Dr. Laszlo Janovak

Dr. Laszlo Janovak |Clyto Access

University of Szeged, Hungary




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.



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


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 [1]. 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” [2]. During the
photocatalytic process the irradiated photocatalyst 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 photocatalyst particles can degrade
many organic compounds [2] and inactivate microorganisms via destroying the cell wall and
the DNA [3].

The main goal of our present work was to synthetized inorganic/ organic hybrid layers
withsuperhydrophobic and photoreactive 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 photocatalyst 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 photocatalyst
particle/ fluoropolymer ratio. According to the photocatalytic measurements the layers were
shown not only photoreactive but also superhydrophobic properties. Moreover, the thin films
were prepared by simply spray- coating method which is a low-cost, fast and large-scale filmforming
technique. This dual superhydrophobic and photoreactive coatings with selective
surface wetting properties are very attractive in different applications.


Related Conferences :

World Summit on Nanotechnology and Nanomedicine Research