Lucian Baia
@ubbcluj.ro
Babes-Bolyai University
RESEARCH, TEACHING, or OTHER INTERESTS
Materials Science, Biomaterials, Environmental Science
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Alexandra Feraru, Zsejke-Réka Tóth, Klára Magyari, Monica Baia, Tamás Gyulavári, Emőke Páll, Emilia Licarete, Codrut Costinas, Oana Cadar, Ionel Papuc,et al.
Elsevier BV
Anca Peter, Lucica Pop, Leonard Mihaly Cozmuta, Camelia Nicula, Anca Mihaly Cozmuta, Goran Drazic, Klara Magyari, Marieta Muresan-Pop, Milica Todea, and Lucian Baia
Elsevier BV
Emma Bobu, Kata Saszet, Zsejke-Réka Tóth, Emőke Páll, Tamás Gyulavári, Lucian Baia, Klara Magyari, and Monica Baia
MDPI AG
The UV-B component of sunlight damages the DNA in skin cells, which can lead to skin cancer and premature aging. Therefore, it is necessary to use creams that also contain UV-active substances. Many sunscreens contain titanium dioxide due to its capacity to absorb UV-B wavelengths. In the present study, titan dioxide was introduced in alginate and chitosan–alginate hydrogel composites that are often involved as scaffold compositions in tissue engineering applications. Alginate and chitosan were chosen due to their important role in skin regeneration and skin protection. The composites were cross-linked with calcium ions and investigated using FT-IR, Raman, and UV–Vis spectroscopy. The stability of the obtained samples under solar irradiation for skin protection and regeneration was analyzed. Then, the hydrogel composites were assayed in vitro by immersing them in simulated body fluid and exposing them to solar simulator radiation for 10 min. The samples were found to be stable under solar light, and a thin apatite layer covered the surface of the sample with the two biopolymers and titanium dioxide. The in vitro cell viability assay suggested that the anatase phase in alginate and chitosan–alginate hydrogel composites have a positive impact.
Carmen I. Fort, Mihai M. Rusu, Liviu C. Cotet, Adriana Vulpoi, Milica Todea, Monica Baia, and Lucian Baia
MDPI AG
In this study, bismuth- and iron-embedded carbon xerogels (XG) were obtained using a modified resorcinol formaldehyde sol–gel synthesis method followed by additional enrichment with iron content. Pyrolysis treatment was performed at elevated temperatures under Ar or N2 atmosphere to obtain nanocomposites with different reduction yields (XGAr or XGN). The interest was focused on investigating the extent to which changes in the pyrolysis atmosphere of these nanocomposites impact the structure, morphology, and electrical properties of the material and consequently affect the electroanalytical performance. The structural and morphological particularities derived from X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) measurements revealed the formation of the nanocomposite phases, mostly metal/oxide components. The achieved performances for the two modified electrodes based on XG treated under Ar or N2 atmosphere clearly differ, as evidenced by the electroanalytical parameters determined from the detection of heavy metal cations (Pb2+) or the use of the square wave voltammetry (SWV) technique, biomarkers (H2O2), or amperometry. By correlating the differences obtained from electroanalytical measurements with those derived from morphological, structural, and surface data, a few utmost important aspects were identified. Pyrolysis under Ar atmosphere favors a significant increase in the α-Fe2O3 amount and H2O2 detection performance (sensitivity of 0.9 A/M and limit of detection of 0.17 μM) in comparison with pyrolysis under N2 (sensitivity of 0.5 A/M and limit of detection of 0.36 μM), while pyrolysis under N2 atmosphere leads to an increase in the metallic Bi amount and Pb2+ detection performance (sensitivity of 8.44 × 103 A/M and limit of detection of 33.05 pM) in comparison with pyrolysis under Ar (sensitivity of 6.47·103 A/M and limit of detection of 46.37 pM).
Ion Anghel, Catălin Lisa, Silvia Curteanu, Dana Maria Preda, Ioana-Emilia Şofran, Monica Baia, Malvina Stroe, Mirela Paraschiv, Mihaela Baibarac, Virginia Danciu,et al.
Springer Science and Business Media LLC
Zsejke-Réka Tóth, Klara Hernadi, Lucian Baia, Gábor Kovács, and Zsolt Pap
Elsevier BV
Mihai M. Rusu, Carmen I. Fort, Adriana Vulpoi, Lucian Barbu-Tudoran, Monica Baia, Liviu C. Cotet, and Lucian Baia
MDPI AG
Multifunctional materials based on carbon xerogel (CX) with embedded bismuth (Bi) and iron (Fe) nanoparticles are tested for ultrasensitive amperometric detection of lead cation (Pb2+) and hydrogen peroxide (H2O2). The prepared CXBiFe-T nanocomposites were annealed at different pyrolysis temperatures (T, between 600 and 1050 °C) and characterized by X-ray diffraction (XRD), Raman spectroscopy, N2 adsorption, dynamic light scattering (DLS), and electron microscopies (SEM/EDX and TEM). Electrochemical impedance spectroscopy (EIS) and square wave anodic stripping voltammetry (SWV) performed at glassy carbon (GC) electrodes modified with chitosan (Chi)-CXBiFe-T evidenced that GC/Chi-CXBiFe-1050 electrodes exhibit excellent analytical behavior for Pb2+ and H2O2 amperometric detection: high sensitivity for Pb2+ (9.2·105 µA/µM) and outstanding limits of detection (97 fM, signal-to-noise ratio 3) for Pb2+, and remarkable for H2O2 (2.51 µM). The notable improvements were found to be favored by the increase in pyrolysis temperature. Multi-scale parameters such as (i) graphitization, densification of carbon support, and oxide nanoparticle reduction and purification were considered key aspects in the correlation between material properties and electrochemical response, followed by other effects such as (ii) average nanoparticle and Voronoi domain dimensions and (iii) average CXBiFe-T aggregate dimension.
Alexandra Dreanca, Sidonia Bogdan, Andra Popescu, Denisa Sand, Emoke Pall, Andreea Niculina Astilean, Cosmin Pestean, Corina Toma, Sorin Marza, Marian Taulescu,et al.
IOP Publishing
Abstract The most important concept behind using bone scaffolds is the biocompatibility of the material to avoid a local inflammatory response and must have the following properties: osteoinduction, osteoconductivity, angiogenesis, and mechanical support for cell growth. Gold nanoparticles/gold and silver nanoparticles -containing bioactive glasses in biopolymer composites have been used to enhance bone regeneration. These composites were tested in vitro on fibroblast and osteoblast cell lines using MTT tests, immunofluorescence, scanning electron microscopy analysis, and in vivo in an experimental bone defect in Sprague-Dawley rats. Both composites promoted adequate biological effects on human fibroblastic BJ (CRL 2522TM) cell lines and human osteoblastic cells isolated from the human patella in terms of cell proliferation, morphology, migration, and attachment. Most importantly, they did not cause cellular apoptosis and necrosis. According to the histological and immunohistochemical results, both composites were osteoinductive and promoted new bone formation at 60 d. Evidence from this study suggests that the small amount of silver content does not influence negatively the in vitro or in vivo results. In addition, we obtained accurate results proving that the existence of apatite layer and proteins on the surface of the recovered composite, supports the validity of in vitro bioactivity research.
Endre-Zsolt Kedves, Claudiu Fodor, Ákos Fazekas, István Székely, Ákos Szamosvölgyi, András Sápi, Zoltán Kónya, Lucian Cristian Pop, Lucian Baia, and Zsolt Pap
Elsevier BV
Bíborka Boga, Vasile-Mircea Cristea, István Székely, Felix Lorenz, Tamás Gyulavári, Lucian Cristian Pop, Lucian Baia, Zsolt Pap, Norbert Steinfeldt, and Jennifer Strunk
Elsevier BV
Endre-Zsolt Kedves, Enikő Bárdos, Alpár Ravasz, Zsejke-Réka Tóth, Szilvia Mihálydeákpál, Zoltán Kovács, Zsolt Pap, and Lucian Baia
MDPI AG
Orthorhombic molybdenum trioxide (α-MoO3) is well known as a photocatalyst, adsorbent, and inhibitor during methyl orange photocatalytic degradation via TiO2. Therefore, besides the latter, other active photocatalysts, such as AgBr, ZnO, BiOI, and Cu2O, were assessed via the degradation of methyl orange and phenol in the presence of α-MoO3 using UV-A- and visible-light irradiation. Even though α-MoO3 could be used as a visible-light-driven photocatalyst, our results demonstrated that its presence in the reaction medium strongly inhibits the photocatalytic activity of TiO2, BiOI, Cu2O, and ZnO, while only the activity AgBr is not affected. Therefore, α-MoO3 might be an effective and stable inhibitor for photocatalytic processes to evaluate the newly explored photocatalysts. Quenching the photocatalytic reactions can offer information about the reaction mechanism. Moreover, the absence of photocatalytic inhibition suggests that besides photocatalytic processes, parallel reactions take place.
Alexandra Feraru, Zsejke-Réka Tóth, Marieta Mureșan-Pop, Monica Baia, Tamás Gyulavári, Emőke Páll, Romulus V. F. Turcu, Klára Magyari, and Lucian Baia
MDPI AG
In the present study, polysaccharide-based cryogels demonstrate their potential to mimic a synthetic extracellular matrix. Alginate-based cryogel composites with different gum arabic ratios were synthesized by an external ionic cross-linking protocol, and the interaction between the anionic polysaccharides was investigated. The structural features provided by FT-IR, Raman, and MAS NMR spectra analysis indicated that a chelation mechanism is the main process linking the two biopolymers. In addition, SEM investigations revealed a porous, interconnected, and well-defined structure suitable as a scaffold in tissue engineering. The in vitro tests confirmed the bioactive character of the cryogels through the development of the apatite layer on the surface of the samples after immersion in simulated body fluid, identifying the formation of a stable phase of calcium phosphate and a small amount of calcium oxalate. Cytotoxicity tests performed on fibroblast cells demonstrated the non-toxic effect of alginate–gum arabic cryogel composites. In addition, an increase in flexibility was noted for samples with a high gum arabic content, which determines an appropriate environment to promote tissue regeneration. The newly obtained biomaterials that exhibit all these properties can be successfully involved in the regeneration of soft tissues, wound management, or controlled drug release systems.
Alin Grig Mihis, Liviu Cosmin Cotet, Calin Cadar, Lucian Cristian Pop, Milica Todea, Mihai Marius Rusu, Adriana Vulpoi, István Székely, Cătălin Alexandru Sălăgean, Klara Magyari,et al.
Springer Science and Business Media LLC
Zsejke-Réka Tóth, Diána Debreczeni, Tamás Gyulavári, István Székely, Milica Todea, Gábor Kovács, Monica Focșan, Klara Magyari, Lucian Baia, Zsolt Pap,et al.
MDPI AG
The widespread use of Ag3PO4 is not surprising when considering its higher photostability compared to other silver-based materials. The present work deals with the facile precipitation method of silver phosphate. The effects of four different phosphate sources (H3PO4, NaH2PO4, Na2HPO4, Na3PO4·12 H2O) and two different initial concentrations (0.1 M and 0.2 M) were investigated. As the basicity of different phosphate sources influences the purity of Ag3PO4, different products were obtained. Using H3PO4 did not lead to the formation of Ag3PO4, while applying NaH2PO4 resulted in Ag3PO4 and a low amount of pyrophosphate. The morphological and structural properties of the obtained samples were studied by X-ray diffractometry, diffuse reflectance spectroscopy, scanning electron microscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic activity of the materials and the corresponding reaction kinetics were evaluated by the degradation of methyl orange (MO) under visible light. Their stability was investigated by reusability tests, photoluminescence measurements, and the recharacterization after degradation. The effect of as-deposited Ag nanoparticles was also highlighted on the photostability and the reusability of Ag3PO4. Although the deposited Ag nanoparticles suppressed the formation of holes and reduced the degradation of methyl orange, they did not reduce the performance of the photocatalyst.
Codrut Costinas, Catalin Alexandru Salagean, Liviu Cosmin Cotet, Monica Baia, Milica Todea, Klara Magyari, and Lucian Baia
MDPI AG
Understanding graphene oxide’s stability (or lack thereof) in liquid solvents is critical for fine-tuning the material’s characteristics and its potential involvement in future applications. In this work, through the use of structural and surface investigations, the alteration of the structural and edge-surface properties of 2D graphene oxide nanosheets was monitored over a period of eight weeks by involving DLS, zeta potential, XRD, XPS, Raman and FT-IR spectroscopy techniques. The samples were synthesized as an aqueous suspension by an original modified Marcano-Tour method centred on the sono-chemical exfoliation of graphite. Based on the acquired experimental results and the available literature, a phenomenological explanation of the two underlying mechanisms responsible for the meta-stability of graphene oxide aqueous dispersions is proposed. It is based on the cleavage of the carbon bonds in the first 3–4 weeks, while the bonding of oxygen functional groups on the carbon lattice occurs, and the transformation of epoxide and hydroxyl groups into adsorbed water molecules in a process driven by the availability of hydrogen in graphene oxide nanosheets.
Zsolt Czekes, Dóra Bai, Judit Vincze, Emese Gál, Zsuzsanna Réthi-Nagy, Lucian Baia, and Zsolt Pap
Royal Society of Chemistry (RSC)
Commercial titania modified the behavior of ants by changing their cuticular hydrocarbon profile composition through photocatalytic oxidation.
Klára Magyari, Alexandra Dreancă, István Székely, Andra Popescu, Alexandra Feraru, Emőke Páll, Tamás Gyulavári, Maria Suciu, Mihai Cenariu, Emma Bobu,et al.
Springer Science and Business Media LLC
Zoltán Kovács, Csanád Molnár, Tamás Gyulavári, Klára Magyari, Zsejke-Réka Tóth, Lucian Baia, Zsolt Pap, and Klara Hernádi
Elsevier BV
Zoltán Kovács, Viktória Márta, Tamás Gyulavári, Áron Ágoston, Lucian Baia, Zsolt Pap, and Klara Hernadi
Elsevier BV
Zsolt Kása, Enikő Bárdos, Eszter Kása, Tamás Gyulavári, Lucian Baia, Zsolt Pap, and Klara Hernadi
Elsevier BV
Zsejke-Réka Tóth, Alexandra Feraru, Diána Debreczeni, Milica Todea, Radu A. Popescu, Tamás Gyulavári, Alina Sesarman, Giorgiana Negrea, Dan C. Vodnar, Klara Hernadi,et al.
Elsevier BV
Mihai M. Rusu, Adriana Vulpoi, Isabelle Maurin, Liviu C. Cotet, Lucian C. Pop, Carmen I. Fort, Monica Baia, Lucian Baia, and Ileana Florea
Oxford University Press (OUP)
Carbon xerogel nanocomposites with integrated Bi and Fe particles (C–Bi–Fe) represent an interesting model of carbon nanostructures decorated with multifunctional nanoparticles (NPs) with applicability for electrochemical sensors and catalysts. The present study addresses the fundamental aspects of the catalyzed growth of nano-graphites in C–Bi–Fe systems, relevant in charge transport and thermo-chemical processes. The thermal evolution of a C–Bi–Fe xerogel is investigated using different pyrolysis treatments. At lower temperatures (~750°C), hybrid bismuth iron oxide (BFO) NPs are frequently observed, while graphitization manifests under more specific conditions such as higher temperatures (~1,050°C) and reduction yields. An in situ heating TEM experiment reveals graphitization activity between 800 and 900°C. NP motion is directly correlated with textural changes of the carbon support due to the catalyzed growth of graphitic nanoshells and nanofibers as confirmed by HR-TEM and electron tomography (ET) for the graphitized sample. An exponential growth model for the catalyst dynamics enables the approximation of activation energies as 0.68 and 0.29–0.34 eV during reduction and graphitization stages. The results suggest some similarities with the tip growth mechanism, while oxygen interference and the limited catalyst–feed gas interactions are considered as the main constraints to enhanced growth.
Zsejke-Réka Tóth, János Kiss, Milica Todea, Gábor Kovács, Tamás Gyulavári, Alina Sesarman, Giorgiana Negrea, Dan C. Vodnar, Anna Szabó, Lucian Baia,et al.
MDPI AG
Using an ideal biomaterial to treat injured bones can accelerate the healing process and simultaneously exhibit antibacterial properties; thus protecting the patient from bacterial infections. Therefore, the aim of this work was to synthesize composites containing silicate-based bioactive glasses and different types of noble metal structures (i.e., AgI pyramids, AgIAu composites, Au nanocages, Au nanocages with added AgI). Bioactive glass was used as an osteoconductive bone substitute and Ag was used for its antibacterial character, while Au was included to accelerate the formation of new bone. To investigate the synergistic effects in these composites, two syntheses were carried out in two ways: AgIAu composites were added in either one step or AgI pyramids and Au nanocages were added separately. All composites showed good in vitro bioactivity. Transformation of AgI in bioactive glasses into Ag nanoparticles and other silver species resulted in good antibacterial behavior. It was observed that the Ag nanoparticles remained in the Au nanocages, which was also beneficial in terms of antibacterial properties. The presence of Au nanoparticles contributed to the composites achieving high cell viability. The most outstanding result was obtained by the consecutive addition of noble metals into the bioactive glasses, resulting in both a high antibacterial effect and good cell viability.
Endre-Zsolt Kedves, Enikő Bárdos, Tamás Gyulavári, Zsolt Pap, Klara Hernadi, and Lucian Baia
Elsevier BV
E.A. Rusu, K. Magyari, L. Baia, and M. Baia
Elsevier BV