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Prague, Czech Republic

Benkocka M.,J.E. Purkyne University in Usti nad Labem | Knapova T.,J.E. Purkyne University in Usti nad Labem | Braborec J.,J.E. Purkyne University in Usti nad Labem | Matousek J.,J.E. Purkyne University in Usti nad Labem | And 4 more authors.
Chemicke Listy

In this work we studied surface properties of different modified substrates, polymers, glass and silicates. Polymers and glass were firstly activated by Piranha solutions. Activated surfaces of polymers and glass and nonactivated silicates were grafted by amino-compounds and subsequently with borane compounds, one of them being highly fluorescent (B18H22). Surface properties were characterized by X-ray photoelectron spectroscopy, goniometry, electrokinetic analyses and fluorescent spectroscopy. © 2015, Libertas Academica Ltd. All rights reserved. Source

Leitner J.,Ustav inzenyrstvi pevnych latek
Chemicke Listy

Nanomaterials, which in the last two decades penetrated into almost all fields of human activity (new engineering materials, electronics, optoelectronics, communication and information technologies, catalysis, energy conversion and energetics, pharmaceuticals, biomaterials, medicine, ecology), have been the focus of scientific interest for more than hundred years. These materials usually show the physical properties that are quantitatively and qualitatively different from their bulk counterparts. The melting temperature, which is considered a function of size and shape of particles, ranks among essential physicochemical characteristics of solids. Some methods commonly used for determination of the melting point of nanoparticles are briefly described. Various theoretical concepts are introduced (cohesive energy and its relationship to melting temperature, the Lindemann melting theory, solid-liquid phase equilibria) on the basis of which relations between the melting temperature and spherical particle size can be derived. The results of predictions for nanoparticles are compared with experimental data. Source

Reznickova A.,Ustav inzenyrstvi pevnych latek | Novotna Z.,Ustav inzenyrstvi pevnych latek | Kolska Z.,J.E. Purkyne University in Usti nad Labem | Ulbrich P.,Ustav biochemie a mikrobiologie | Svorcik V.,Ustav inzenyrstvi pevnych latek
Chemicke Listy

This review provides an insight into the history of syntheses, functionalizations and applications of noble metal nanoparticles examining their interactions with polymer substrate. A survey of rapidly expanding literature on this topic is presented. The most challenging problems are outlined, among them finding new chemical and physical methods of functionalizing noble metal nanoparticles with compounds that can promote efficient binding and clearance. In addition, we present two procedures of grafting Au and Ag nanoparticles onto plasma-treated poly(ethylene terephthalate) (PET). The changes in the surface physicochemical properties of modified PET, caused by plasma treatment and grafting with a dithiol and Au and Ag nanoparticles, were examined by TEM/ HRTEM, AFM, UV-Vis and XPS spectrometries and by electrokinetic analysis. We achieved a higher concentration of Au and Ag nanoparticles by deposition on PET modified with dithiol. The studied polymers can be used in medicine as a prevention of bacterial film formation. © 2014, Czech Society of Chemical Engineering. All rights reserved. Source

Siegel J.,Ustav inzenyrstvi pevnych latek | Staszek M.,Ustav inzenyrstvi pevnych latek | Svorcik V.,Ustav inzenyrstvi pevnych latek
Chemicke Listy

This review summarizes basic information on some characteristics of metallic nanostructures with special emphasis on noble metal nanoparticles, basic information on the development in this field, especially on the size of metal nanostructures and their possible applications. The review is devoted to the techniques of preparation and characterization of Au and Ag nanoparticles (AuNPs, AgNPs) deposited in liquid media. In addition, the antibacterial effects of aqueous solutions of metal nanoparticles on selected bacterial strains (E. coli, S. epidermidis). While AgNP4–6 completely inhibited both bacterial strains after 24 h, AuNPs exhibited pronounced inhibition selectivity regarding the specific nanoparticle size. Regardless of the AuNP size, no growth inhibition of E. coli occurred. In contrast, AuNP4–6 showed the ability to inhibit the growth of S. epidermidis. © 2014 Czech Society of Chemical Engineering. All Rights reserved. Source

Slepicka P.,Ustav inzenyrstvi pevnych latek | Siegel J.,Ustav inzenyrstvi pevnych latek | Lyutakov O.,Ustav inzenyrstvi pevnych latek | Svorcik V.,Ustav inzenyrstvi pevnych latek
Chemicke Listy

Two approaches to polymer surface nanostructuring by laser beam are discussed: (i) exposure of surface to a polarized excimer laser beam and (ii) scanning of doped polymer surface by a semiconductor laser. The effect of laser fluence, the angle of incident laser beam and its wavelength on the nanostructure formation is described. Nanostructured polymers are used as substrates for deposition of Au nanolayers and biocompatibility studies. The properties of deposited Au nanolayers are significantly influenced by surface structure and chemical nature of the used substrate. Polymer films doped with porphyrin were irradiated with laser and simultaneously mechanically scanned. By combination of these two techniques a regular periodic pattern was formed. The structural properties depend on scanning rate and laser intensity. Nanostructured polymer surfaces are promising substrates in electronics, optics and tissue engineering. Source

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