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PING Junior 2021 is organized with the support of funds for specific university research project SVK1-2021-008 and ERDF "Research of additive technologies for future applications in the machinery industry - RTI plus" (No. CZ.02.1.01/0.0/0.0/18_069/0010040). There is a great interest in the synthesis of various nanosized green reusable catalysts which would better assist various chemical reactions in wastewater technologies. Pulsed laser irradiation of iron and cobalt sulphides in different environments (FeS in water and ethanol; CoS2 in vacuum) allows laser ablation and generation of FeS, CoS2 nano/micro particles. The FeS-derived colloidal nanoparticles were absorbed onto immersed porous ceramic substrates and create solar-light photocatalytic surfaces. CoS2-based films were deposited on Ta and Cu substrate. Generated nanoparticles were analyzed using scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, high resolution electron microscopy and electron diffraction. These complementary analyses revealed that the film on Ta consists of the parent cubic CoS2 whereas the film on Cu exhibits a multiphase structure containing the cubic CoS2 and cubic Co2CuS4. In a case of FeS analysis reveal high-pressure orthorhombic FeS, cubic magnetite Fe3O4 and tetragonal maghemite γ-Fe2O3 produced in water, while those formed in ethanol contain hexagonal FeS and cubic magnetite Fe3O4. FeS-derived and CoS2-based nanoparticles were examined for their catalytic effect in Fenton degradation or photodegradation of methylene blue (MB).

PING Junior 2021 is organized with the support of funds for specific university research project SVK1-2021-008 and ERDF "Research of additive technologies for future applications in the machinery industry - RTI plus" (No. CZ.02.1.01/0.0/0.0/18_069/0010040). Laser ablation in liquids (LAL) has been developed into a simple and versatile technique producing various colloidal nanoparticles with novel properties and applications (e.g. biodetection, bioactive materials and photocatalysis). One of the typical problems faced in the bio/photo catalytic applications nanoparticles is their instability towards aggregation and the formation of larger particles, which change the catalytic properties and can even lead to inactive materials. A strong effort is therefore devoted to achieving a higher colloidal stability by various stabilizers or by suitable liquid media. However, the stabilizers are usually not environmentally friendly and freely moveable nanocatalysts can enter biogeochemical cycles and become harmful to the environment living organisms. It is therefore a novel and attractive idea to make use of the adsorption of nanoparticles on rough surfaces to bind these nanoparticles before they agglomerate in the liquid phase. In this simple way, colloidal photo/bio catalytic nanoparticles could adhere on a porous carrier, functionalize its surface. This unexplored potential of LAL we have revealed for laser ablation of FeS in water and ethanol which produces FeS-derived colloidal nanoparticles that absorb onto immersed porous ceramic substrates and create solar-light photocatalytic surfaces. The laser induced process thus offers an easy and efficient way for the functionalization of porous surfaces by photocatalytic nanoparticles that avoids aggregation in the liquid phase. Moreover, LAL induced functionalization has been found as perspective technique also for enhancing of bioactivity of titanium porous/textured surfaces. The importance of the synergy between the two disciplines: (i) chemical reactions of bone growth stimulants under LAL conditions and (ii) the functionalization of laser-shaped micro/nanotopography of titanium surface with colloidal particles generated from targets of bone growth stimulants by laser ablation in selected liquids is examined. The LAL synthesis of bioconductive colloidal particles of CaTiO3, MgTiO3 and CaSi2 allowing productivity, zeta potential, size and dispersity control through selected irradiation parameters and different liquid medium. The structure and adhesion of the nanosols to titanium surface is assessed by IR, Raman and XP spectroscopy and SEM and TEM analyses. In vitro osseointegration activity of the functionalized surfaces are evaluated by examining the growth of Messenchymal Stem cells.

Smíšené oxidy křemičito-titanové a jejich kompozity byly rozsáhle studovány, zatímco jejich protějškům oxidu titaničitého (TiO) a oxidu křemičitého (SiO) byla věnována velmi malá pozornost. Laserová ablace SiO a TiO v kapalinách je podle literatury zcela neprobádána. Tento článek popisuje Nd: YAG pulzní laserovou ablaci SiO a TiO v ethanolu, která umožňuje tvorbu nanočástic na bázi SiO a TiO a jejich aglomerátů. Smíšený koloid SiO-TiO byl připraven jednoduchým smísením jednotlivých ablativně připravených koloidů v objemovém poměru 1: 1. Měření velikosti částic pomocí dynamického rozptylu světla (DLS) určuje velikosti 24,85 nm a 262,3 nm pro koloid SiO, 494,8 nm pro koloid TiO a 35,2 nm a 397,5 nm pro směsný koloid. Hodnoty Zeta potenciálu naznačují počáteční nestabilitu pro všechny měřené systémy. Morfologie částic zachycených na substrátu Ta odpařením ethanolu byla studována pomocí skenovací elektronové mikroskopie (SEM). Byly pozorovány kulaté, oválné a listové částice a jejich aglomeráty. Ramanova spektroskopie smíšeného koloidu SiO-TiO odhalila vícefázovou strukturu sestávající se z anatasu a rutilu, krystalického a amorfního křemíku a oxidu křemičitého a krystalického a amorfního silicidu titanu TiSi2. Tvorba TiSi2 demonstruje neočekávanou nízkoteplotní disproporci druhů na bázi SiO a TiO a vzájemné redukční interakce. Katalytická aktivita jednotlivých koloidů SiO a TiO a jejich směsí byla testována pomocí degradace methylenové modři (MB) za denního světla. Směs TiO-SiO vykazuje vyšší katalytickou aktivitu vůči slunečnímu světlu ve srovnání s jednotlivými koloidy, což lze vysvětlit přítomností vysoce fotokatalytického TiSi2. Tyto výsledky představují potenciál interakcí redukujících SiO a TiO, které jsou příznivé pro generování fotokatalytických materiálů a sanaci vody. Silica–titania mixed oxides and composites have been extensively studied, whereas to the titanium monoxide (TiO) –silicon monoxide (SiO) counterparts has been devoted very little attention. Laser ablation of SiO and TiO in liquids is in according with literature completely unexplored. Here we report on Nd:YAG pulse laser ablation of SiO and TiO in ethanol which allows generation of SiO- and TiO-based nanoparticles and their agglomerates. Mixed SiO-TiO colloid has been prepared by simple mixing of ablatively prepared individual colloids in 1:1 volume ratio. Measurement of size distribution by Dynamic Light Scattering (DLS) determines sizes of 24.85 nm and 262.3 nm for SiO colloid, 494.8 nm for TiO colloid and 35.2 nm and 397.5 nm for mixed colloid. Zeta potential values suggest incipient instability for all measured systems. Morphology of the particles captured on Ta substrate by evaporation of ethanol was studied using Scanning Electron Microscopy (SEM). Round-shaped, oval, and sheet-like particles and their agglomerates have been observed. Raman spectroscopy of the mixed SiO-TiO colloid revealed multiphase structure consisting of anatase and/or rutile, crystalline and amorphous silicon and silica and crystalline and amorphous titanium silicide TiSi2. Formation of TiSi2 demonstrates unexpected low temperature disproportionation of SiO and TiO-based species and mutual reducing interactions. Catalytic activity of individual SiO and TiO colloids and of their mixture has been tested in terms of methylene blue (MB) degradation under the daylight. TiO-SiO mixture exhibits higher solar-light catalytic activity compared to individual colloids which could by explain by the presence of highly photocatalytic TiSi2. These results represent potential of SiO and TiO reducing interactions which are favorable for generation of photocatalytic materials for water remediation.

Zájem o možnosti přípravy různých oxidů zirkonia z vědeckého i aplikačního hlediska roste. Laserová ablace pevného terče sestávajícího ze slinutých zrn kovového hexagonálního Zr3O a monoklinického ZrO2 vede k odpařování Zr, O částic (iontů, atomů) a následné depozice Zr-O filmu. Jako substráty byly použity Ta a Cu. Filmy byly analyzovány pomocí SEMEDX, Ramanovy a FTIR spektroskopie a rentgenové difrakce. SEM analýza odhalila kontinuálním povlak a kruhovité objekty o velikosti μm / sub-μm. Pomocí Ramanovy spektroskopie byly detekovány široké píky, které mohou naznačovat částečnou laserem indukovanou amorfizaci Zr-O depozitu. FTIR spektroskopie ukazuje pásy, které lze přiřadit vibracím Zr-O nanostrukturovaného oxidu zirkoničitého. Rentgenová difrakční analýza poskytuje jasnější přiřazení deponovaných fází, kde depozice na Ta vykazuje přítomnost monoklinické Zr02, rhombohedrické Zr03 s nedostatkem kyslíku a zajímavě ukazuje přítomnost vysokotlaké ortorombické fáze Zr02. Povlak na Cu sestává z monoklinické Zr02, rhombohedrické Zr30 a metastabilní tetragonální Zr02 fáze. There is a growing interest about the possibilities for preparation of various zirconium oxides from scientific as well asapplication point of view. Laser ablation of solid target consisting of sintered grains of metallic hexagonal Zr3O and monoclinic ZrO2 results in evaporation of Zr, O species (ions, atoms) and subsequent deposition of Zr-O film. Ta and Cu have been used as substrates. The films were analyzed by SEM-EDX, Raman and FTIR spectroscopy and X-ray diffraction. SEM analysis revealed μm/sub-μm sized roundshape and ring-like objects on continuous coat. Using Raman spectroscopy broad peaks which can suggest partial laser induced amorphization of Zr-O deposits were detected. FTIR spectroscopy shows bands which are assignable to Zr-O vibration of nanostructured zirconia. X-ray diffraction analysis provides more explicit assignment of deposited phases where the deposit on Ta exhibits presence of monoclinic ZrO2, oxygen deficient rhombohedric Zr3O and interestingly indicates presence of high-pressure orthorhombic ZrO2 phase. The coat on Cu consists of monoclinic ZrO2, rhombohedric Zr3O, and metastable tetragonal ZrO2 phase.

PING 2019 is organized with the support of funds for specific university research project SVK1-2019-002. Despite the great progress that has been achieved in orthopedics biomaterials, fixation of implants to the bone host remains a problem. Mismatch of Young’s moduli of the biomaterials and the surrounding bone has been identified as a major reason for implant loosening following stress shielding of bone. However, the implanted material must be strong enough and durable to withstand the physiological loads placed upon it over the years. A suitable balance between strength and stiffness has to be found to the best match of bone behaviour. Titanium and its alloy (Ti6Al4V) have elastic moduli less than 50% of that commonly used Co–Cr implants so that their use helps reduce the extent of stress shielding. One consideration to achieve this has been the development of materials that exhibit substantial surface or total bulk porosity in medical applications. Moreover, bioactive surface chemical composition and suitable surface morphology on micro- and nanoscale level is necessary for efficient osseointegration. Here we report on novel concept of hierarchically functionalized titanium based biomaterials consists in (i) laser induced surface porosity, (ii) micro/messoporous bioactive glass fillers, (iii) chemical activation and/or ablative deposition of bioactive CaTiO3 nanoparticles. Prepared biomaterials were analyzed using SEM/EDX, XRD, Raman spectroscopy and test in terms of cell cultivation in order to reveal biocompatibility, cell viability and osseointegration ability.

PING 2019 is organized with the support of funds for specific university research project SVK1-2019-002. Recently, wastewater treatment has become a critical issue due to particular concerns for sustainable environment, climate change and industrial growth. There has been a need for readily available and inexpensive solutions between research and industry. Porous aluminosilicate materials based on geopolymer systems have proven their effectiveness as adsorbents, ion-exchangers, membranes, anti-microbial filters, pH buffers and stabilizers for water treatment residues. Furthermore, catalysts and/or catalyst supports for pollutant degradation in liquid phase reactions have been studied. High permeability, surface area, chemical resistance and mechanical strength are essential for these applications. Here we present a facile synthesis routes based on replica technique and sol-gel pipetting of highly porous substrates with open cells and water-floatable spherical beads with closed porosity. Characterization of prepared structures was performed with respect to their porous architecture, surface properties and mechanical integrity. Scanning electron microscopy (SEM) and micro-computed tomography (micro CT) revealed the relationship between the inner/outer structure and the open/closed porosity ratio. Thermal behavior was studied by thermogravimetric (TGA) and differential thermal analysis (DTA) up to 1000 °C and 1300 °C, respectively. In addition, mechanical stability was determined and a procedure for coating nanoparticles with respect to their photocatalytic activities was proposed.

PING 2019 is organized with the support of funds for specific university research project SVK1-2019-002. There is a great interest in the synthesis of various nanosized green reusable catalysts which would better assist various chemical reactions in industrially important technologies. Heterogeneous catalysts are widely used in advanced oxidation processes. Its can remove organic pollutants in wastewater effluents by facilitting their degradation through ozonization, photolysis, semiconductor photocatalysis, electrochemical treatment and Fenton’s oxidation. In the case of using Fenton´s oxidation. Pulsed laser irradiation of iron and cobalt sulfides in different enviroments allows laser ablation and generation of FeS, CoS2 nano/micro particles. The FeS and CoS2-based films deposited on Ta deposited on Cu were examined for their catalytic effect in Fenton degradation of methylene blue (MB). However, there is still necessary presence of additional H2O2 which is expensive for wider industrial application. Therefore, these substances are tested for their photocatalytic properties.

PING 2019 is organized with the support of funds for specific university research project SVK1-2019-002. In recent years, the synthesis of sol-gel derived porous glasses has drawn widespread attention owing to the convenience and versatility of the sol-gel method. The sol-gel synthesis process mainly involves hydrolysis and condensation of precursors followed by drying and stabilization. The characteristics such as pore structure, morphology and compositions of sol-gel derived glasses significantly affect their final properties. In the present study, silica-titania (Si-Ti) based porous glasses with different compositions were synthesized using the sol-gel method. Metal alkoxides such as tetraethoxysilane (TEOS) and titanium isopropoxide (TIP) were used as a source as the source for silica and titania respectively. Nitric acid (HNO3) was used as catalysts to trigger the hydrolysis reaction and polyethylene glycol (PEG) was used as a polymeric component to induce phase separation. The influence of different processing parameters on the microstructural and thermal properties was investigated. The microstructure of the synthesized Si-Ti based porous glasses was investigated using Scanning electron microscopy (SEM) and the thermal characteristics were evaluated using thermogravimetric analysis (TGA) and thermomechanical analysis (TMA). The main objective of this study is to ascertain the application of sol-gel derived Si-Ti porous glasses as a potential biomaterial for bone tissue regeneration. To understand this facet of Si-Ti porous glasses, the biological performance will be investigated and their porous architecture will be explored in relation to their interaction with the bioactive nanoparticles.

Geoplymerní kompozit byl připraven z metakaolinu, roztoku alkalického křemičitanu draselného a keramického ostřiva na bázi páleného jílovce. Keramické plnivo byl přidáno v rozmezí 250 až 325 hmot.% metakaolinu. Pro detailní studium keramického plniva byla využita standardní sítová analýza, analyzátor velikosti částic a elektronová mikroskopie. V rámci experimentu, byl sledován vliv skladby plniva dle Fullerova zrnitostního modelu na výsledné termomechanické vlastnosti kompozitu. Geopolymerní matrice byla připravena ve složení definované molárními poměry SiO2/Al2O3 = 2.6 a H2O/K2O = 18.50. Teplotní odolnost byla studována pomocí TGA/DSC. Vývoj krystalických fází byl sledován pomocí měření RTG difrakce. Z výsledků TMA je patrný významný vliv vyššího objemu jemných keramických částic (< 90 μm) na teplotní stabilitu v oblasti do 1000°C. Aplikací zrnitostní skladby dle Fullerova modelu se snižuje objemové smrštění z původních 2.243% na 1.212 při 1000°C. Mechanické parametry, po teplotní expozici, u této skladby vykazují konstantní pevnost v ohybu (průměrná hodnota 12MPa) a v tlaku (prům. hodnota 90 MPa). Geopolymer composite has been synthesized at room temperature by mixing metakaolin, potassium silica solution and ceramic grog based on sintered schistous clay. Ceramic aggregate has been added in an amount from 250 to 325% of metakaolin weight. In this study, standard sieve analysis, particle size analyzer and electron microscopy were applied for a detailed investigation of the ceramic filler. The effect of aggregate gradation according to Fuller’s model on mechanical strength and thermomechanical behavior during and after thermal exposure at 1000 °C was investigated. A significant weight decrease was observed up to 250 °C, which is attributed to the loss of free and tightly absorbed water. According to DSC, the temperature range from 800 °C to 1000 °C represents a stable region without additional crystallization. XRD revealed that after thermal exposure at 1000 C, the kaolinite phase disintegrated completely and quartz content was significantly reduced. The results have shown that a higher content of fine ceramic particles under 90 mm and gradual distribution of other fractions from 150 to 710 mm leads to an improved dimensional stability after thermal exposure. Potassium-based geopo

Směsné oxidy a kompozity oxidu TiO2/SiO2 byly intenzivně studovány, zatímco kekich protějšky oxidu titanatého (TiO) a oxidu křemnatého (SiO) stále zůstávají neprozkoumány. Tato studie odhaluje strukturální změny ve zahřátých směsích SiO-TiO. Změny složení ve smísených mikro-částicích TiO a SiO zahřívaných při 1000 ° C byly zkoumány pomocí FTIR, UV-Vis a Ramanovy spektroskopie, rentgenové difrakce a elektronové mikroskopie (SEM a TEM). Ukazuje se, že dochází k úbytku krystalického TiO a tvorbě suboxidů titanu (Ti2.5O3, Ti2O3), rutilu, elementárního křemíku, silicidu titanu Ti5Si3 a amorfních binárních SiOx, TiOx a ternárních nanostruktur SixTiyOz. Tvorba tohoto Si/Ti/O kompozitu je vysvětlena disproprciací SiO, redukcí TiO křemíkem, přenosem kyslíku (redoxní reakce) mezi TiOx a SiOx a kombinací Ti a Si k získání silicidu titanu. Vytvořený Si/Ti/O kompozit absorbuje viditelné světlo a jeho fotokatalytická aktivita ve slunečním záření byla testována na odbarvování methylenové modři (bBlue) a porovnávána s práškem nezahřátého SiO, TiO a Ti5Si3. Silica–titania mixed oxides and composites have been extensively studied, whereas the titanium monoxide (TiO)–silicon monoxide (SiO) counterparts still remain to be explored. Here, we report on structural changes in heated SiO–TiO mixtures. The changes in composition in intimately mixed μm-sized particles of TiO and SiO heated at 1000 °C were examined by FTIR, UV–Vis and Raman spectroscopy, X-ray diffraction and electron (SEM and TEM) microscopy. They are shown to involve depletion of crystalline TiO and formation of titanium suboxides (Ti2.5O3, Ti2O3), rutile, elemental silicon, titanium silicide Ti5Si3 and amorphous binary SiOx, TiOx and ternary SixTiyOz nano-structures. These constituents of the developed Si/Ti/O composite are explained by SiO disproportionation, reduction of TiO by silicon, oxygen transfer (redox) reactions between TiOx and SiOx species and the combination of Ti and Si to obtain titanium silicide. The produced Si/Ti/O composite absorbs visible light and its solar-light photocatalytic activity in decolorization of methylene bBlue is compared to that of the unheated SiO, TiO and Ti5Si3 powders.

Předmětem této studie je optická emisní spektroskopická studie plasmy vzniklé laserovou ablací sulfidu železnatého (FeS) ve vakuu. Emise plasmy byla charakterizována časovým a prostorovým rozlišením. Spektroskopické měření bylo použito pro kalkulaci parametrů plasmy. Elektronová teplota byla počítána pomocí Boltzmanovy metody a hustota elektronů Starkovým rozšířením emisních linií. Optical emission spectroscopy studies are reported of laser ablation plasma from an iron sulphide (FeS) target in vacuum. The plasma emission is characterized with spatial and tempoal resolution. The spectral observations are used to calculate the electron plasma parameters. The electron temperature is calculated by the Boltzmann plot method and the electron number density, by the Stark broadening of the emission lines.