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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). 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.

Směsné oxidy křemíku a titanu a jejich kompozity byly široce studovány pro jejich fyzikální a katyltické vlastnosti, ale jejich protějšku v podobě monooxidů byla zatím věnována jen malá pozornost. Zde publikujeme laserově indukovaný proces směsi monooxidů křemíku a titanu, který vede k reakci a vytváří nanostrukturovaný Ti/Si/O komposit absorbující viditelné světlo. Změny ve složení důkladně promísených μm-rozměrných částic monooxidu křemíku (SiO) a monooxidu titanu (TiO) indukované ozařováním paprskem cw CO2 laseru povrchu TiO-SiO pelety byly zkoumány FTIR a Ramanovou spektroskopií, rentgenovou difrakcí a elektronovou mikroskopií. Bylo odhaleno, že změny spočívají v tvorbě TiO2 (rutil, anatase), suboxidů titanu (Ti 4.5O5, Ti2O3), křemíku a amorfních SiOx, TiOx a ternárního SixTiyOz nanofází, které obsahují více, či méně O, než SiO a TiO monooxidy. Tyto produkty jsou přiřazeny k souběžné termální redukci křemíkem, který redukuje TiO a probíhá transfer O mezi SiO a TiO skrze interdifuzi fází na bázi Si a Ti. Tyto reakce probíhající vlivem přechodného lokálního záhřevu nejsou zamezeny pasivační vrstvou kolem SiO a TiO částic. Laserem vytvořený Ti/Si/O komposit vykazuje absorpční pás na 425 nm sahající do 1100 nm. Jeho solární katalytická aktivita ukázaná na odbarvení methylenové modři je srovnávána s nezahřátým SiO a TiO práškem absorbujícím pouze v UV oblasti. Silica–titania mixed oxides and composites have been broadly examined for their physical and catalytic properties, but titanium monoxide–silicon monoxide counterparts have yet drawn very little attention. Here we report that laser-induced processing of mixed silicon and titanium monoxides results in reactions yielding a nanostructured Ti/Si/O composite absorbing visible light. Changes in the composition of intimately mixed μm-sized particles of silicon monoxide (SiO) and titanium monoxide (TiO) induced by scanning of a cw CO2 laser beam along the TiO–SiO pellet surface were examined by FTIR and Raman spectroscopy, X-ray diffraction and electron microscopy. They are shown to consist in the evolution of TiO2 (rutile and anatase), titanium suboxides (Ti 4.5O5, Ti2O3), silica and amorphous binary SiOx, TiOx and ternary SixTiyOz nanophases which contain less or more O than SiO and TiO monoxides. These products are ascribed to concurrent silicothermal reduction of TiO and O-transfer between SiO and TiO due to interdiffusion of Si- and Ti-based species. These reactions taking place under transient localized heating are not inhibited by passivation shells around SiO and TiO particles. The laser-produced Ti/Si/O composite shows absorption band at 425 nm tailing up to 1100 nm. Its solarlight photocatalytic activity in decolorization of Methylene Blue is compared to that of the unheated SiO and TiO powders absorbing only in UV region.

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.

The cleaning of particles from library materials (paper, textile, and collagen materials) using a high-speed CO2 snow jet was investigated. The measurements included\ndetermination of the cleaning efficiency, and evaluation of possible adverse effects. The method was compared with nitrogen jet cleaning. The results showed that the CO2 snow\njet is able to effectively remove particles from the surfaces. Any adverse effects were not observed at paper and textile. However, application on collagen materials caused\ndegradation of the surface.

The catalysts investigated in this work were prepared by co-precipitation of nitrates with aqueous K2CO3/KOH solution, followed by washing the precipitates to varying degrees of potassium content and calcining the precursors at 500 °C for 4 h. Mn-Al potassium salt followed by calcination at 500 °C. Before the catalytic reaction, they were calcined at 700 °C. The catalysts and their precursors were characterized by the following measurement techniques: ICP, DTG, XRD, N2 physisorption, FTIR, H2-TPR, CO2-TPD, XPS, and thermal alkali metal desorption (SR-TAD).\n\n

The nucleation of nanoparticles was applied during gold deposition onto TiO2 layers. For nucleation, up to 10 Pa of inert gas (argon) was used. Argon molecules efficiently helped to cool temperature of evolving plume and initiated the nucleation which resulted in deposition of gold nanoislands. Gold nanoparticles incorporated in TiO2 layers provided plasmonic properties. Au/TiO2 layers were used for water splitting as proved by photoelectrochemical measurements.

In this work, the scCO2 modified by mixture of water and ethanol was used for a preparation of crystalline and pure nanostructured TiO2 thin films in one step processing. All the experiments were performed over precursor titania thin films prepared by reverse micelles assisted sol-gel method, using hardly removable nonionic surfactant Triton X-114, however, forming uniform nano-domains. The effect of temperature (40-150 °C), pressure (10-30 MPa), modifier composition \n(20, 50 and 80 % w/w of water in ethanol) and concentration inscCO2 (5-15 wt. %) and consumed amount of solvent (50-200 g) on microstructure and purity\nof TiO2 thin films was thoroughly studied by means of Raman spectroscopy, X-ray diffraction, and contact angle measurements.

This work is focused on a study of TiO2 aerogel SFC with scCO2 modified by mixture of ethanol and water in a ratio 1:1. The effect of temperature (40-100 °C), pressure (10-30 MPa) and modifie concentration in scCO2 (5-15 wt.%) and the additional drying with pure CO2 on microstructure, purity and textural properties of TiO2 aerogel was investigated. Processed monoliths were characterized by XRD analysis, Raman spectroscopy and N2 physisorption.

This contribution is accomplished by the study of the membrane affinity via contact angle measurements and by structural analysis via electron he transport properties of the TFC PA were studied at various experimental conditions and the obtained results will be discussed.

In the present study, the effect both of the botanical source and proportion of starch produced from agricultural surplus on the microstructure properties of starch/chitosan/glycerin films was tested. Effective gas transport properties gas diffusion transfer was performed. Starch/chitosan/glycerol biodegradable films were obtained by casting method from giant squid (Dosidicus gigas) pen chitosan mixed with glycerin and starch. Four starch samples were prepared using exceeding or low quality biomass including broken rice grains, hard yellow corn surplus, banana surplus form exportation activity and low quality cassava in three different weight proportion (chitosan/starch) corresponding to 1/1, 2/1 and 5/1. Extraction of starch from the raw material was carried out by mixing it with a water solution of sodium disulfite (5 wt.%). Afterwards, the obtained suspension was filtered and then decanted at 5°C for 24 h. The obtained starch was washed repeatedly with distilled water and ethanol (96 vol.%). Finally, the starch samples were dried at 55°C for 48 h, crushed and sieved. It was found that the gas diffusion transport properties significantly depend on the starch source used. Differences in diffusion transport rates through the films prepared with different starches are related to the size and distribution of granules of starch in the films and/or the amylose conten.

The present work deals with the crystallization of monolithic TiO2 aerogels in environment of pure and water modified scCO2. To remove organic precursors used during sol-gel synthesis and to crystallize TiO2 the combination of several steps with pure and watermodified scCO2 was tested with respect the high porosity and the specific surface area of titania blocks.

In this work, the method using pure and modified supercritical carbon dioxide was tested to prepare a set of crystalline TiO2 thin films deposited on soda-lime glass. Precursor solution for TiO2 films was prepared by a templated sol-gel method in the reverse micelle environment. Simple approach or combination of several steps performed at different temperature (40-150 °C) and solvent composition was applied at pressure 30 MPa. Water, ethanol and water : ethanol (1:1) mixture were added into supercritical CO2 as modifiers at concentration 10-30 wt.%. The effect of extraction design on microstructure and purity of TiO2 thin films were examined.

Extrakce čistým a modifikovaným superkritickým oxidem uhličitým (SFE) a extrakce podkritickou vodou byla využita k získání krystalických a čistých nanostrukturních tenkých filmů TiO2 a současně k odstranění organických prekurzorů ze syntézy solu sol-gel metodou. Při SFE byl sledován vliv teploty a použitého modifikátoru (vody, metanolu, etanolu a acetonu) na čistotu a mikrostrukturu tenkých filmů TiO2. Byl testován i kombinovaný postup extrakce, kdy se střídaly kroky s CO2 modifikovaným vodou a s CO2 modifikovaným organickými rozpouštědly. Čistota a krystalinita tenkých filmů byla zjištěna pomocí Ramanovy spektroskopie. Fázová složení a velikosti krystalů anatasu, žádané krystalické struktury, byly vyhodnoceny rentgenovou difrakční analýzou (XRD).