Andrei Popescu

Dr. Andrei Popescu


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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9 November 2021 in Polymers
Verified
Journal Article
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VPVasilica Popescu
Vasilica Popescu
Alexandra BlagaAlexandra Blaga
Alexandra Blaga
Pruneanu MelindaPruneanu Melinda
Pruneanu Melinda
ICIrina Cristian
Irina Cristian
Marius PislaruMarius Pislaru
Marius Pislaru
DCDan Cascaval
Dan Cascaval
The beetroot peels can be a sustainable source of betalains that can dye the wool materials through green processes based on low water and energy consumption. Green chemistry in the extraction of betalains from colored food waste/peels from red beetroot involved the use of water as a solvent, without other additives. In order for the extract obtained to be able to dye the wool, it was necessary to functionalize betalains or even the wool. Three types of sustainable functionalizations were performed, with (1) acetic acid; (2) ethanol; and (3) arginine. For each functionalization, the mechanism that can justify dyeing the wool in intense colors was elucidated. The characterization of the extract was performed with the data provided by UV-VIS and HPLC-MS analyses. The characterization of the wool dyed with the extract obtained from the red beetroot peels was possible due to the information resulting from the FTIR and CIELab analyses. The functionalizations of betalains and wool in acid environments lead to the most intense red colors. The color varies depending on the pH and the concentration of betalains.

9 May 2023 in Plants
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Journal Article
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VPVasilica Popescu
Vasilica Popescu
Alexandra BlagaAlexandra Blaga
Alexandra Blaga
DCDan Cascaval
Dan Cascaval
APAndrei Popescu
Andrei Popescu
Beta vulgaris L. is a biennial plant easily accessible all over the world, rich in various biologically active compounds, especially a class of extremely bioactive pigments known as betalains. These dyes predominate in the pulp and peels of beetroot, which is why they can be valorized in food, medicine or in the textile industry. In this work, betalains extractions were carried out applying 3 sustainable options: (1) dissolving/solubilizing betalains in water; (2) extraction under pressure; (3) extraction assisted by an enzyme/pectinase. The obtained extracts were analyzed in the UV-Vis domain, which allowed their characterization by determining the total monomeric anthocyanins, color density (control), polymeric density and browning index. The HPLC-MS analysis highlighted the extracts composition. The colors characteristics were determined through CIELab measurements. The performances of these 3 extracts, during green dyeing (without mordants), were evaluated according to the color characteristics (L*, a*, b* and K/S) of the dyed wool samples under different conditions: pH, temperature, duration of dyeing and volume of extract and stabilizers (Vitamin E and EDTA). Betalains can be considered acid dyes, with a low affinity for wool, which in a pronounced acidic environment dye the wool in an intense, uniform way and with good resistance to washing and rubbing.

31 March 2025 in Applied Sciences
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Journal Article
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VSValentina Gabi Stănescu
Valentina Gabi Stănescu
VPVasilica Popescu
Vasilica Popescu
VVViorica Vasilache
Viorica Vasilache
GPGabriel Popescu
Gabriel Popescu
CRISTINA MIHAELA RÎMBUCRISTINA MIHAELA RÎMBU
CRISTINA MIHAELA RÎMBU
APAndrei Popescu
Andrei Popescu
This article demonstrates that the quality of laundry soap obtained by hot/cold saponification of two vegetable oils (olive and coconut) and an essential oil (such as Neem, Tea Tree or Thyme) influences the effects obtained after washing textiles: cleansing capacity and antibacterial effect. The results of FTIR, SEM, EDX, thermogravimetry and colorimetry analyses are presented comparatively for hot- and cold-prepared soaps. Saponification, Iodine number and Iodine Number Saponification values are determined for each oil but also for the mixture used in soap-making. Soap quality refers to texture, hardness, foaming capacity, stability, durability, cleansing capacity after washing and antimicrobial capacity. The removal power of greasy dirt (heavy used engine oil) of these laundry soaps is higher than that of some commercial soaps, obtaining dirt visibility <2.6% after washing at 100 °C, soiling addition density SAD < 0.0229 and cleansing capacity between 80.88 and 92.16%. UV-VIS analysis confirms the presence of essential oil in soaps (even after 10 months from manufacture) but also in textiles washed with them. The essential oil imparts strong antimicrobial properties to the laundry soaps (since they do not allow for attachment or multiplication of microorganisms from the environment), which makes them particularly useful in washing and disinfecting textile products used in hospitals.

24 October 2021 in Polymers
Verified
Journal Article
Open access
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VPVasilica Popescu
Vasilica Popescu
IBIngrid Ioana Buciscanu
Ingrid Ioana Buciscanu
Pruneanu MelindaPruneanu Melinda
Pruneanu Melinda
SMStelian Sergiu Maier
Stelian Sergiu Maier
ADAngela Danila
Angela Danila
MMMarina Marin
Marina Marin
This study may open a new way to obtain the coloration of a polymer during functionalization. Two polyacrylonitrile (PAN) polymers in the form of textile fibers (Melana and Dralon L) were subjected to functionalization treatments in order to improve the dyeing capacity. The functionalizations determined by an organo-hypervalent iodine reagent developed in situ led to fiber coloration without using dyes. KIO3 was formed in situ from the interaction of aqueous solutions of 3–9% KOH with 3–9% I2, at 120 °C. The yellow-orange coloration appeared as a result of the transformations in the chemical structure of each functionalized polymer, with the formation of iodinehydrin groups. The degree of functionalization directly influenced the obtained color. The results of the Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Map and Temogravimetric Analysis (TG) plus Differential Thermal (DTA) analyses indicated the presence of new functional groups, such as iodine-oxime. The X-ray diffraction (XRD) analysis confirmed the change of the crystalline/amorphous ratio in favor of the former. The new groups introduced by functionalization make it possible to dye with classes of dyes specific to these groups, but not specific to PAN fibers, thus improving their dyeing capacity.

27 January 2021 in Polymers
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Journal Article
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VPVasilica Popescu
Vasilica Popescu
MPMarioara Petrea
Marioara Petrea
APAndrei Popescu
Andrei Popescu
Multifunctionalization of cotton using a single product has not been made until now. Such a product was synthesized using compounds with multiple functions (glyoxal, ethylenediamine (ED) and monochlorotriazinyl-β–cyclodextrin (MCT-β-CD)), under different mass ratios. Obtaining this multifunctional derivative has been confirmed by spectroscopic analyses (1H-NMR and FTIR) and a scanning electron microscope (SEM). Treatment of cotton with the MCT-β-CD derivative (D-CD) has been realized with the pad dry-cure technology. The presence of this multifunctional derivative on cotton was highlighted with spectroscopic (FTIR, EDAX, XRD) and thermoanalytical (DSC) methods. The objective of treating cotton with D-CD was to achieve four simultaneous effects: large wrinkle recovery angle (WRA), hydrophilicity, antibacterial capacity and a good breaking resistance. This objective has been achieved, so the garments that will be manufactured with such multifunctional cotton will be more comfortable. The efficiency of treatments with D-CD was marked out by multiple linear regression (MLR) and certain quality indices. Using MLR, the behavior of the treated cotton was mathematically modeled and the stationary/optimal points corresponding to each effect were calculated. Quality indices have been calculated and all final samples had values higher than 1, which confirmed the positive effects exerted by D-CDs on cotton.

1 March 2022 in Bulletin of the Polytechnic Institute of Iași. Machine constructions Section
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Journal Article
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APAndrei Popescu
Andrei Popescu
GPGabriel Popescu
Gabriel Popescu
The present paper proposes a method for an almost uniform pressure distribution between the rolling elements, based on the modification of the roller’s initial straight profile and accounting for material parameters related to the operating temperature. The optimization process is analyzed by including the possible misalignment and/or tilting angles of the roller due to operating conditions. A computer program was developed in the Borland C++ programming language. The contact pressure distribution is evaluated by using a three-dimensional contact analysis model based on the Boussinesq force-displacement relations for a half-space combined with the flexibility approach. For a fast analysis, the algorithm uses a Conjugate Gradient Method in deriving the contact pressures and the real contact area.