Characterization of kaolinite-cetyltrimethylammonium chloride intercalation complex synthesized through eco-friend kaolinite-urea pre-intercalation complex

Because of its suitability for producing kaolinite nanoscrolls, the kaolinite-cetyltrimethylammonium chloride intercalation complex is of interest in the research area of kaolinite nanocomposites. Experimental and molecular simulation analyses are used to investigate this intercalation complex, revealing its real structure formed through partially methoxy-modified kaolinite. Cost-efficient homogenization method is applied to synthesize the eco-friend kaolinite-urea pre-intercalation complex, which was found to be favorable to intercalate cetyltrimethylammonium chloride into the interlayer space of kaolinite. The influence of the pre-intercalated urea molecules, the partial modification of kaolinite structure with methoxy groups, and the presence of methanol molecules in the interlayer space of kaolinite on the intercalation of cetyltrimethylammonium chloride is characterized experimentally by X-ray diffraction, thermal analysis, Fourier transform infrared spectroscopy, and electron microscopy. The kaolinite-cetyltrimethylammonium chloride complex is identified at the basal spacing of 3.82 nm with the chemical formula of Al2Si2O5(OH)3.7(OCH3)0.3(CTAC)1.6(Me)1.6. Our molecular simulations predict methanol-containing structures between methoxy-functionalized kaolinite layers with diffuse guest molecular arrangements

Oxid-bázisú bevonatrendszerek, réteges szekezetű anyagok szintézise és felületi tulajdonságainak vizsgálata = Synthesis and surface characterization of oxide-based coatings and layer-structured materials“.

Prekurzor sók vizes, illetve alkoholos oldatából szol-gél eljárással titánlemez hordozón hőkezeléssel kialakított IrO2, RuO2, SnO2 egykomponensű rendszerek, valamint IrO2 – SnO2, RuO2 – SnO2, IrO2 – Ta2O5, illetve RuO2 – IrO2 – SnO2 vegyesoxid filmek képződési mechanizmusának in situ tanulmányozását végeztük el. A bevonat tulajdonságait jelentősen befolyásoló szekunder reakciókat (intramolekuláris hidrolízis, felületi karbonilok, karboxilátok, karbonátok, Zundel-típusú szerkezetek képződése és bomlása) részletesen elemeztük. Összefüggést mutattunk ki a filmkialakulás hőmérséklete és a bevonat összetétele, illetve az elektrokémiai aktivitás és a bevonat nemesfém-tartalma között. Gyógyszeripari technológiai szennyvíz, illetve fenolát-tartalmú víz detoxikálására a kifejlesztett katalitikus aktivitású bevonatok segítségével sikeres kísérleteket végeztünk. Kaolinit nano-komplexek, mechanokémiai úton módosított felületű, illetve OH-csoportokat tartalmazó ásványok szerkezetének, bomlásmechanizmusának szisztematikus vizsgálatát végeztük el. A karbamid nano-komplexbe történő beépülési mechanizmusára vonatkozóan új modellt állítottunk fel. A mechanikai tulajdonságok javítása céljából polimerbe ágyazható, nanométer-tartományba eső delaminált kaolinit előállítására sikeres előkísérleteket végeztünk. | A detailed study of the formation mechanism of IrO2, RuO2, SnO2 one-components systems as well as IrO2 – SnO2, RuO2 – SnO2, IrO2 – Ta2O5, and RuO2 – IrO2 – SnO2 mixed oxide coatings prepared from aqueous and alcoholic precursor solutions onto titanium metal supports by heat treatment has been carried out under in situ conditions. The role of the side reactions significantly influencing the coating characteristics (intramolecular hydrolysis, formation and subsequent decomposition of surface carbonyls, carboxylates, carbonates, Zundel-type structures) was identified and described in detail. Close correlations were found between the film evolution temperature and coating composition as well as between the electrochemical activity and the noble-metal content of the film. The coatings were successfully used for the detoxification of pharmaceutical process waste water and phenolate-containing water. The systematic study of the structure and decomposition mechanism of organo-clay nano-complexes, mechanochemically modified kaolinite surfaces and minerals containing OH-groups has been carried out. A new model has been proposed for the mechanism of urea incorporation in the nano-complex formed. Successful preliminary experiments were made for the delamination of kaolinite and for the incorporation of the nano-sized mineral thus formed into polymer matrices

Emerging organizational architecture of algorithmic management and the institutional context of weak collective voice : Hungary

The INCODING project studies dynamics in the (co)governance of Algorithmic Management and Artificial Intelligence-techniques from a Comparative Industrial Relations-perspective. By identifying the main challenges for workers and their representatives, it aims to explore how to contribute to Inclusive and Transparent Algorithmic Management

Coumarin-based quantification of hydroxyl radicals and other reactive species generated on excited nitrogen-doped TiO2

In order to extend the photoactivity of titanium dioxide into the visible region, highly porous nitrogen-doped TiO2 catalysts (NTiO2) were successfully synthesized by a modified co-precipitation method with ammonium hydroxide as a nitrogen source. Different approaches such as dosing order of the reagents and temperature of the synthesis, calcination period and temperature were tested to examine the optimum outcome regarding photocatalytic OH radical formation under UV and visible light. Coumarin as a traditional probe for this purpose was applied; measuring the luminescence of 7-hydroxycoumarin produced in the reaction with OH radicals, beside the formation of other hydroxylated derivatives. Only a few percentages of the coumarin molecules reacted with OH radicals, while most of them underwent reactions with other photogenerated species such as electrons (anaerobic/aerobic) and superoxide anion radicals (aerobic). Accordingly, our observations suggest that coumarin can also be used as a probe to quantify the formation of other reactive species. The results were obtained from the difference between the amounts of degraded coumarin and hydroxylated coumarin derivatives formed during photocatalytic experiments. These coumarin-based quantifications of photoactivity was applied for the characterization of the prepared nitrogen-doped TiO2 catalysts (NTiO2). In addition, material analysis (X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectrometry, and Fourier transform infrared spectroscopy) showed that crystallinity and nitrogen content were found to be crucial features in the photocatalytic performance of the catalysts

The Photocatalytic and antibacterial performance of Nitrogen-Doped TiO2: Surface-structure dependence and Silver-deposition effect

Catalysts for visible-light-driven oxidative cleaning processes and antibacterial applications (also in the dark) were developed. In order to extend the photoactivity of titanium dioxide into the visible region, nitrogen-doped TiO2 catalysts with hollow and non-hollow structures were synthesized by co-precipitation (NT-A) and sol–gel (NT-U) methods, respectively. To increase their photocatalytic and antibacterial efficiencies, various amounts of silver were successfully loaded on the surfaces of these catalysts by using a facile photo-deposition technique. Their physical and chemical properties were evaluated by using scanning electron microscopy (SEM), transmission electron microscopy–energy dispersive X-ray spectroscopy (TEM–EDS), Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction (XRD), and diffuse reflectance spectra (DRS). The photocatalytic performances of the synthesized catalysts were examined in coumarin and 1,4-hydroquinone solutions. The results showed that the hollow structure of NT-A played an important role in obtaining high specific surface area and appreciable photoactivity. In addition, Ag-loading on the surface of non-hollow structured NT-U could double the photocatalytic performance with an optimum Ag concentration of 10−6 mol g−1, while a slight but monotonous decrease was caused in this respect for the hollow surface of NTA upon increasing Ag concentration. Comparing the catalysts with different structures regarding the photocatalytic performance, silverized non-hollow NT-U proved competitive with the hollow NT-A catalyst without Ag-loading for efficient visible-light-driven photocatalytic oxidative degradations. The former one, due to the silver nanoparticles on the catalyst surface, displayed an appreciable antibacterial activity, which was comparable to that of a reference material practically applied for disinfection in polymer coatings