interfaces under the supervision of Professors Savvas Hatzikiriakos and Peter Englezos. The introduction to superhydrophobic surfaces early in her academic career led Mirkvakili to continue working on fabricating green and sustainable hydrophobic papers as a PhD candidate. Traditionally, layers of polymer coating are combined or laminated on paper to impart water or oil repellence with high strength for packaging applications. However, this thick coating makes paper heavy and difficult to recycle. In Canada, the current recovery rate for packaging is very low with the national recycling rate of about 22%. There is a need for an alternative, more sustainable approach to preparing paper for packaging applications.
The main goal of Mirkvakili’s study is to develop a technology making superhydrophobic paper by altering and/or modifying the filler and fiber surface of handsheets to mimic the lotus leaf effect. A combination of surface roughness and low surface energy enable creation of surfaces with superhydrophobic behaviour. The cellulose fibers are naturally hydrophilic and this property enables the fiber to bond together and make the formation of paper possible. The method employed in this study was plasma enhanced chemical vapour deposition. The nanoscale roughness was created on the surface of handsheets by oxygen plasma. CF4 was then deposited on the surface of handsheets. The contact angle was increased on average from 5° to 160° after the treatment. Paper fabricated with this method proves to be more green and sustainable while maintaining water repellency. The video below showcases how water droplets react to paper fabricated by Mirkvakili’s method.