TY - CONF AU - Nyul, Dávid AU - Nagy, Lajos AU - Kuki, Ákos AU - Nagy, Tibor AU - Bányai, István AU - Zsuga, Miklós AU - Kéki, Sándor ED - Majdik, Cornelia TI - 7Li-NMR relaxációs módszerek alkalmazása lítium-levegő akkumulátorok határfelületeinek vizsgálatára T2 - XXIX. Nemzetközi Vegyészkonferencia / 29th International Conference on Chemistry PB - Erdélyi Magyar Műszaki Tudományos Társaság (EMT) C1 - Kolozsvár T3 - Nemzetközi Vegyészkonferencia, ISSN 1843-6293 PY - 2023 SP - 59 EP - 60 PG - 2 UR - https://m2.mtmt.hu/api/publication/34271518 ID - 34271518 AB - A modern kor egyik legégetőbb problémája a megtermelt energia tárolása, hiszen megfelelő tárolókapacitás nélkül nem képzelhető el olyan elektromos hálózat, ami tisztán megújuló energiaforrásokkal üzemel. A különböző kémiájú akkumulátorok közt a lítium-ion alapú cellák kimagaslóan nagy fajlagos és volumetrikus energiasűrűséggel rendelkeznek. A legnagyobb energiasűrűséggel a lítium-levegő akkumulátor rendelkezik. Az NMR spektroszkópia egy igen gyorsan fejlődő és sokoldalú szerkezetvizsgáló és képalkotó módszercsalád. Szilárd fázisú NMR technikákkal már vizsgálták az elektródanyagok és az alkálifémek kölcsönhatását, például porózus szénben interkalált nátrium vagy grafitban interkalált lítium viselkedését. A szilárd fázisú módszereknek viszont nagy hátránya, hogy nem tudják ezeket a rendszereket valós körülmények közt vizsgálni. A folyadék fázisú NMR módszerek közvetlen információt nem képesek szolgáltatni egy szilárd anyagról, de a felület és a folyadék fázis közti kölcsönhatások vizsgálatával értékes többletinformációt nyerhetünk az adott rendszerről. Minden alkálifémnek van NMR aktív izotópja és ezek az izotópok kivétel nélkül kvadrupólusmagok. A kvadrupólus csatolás megjelenése oldat fázisban nem lehetséges, hiszen az alkálifém ionok gyors mozgása és rotációja miatt a kvadrupólus kölcsönhatások kiátlagolódnak. Ha az alkálifém-ion egy lassan mozgó részecskéhez vagy egy felülethez kötődik, akkor a rotációja eléggé lelassul ahhoz, hogy kvadrupólus relaxáció is megfigyelhető legyen. A kvadrupólus vagy többkvantum (MQ) relaxációs útvonalak detektálása MQ szűrők segítségével vagy TQTPPI (triplakvantum időarányos fázistolás) szekvencia segítségével történhet. LA - English DB - MTMT ER - TY - JOUR AU - Novák, Levente AU - Miklósi, Tamás Sándor AU - Nyul, Dávid AU - Shi, Xiangyang AU - Bányai, István TI - Synthesis and Characterization of Carboxymethylated Polyethylenimines JF - ACS APPLIED POLYMER MATERIALS J2 - ACS APPL POLYM MATER VL - 5 PY - 2023 IS - 9 SP - 7208 EP - 7219 PG - 12 SN - 2637-6105 DO - 10.1021/acsapm.3c01090 UR - https://m2.mtmt.hu/api/publication/34151774 ID - 34151774 LA - English DB - MTMT ER - TY - JOUR AU - Papp, Vanda AU - Janovics, Róbert AU - Kertész, Tamás Péter AU - Nemes, Zoltán AU - Fodor, Tamás AU - Bányai, István AU - Kéri, Mónika TI - State and role of water confined in cement and composites modified with metakaolin and additives JF - JOURNAL OF MOLECULAR LIQUIDS J2 - J MOL LIQ VL - 388 PY - 2023 PG - 10 SN - 0167-7322 DO - 10.1016/j.molliq.2023.122716 UR - https://m2.mtmt.hu/api/publication/34090611 ID - 34090611 N1 - University of Debrecen, Department of Physical Chemistry, Egyetem tér 1, Debrecen, H-4032, Hungary Isotoptech Zrt., Debrecen, H-4026, Hungary International Radiocarbon AMS Competence and Training Center INTERACT, Institute for Nuclear Research, Bem tér 18/C, Debrecen, H-4026, Hungary Institute for Nuclear Research, H-4026, Debrecen, Bem tér 18/C, Hungary Export Date: 15 August 2023 CODEN: JMLID Correspondence Address: Papp, V.; University of Debrecen, Egyetem tér 1, Hungary; email: papp.vanda@science.unideb.hu AB - Cement as a porous material contains pores and cracks on the whole nanoscale forming an interconnected pore structure. Its interaction with water during the rehydration of cement plays a key role in every application, such as in nuclear waste treatment, where cement binders are commonly used for conditioning liquid radioactive waste. In the prediction of the long-term disposal the knowledge of water mobility and distribution in the formed porous cement matrix is essential. In this study we systematically investigate the effects of metakaolin and several components of the liquid phase (complexing agents, model ions, boric acid, etc.) on the hydrated solid structure by various nuclear magnetic resonance (NMR) methods. The novelty lies in the complex use of such non-conventional techniques that separately provide only partial information of the cement structure; however, the gained results complete each other to offer a new approach in the structural study under several conditions. Water mobility is deduced from NMR T2 relaxation distributions and D2O-H2O exchange diffusion measurements, and the conclusion on structural properties is supported by the macropore structure revealed from NMR cryoporometry and SEM (scanning electron microscopy) images, as well as by following the formation of pores and water domains in the curing process with NMR relaxometry. The results confirm that metakaolin was built into the CSH (calcium silicate hydrate) gel region without altering its mesoporous structure, however, it significantly decreased the capillary pore size and the diffusion coefficient of water. Complexing agent concentration between 2 and 20 g/l and the presence of model ions did not cause significant structural changes, while the rehydration decreased the size of capillary pores due to swelling. LA - English DB - MTMT ER - TY - JOUR AU - Bányai, István TI - Joó Pál (1942–2022) JF - MAGYAR KÉMIKUSOK LAPJA J2 - MAGY KEM LAP VL - 77 PY - 2022 IS - 12 SP - 380 EP - 380 PG - 1 SN - 0025-0163 UR - https://m2.mtmt.hu/api/publication/33564840 ID - 33564840 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Bányai, István TI - Bemutatkozás, út a Polányi-díjhoz JF - MAGYAR KÉMIKUSOK LAPJA J2 - MAGY KEM LAP VL - 77 PY - 2022 IS - 10 SP - 289 EP - 290 PG - 2 SN - 0025-0163 UR - https://m2.mtmt.hu/api/publication/33552464 ID - 33552464 N1 - "Polányi-díjas kémikusok A Magyar Tudományos Akadémia Kémiai Tudományok Osztálya és a Fizika Kémiai Tudományos Bizottság 2021. december 9-én és 10-én rendezte ünnepi üléseit, ahol pótolták az elmúlt három évben technikai okok, illetve a járványhelyzet miatt elmaradt díjátadásokat. A kitüntetetteket az adott években a MKL köszöntötte. A Polányi-díjasok listája a https://mta.hu/vii-osztaly/a-polanyi-mihaly-dij-105427 linken tekinthető meg. A kitüntettek egyikének, Bányai Istvánnak, a Debreceni Egyetem egyetemi tanárának gondolatait olvashatják a következőkben." LA - Hungarian DB - MTMT ER - TY - JOUR AU - Nyul, Dávid AU - Novák, Levente AU - Kéri, Mónika AU - Bányai, István TI - A Simple Elimination of the Thermal Convection Effect in NMR Diffusiometry Experiments JF - MOLECULES J2 - MOLECULES VL - 27 PY - 2022 IS - 19 PG - 10 SN - 1420-3049 DO - 10.3390/molecules27196399 UR - https://m2.mtmt.hu/api/publication/33171187 ID - 33171187 N1 - Export Date: 16 November 2022 CODEN: MOLEF Correspondence Address: Bányai, I.; Department of Physical Chemistry, Hungary; email: banyai.istvan@science.unideb.hu Funding details: PD_135169 Funding details: Nemzeti Kutatási Fejlesztési és Innovációs Hivatal, NKFIH, NKFIH K_131989 Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA, TKP-17-1/PALY-2020 Funding text 1: The research has been implemented with the support provided from the National Research, Development and Innovation Office of Hungary (NKFIH), financed under the NKFIH K_131989 funding scheme. Mónika Kéri is grateful to the NKFIH of Hungary (NKFIH: PD_135169) for financial support. István Bányai and Dávid Nyul are grateful for the support from the University of Miskolc in the frame of the project titled as “Developments aimed at increasing social benefits deriving from more efficient exploitation and utilization of domestic subsurface natural resources” supported by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund in line with the Grant Contract issued by theNKFIH (Grant Contract reg. nr.: TKP-17-1/PALY-2020). Funding text 2: This research was funded by the National Research, Development and Innovation Office of Hungary, grant number NKFIH K_131989. AB - Thermal convection is always present when the temperature of an NMR experiment is different from the ambient one. Most often, it falsifies the value of the diffusion coefficient determined by NMR diffusiometry using a PGSE NMR experiment. In spite of common belief, it acts not only at higher temperatures but also at temperatures lower than in the laboratory. Sodium alkyl-sulfate monomers and micelles in D2O solvent were used as model molecules measured at T = 319 K in order to show that thermal convection sometimes remains hidden in experiments. In this paper, we demonstrate that the increase in apparent diffusion coefficient with increasing diffusion time is a definite indicator of thermal convection. Extrapolation to zero diffusion time can also be used to obtain the real diffusion coefficient, likewise applying the less sensitive pulse sequences designed for flow compensation or the expensive hardware, e.g., sapphire or Shigemi NMR tubes, to decrease the temperature gradient. Further, we show experiments illustrating the effect of a long diffusion time in which the periodic changes of the echo intensity with gradient strength appear as predicted by theories. LA - English DB - MTMT ER - TY - JOUR AU - Zhang, Luyao AU - Li, Gaoming AU - Ouyang, Zhijun AU - Yang, Rui AU - Gao, Yue AU - Cao, Xueyan AU - Bányai, István AU - Shi, Xiangyang AU - Guo, Rui TI - Intelligent design of iron-doped LDH nanosheets for cooperative chemo-chemodynamic therapy of tumors JF - BIOMATERIALS SCIENCE J2 - BIOMATER SCI-UK VL - 10 PY - 2022 IS - 8 SP - 2029 EP - 2039 PG - 11 SN - 2047-4830 DO - 10.1039/d2bm00102k UR - https://m2.mtmt.hu/api/publication/32874378 ID - 32874378 AB - Chemodynamic therapy (CDT) has received increasing attention due to its unique tumor microenvironment (TME) responsiveness and minimal adverse side effects, but the therapeutic effect of CDT alone is always limited due to the low Fenton or Fenton-like reaction efficiency at tumor sites. Herein, Fe-doped layered double hydroxide (LDH) nanosheets were synthesized to load the anticancer drug epigallocatechin-3-O-gallate (EGCG) and then conjugated with boronic acid-modified hyaluronic acid for targeted and cooperative chemo-chemodynamic therapy of tumors. The formed LDH-EGCG-HA nanoplatforms could specifically target tumor cells overexpressing CD44 receptors, quickly release iron ions and EGCG in the TME, and efficiently generate toxic hydroxyl radicals with the acceleration of Fe3+/Fe2+ cycling in the Fenton reaction by EGCG. The cooperative cancer cell inhibition effect through chemotherapy and chemodynamic therapy was achieved by the significant upregulation of caspase-3 and p53 expression to induce cell apoptosis, and the deactivation of xCT and GPX-4 to inhibit GSH synthesis and reduce lipid peroxides for reinforced ferroptosis. In vivo experiments further verified that the intelligently designed LDH-EGCG-HA nanoplatforms had a superior biocompatibility with normal organs with an excellent inhibition efficacy towards tumors overexpressing CD44 receptors by targeted chemo-chemodynamic therapy. LA - English DB - MTMT ER - TY - JOUR AU - Kéri, Mónika AU - Nyul, Dávid AU - Nagyné László, Krisztina AU - Novák, Levente AU - Bányai, István TI - Interaction of resorcinol-formaldehyde carbon aerogels with water: A comprehensive NMR study JF - CARBON J2 - CARBON VL - 189 PY - 2022 SP - 57 EP - 70 PG - 14 SN - 0008-6223 DO - 10.1016/j.carbon.2021.12.045 UR - https://m2.mtmt.hu/api/publication/32546275 ID - 32546275 N1 - Funding details: European Commission, EC Funding details: European Regional Development Fund, ERDF, 734641, GINOP-2.3.2-15-2016-00008, H2020-MSCA-RISE-2016, VEKOP-2.3.2-16-2017-00013 Funding details: Nemzeti Kutatási Fejlesztési és Innovációs Hivatal, NKFIH, PD_135169 Funding text 1: The research has been implemented with the support provided from the National Research, Development and Innovation Office of Hungary , financed under the NKFIH K_131989 funding scheme. Mónika Kéri is grateful for the National Research, Development and Innovation Office of Hungary ( NKFIH: PD_135169 ) for financial support. The research was also supported by the EU and co-financed by the European Regional Development Fund under the project GINOP-2.3.2-15-2016-00008 . Financial support of VEKOP-2.3.2-16-2017-00013 (supported by the EU and by Hungary, co-financed by the European Regional Development Fund ) is acknowledged. The work is also part of the EU project NANOMED (H2020-MSCA-RISE-2016, #734641). We are grateful to Balázs Nagy for the aerogel synthesis. Funding text 2: The research has been implemented with the support provided from the National Research, Development and Innovation Office of Hungary, financed under the NKFIH K_131989 funding scheme. M?nika K?ri is grateful for the National Research, Development and Innovation Office of Hungary (NKFIH: PD_135169) for financial support. The research was also supported by the EU and co-financed by the European Regional Development Fund under the project GINOP-2.3.2-15-2016-00008. Financial support of VEKOP-2.3.2-16-2017-00013 (supported by the EU and by Hungary, co-financed by the European Regional Development Fund) is acknowledged. The work is also part of the EU project NANOMED (H2020-MSCA-RISE-2016, #734641). We are grateful to Bal?zs Nagy for the aerogel synthesis. AB - Carbon aerogels prepared from resorcinol-formaldehyde aerogels are promising platforms for electrodes, catalysts, adsorbents in environmental chemistry and as electric conductors. For these applications the knowledge of their structure and behavior in aqueous medium is essential. In this work two resorcinol-formaldehyde (RF) carbon aerogels prepared in different ways were characterized with various NMR methods while their pore structure was stepwise saturated with water. The wetting properties were studied by vapor adsorption and low-field NMR relaxometry, while the morphology was followed by NMR cryoporometry during the hydration process. At several water saturation levels the self-diffusion of water was measured. The comprehensive evaluation of the results led to a detailed description of the wetting process of these carbon aerogels beyond the pore size distributions. At low hydration level water clusters formed on and around the hydrophilic functional groups of the surface being able to adsorb water, but no continuous water layer developed on the surface. With increasing water content, spherical water drops formed inside the pore system, and vapor phase diffusion was observed in the partially filled pores. Subsequently the interconnected pore structure was saturated. The determined wet structure was compared to low temperature nitrogen gas adsorption results and scanning electron microscopy images. LA - English DB - MTMT ER - TY - JOUR AU - Molnár, Enikő AU - Lihi, Norbert AU - Gál, Gyula Tamás AU - De, Sourav AU - Bombicz, Petra AU - Bányai, István AU - Szikra, Dezső AU - Dénes, Eleonóra AU - Tircsó, Gyula AU - Tóth, Imre AU - Kálmán, Ferenc Krisztián TI - Exploring Cyclic Aminopolycarboxylate Ligands for Sb(III) Complexation: PCTA and Its Derivatives as a Promising Solution JF - INORGANIC CHEMISTRY J2 - INORG CHEM VL - 60 PY - 2021 IS - 18 SP - 14253 EP - 14262 PG - 10 SN - 0020-1669 DO - 10.1021/acs.inorgchem.1c01765 UR - https://m2.mtmt.hu/api/publication/32219957 ID - 32219957 N1 - Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, H-4032, Hungary Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, H-4032, Hungary Research Laboratory of Chemical Crystallography, Research Centre for Natural Sciences, Budapest, H-1117, Hungary Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, University of Debrecen, Debrecen, H-4032, Hungary Centre of Supramolecular Organic and Organometallic Chemistry, Department of Chemistry, Babeş-Bolyai University, Cluj-Napoca, RO-400028, Romania Export Date: 28 January 2022 CODEN: INOCA Correspondence Address: Kálmán, F.K.; Department of Physical Chemistry, Hungary; email: kalman.ferenc@science.unideb.hu Funding details: Erasmus+ Funding details: Nemzeti Kutatási Fejlesztési és Innovációs Hivatal, NKFIH, 124544, 128201, FK-134551, K-120224, PD-128326 Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA, ÚNKP-20-4-II Funding details: Innovációs és Technológiai Minisztérium Funding text 1: The research was funded by the Hungarian National Research, Development and Innovation Office (NKFIH K-120224, 128201, 124544, PD-128326, and FK-134551 projects). Eleonóra Dénes thanks Erasmus+ Traineeship for the financial support. N.L. is indebted to the New National Excellence Program of the Ministry for Innovation and Technology from the source of the National Research, Development and Innovation Fund (ÚNKP-20-4-II). The authors are indebted to KIFÜ for awarding access to resource based in Hungary. LA - English DB - MTMT ER - TY - JOUR AU - Garda, Zoltán AU - Kócs, Tamara AU - Bányai, István AU - Martins, José A. AU - Kálmán, Ferenc Krisztián AU - Tóth, Imre AU - Geraldes, Carlos F. G. C. AU - Tircsó, Gyula TI - Complexes of Bifunctional DO3A-N-(α-amino)propinate Ligands with Mg(II), Ca(II), Cu(II), Zn(II), and Lanthanide(III) Ions: Thermodynamic Stability, Formation and Dissociation Kinetics, and Solution Dynamic NMR Studies JF - MOLECULES J2 - MOLECULES VL - 26 PY - 2021 IS - 16 PG - 26 SN - 1420-3049 DO - 10.3390/molecules26164956 UR - https://m2.mtmt.hu/api/publication/32138794 ID - 32138794 N1 - Funding Agency and Grant Number: Hungarian National Research, Development and Innovation OfficeNational Research, Development & Innovation Office (NRDIO) - Hungary [NKFIH K-128201, K-134694, FK-134551] Funding text: This research was funded by the Hungarian National Research, Development and Innovation Office (Projects NKFIH K-128201, K-134694, and FK-134551). AB - The thermodynamic, kinetic, and structural properties of Ln3+ complexes with the bifunc‐ tional DO3A‐ACE4− ligand and its amide derivative DO3A‐BACE4− (modelling the case where DO3A‐ACE4− ligand binds to vector molecules) have been studied in order to confirm the usefulness of the corresponding Gd3+ complexes as relaxation labels of targeted MRI contrast agents. The sta‐ bility constants of the Mg2+ and Ca2+ complexes of DO3A‐ACE4− and DO3A‐BACE4− complexes are lower than for DOTA4− and DO3A3−, while the Zn2+ and Cu2+ complexes have similar and higher stability than for DOTA4− and DO3A3− complexes. The stability constants of the Ln(DO3A‐BACE)− complexes increase from Ce3+ to Gd3+ but remain practically constant for the late Ln3+ ions (repre‐ sented by Yb3+). The stability constants of the Ln(DO3A‐ACE)4− and Ln(DO3A‐BACE)4− complexes are several orders of magnitude lower than those of the corresponding DOTA4− and DO3A3− com‐ plexes. The formation rate of Eu(DO3A‐ACE)− is one order of magnitude slower than for Eu(DOTA)−, due to the presence of the protonated amine group, which destabilizes the protonated intermediate complex. This protonated group causes the Ln(DO3A‐ACE)− complexes to dissociate several orders of magnitude faster than Ln(DOTA)− and its absence in the Ln(DO3A‐BACE)− com‐ plexes results in inertness similar to Ln(DOTA)− (as judged by the rate constants of acid assisted dissociation). The 1H NMR spectra of the diamagnetic Y(DO3A‐ACE)− and Y(DO3A‐BACE)− reflect the slow dynamics at low temperatures of the intramolecular isomerization process between the SA pair of enantiomers, R‐Λ(λλλλ) and S‐Δ(δδδδ). The conformation of the Cα‐substituted pendant arm is different in the two complexes, where the bulky substituent is further away from the macrocyclic ring in Y(DO3A‐BACE)− than the amino group in Y(DO3A‐ACE)− to minimize steric hindrance. The temperature dependence of the spectra reflects slower ring motions than pendant arms rearrange‐ ments in both complexes. Although losing some thermodynamic stability relative to Gd(DOTA)−, Gd(DO3A‐BACE)− is still quite inert, indicating the usefulness of the bifunctional DO3A‐ACE4− in the design of GBCAs and Ln3+‐based tags for protein structural NMR analysis. LA - English DB - MTMT ER -