Béla Fiser

• PhD - Materials Science & Technology, PhD - Chemistry, MSc - Biophysics
• Research Associate at University of Miskolc

In this work, α-tocopherol and trolox were studied as compounds that have high biological activity. α-Tocopherol is considered a food additive because the refining process of vegetable oils causes the depletion of this vitamin, and thus, its inclusion is required to keep them from oxidizing. Computational tools have determined the antioxidant activ...

Activated carbon (AC) and biochar (BC) are porous materials with large surface areas and widely used in environmental and industrial applications. In this study, different types of AC and BC samples were produced from Sargassum sp. by a chemical activation and pyrolysis process and compared to commercial activated carbon samples. All samples were c...

Glass ionomer cement (GIC) is one of the most widely used restorative materials for temporary fillings and reconstructions in dentistry, but it has relatively poor mechanical properties that make its use limited, especially in places subject to high pressure. Thus, to extend the applicability of GIC, samples based on SiO2, P2O5, Al2O3, CaF2, and Na...

The enantioselective binding of three proton pump inhibitors (PPIs)—omeprazole, rabeprazole, and lansoprazole—to two key plasma proteins, α1-acid glycoprotein (AGP) and human serum albumin (HSA), was characterized. The interactions between PPI enantiomers and proteins were investigated using a multifaceted analytical approach, including high-perfor...

In Europe mainly at winter season the PM levels exceed air quality limits, which correlated with the operation of solid-fired boilers. More and more people are returning to using these devices due to energy shortage caused by the pandemic and regional conflicts. In addition, the phenomena of co-burning fuels and municipal waste in residential boile...

Polyurethanes (PUs) are a special class of polymeric materials that differ significantly from most other types of plastic in many aspects. They can be utilized in a wide range of products, including paints, coatings, elastomers, insulators, elastic fibers, and foams. PU foams are especially important as part of various convenience products. PU prod...

Flexible pressure sensors (FPS) are crucial for emerging applications like wearable electronics, human activity monitoring, and soft robotics. This study reports a scalable and cost‐effective approach to fabricate high‐performance piezoresistive FPS based on polyurethane‐silicone rubber (PU‐SR) nanocomposites. The synergistic integration of nitroge...

Enticed by the present scenario of infectious diseases, four new Co(II), Ni(II), Cu(II), and Cd(II) complexes of Schiff base ligand were synthesized from 6,6′-((1E-1′E)(phenazine-2,3-dielbis(azanylidene)-bis-(methanylidene)-bis-(3-(diethylamino)phenol)) (H 2 L) to ascertain as effective drug for antituberculosis, anti-inflammatory, antioxidant, cyt...

Carbodiimides are important crosslinkers in organic synthesis and are used in the iso-cyanate industry as modifier additives. Therefore, the understanding of their formation is of highimportance. In this work, we present a theoretical B3LYP/6-31G(d) and SMD solvent model andexperimental investigation of the formation of diphenylcarbodiimide (CDI) f...

The 2,4-toluenediamine (TDA) is one of the most important chemicals in the polyurethane industry, produced by the catalytic hydrogenation of 2,4-dinitrotoluene (DNT). The development of novel catalysts that can be easily recovered from the reaction mixture is of paramount importance. In our work, a NiFe2O4/N-BCNT supported magnetic catalyst was pre...

A general mechanism for catalytic urethane formation in the presence of acid catalysts, dimethyl hydrogen phosphate (DMHP), methanesulfonic acid (MSA), and trifluoromethanesulfonic acid (TFMSA), has been studied using theoretical methods. The reaction of phenyl isocyanate (PhNCO) and butan-1-ol (BuOH) has been selected to describe the energetic and...

Drug repositioning is a high-priority and feasible strategy in the field of oncology research, where the unmet medical needs are continuously unbalanced. Disulfiram is a potential non-chemotherapeutic, adjuvant anticancer agent. However, the clinical translation is limited by the drug`s poor bioavailability. Therefore, the molecular encapsulation o...

A reversed-phase high-performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of the potential impurities of dexketoprofen, including the distomer R-ketoprofen. After screening the separation capability of four polysaccharide columns (Lux Amylose-1, Lux Amylose-2, Lux Cellulose-1 and Lux Cellulose-2) in pol...

Toluene diamine (TDA) is a major raw material in the polyurethane industry and thus, its production is highly important. TDA is obtained through the catalytic hydrogenation of 2,4-dinitrotoluene (2,4-DNT). In this study a special hydrogenation catalyst has been developed by decomposition cobalt ferrite nanoparticles onto a natural clay-oxide nanoco...

A computational study of the stoichiometric reaction and catalytic effect of 2-dimethylaminoethanol (DMEA) in urethane formation was performed.

Vildagliptin (VIL) is a dipeptidyl peptidase-4 inhibitor used in the treatment of type 2 diabetes mellitus; in therapy, it is available as the enantiomerically pure S-VIL, the other enantiomer R-VIL being considered as an enantiomeric impurity. A systematic screening of 16 cyclodextrin (CD) derivatives as chiral selectors was performed at three pH...

Catalysts with magnetic properties can be easily recovered from the reaction medium without loss by using a magnetic field, which highly improves their applicability. To design such systems, we have successfully combined the magnetic properties of nickel ferrite nanoparticles with the positive properties of carbon-based catalyst supports. Amine-fun...

In this work, molecular dynamics simulation is used to describe and analyze the behavior of model collagen polymer (Pro-Pro-Gly)9. This project aims to highlight the important role of molecular dynamic simulation in determining the structural stability of collagen, and establishing collagen as a hydrophobic or hydrophilic protein under different te...

Polyurethane is the most important class of polymers. It contains several urethane bonds, which connect the building blocks of the polymer. Thus, the chemical recycling and the degradation of the polymer depend on the strength of the urethane bond. To better understand polyurethane degradation at the molecular level, three model systems were create...

A theoretical study of urethane formation through the reaction of phenyl isocyanate and butan-1-ol was carried out, without and in the presence of morpholine, and 4-methylmorpholine catalysts. The reaction with and without catalysts was studied at BHandHLYP/6-31G(d) and G3MP2BHandHLYP levels of theories. The reaction mechanism in the presence of ca...

The chiral separation capability of Chiral-CD-Ph column, containing phenylcarbamate-β-cyclodextrin as the chiral selector in polar organic mode was investigated. A total of twenty-five compounds with different structures and acid–base properties were evaluated, and twenty of them were separated using acetonitrile or methanol as eluent. The effects...

Utilization of multivariate data analysis in catalysis research has extraordinary importance. The aim of the MIRA21 (MIskolc RAnking 21) model is to characterize heterogeneous catalysts with bias-free quantifiable data from 15 different variables to standardize catalyst characterization and provide an easy tool to compare, rank, and classify cataly...

Small ring nitrogen heterocycles, azabicyclobutanes and azirines, were investigated by computational methods in order to address the discrepancy between their regioisomers 1‐ and 2‐azabicyclobutane and 1H‐ and 2H‐azirines. Both 1‐azabicyclobutane and 2H‐azirine are well known synthetic starting points to larger nitrogen heterocycles whereas 2‐azabi...

The chiral separation capability of Chiral-CD-Ph column, containing phenylcarbamate-β-cyclodextrin as the chiral selector in polar organic mode was investigated. A total of 25 compounds with different structures and acid-base properties were tested, and 20 of them were separated using acetonitrile or methanol as eluent. The effects of various chrom...

Comparative chiral separations of enantiomeric pairs of four oxazolidinone and two related thio-derivatives were performed by capillary electrophoresis, using cyclodextrins (CDs) as chiral selectors. Since the selected analytes are neutral, the enantiodiscrimination capabilities of nine anionic CD derivatives were determined, in 50 mM phosphate buf...

Our daily lives depend heavily on polyurethane (PU) and other polymers. As PU foam is utilized in so many different areas, polyurethane waste builds up in our surroundings (e.g. water, soil). While there are various methods for managing waste, biodegradation is one that is comparatively underutilized. The benefit of biodegradation is that it may fu...

Oxidative stress makes it difficult to preserve food and negatively affect the applicability of polymeric packaging. It is typically caused by an excess of free radicals, and it is dangerous to human health, resulting in the onset and development of diseases. The antioxidant ability and activity of ethylenediaminetetraacetic acid (EDTA) and Irganox...

Pressure sensors based on nitrogen-doped bamboo-shaped carbon nanotubes (N-BCNT) and carbon black (CB) as nanofillers, polyurethane foam (PU) as supporting substrate, and silicone rubber (SR) as a matrix were prepared. Dip coating was used to coat PU with 0.44 wt% nanofiller, including different mixing ratios of N-BCNT and CB (5:5; 6:4; 7:3; 8:2; 9...

Interfacial magnetism and metal-insulator transition at LaNiO $$_3$$ 3 -based oxide interfaces have triggered intense research efforts, because of the possible implications in future heterostructure device design and engineering. Experimental observation lack in some points a support from an atomistic view. In an effort to fill such gap, we hereby...

The interaction between human serum albumin (HSA) and apremilast (APR), a novel antipsoriatic drug, was characterized by multimodal analytical techniques including high-performance liquid chromatography (HPLC), fluorescence spectroscopy and molecular docking for the first time. Using an HSA chiral stationary phase, the APR enantiomers were well sep...

2,4-diaminotoluene (TDA) is one of the most important polyurethane precursors produced in large quantities by the hydrogenation of 2,4-dinitrotoluene using catalysts. Any improvement during the catalysis reaction is therefore of significant importance. Separation of the catalysts by filtration is cumbersome and causes catalyst loss. To solve this p...

2,4- and 2,6-isomers of toluene diisocyanates (2,4-TDI and 2,6-TDI) are important raw materials in the polyurethane industry. These reactive compounds associate even under ambient conditions to form oligomers, changing the physicochemical properties of the raw material. Kinetically and thermodynamically relevant dimerization reactions were selected...

The lipid peroxidation end product, 4-hydroxy-2-nonenal (HNE), is a secondary mediator of oxidative stress due to its strong ability to form adducts to the side chains of lysine, histidine, and cysteine residues (Cys) at increasing reactivities. This reaction can take place in various cellular environments and may be dependent on solvent. Moreover,...

Granulated carbon nanotube-supported palladium and platinum-containing catalysts were developed. By using these, remarkable catalytic activity was achieved in chlorate ion hydrogenation. Nitrogen-doped bamboo-like carbon nanotubes (N-BCNTs) loaded gel beads were prepared by using Ca2+, Ni2+ or Fe3+ ions as precursors for cross-linking of sodium alg...

In this work, three different polyurethane (PU) foams were prepared by mixing commonly used isocyanate and polyol with different isocyanate indices (1.0:0.8, 1.0:1.0, 1.0:1.1). Then, the prepared polyurethane foam samples were coated by dip-coating with a fixed ratio of nitrogen-doped, bamboo-shaped carbon nanotubes (N-BCNTs) to obtain pressure sen...

A wide variety of additives are used to improve specific characteristics of the final polymeric product. Antioxidant additives (AAs) can prevent oxidative stress and thus the damage of polymeric materials. In this work, the antioxidant potential and thus the applicability of Santowhite (SW) as synthetic and ascorbic acid (Asc) as natural AAs were e...

A kinetic and mechanistic investigation of the alcoholysis of phenyl isocyanate (PhNCO) using stoichiometric butan-1-ol (BuOH) in acetonitrile in the presence of different tertiary amine catalysts was undertaken. The reaction mechanisms without and in the presence of the experimentally applied catalysts were described by using the G3MP2BHandHLYP co...

Creating supersaturating drug delivery systems to overcome the poor aqueous solubility of active ingredients became a frequent choice for formulation scientists. Supersaturation as a solution phenomenon is, however, still challenging to understand, and therefore many recent publications focus on this topic. This work aimed to investigate and better...

The alcoholysis of phenyl isocyanate (PhNCO) using stoichiometric butan-1-ol (BuOH) in acetonitrile in the presence of different cyclic amine catalysts was examined using a combined kinetic and mechanistic approach. The molecular mechanism of urethane formation without and in the presence of cyclic amine catalysts was studied using the G3MP2BHandHL...

Aniline is one of the most important chemical in the polyurethane industry and it is produced by the catalytic hydrogenation of nitrobenzene. The development of novel, multifunctional catalysts, which are easily recoverable from the reaction mixture is therefore of paramount importance. Transition metal-containing ferrites decorated with palladium...

Additives play a significant role in processing and improving the properties of polymers used in many applications. Antioxidant additives are substances that can prevent oxidative stress induced deterioration of the materials. There are two main types of antioxidants, synthetic and natural. The antioxidant potential of commonly used synthetic and n...

Aniline (AN) is one of the most important compounds in the chemical industry and is prepared by the catalytic hydrogenation of nitrobenzene (NB). The development of novel, multi-functional catalysts which are easily recoverable from the reaction mixture is, therefore, of paramount importance. Compared to conventional filtration, magnetic separation...

Carbon foam was synthesized by the carbonization of 4-nitroaniline. The reaction is an alternative of the well-known “carbon snake” (or sugar snake) demonstration experiment, which leads to the formation of nitrogen-doped carbon foils due to its nitrogen content. The synthesized carbon foils were grinded to achieve an efficient catalyst support. Pa...

The combination of the sonochemical activation of Ni(NO3)2 and Co(NO3)2 in the presence of Fe(NO3)3 and polyethylene glycol and consecutive heat treatment of the formed metal hydroxides offers a cheap and efficient method for the preparation of nickel ferrite and cobalt ferrite magnetic nanoparticles, which can be successfully applied in the select...

The antioxidant potential of commonly used synthetic and natural antioxidant additives, including butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), tert-butylhydroquinone (TBHQ), and natural additive, curcumin have been studied and compared by calculating the bond dissociation enthalpy (BDE), ionization potential (IP), proton dissocia...

Reaction initiation points of the 16 priority polycyclic aromatic hydrocarbons (PAHs) have been determined by calculating all the different C-H bond dissociation enthalpy (BDE) values. Six density functional theory methods (B3LYP, B3LYP-D3, B97D3, M06-LD3, M06-2X-D3, and ωB97X-D) in combination with 4 basis sets (6-31G(d), 6-31+G(d,p), 6-311++G(d,p...

Isocyanoaminoarenes (ICAAr-s) are a novel and versatile group of solvatochromic fluorophores. Despite their versatile applicability, such as antifungals, cancer drugs and analytical probes, they still represent a mostly unchartered territory among intramolecular charge-transfer (ICT) dyes. The current paper describes the preparation and detailed op...

Polyurethane flexible foams are widely used for a variety of applications to improve comfort and durability. Their long-term frequent use inevitably leads to the generation of waste that needs to be treated. The recycling and reuse of polyurethane waste are essential to achieve an environmentally friendly economy. The present study investigates the...

Polyurethanes (PUs) are widely used in different applications, and thus various synthetic procedures including one or more catalysts are applied to prepare them. For PU foams, the most important catalysts are nitrogen-containing compounds. Therefore, in this work, the catalytic effect of eight different nitrogen-containing catalysts on urethane for...

Maghemite particles were synthesized by using a combined combustion method and sonochemical step. Maghemite was used as carrier to prepare supported Pt and Pd catalysts after deposition via a sonochemical step. The catalysts were immediately ready to be used (metals were catalytically active) for the 2,4-dinitrotoluene hydrogenation to produce 2,4-...

Polycyclic aromatic hydrocarbons (PAHs) are mostly formed during the incomplete combustion of organic materials, but their importance and presence in materials science, and astrochemistry has also been proven. These carcinogenic persistent organic pollutants are essential in the formation of combustion generated particles as well. Due to their sign...

Cellulose grains were carbonized and applied as catalyst supports for nickel- and magnetite-promoted bimetallic palladium- and platinum-containing catalysts. The bimetallic spherical aggregates of Pd and Pt particles were created to enhance the synergistic effect among the precious metals during catalytic processes. As a first step, the cellulose b...

Carbon black supported palladium-platinum catalysts were prepared with and without nickel(II) oxide or iron(III) oxide promoter materials. By applying ultrasonic cavitation highly efficient carbon black supported catalysts were created. The designed catalyst preparation is a one-step procedure, as post-treatments (e.g. calcination, hydrogen activat...

Pomalidomide (POM), a potent anticancer thalidomide analogue was characterized in terms of cyclodextrin complexation to improve its aqueous solubility and maintain its anti-angiogenic activity. The most promising cyclodextrin derivatives were selected by phase-solubility studies. From the investigated nine cyclodextrins – differing in cavity size,...

Abstract: In this study, a novel technology is reported to prepare a piezoresistive polyurethane-silicone rubber nanocomposite. Polyurethane (PU) foam was loaded with a nitrogen-doped bamboo-shaped carbon nanotube (N-BCNT) by using dip-coating, and then, impregnated with silicone rubber. PU was used as a supporting substrate for N-BCNT, while silic...

Cobalt, copper, and nickel ferrite spinel nanoparticles have been synthesized by using a combination of sonochemical treatment and combustion. The magnetic nanoparticles have been used as supports to prepare ~4 wt% palladium catalysts. The ferrites were dispersed in an ethanolic solution of Pd(II) nitrate by ultrasonication. The palladium ions were...

DFT calculations were used to determine the structures and energies of bicyclobutane and oxabicyclobutane as valence isomers derived from electronic excitation of their corresponding precursors, 1,3‐butadiene and acrolein, respectively. Proton affinities of these strained compounds were determined and compared to their simple ring components, cyclo...

The catalytic hydrogenation of 2,4-dinitrotoluene (DNT) to 2,4-toluenediamine (TDA) is a key step in the production of polyurethanes; therefore, the development of efficient hydrogenation catalysts for industrial use is of paramount importance. In the present study, chromium(IV) oxide nanowires were decorated by palladium and platinum nanoparticles...

The reduction of undesirable chlorate (ClO3-) is important from both an environmental and an industrial point of view. In our work, cellulose-based catalysts have been designed for chlorate reduction by using palladium, platinum, and iron oxide. The produced catalysts were characterized by SEM, TEM, XRD, FTIR, and ICP. Even though low precious meta...

Polycyclic aromatic hydrocarbons (PAH) are harmful chemicals emitted to the environment by incomplete combustion. As the aromatic structure grows, the carcinogenic effect increases, and thus, to understand their formation mechanisms is crucial. In this work, new reaction pathways leading to benzo(a)pyrene, a PAH with well-known carcinogenic effects...

Antioxidants are compounds used to prevent the thermal and photo-oxidative effects of the environment. These molecules are highly important to preserve and prolong various products. A wide variety of synthetic and natural antioxidants applied in the food and polymer industry. A good number of such molecules have phenolic character, such as in the c...

A theoretical investigation of urethane formation through the reaction of phenyl iso-cyanate and methanol without and in the presence of a secondary ketimine catalyst (DBU) was carried out by using density functional theory method in gas phase and in organic solvent (THF). The reaction mechanisms have been explored, and the corresponding thermodyna...

Converting carbon dioxide to fine chemicals such as methanol using electrolytic hydrogen could be an efficient way of renewable energy storage. The conversion of CO2 to methanol is a rather complicated multistep process which is usually performed catalytically in gas phase. However, the aqueous phase conversion of CO2 is also feasible in certain co...

Among many theories on the life’s origins, the regions between star systems in a galaxy are hypothesized to provide prebiotic material on Earth. Simple sugars, including glycolaldehyde, are confirmed to exist in interstellar medium (ISM) and can be intermediates in the formose reaction to form dihydroxyacetone (DHA). In the studied segment of the f...