Noble Metal Nanoparticles Prepared by Metal Sputtering into Glycerol and their Grafting to Polymer Surface

This chapter summarizes the basic information about elementary characteristics and technology of preparation of noble metal nanoparticles. The introduction gives some basic information on the history of development in this area, especially in terms of dimensionality of metal nanostructures and their possible applications.The first subsection is devoted to the preparation and characterization of Au, Ag, Pt, and Pd nanoparticles (NPs), which were synthesized by direct metal sputtering in liquid propane-1,2,3,-triole (glycerol). This method provides an interesting alternative to time-consuming, wet-based chemical synthesis techniques. Moreover, the suggested technique allows targeted variation of metal nanoparticle size, which is demonstrated in detail in case of AuNPs by variation of capturing media temperature. Nanoparticle size and shape were studied by transmission electron microscopy and dynamic light scattering. Optical properties of nanoparticle solution were determined by measuring its UV–Vis spectra. Concentration of metal nanoparticles in prepared solutions was determined by atomic absorption spectroscopy. Antibacterial properties were tested against two common pollutants (Escherichia coli, a Gram-negative bacteria, and Staphylococcus epidermidis, a Gram-positive bacteria). In the presence of Ag nanoparticles, the growth of E. coli and S. epidermidis was completely inhibited after 24 h. Any growth inhibition of E. coli was observed neither in the presence of “smaller” (4–6 nm, AuNP4–6) nor “bigger” (9–12 nm, AuNP8–12) AuNPs during the whole examination period. AuNP4–6, but not AuNP8–12, was able to inhibit the growth of. S epidermidis. We also observed significant difference in biological activities of Pt and PdNPs. More specifically, PdNPs exhibited considerable inhibitory potential against both E. coli and S. epidermidis, which was in contrast to ineffective PtNPs. Our results indicate that Ag, Pd, and partially AuNPs have high potential to combat both Gram-positive and Gram-negative bacterial strains.The second subsection describes the effort to anchor metal nanoparticles onto polyethyleneterephthalate (PET) carrier. Two different procedures of grafting of polymeric carrier, activated by plasma treatment, with Au and AgNPs are described. In the first procedure, the PET foil was grafted with biphenyl-4,4’-dithiol (BPD) and subsequently with Au and AgNPs. In the second one, the PET foil was grafted with Au and AgNPs previously coated by the same BPD. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and electrokinetic analysis were used for characterization of the polymer surface at different modification steps. Au and AgNPs were characterized by UV–Vis spectroscopy. In case of both types of nanoparticles, the first procedure was found to be more effective. It was proved that the BPD was chemically bonded to the surface of the plasma-activated PET and it mediates subsequent grafting of the AuNPs

Proceedings of the 12th International Conference on Kinanthropology

Proceedings of the 12th Conference of Sport and Quality of Life 2019 gatheres submissions of participants of the conference. Every submission is the result of positive evaluation by reviewers from the corresponding field. Conference is divided into sections – Analysis of human movement; Sport training, nutrition and regeneration; Sport and social sciences; Active ageing and sarcopenia; Strength and conditioning training; section for PhD students

Legal Regulation of Taxes and Charges Relating to Various Types of Lottery Prizes

Department of Financial Law and FinancesKatedra finančního práva a finanční vědyFaculty of LawPrávnická fakult

Surface Modification of Polymer Substrates for Biomedical Applications

While polymers are widely utilized materials in the biomedical industry, they are rarely used in an unmodified state. Some kind of a surface treatment is often necessary to achieve properties suitable for specific applications. There are multiple methods of surface treatment, each with their own pros and cons, such as plasma and laser treatment, UV lamp modification, etching, grafting, metallization, ion sputtering and others. An appropriate treatment can change the physico-chemical properties of the surface of a polymer in a way that makes it attractive for a variety of biological compounds, or, on the contrary, makes the polymer exhibit antibacterial or cytotoxic properties, thus making the polymer usable in a variety of biomedical applications. This review examines four popular methods of polymer surface modification: laser treatment, ion implantation, plasma treatment and nanoparticle grafting. Surface treatment-induced changes of the physico-chemical properties, morphology, chemical composition and biocompatibility of a variety of polymer substrates are studied. Relevant biological methods are used to determine the influence of various surface treatments and grafting processes on the biocompatibility of the new surfaces—mammalian cell adhesion and proliferation is studied as well as other potential applications of the surface-treated polymer substrates in the biomedical industry

Testing the applicability of LDPE/HNT composites for cable core insulation

Composites prepared from low-density polyethylene (LDPE) and tubular halloysite nanotubes (HNTs) with different contents of HNTs were comprehensively tested. HNTs were utilized to suppress the intensity of heat release from the ignition of LDPE. The results revealed that the large polarity discrepancies and high levels of chemical inertness of LDPE and HNTs led to a reduced level of HNT dispersion in the polymer matrix. Nevertheless, even for small quantities of HNTs, differential scanning calorimetry (DSC) confirmed the decrease in the intensity of heat release during the LDPE/HNT thermal decomposition. Mechanical tests demonstrated that the presence of HNTs did not significantly influence the yield strength but did contribute to toughening of the LDPE matrix. Measurement of the dielectric properties revealed that the presence of HNTs also contributes to an increase in the number of permanent dipoles and charge carriers. However, the non-polar nature of the LDPE matrix can effectively suppress this disadvantage

Laser-Processed PEN with Au Nanowires Array: A Biocompatibility Assessment

Although many noble metals are known for their antibacterial properties against the most common pathogens, such as Escherichia coli and Staphylococcus epidermidis, their effect on healthy cells can be toxic. For this reason, the choice of metals that preserve the antibacterial effect while being biocompatible with health cells is very important. This work aims to validate the effect of gold on the biocompatibility of Au/Ag nanowires, as assessed in our previous study. Polyethylene naphthalate (PEN) was treated with a KrF excimer laser to provide specific laser-induced periodic structures. Then, Au was deposited onto the modified PEN via a vacuum evaporation method. Atomic force microscopy and scanning electron microscopy revealed the dependence of the surface morphology on the incidence angle of the laser beam. A resazurin assay cytotoxicity test confirmed safety against healthy human cells and even cell proliferation was observed after 72 h of incubation. We have obtained satisfactory results, demonstrating that monometallic Au nanowires can be applied in biomedical applications and provide the biocompatibility of bimetallic Au/AgNWs

Cytocompatibility of Plasma and Thermally Treated Biopolymers

This paper is focused on the surface characterization of plasma and consequently thermally treated biocompatible polymers. PLLA (poly(L-lactide acid) and PMP (poly-4-methyl-1-pentene) are studied. The influence of Ar plasma treatment on the surface polarity of substrate measured immediately after treatment and during the polymer surface aging is studied. Surface roughness, morphology, wettability, and surface chemistry were determined. Plasma treatment leads to significant changes in PLLA surface morphology and chemistry, with the PMP being slightly affected. The higher resistance to plasma fluence results in smaller ablation of PMP than that of PLLA. The plasma treatment improves cell adhesion and proliferation on the PMP. Plasma treatment of PLLA influences mostly the homogeneity of adhered and proliferated VSMC