Paula Sfirloaga

Dr. Paula Sfirloaga

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 January 2021 in Nanomaterials
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Nina FinčurNina Finčur
Nina Finčur
PSPaula Sfirloaga
Paula Sfirloaga
Predrag PutnikPredrag Putnik
Predrag Putnik
VDVesna Despotovic
Vesna Despotovic
MLMarina Lazarevic
Marina Lazarevic
Daniela Šojić MerkulovDaniela Šojić Merkulov
Daniela Šojić Merkulov
Pharmaceuticals and pesticides are emerging contaminants problematic in the aquatic environment because of their adverse effects on aquatic life and humans. In order to remove them from water, photocatalysis is one of the most modern technologies to be used. First, newly synthesized photocatalysts were successfully prepared using a sol–gel method and characterized by different techniques (XRD, FTIR, UV/Vis, BET and SEM/EDX). The photocatalytic properties of TiO2, ZnO and MgO nanoparticles were examined according to their removal from water for two antibiotics (ciprofloxacin and ceftriaxone) and two herbicides (tembotrione and fluroxypyr) exposed to UV/simulated sunlight (SS). TiO2 proved to be the most efficient nanopowder under UV and SS. Addition of (NH4)2S2O8 led to the faster removal of both antibiotics and herbicide fluroxypyr. The main intermediates were separated and identified for the herbicides and antibiotic ciprofloxacin. Finally, the toxicity of each emerging pollutant mixture and formed intermediates was assessed on wheat germination and biomass production.

18 March 2020 in Journal of Materials Chemistry C
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Ioan BicaIoan Bica
Ioan Bica
EAEugen Mircea Anitas
Eugen Mircea Anitas
HCHyoung Jin Choi
Hyoung Jin Choi
PSPaula Sfirloaga
Paula Sfirloaga
We report a simple, versatile and low-cost method to synthesize iron oxide microfibers with high efficiency and in large quantity. The method is based on the thermal decomposition of iron pentacarbonyl (Fe(CO)5) and silicone oil (SO), and vaporization of carbonyl iron (CI) in a microwave plasma. In this process, the mixture of CI and Fe(CO)5 is brought to a bursting state, and the triggered pressure sprays the reaction products in the form of gas–vapor iron columns. At temperatures lower than that of the iron vapor dew point, the columns freeze, and within tens of seconds microfibers are formed whose dimensions can be controlled by the temperature of the environment or by the microwave field power. SEM images show that their diameters are up to about two microns, arranged in a complex hierarchical structure. Magnetic measurements and EDX elemental analysis show the presence of magnetizable fibers containing iron/oxygen atoms in two proportions. XRD measurements show that the fibers consist of α-Fe2O3, γ-Fe2O3 and Fe3O4 iron oxides. We explain the physical mechanisms underlying microfiber formation by developing a theoretical framework based on the Higbie model. The obtained results can be used for fabrication of composite materials with magnetodielectric properties.

29 June 2023 in Pharmaceuticals
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SAStefana Avram
Stefana Avram
LBLarisa Bora
Larisa Bora
LVLavinia Vlaia
Lavinia Vlaia
ACAna Maria Cotan
Ana Maria Cotan
Gheorghe-Emilian OlteanuGheorghe-Emilian Olteanu
Gheorghe-Emilian Olteanu
Danciu CorinaDanciu Corina
Danciu Corina
Origanum vulgare var. vulgare essential oil (OEO) is known as a natural product with multiple beneficial effects with application in dermatology. Oregano essential oil represents a potential natural therapeutic alternative for fibroepithelial polyps (FPs), commonly known as skin tags. Innovative formulations have been developed to improve the bioavailability and stability of essential oils. In this study, we aimed to evaluate the morphology of a polymeric-micelles-based hydrogel (OEO-PbH), the release and permeation profile of oregano essential oil, as well as to assess in vivo the potential effects on the degree of biocompatibility and the impact on angiogenesis in ovo, using a chick chorioallantoic membrane (CAM). Scanning electron microscopy (SEM) analysis indicated a regular aspect after the encapsulation process, while in vitro release studies showed a sustained release of the essential oil. None of the tested samples induced any irritation on the CAM and the limitation of the angiogenic process was noted. OEO-PbH, with a sustained release of OEO, potentially enhances the anti-angiogenic effect while being well tolerated and non-irritative by the vascularized CAM, especially on the blood vessels (BVs) in the presence of leptin treatment. This is the first evidence of in vivo antiangiogenic effects of a polymeric-micelle-loaded oregano essential oil, with further mechanistic insights for OEO-PbH formulation, involving leptin as a possible target. The findings suggest that the OEO-containing polymeric micelle hydrogel represents a potential future approach in the pathology of cutaneous FP and other angiogenesis-related conditions.

13 December 2022 in Processes
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PSPaula Sfirloaga
Paula Sfirloaga
MIMadalina Gabriela Ivanovici
Madalina Gabriela Ivanovici
MPMaria Poienar
Maria Poienar
Ianasi CatalinIanasi Catalin
Ianasi Catalin
PVPaulina Vlazan
Paulina Vlazan
LaMnO3 and 1% Pd-, Ag-, or Y-doped perovskite type nanomaterials were prepared by the sol-gel method, followed by heat treatment at a low temperature (600 °C for 6 h). The investigation through X-ray diffraction and FT-IR spectroscopy indicated that all samples were well crystallized, without secondary phases, and that the transition metal doping changed the crystal structure from the R-3c space group for the undoped LaMnO3 to the Pm-3m space group for the doped perovskite compounds. In this research paper, the efficiencies of the perovskite LaMnO3 materials for methyl orange removal were analyzed, wherein the effect of the doping ions and of the pH on the catalytic activity were studied together with a kinetic approach for the LaMnO3 materials at different values of the pH. Moreover, in the catalytic activity, it should be noted that a slightly better performance was obtained for the Ag-doped materials compared to the Y- and Pd-doped perovskite samples. The results presented for the perovskite LaMnO3 nanomaterials reinforce the interest in these multifunctional materials to be used in industrial applications; e.g., in water treatment.

8 April 2023 in Materials
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IIIoana Maria Carmen Ienascu
Ioana Maria Carmen Ienascu
ACAdina Elena Cata
Adina Elena Cata
CAChis Adriana Aurelia
Chis Adriana Aurelia
MŞMariana Nela Ştefănuț
Mariana Nela Ştefănuț
PSPaula Sfirloaga
Paula Sfirloaga
CDCarmen Dobrea
Carmen Dobrea
Glucosinolates-rich extracts of some Brassicaceae sources, such as broccoli, cabbage, black radish, rapeseed, and cauliflower, were obtained using an eco-friendly extraction method, in a microwave field, with 70% ethanol, and evaluated in order to establish their in vitro antioxidant activities and anticorrosion effects on steel material. The DPPH method and Folin-Ciocâlteu assay proved good antioxidant activity (remaining DPPH, 9.54–22.03%) and the content of total phenolics between 1008–1713 mg GAE/L for all tested extracts. The electrochemical measurements in 0.5 M H2SO4 showed that the extracts act as mixed-type inhibitors proving their ability to inhibit corrosion in a concentration-dependent manner, with a remarkable inhibition efficiency (92.05–98.33%) achieved for concentrated extracts of broccoli, cauliflower, and black radish. The weight loss experiments revealed that the inhibition efficiency decreased with an increase in temperature and time of exposure. The apparent activation energies, enthalpies, and entropies of the dissolution process were determined and discussed, and an inhibition mechanism was proposed. An SEM/EDX surface examination shows that the compounds from extracts may attach to the steel surface and produce a barrier layer. Meanwhile, the FT-IR spectra confirm bond formation between functional groups and the steel substrate.

21 March 2022 in Materials
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ATAlexandrina Teusdea
Alexandrina Teusdea
IMIosif Malaescu
Iosif Malaescu
PSPaula Sfirloaga
Paula Sfirloaga
Catalin Nicolae MarinCatalin Nicolae Marin
Catalin Nicolae Marin
Understanding the electrical conduction and dielectric polarization properties of elastomer-based composites is important for the design of flexible and elastic electronic devices and circuits. Five samples were manufactured by mixing silicone rubber (RTV-530) with Al particles in different volume fractions, x equal to 0%, 0.5%, 1%, 2.5% and 5.1%. Using the complex impedance measurements, the electric modulus, M, the electrical conductivity, σ, and the dielectric permittivity, ε, over the frequency range 100 Hz–200 kHz were analyzed. The electrical conductivity spectrum, σ(f), follows the Jonscher universal law and the DC conductivity of the samples, σDC, increases from 2.637·10−8 S/m to 5.725·10−8 S/m, with increasing x from, 0 to 5.1%. The conduction process was analyzed in terms of Mott’s variable-range-hopping (VRH) model. The hopping distance of the charge carriers, Rh decreases with increasing x, from 7.30 nm (for x = 0) to 5.92 nm (for x = 5.1%). The frequency dependence of permittivity, ε(f) = ε′(f) − iε″(f), reveals a relaxation process with the maximum of ε″(f) shifting from 301 Hz to 385 Hz and values of ε′(f) increasing with the increase of x.