Maria-Daniela Ionita

Dr. Maria-Daniela Ionita


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

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

Representative Publications

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11 November 2018 in Polymers
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DPDenis Mihaela Panaitescu
Denis Mihaela Panaitescu
EIEusebiu Rosini Ionita
Eusebiu Rosini Ionita
CNCristian-Andi Nicolae
Cristian-Andi Nicolae
Antonella Daniela PontorieroAntonella Daniela Pontoriero
Antonella Daniela Pontoriero
MIMaria-Daniela Ionita
Maria-Daniela Ionita
GDGheorghe Dinescu
Gheorghe Dinescu
In this work, a new eco-friendly method for the treatment of poly(3-hydroxybutyrate) (PHB) as a candidate for food packaging applications is proposed. Poly(3-hydroxybutyrate) was modified by bacterial cellulose nanofibers (BC) using a melt compounding technique and by plasma treatment or zinc oxide (ZnO) nanoparticle plasma coating for better properties and antibacterial activity. Plasma treatment preserved the thermal stability, crystallinity and melting behavior of PHB‒BC nanocomposites, regardless of the amount of BC nanofibers. However, a remarkable increase of stiffness and strength and an increase of the antibacterial activity were noted. After the plasma treatment, the storage modulus of PHB having 2 wt % BC increases by 19% at room temperature and by 43% at 100 °C. The tensile strength increases as well by 21%. In addition, plasma treatment also inhibits the growth of Staphylococcus aureus and Escherichia coli by 44% and 63%, respectively. The ZnO plasma coating led to important changes in the thermal and mechanical behavior of PHB‒BC nanocomposite as well as in the surface structure and morphology. Strong chemical bonding of the metal nanoparticles on PHB surface following ZnO plasma coating was highlighted by infrared spectroscopy. Moreover, the presence of a continuous layer of self-aggregated ZnO nanoparticles was demonstrated by scanning electron microscopy, ZnO plasma treatment completely inhibiting growth of Staphylococcus aureus. A plasma-treated PHB‒BC nanocomposite is proposed as a green solution for the food packaging industry.

13 December 2016 in Molecules
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Journal Article
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VSVeronica Satulu
Veronica Satulu
MIMaria-Daniela Ionita
Maria-Daniela Ionita
SVSorin Vizireanu
Sorin Vizireanu
Bogdana MituBogdana Mitu
Bogdana Mitu
GDGheorghe Dinescu
Gheorghe Dinescu
Using plasma in conjunction with fluorinated compounds is widely encountered in material processing. We discuss several plasma techniques for surface fluorination: deposition of fluorocarbon thin films either by magnetron sputtering of polytetrafluoroethylene targets, or by plasma-assisted chemical vapor deposition using tetrafluoroethane as a precursor, and modification of carbon nanowalls by plasma treatment in a sulphur hexafluoride environment. We showed that conformal fluorinated thin films can be obtained and, according to the initial surface properties, superhydrophobic surfaces can be achieved.

13 March 2020 in Materials
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IKIryna Kuchakova
Iryna Kuchakova
MIMaria-Daniela Ionita
Maria-Daniela Ionita
EIEusebiu Rosini Ionita
Eusebiu Rosini Ionita
ALAndrada LAZEA-STOYANOVA
Andrada LAZEA-STOYANOVA
SBSimona Brajnicov
Simona Brajnicov
ANAnton Nikiforov
Anton Nikiforov
Thin film deposition with atmospheric pressure plasmas is highly interesting for industrial demands and scientific interests in the field of biomaterials. However, the engineering of high-quality films by high-pressure plasmas with precise control over morphology and surface chemistry still poses a challenge. The two types of atmospheric-pressure plasma depositions of organosilicon films by the direct and indirect injection of hexamethyldisiloxane (HMDSO) precursor into a plasma region were chosen and compared in terms of the films chemical composition and morphology to address this. Although different methods of plasma excitation were used, the deposition of inorganic films with above 98% of SiO2 content was achieved for both cases. The chemical structure of the films was insignificantly dependent on the substrate type. The deposition in the afterglow of the DC discharge resulted in a soft film with high roughness, whereas RF plasma deposition led to a smoother film. In the case of the RF plasma deposition on polymeric materials resulted in films with delamination and cracks formation. Lastly, despite some material limitations, both deposition methods demonstrated significant potential for SiOx thin-films preparation for a variety of bio-related substrates, including glass, ceramics, metals, and polymers.

8 September 2020 in Molecules
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RBRuxandra Birjega
Ruxandra Birjega
AMAndreea Matei
Andreea Matei
VMValentina Marascu
Valentina Marascu
AVAngela Vlad
Angela Vlad
MIMaria-Daniela Ionita
Maria-Daniela Ionita
Mihai Cosmin CorobeaMihai Cosmin Corobea
Mihai Cosmin Corobea
We report on the investigation of stearic acid-layered double hydroxide (LDH) composite films, with controlled wettability capabilities, deposited by a combined pulsed laser deposition (PLD)-matrix-assisted pulsed laser evaporation (MAPLE) system. Two pulsed lasers working in IR or UV were used for experiments, allowing the use of proper deposition parameters (wavelength, laser fluence, repetition rate) for each organic and inorganic component material. We have studied the time stability and wettability properties of the films and we have seen that the morphology of the surface has a low effect on the wettability of the surfaces. The obtained composite films consist in stearic acid aggregates in LDH structure, exhibiting a shift to hydrophobicity after 36 months of storage.

5 February 2022 in Nanomaterials
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LDLuminita Nicoleta Dumitrescu
Luminita Nicoleta Dumitrescu
EIEusebiu Rosini Ionita
Eusebiu Rosini Ionita
RBRuxandra Birjega
Ruxandra Birjega
ALAndrada LAZEA-STOYANOVA
Andrada LAZEA-STOYANOVA
MIMaria-Daniela Ionita
Maria-Daniela Ionita
AMAndreea Matei
Andreea Matei
In this work, thin films of lamellar clays were deposited by laser techniques (matrix assisted pulsed laser evaporation (MAPLE) and pulsed laser deposition (PLD)). The focus of this paper is the optimization of deposition parameters for the production of highly oriented crystalline films. The films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Contact angle measurements were employed to identify the wetting properties of the deposited thin films. Hydrophobic to superhydrophilic films can be prepared by using different deposition techniques and deposition parameters. MAPLE led to superhydrophilic films with contact angles in the range 4°–8°, depending on the microstructure and surface roughness at micro and nano scale. The 1064 nm PLD had a high deposition rate and produced a textured film while at λ = 193 nm an extremely thin and amorphous layer was depicted. Oriented kaolinite films were obtained by MAPLE even at 5 wt.% kaolinite in the target.