TY - JOUR AU - Fazekas, Ákos Ferenc AU - Gyulavári, Tamás AU - Ágoston, Áron AU - Janovák, László AU - Heszlerné Kopniczky, Judit AU - László, Zsuzsanna AU - Veréb, Gábor TI - Enhanced Photocatalytic and Filtration Performance of TiO2-Ag Composite-Coated Membrane Used for the Separation of Oil Emulsions JF - SEPARATIONS J2 - SEPARATIONS VL - 11 PY - 2024 IS - 4 SP - 112 SN - 2297-8739 DO - 10.3390/separations11040112 UR - https://m2.mtmt.hu/api/publication/34823133 ID - 34823133 AB - Polyvinylidene fluoride (PVDF) membranes were coated with TiO2 and TiO2-Ag to enhance their efficiency for oil-in-water emulsion separation. The photocatalytic activities of the two modified membranes and their filtration performances were compared in detail. The significantly enhanced photocatalytic activity of the TiO2-Ag composite was proved using a methyl orange (MO) solution (c = 10−5 M) and a crude oil emulsion (c = 50 mg·L−1). The TiO2-Ag-coated membrane reduced the MO concentration by 87%, whereas the TiO2-modified membrane reached only a 46% decomposition. The photocatalytic reduction in the chemical oxygen demand of the emulsion was also ~50% higher using the TiO2-Ag-coated membrane compared to that of the TiO2-coated membrane. The photoluminescence measurements demonstrated a reduced electron/hole recombination, achieved by the Ag nanoparticle addition (TiO2-Ag), which also explained the enhanced photocatalytic activity. A significant improvement in the oil separation performance with the TiO2-Ag-coated membrane was also demonstrated: a substantial increase in the flux and flux recovery ratio (up to 92.4%) was achieved, together with a notable reduction in the flux decay ratio and the irreversible filtration resistance. Furthermore, the purification efficiency was also enhanced (achieving 98.5% and 99.9% COD and turbidity reductions, respectively). Contact angle, zeta potential, scanning electron microscopy (SEM), and atomic force microscopy (AFM) measurements were carried out to explain the results. SEM and AFM images revealed that on the TiO2-Ag-coated membrane, a less aggregated, more continuous, homogeneous, and smoother nanolayer was formed due to the ~50% more negative zeta potential of the TiO2-Ag nanocomposite compared to that of the TiO2. In summary, via Ag addition, a sufficiently hydrophilic, beneficially negatively charged, and homogeneous TiO2-Ag-coated PVDF membrane surface was achieved, which resulted in the presented advantageous filtration properties beyond the photocatalytic activity enhancement. LA - English DB - MTMT ER - TY - JOUR AU - Szabó, Diána AU - Janovák, László AU - Abdelghafour, Mohamed M. AU - Takács, Tamás AU - Csanády, Miklós ifj. AU - Spengler, Gabriella AU - Szakács, László AU - Csanády, Miklós AU - Rovó, László TI - Új minimálinvazív kezelési lehetőségek jó- és rosszindulatú fül-orr-gégészeti betegségekben nanoszerkezetű hatóanyag-leadó rendszerek alkalmazásával = New minimally invasive treatment options in benign and malignant otorhinolaryngological diseases using nanostructured drug delivery systems JF - ORVOSI HETILAP J2 - ORV HETIL VL - 165 PY - 2024 IS - 10 SP - 370 EP - 378 PG - 9 SN - 0030-6002 DO - 10.1556/650.2024.32978 UR - https://m2.mtmt.hu/api/publication/34729015 ID - 34729015 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Takács, Tamás AU - Abdelghafour, Mohamed M. AU - Sebők, Dániel AU - Kukovecz, Ákos AU - Janovák, László TI - Structural and thermoanalytical characterization of self-healing polymer: the effect of cross-linking density JF - JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY J2 - J THERM ANAL CALORIM VL - https://doi.org/10.1007/s10973-023-12862-2 PY - 2024 SP - https://doi.org/10.1007/s10973-023-12862-2 SN - 1388-6150 DO - 10.1007/s10973-023-12862-2 UR - https://m2.mtmt.hu/api/publication/34547597 ID - 34547597 AB - The effect of the gradually formed cross-linked structure on the thermal properties and swelling behaviour of modified poly(vinyl alcohol) was investigated. To this aim, the semi-crystalline polymer was functionalized with aldehyde and amino moieties to produce polymers with dynamic imine cross-links, and, thus, with self-healing or curing ability. With increasing degree of functionalization (0.89–7.12%), denser polymer networks cross-linked by dynamic imine bonds were formed, the samples systematically developed thermoset-like properties compared to the pristine, initially thermoplastic PVA. As a result, the introduction of new moieties into the initial PVA lowered the glass transition (from 65.3 to 35.0 °C) and melting temperatures (from 194 to 161 °C), however, a new peak (T crd ) with growing enthalpy values appeared on the DSC curves, which indicates that more and more energy must be supplied in order to break the imine cross-links formed between the introduced aldehyde and amino groups. The significant impact of the degree of functionalization and cross-linking density on the polymer structure was also clearly demonstrated: the crystallinity decreased as the abundance of the introduced moieties increased and the formation of cross-links proceeded. At the same time, the water desorption enthalpies of the samples increased, suggesting a stronger, chemically cross-linked thermoset-like polymer network compared to the thermoplastic poly(vinyl alcohol). LA - English DB - MTMT ER - TY - GEN AU - Puskás, Sándor AU - Törő, Mária AU - Vágó, Árpád AU - Ördög, Tibor AU - Tóth, Marianna AU - Kálmán, Gyula AU - Mátrai, Andrea AU - Nagy, Roland AU - Bartha, László AU - Hartyányi, Máté AU - Lakatos, István AU - Szentes, Gabriella AU - Dékány, Imre AU - Janovák, László AU - Geiger, János TI - Surfactant-Polymer Enhanced Oil Recovery Project at Algyő Field = Tenzides-Polimeres EOR Projekt Algyő mezőben PY - 2023 UR - https://m2.mtmt.hu/api/publication/34484377 ID - 34484377 LA - English DB - MTMT ER - TY - JOUR AU - Amin, Keristina AU - Abdelghafour, Mohamed M. AU - Varga, Viktória AU - Kiss, Tamás AU - Szabó, Diána AU - Rovó, László AU - Janovák, László TI - Mitomycin loaded self-assembled colloidal prodrug nanoparticles for magnetic drug targeting JF - JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY J2 - J DRUG DELIV SCI TEC VL - 88 PY - 2023 PG - 11 SN - 1773-2247 DO - 10.1016/j.jddst.2023.104948 UR - https://m2.mtmt.hu/api/publication/34154074 ID - 34154074 LA - English DB - MTMT ER - TY - JOUR AU - Kormányos, Attila AU - Endrődi, Balázs AU - Zhang, Zheng AU - Samu, Angelika Anita AU - Mérai, László AU - Samu, Gergely Ferenc AU - Janovák, László AU - Janáky, Csaba TI - Local hydrophobicity allows high-performance electrochemical carbon monoxide reduction to C 2+ products JF - EES CATALYSIS J2 - EES. CATAL VL - 1 PY - 2023 IS - 3 SP - 263 EP - 273 PG - 11 SN - 2753-801X DO - 10.1039/D3EY00006K UR - https://m2.mtmt.hu/api/publication/33714392 ID - 33714392 AB - Tailoring the hydrophobicity of the cathode gas diffusion electrode mitigates flooding in parallel with enhancing the selectivity of the electrochemical carbon monoxide reduction reaction. LA - English DB - MTMT ER - TY - JOUR AU - Fekete, Laura AU - Fazekas, Ákos Ferenc AU - Hodúr, Cecilia AU - László, Zsuzsanna AU - Ágoston, Áron AU - Janovák, László AU - Gyulavári, Tamás AU - Pap, Zsolt AU - Hernádi, Klára AU - Veréb, Gábor TI - Outstanding Separation Performance of Oil-in-Water Emulsions with TiO2/CNT Nanocomposite-Modified PVDF Membranes JF - MEMBRANES (BASEL) J2 - MEMBRANES-BASEL VL - 13 PY - 2023 IS - 2 PG - 14 SN - 2077-0375 DO - 10.3390/membranes13020209 UR - https://m2.mtmt.hu/api/publication/33636061 ID - 33636061 AB - Membrane filtration is an effective technique for separating micro- and nano-sized oil droplets from harmful oil-contaminated waters produced by numerous industrial activities. However, significant flux reduction discourages the extensive application of this technology; therefore, developing antifouling membranes is necessary. For this purpose, various titanium dioxide/carbon nanotube (TiO2/CNT) nanocomposites (containing 1, 2, and 5 wt.% multi-walled CNTs) were used for the modification of polyvinylidene fluoride (PVDF) ultrafilter (250 kDa) membrane surfaces. The effects of surface modifications were compared in relation to the flux, the filtration resistance, the flux recovery ratio, and the purification efficiency. TiO2/CNT2% composite modification reduced both irreversible and total filtration resistances the most during the filtration of 100 ppm oil emulsions. The fluxes were approximately 4–7 times higher compared to the unmodified PVDF membrane, depending on the used transmembrane pressure (510, 900, and 1340 L/m2h fluxes were measured at 0.1, 0.2, and 0.3 MPa pressures, respectively). Moreover, the flux recovery ratio (up to 68%) and the purification efficiency (95.1–99.8%) were also significantly higher because of the surface modification, and the beneficial effects were more dominant at higher transmembrane pressures. TiO2/CNT2% nanocomposites are promising to be applied to modify membranes used for oil–water separation and achieve outstanding flux, cleanability, and purification efficiency. LA - English DB - MTMT ER - TY - JOUR AU - Ágoston, Áron AU - Balassa, Lilla AU - Imre-Deák, Ágota AU - Samu, Gergely Ferenc AU - Tallósy, Szabolcs Péter AU - Gombár, Gyöngyi AU - Janovák, László TI - Photocatalytic and antimicrobial activity of sulfur functionalized TiO 2 containing composite films JF - CHEMICAL ENGINEERING & TECHNOLOGY J2 - CHEM ENG TECHNOL VL - 46 PY - 2023 IS - 5 SP - 927 EP - 933 PG - 7 SN - 0930-7516 DO - 10.1002/ceat.202200489 UR - https://m2.mtmt.hu/api/publication/33610276 ID - 33610276 N1 - CODEN: CETEE AB - Facile sulfation of TiO2 semiconductor photocatalyst was achieved by a simple grinding and calcination method using elemental sulfur from desulfurization of petroleum. The successful sulfation of the prepared visible-light-active photocatalyst was also proved by infrared and X-ray photoelectron spectroscopic measurements. Photocatalytic tests revealed that the most efficient member of the series has higher photocatalytic activity than TiO2 in the photodegradation of formic acid under both UV and visible-light activation. Moreover, the improved electrokinetic and water dispersibility behaviors of the sulfur-modified photocatalyst allowed the preparation of polyacrylate-based photoreactive thin films with increased photocatalytic activity, strong antimicrobial properties, and improved mechanical behavior. LA - English DB - MTMT ER - TY - JOUR AU - Ágoston, Áron AU - Janovák, László TI - Hydrothermal Co-Crystallization of Novel Copper Tungstate-Strontium Titanate Crystal Composite for Enhanced Photocatalytic Activity and Increased Electron–Hole Recombination Time JF - CATALYSTS J2 - CATALYSTS VL - 13 PY - 2023 IS - 2 SP - 287 SN - 2073-4344 DO - 10.3390/catal13020287 UR - https://m2.mtmt.hu/api/publication/33606755 ID - 33606755 AB - The development of catalysts continues to have a significant influence on science today since we can utilize them to efficiently destroy some contaminants. A study in this field is justified because there is a dearth of comprehensive literature on the creation of SrTiO3-based photocatalysts. Related to this topic, here we report the facile preparation of a structure-modified SrTiO3 photocatalyst, by incorporating CuWO4. Within the case of the CuWO4-modified samples (0.5–3 wt% nominal CuWO4 content), the photo-oxidation of phenol, as a contaminant, was more than two times higher than the initial SrTiO3. However, the photocatalytic activity does not change linearly with increasing CuWO4 content, and the CWS2.5 (2.5 wt% nominal CuWO4 content and 4.25 wt% measured content) has the highest photo-activity under the applied conditions. The reason for the better activity was the increased recombination time of charge separation on the catalyst surface. Slower recombination can result in more water being oxidized to hydroxyl radicals, leading to the faster decomposition of the phenol. LA - English DB - MTMT ER - TY - JOUR AU - Ádám, Anna Adél AU - Ziegenheim, Szilveszter AU - Janovák, László AU - Szabados, Márton AU - Bús, Csaba AU - Kukovecz, Ákos AU - Kónya, Zoltán AU - Dékány, Imre AU - Sipos, Pál Miklós AU - Kutus, Bence TI - Binding of Ca2+ Ions to Alkylbenzene Sulfonates: Micelle Formation, Second Critical Concentration and Precipitation JF - MATERIALS J2 - MATERIALS VL - 16 PY - 2023 IS - 2 PG - 12 SN - 1996-1944 DO - 10.3390/ma16020494 UR - https://m2.mtmt.hu/api/publication/33543168 ID - 33543168 AB - Anionic surfactants, such as sodium linear alkylbenzene sulfonates (NaLAS), are utilized in various fields, including industry, household, and agriculture. The efficiency of their use in aqueous environments is significantly affected by the presence of cations, Ca2+ and Mg2+ in particular, as they can decrease the concentration of the surfactant due to precipitation. To understand cation–sulfonate interactions better, we study both NaLAS colloidal solutions in the presence of CaCl2 and precipitates forming at higher salt concentrations. Upon addition of CaCl2, we find the surface tension and critical micelle concentration of NaLAS to decrease significantly, in line with earlier findings for alkylbenzylsulfonates in the presence of divalent cations. Strikingly, an increase in the surface tension is discernible above 0.6 g L–1 NaLAS, accompanied by the decrease of apparent micelle sizes, which in turn gives rise to transparent systems. Thus, there appears to be a second critical concentration indicating another micellar equilibrium. Furthermore, the maximum salt tolerance of the surfactant is 0.1 g L–1 Ca2+, above which rapid precipitation occurs yielding sparingly soluble CaLAS2∙2H2O. LA - English DB - MTMT ER -