Conference Proceeding

Structural and morphological characterization of hybrid thin films with superhydrophobic and photoreactive dual properties

Dr. Laszlo Janovak,
University of Szeged, Hungary

Superhydrophobic surfaces, with a liquid contact angle θ greater than 150°, have important practical applications.

Dr. László Janovák is an assistant professor at the Department of Physical Chemistry and Materials Science at the University of Szeged, Hungary. He received his Ph.D. degree in polymer chemistry at the University of Szeged in 2010. Scientific fields of interest: polymer based composite materials for biomedical applications, investigation of superhydrophobic and photocatalytic hybrid surfaces. Teaching of Colloid Chemistry and Macromolecular Chemistry.

Superhydrophobic surfaces, with a liquid contact angle θ greater than 150°, have important practical applications. It is known in the literature that many efforts have been made to develop an artificial superhydrophobic surface by mimicking the lotus leaf structure. In general, to create a superhydrophobic surface, are needed a surface with low energy and a surface roughness. For a slightly hydrophobic solid surface with a water the contact angle (CA) θ>90° becomes very hydrophobic after roughening, and the CA could be higher than 150°. The second class of self-cleaning surfaces is photocatalytic coating which can chemically degrade organic materials when exposed to light, a process known as “photocatalysis” . During the photo catalytic process the irradiated photo catalyst particles (e.g TiO2 or ZnO) produce highly reactive oxygen species [such as superoxide (O2−) hydrogen peroxide (H2O2), or hydroxyl radical (˙HO). Due to these formed reactive radicals the photo catalyst particles can degrade many organic compounds and inactivate microorganisms via destroying the cell wall and the DNA. The main goal of our present work was to synthesized inorganic/ organic hybrid layers with superhydrophobic and photo reactive dual properties. The hybrid thin film consist of hydrophilicphotocatalyst particles and low surface energy poly (perfluorodecyl acrylate) fluoropolymer, because the surface free energy of the photo catalyst particles was lowered by the using of a low energy fluoropolymer binder material. The surface roughness and wetting properties of the two component hybrid layers were gently adjustable by the photo catalyst particle/ fluoropolymer ratio. According to the photo catalytic measurements the layers were shown not only photo reactive but also super hydrophobic properties. Moreover, the thin films were prepared by simply spray- coating method which is a low-cost, fast and large-scale film forming technique. These dual superhydrophobic and photoreactive coatings with selective surface wetting properties are very attractive in different applications.

Published: 27 April 2017