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Costas A, Preda N, Zgura I, Kuncser A, Apostol N, Curutiu C, Enculescu I. Silver nanoparticles decorated ZnO-CuO core-shell nanowire arrays with low water adhesion and high antibacterial activity. Sci Rep 2023; 13:10698. [PMID: 37400545 PMCID: PMC10318101 DOI: 10.1038/s41598-023-37953-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 06/30/2023] [Indexed: 07/05/2023] Open
Abstract
Nanostructured surfaces based on silver nanoparticles decorated ZnO-CuO core-shell nanowire arrays, which can assure protection against various environmental factors such as water and bacteria were developed by combining dry preparation techniques namely thermal oxidation in air, radio frequency (RF) magnetron sputtering and thermal vacuum evaporation. Thus, high-aspect-ratio ZnO nanowire arrays were grown directly on zinc foils by thermal oxidation in air. Further ZnO nanowires were coated with a CuO layer by RF magnetron sputtering, the obtained ZnO-CuO core-shell nanowires being decorated with Ag nanoparticles by thermal vacuum evaporation. The prepared samples were comprehensively assessed from morphological, compositional, structural, optical, surface chemistry, wetting and antibacterial activity point of view. The wettability studies show that native Zn foil and ZnO nanowire arrays grown on it are featured by a high water droplet adhesion while ZnO-CuO core-shell nanowire arrays (before and after decoration with Ag nanoparticles) reveal a low water droplet adhesion. The antibacterial tests carried on Escherichia coli (a Gram-negative bacterium) and Staphylococcus aureus (a Gram-positive bacterium) emphasize that the nanostructured surfaces based on nanowire arrays present excellent antibacterial activity against both type of bacteria. This study proves that functional surfaces obtained by relatively simple and highly reproducible preparation techniques that can be easily scaled to large area are very attractive in the field of water repellent coatings with enhanced antibacterial function.
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Affiliation(s)
- Andreea Costas
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania
| | - Nicoleta Preda
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania.
| | - Irina Zgura
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania
| | - Andrei Kuncser
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania
| | - Nicoleta Apostol
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania
| | - Carmen Curutiu
- Microbiology Immunology Department, Faculty of Biology, University of Bucharest, Aleea Portocalelor 1-3, 060101, Bucharest, Romania
| | - Ionut Enculescu
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania
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Ciobotaru IC, Enculescu M, Polosan S, Enculescu I, Ciobotaru CC. Organic Light-Emitting Diodes with Electrospun Electrodes for Double-Side Emissions. Micromachines (Basel) 2023; 14:543. [PMID: 36984949 PMCID: PMC10056642 DOI: 10.3390/mi14030543] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Transparent conductive electrodes (TCE) obtained by the electrospinning method and gold covered were used as cathodes in the organic light-emitting diodes (OLEDs) to create double side-emission. The electro-active nanofibers of poly(methyl methacrylate) (PMMA) with diameters in the range of several hundreds of nanometers, were prepared through the electrospinning method. The nanofibers were coated with gold by sputtering deposition, maintaining optimal transparency and conductivity to increase the electroluminescence on both electrodes. Optical, structural, and electrical measurements of the as-prepared transparent electrodes have shown good transparency and higher electrical conductivity. In this study, two types of OLEDs consisting of indium tin oxide (ITO)/ poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT-PSS)/ Ir(III) complex (8-hydroxyquinolinat bis(2-phenylpyridyl) iridium-IrQ(ppy)2 20 wt% embedded in N, N'-Dicarbazolyl-4,4'-biphenyl (CBP) sandwich structure and either gold-covered PMMA electrospun nanoweb (OLED with electrospun cathode) were fabricated together with a similar structure containing thin film gold cathodes (OLED with thin film cathode). The luminance-current-voltage characteristics, the capacitance-voltage, and the electroluminescence properties of these OLEDs were investigated.
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Beregoi M, Beaumont S, Evanghelidis A, Otero TF, Enculescu I. Bioinspired polypyrrole based fibrillary artificial muscle with actuation and intrinsic sensing capabilities. Sci Rep 2022; 12:15019. [PMID: 36056150 PMCID: PMC9440232 DOI: 10.1038/s41598-022-18955-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 08/23/2022] [Indexed: 11/09/2022] Open
Abstract
A non-conventional, bioinspired device based on polypyrrole coated electrospun fibrous microstructures, which simultaneously works as artificial muscle and mechanical sensor is reported. Fibrous morphology is preferred due to its high active surface which can improve the actuation/sensing properties, its preparation still being challenging. Thus, a simple fabrication algorithm based on electrospinning, sputtering deposition and electrochemical polymerization produced electroactive aligned ribbon meshes with analogous characteristics as natural muscle fibers. These can simultaneously generate a movement (by applying an electric current/potential) and sense the effort of holding weights (by measuring the potential/current while holding objects up to 21.1 mg). Electroactivity was consisting in a fast bending/curling motion, depending on the fiber strip width. The amplitude of the movement decreases by increasing the load, a behavior similar with natural muscles. Moreover, when different weights were hung on the device, it senses the load modification, demonstrating a sensitivity of about 7 mV/mg for oxidation and - 4 mV/mg for reduction. These results are important since simultaneous actuation and sensitivity are essential for complex activity. Such devices with multiple functionalities can open new possibilities of applications as e.g. smart prosthesis or lifelike robots.
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Affiliation(s)
- Mihaela Beregoi
- Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics, Atomistilor Str. 405A, 077125, Magurele, Romania
| | - Samuel Beaumont
- Laboratory of Electrochemistry Intelligent Materials and Devices, Technical University of Cartagena, Campus Alfonso XIII, 30203, Cartagena, Spain
- Department of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University, Ueda Campus, 3-15-1 Tokida, Ueda, Japan
| | - Alexandru Evanghelidis
- Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics, Atomistilor Str. 405A, 077125, Magurele, Romania
| | - Toribio F Otero
- Laboratory of Electrochemistry Intelligent Materials and Devices, Technical University of Cartagena, Campus Alfonso XIII, 30203, Cartagena, Spain.
| | - Ionut Enculescu
- Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics, Atomistilor Str. 405A, 077125, Magurele, Romania.
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Boukhoubza I, Matei E, Jorio A, Enculescu M, Enculescu I. Electrochemical Deposition of ZnO Nanowires on CVD-Graphene/Copper Substrates. Nanomaterials (Basel) 2022; 12:2858. [PMID: 36014723 PMCID: PMC9415633 DOI: 10.3390/nano12162858] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/11/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
ZnO nanostructures were electrochemically synthesized on Cu and on chemical vapor deposited (CVD)-graphene/Cu electrodes. The deposition was performed at different electrode potentials ranging from -0.8 to -1.2 V, employing a zinc nitrate bath, and using voltametric and chronoamperometric techniques. The effects of the electrode nature and of the working electrode potential on the structural, morphological, and optical properties of the ZnO structures were investigated. It was found that all the samples crystallize in hexagonal wurtzite structure with a preferential orientation along the c-axis. Scanning electron microscopy (SEM) images confirm that the presence of a graphene covered electrode led to the formation of ZnO nanowires with a smaller diameter compared with the deposition directly on copper surface. The photoluminescence (PL) measurements revealed that the ZnO nanowires grown on graphene/Cu exhibit stronger emission compared to the nanowires grown on Cu. The obtained results add another possibility of tailoring the properties of such nanostructured films according to the specific functionality required.
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Affiliation(s)
- Issam Boukhoubza
- Group of Nanomaterials and Renewable Energies, Laboratory of Solid State Physics, Faculty of Sciences Dhar El Mahraz, Sidi Mohammed Ben Abdellah University, P.O. Box 1796, Atlas Fez 30000, Morocco
| | - Elena Matei
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania
| | - Anouar Jorio
- Group of Nanomaterials and Renewable Energies, Laboratory of Solid State Physics, Faculty of Sciences Dhar El Mahraz, Sidi Mohammed Ben Abdellah University, P.O. Box 1796, Atlas Fez 30000, Morocco
| | - Monica Enculescu
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania
| | - Ionut Enculescu
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania
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Ciobotaru IC, Polosan S, Enculescu M, Nitescu A, Enculescu I, Beregoi M, Ciobotaru CC. Charge transport mechanisms in free-standing devices with electrospun electrodes. Nanotechnology 2022; 33:395203. [PMID: 35728559 DOI: 10.1088/1361-6528/ac7ac1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
Embedding electronic and optoelectronic devices in common, daily use objects is a fast developing field of research. New architectures are needed for migrating from the classic wafer- based substrates. Novel types of flexible PMMA/Au/Alq3/LiF/Al structures were obtained starting from electrospun polymer fibers. Thus, using an electrospinning process poly (methyl metacrylate) (PMMA) nanofibers were fabricated. A thin Au layer deposition rendered the fiber array conductive, this being further employed as the anode. The next steps consisted of the thermal evaporation of tris(8-hydroxyquinolinato) aluminum (Alq3) and aluminum deposition as the cathode. The Au covered PMMA nanofiber layer had a similar behavior with an indium tin oxide film i.e. low sheet resistance 10.6 Ω/sq and high transparency. The low electrode resistivities allow an electron drift mobility of about 10-6cm2V-1s-1at a low applied field, similar to the counterpart structures based on thin films. Concerning the relaxation processes in these structures, the Cole-Cole plots exhibit a slightly deformed semicircle, indicating a more complex equivalent circuit for the processes between metal electrodes and the active layer. This equivalent circuit includes reactance equivalent processes at the anode, cathode, in the active layer and most probably originates from the roughness of the metallic electrodes.
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Affiliation(s)
| | - Silviu Polosan
- National Institute of Materials Physics, Magurele, PO Box MG 7, Romania
| | - Monica Enculescu
- National Institute of Materials Physics, Magurele, PO Box MG 7, Romania
| | - Andrei Nitescu
- National Institute of Materials Physics, Magurele, PO Box MG 7, Romania
| | - Ionut Enculescu
- National Institute of Materials Physics, Magurele, PO Box MG 7, Romania
| | - Mihaela Beregoi
- National Institute of Materials Physics, Magurele, PO Box MG 7, Romania
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Costas A, Florica C, Preda N, Besleaga C, Kuncser A, Enculescu I. Self-connected CuO-ZnO radial core-shell heterojunction nanowire arrays grown on interdigitated electrodes for visible-light photodetectors. Sci Rep 2022; 12:6834. [PMID: 35478207 PMCID: PMC9046224 DOI: 10.1038/s41598-022-10879-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 02/11/2022] [Indexed: 12/02/2022] Open
Abstract
An original photodetector system based on self-connected CuO–ZnO radial core–shell heterojunction nanowire arrays grown on metallic interdigitated electrodes, operating as visible-light photodetector was developed by combining simple preparation approaches. Metallic interdigitated electrodes were fabricated on Si/SiO2 substrates using a conventional photolithography process. Subsequently, a Cu layer was electrodeposited on top of the metallic interdigitated electrodes. The CuO nanowire arrays (core) were obtained by thermal oxidation in air of the Cu layer. Afterwards, a ZnO thin film (shell) was deposited by RF magnetron sputtering covering the surface of the CuO nanowires. The morphological, structural, compositional, optical, electrical and photoelectrical properties of the CuO nanowire arrays and CuO–ZnO core–shell nanowire arrays grown on metallic interdigitated electrodes were investigated. The performances of the devices were evaluated by assessing the figures of merit of the photodetectors based on self-connected CuO–ZnO core–shell heterojunction nanowire arrays grown on the metallic interdigitated electrodes. The radial p–n heterojunction formed between CuO and ZnO generates a type II band alignment that favors an efficient charge separation of photogenerated electron–hole pairs at the CuO–ZnO interface, suppressing their recombination and consequently enhancing the photoresponse and the photoresponsivity of the photodetectors. The electrical connections in the fabricated photodetector devices are made without any additional complex and time-consuming lithographic step through a self-connecting approach for CuO–ZnO core–shell heterojunction nanowire arrays grown directly onto the Ti/Pt metallic interdigitated electrodes. Therefore, the present study provides an accessible path for employing low dimensional complex structures in functional optoelectronic devices such as photodetectors.
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Affiliation(s)
- Andreea Costas
- National Institute of Materials Physics, Nanostructures Laboratory, 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania.
| | - Camelia Florica
- National Institute of Materials Physics, Nanostructures Laboratory, 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania
| | - Nicoleta Preda
- National Institute of Materials Physics, Nanostructures Laboratory, 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania
| | - Cristina Besleaga
- National Institute of Materials Physics, Nanostructures Laboratory, 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania
| | - Andrei Kuncser
- National Institute of Materials Physics, Nanostructures Laboratory, 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania
| | - Ionut Enculescu
- National Institute of Materials Physics, Nanostructures Laboratory, 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania.
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Leote RJ, Matei E, Apostol NG, Enculescu M, Enculescu I, Diculescu VC. Monodispersed nanoplatelets of samarium oxides for biosensing applications in biological fluids. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2021.139532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Aldea A, Leote RJB, Matei E, Evanghelidis A, Enculescu I, Diculescu VC. Gold coated electrospun polymeric fibres as new electrode platform for glucose oxidase immobilization. Microchem J 2021. [DOI: 10.1016/j.microc.2021.106108] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Enculescu M, Costas A, Evanghelidis A, Enculescu I. Fabrication of ZnO and TiO 2 Nanotubes via Flexible Electro-Spun Nanofibers for Photocatalytic Applications. Nanomaterials (Basel) 2021; 11:1305. [PMID: 34063351 PMCID: PMC8156990 DOI: 10.3390/nano11051305] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/08/2021] [Accepted: 05/11/2021] [Indexed: 01/09/2023]
Abstract
Web-like architectures of ZnO and TiO2 nanotubes were fabricated based on a three-step process of templating polymer nanofibers produced by electrospinning (step 1). The electrospun polymer nanofibers were covered by radio-frequency magnetron sputtering with thin layers of semiconducting materials (step 2), with FESEM observations proving uniform deposits over their entire surface. ZnO or TiO2 nanotubes were obtained by subsequent calcination (step 3). XRD measurements proved that the nanotubes were of a single crystalline phase (wurtzite for ZnO and anatase for TiO2) and that no other crystalline phases appeared. No other elements were present in the composition of the nanotubes, confirmed by EDX measurements. Reflectance spectra and Tauc plots of Kubelka-Munk functions revealed that the band gaps of the nanotubes were lower than those of the bulk materials (3.05 eV for ZnO and 3.16 eV for TiO2). Photocatalytic performances for the degradation of Rhodamine B showed a large degradation efficiency, even for small quantities of nanotubes (0.5 mg/10 mL dye solution): ~55% for ZnO, and ~95% for TiO2.
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Preda N, Costas A, Beregoi M, Apostol N, Kuncser A, Curutiu C, Iordache F, Enculescu I. Functionalization of eggshell membranes with CuO-ZnO based p-n junctions for visible light induced antibacterial activity against Escherichia coli. Sci Rep 2020; 10:20960. [PMID: 33262424 PMCID: PMC7708484 DOI: 10.1038/s41598-020-78005-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/17/2020] [Indexed: 11/30/2022] Open
Abstract
Biopolymers provide versatile platforms for designing naturally-derived wound care dressings through eco-friendly pathways. Eggshell membrane (ESM), a widely available, biocompatible biopolymer based structure features a unique 3D porous interwoven fibrous protein network. The ESM was functionalized with inorganic compounds (Ag, ZnO, CuO used either separately or combined) using a straightforward deposition technique namely radio frequency magnetron sputtering. The functionalized ESMs were characterized from morphological, structural, compositional, surface chemistry, optical, cytotoxicity and antibacterial point of view. It was emphasized that functionalization with a combination of metal oxides and exposure to visible light results in a highly efficient antibacterial activity against Escherichia coli when compared to the activity of individual metal oxide components. It is assumed that this is possible due to the fact that an axial p-n junction is created by joining the two metal oxides. This structure separates into components the charge carrier pairs promoted by visible light irradiation that further can influence the generation of reactive oxygen species which ultimately are responsible for the bactericide effect. This study proves that, by employing inexpensive and environmentally friendly materials (ESM and metal oxides) and fabrication techniques (radio frequency magnetron sputtering), affordable antibacterial materials can be developed for potential applications in chronic wound healing device area.
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Affiliation(s)
- Nicoleta Preda
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania.
| | - Andreea Costas
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania
| | - Mihaela Beregoi
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania
| | - Nicoleta Apostol
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania
| | - Andrei Kuncser
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania
| | - Carmen Curutiu
- Microbiology Immunology Department, Faculty of Biology, University of Bucharest, Aleea Portocalelor 1-3, 060101, Bucharest, Romania
| | - Florin Iordache
- University of Agronomic Sciences and Veterinary Medicine of Bucharest, 011464, Bucharest, Romania
| | - Ionut Enculescu
- National Institute of Materials Physics, Atomistilor 405A, 077125, Magurele, Romania.
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Aldea A, Matei E, Leote RJ, Rau I, Enculescu I, Diculescu VC. Ionophore- Nafion™ modified gold-coated electrospun polymeric fibers electrodes for determination of electrolytes. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.137239] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Costas A, Florica C, Preda N, Kuncser A, Enculescu I. Photodetecting properties of single CuO-ZnO core-shell nanowires with p-n radial heterojunction. Sci Rep 2020; 10:18690. [PMID: 33122742 PMCID: PMC7596234 DOI: 10.1038/s41598-020-74963-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/06/2020] [Indexed: 11/08/2022] Open
Abstract
CuO-ZnO core-shell radial heterojunction nanowire arrays were obtained by a simple route which implies two cost-effective methods: thermal oxidation in air for preparing CuO nanowire arrays, acting as a p-type core and RF magnetron sputtering for coating the surface of the CuO nanowires with a ZnO thin film, acting as a n-type shell. The morphological, structural, optical and compositional properties of the CuO-ZnO core-shell nanowire arrays were investigated. In order to analyse the electrical and photoelectrical properties of the metal oxide nanowires, single CuO and CuO-ZnO core-shell nanowires were contacted by employing electron beam lithography (EBL) and focused ion beam induced deposition (FIBID). The photoelectrical properties emphasize that the p-n radial heterojunction diodes based on single CuO-ZnO core-shell nanowires behave as photodetectors, evidencing a time-depending photoresponse under illumination at 520 nm and 405 nm wavelengths. The performance of the photodetector device was evaluated by assessing its key parameters: responsivity, external quantum efficiency and detectivity. The results highlighted that the obtained CuO-ZnO core-shell nanowires are emerging as potential building blocks for a next generation of photodetector devices.
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Affiliation(s)
- Andreea Costas
- Multifunctional Materials and Structures Laboratory, Functional Nanostructures Group, National Institute of Materials Physics, 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania.
| | - Camelia Florica
- Multifunctional Materials and Structures Laboratory, Functional Nanostructures Group, National Institute of Materials Physics, 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania.
| | - Nicoleta Preda
- Multifunctional Materials and Structures Laboratory, Functional Nanostructures Group, National Institute of Materials Physics, 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania
| | - Andrei Kuncser
- Multifunctional Materials and Structures Laboratory, Functional Nanostructures Group, National Institute of Materials Physics, 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania
| | - Ionut Enculescu
- Multifunctional Materials and Structures Laboratory, Functional Nanostructures Group, National Institute of Materials Physics, 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania.
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Serban A, Evanghelidis A, Onea M, Diculescu V, Enculescu I, Barsan MM. Electrospun conductive gold covered polycaprolactone fibers as electrochemical sensors for O2 monitoring in cell culture media. Electrochem commun 2020. [DOI: 10.1016/j.elecom.2020.106662] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Diculescu VC, Beregoi M, Evanghelidis A, Negrea RF, Apostol NG, Enculescu I. Palladium/palladium oxide coated electrospun fibers for wearable sweat pH-sensors. Sci Rep 2019; 9:8902. [PMID: 31222160 PMCID: PMC6586619 DOI: 10.1038/s41598-019-45399-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 05/29/2019] [Indexed: 01/22/2023] Open
Abstract
The work describes the development of a flexible, hydrogel embedded pH-sensor that can be integrated in inexpensive wearable and non-invasive devices at epidermal level for electrochemical quantification of H+ ions in sweat. Such a device can be useful for swift, real time diagnosis and for monitoring specific conditions. The sensors’ working electrodes are flexible poly(methyl methacrylate) electrospun fibers coated with a thin gold layer and electrochemically functionalized with nanostructured palladium/palladium oxide. The response to H+ ions is investigated by cyclic voltammetry and electrochemical impedance spectroscopy while open circuit potential measurements show a sensitivity of aprox. −59 mV per pH unit. The modification of the sensing interface upon basic and acid treatment is characterized by scanning and transmission electron microscopy and the chemical composition by X-ray photoelectron spectroscopy. In order to demonstrate the functionality of the pH-sensor at epidermal level, as a wearable device, the palladium/palladium oxide working electrode and silver/silver chloride reference electrode are embedded within a pad of polyacrylamide hydrogel and measurements in artificial sweat over a broad pH range were performed. Sensitivity up to −28 mV/pH unit, response time below 30 s, temperature dependence of approx. 1 mV/°C as well as the minimum volume to which the sensor responses of 250 nanoliters were obtained for this device. The proposed configuration represents a viable alternative making use of low-cost and fast fabrication processes and materials.
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Affiliation(s)
- Victor C Diculescu
- National Institute of Materials Physics Bucharest, Magurele, 077125, Romania.
| | - Mihaela Beregoi
- National Institute of Materials Physics Bucharest, Magurele, 077125, Romania
| | - Alexandru Evanghelidis
- National Institute of Materials Physics Bucharest, Magurele, 077125, Romania.,University of Bucharest, Faculty of Physics, 405 Atomistilor Street, 077125, Magurele, Romania
| | - Raluca F Negrea
- National Institute of Materials Physics Bucharest, Magurele, 077125, Romania
| | - Nicoleta G Apostol
- National Institute of Materials Physics Bucharest, Magurele, 077125, Romania
| | - Ionut Enculescu
- National Institute of Materials Physics Bucharest, Magurele, 077125, Romania.
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Evanghelidis A, Beregoi M, Diculescu VC, Galatanu A, Ganea P, Enculescu I. Flexible Delivery Patch Systems based on Thermoresponsive Hydrogels and Submicronic Fiber Heaters. Sci Rep 2018; 8:17555. [PMID: 30510166 PMCID: PMC6277443 DOI: 10.1038/s41598-018-35914-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 11/07/2018] [Indexed: 11/26/2022] Open
Abstract
This paper proposes a novel, flexible, low cost administration patch which could be used as a non-invasive, controlled transdermal drug delivery system. The fabricated device consists in a flexible microfiber architecture heater covered with a thermoresponsive hydrogel, namely poly(N-isopropylacrylamide), as a matrix for the incorporation of active molecules. The manufacturing process consists of two main steps. First, the electrospun poly(methyl methacrylate) fiber networks are sputter coated with a thin gold layer and attached to flexible poly(ethylene terephthalate) substrates to obtain the heating platforms. Second, the heaters are encapsulated in poly(ethylene terephthalate) foils and covered with poly(N-isopropylacrylamide) hydrogel sheets. In order to illustrate the functionality of the fabricated patch, the hydrogel layer is loaded with methylene blue aqueous solution and is afterwards heated via Joule effect, by applying a voltage on the metalized fibers. The methylene blue releasing profiles of the heated patch are compared with those of the unheated one and the influence of parameters such as hydrogel composition and morphology, as well as the applied voltage values for microheating are investigated. The results indicate that the fabricated patch can be used as a drug administration instrument, while its performance can be tuned depending on the targeted application.
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Affiliation(s)
- Alexandru Evanghelidis
- Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics, Atomistilor Street, Magurele, Bucharest, 077125, Romania
| | - Mihaela Beregoi
- Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics, Atomistilor Street, Magurele, Bucharest, 077125, Romania
| | - Victor C Diculescu
- Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics, Atomistilor Street, Magurele, Bucharest, 077125, Romania
| | - Andrei Galatanu
- Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics, Atomistilor Street, Magurele, Bucharest, 077125, Romania
| | - Paul Ganea
- Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics, Atomistilor Street, Magurele, Bucharest, 077125, Romania
| | - Ionut Enculescu
- Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics, Atomistilor Street, Magurele, Bucharest, 077125, Romania.
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Costas A, Florica C, Matei E, Toimil-Molares ME, Stavarache I, Kuncser A, Kuncser V, Enculescu I. Magnetism and magnetoresistance of single Ni-Cu alloy nanowires. Beilstein J Nanotechnol 2018; 9:2345-2355. [PMID: 30202703 PMCID: PMC6122149 DOI: 10.3762/bjnano.9.219] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/26/2018] [Indexed: 06/08/2023]
Abstract
Arrays of magnetic Ni-Cu alloy nanowires with different compositions were prepared by a template-replication technique using electrochemical deposition into polycarbonate nanoporous membranes. Photolithography was employed for obtaining interdigitated metallic electrode systems of Ti/Au onto SiO2/Si substrates and subsequent electron beam lithography was used for contacting single nanowires in order to investigate their galvano-magnetic properties. The results of the magnetoresistance measurements made on single Ni-Cu alloy nanowires of different compositions have been reported and discussed in detail. A direct methodology for transforming the magnetoresistance data into the corresponding magnetic hysteresis loops was proposed, opening new possibilities for an easy magnetic investigation of single magnetic nanowires in the peculiar cases of Stoner-Wohlfarth-like magnetization reversal mechanisms. The magnetic parameters of single Ni-Cu nanowires of different Ni content have been estimated and discussed by the interpretation of the as derived magnetic hysteresis loops via micromagnetic modeling. It has been theoretically proven that the proposed methodology can be applied over a large range of nanowire diameters if the measurement geometry is suitably chosen.
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Affiliation(s)
- Andreea Costas
- National Institute of Materials Physics, PO Box MG-7, 077125, Magurele-Bucharest, Romania
| | - Camelia Florica
- National Institute of Materials Physics, PO Box MG-7, 077125, Magurele-Bucharest, Romania
| | - Elena Matei
- National Institute of Materials Physics, PO Box MG-7, 077125, Magurele-Bucharest, Romania
| | | | - Ionel Stavarache
- National Institute of Materials Physics, PO Box MG-7, 077125, Magurele-Bucharest, Romania
| | - Andrei Kuncser
- National Institute of Materials Physics, PO Box MG-7, 077125, Magurele-Bucharest, Romania
- University of Bucharest, Faculty of Physics, PO Box MG-11, 077125, Magurele-Bucharest, Romania
| | - Victor Kuncser
- National Institute of Materials Physics, PO Box MG-7, 077125, Magurele-Bucharest, Romania
| | - Ionut Enculescu
- National Institute of Materials Physics, PO Box MG-7, 077125, Magurele-Bucharest, Romania
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Enculescu M, Evanghelidis A, Enculescu I. White-Light Emission of Dye-Doped Polymer Submicronic Fibers Produced by Electrospinning. Polymers (Basel) 2018; 10:E737. [PMID: 30960662 PMCID: PMC6404093 DOI: 10.3390/polym10070737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 06/29/2018] [Accepted: 07/02/2018] [Indexed: 01/12/2023] Open
Abstract
Lighting and display technologies are evolving at tremendous rates nowadays; new device architectures based on new, microscopic building blocks are being developed. Besides high light-emission efficiencies, qualities including low cost, low environmental impact, flexibility, or lightweightness are sought for developing new types of devices. Electrospun polymer fibers represent an interesting type of such microscopic structures that can be employed in developing new functionalities. White-light-emitting fiber mats were prepared by the electrospinning of different dye-doped polymer solutions. Two approaches were used in order to obtain white-light emissions: the overlapping of single-dye-doped electrospun fiber mats, and the electrospinning of mixtures of different ratios of single-dye-doped polymer solutions. Scanning electron microscopy (SEM) was used to investigate the morphologies of the electrospun fibers with diameters ranging between 300 nm and 1 µm. Optical absorption and photoluminescence (PL) were evaluated for single-dye-doped submicronic fiber mats, for overlapping mats, and for fiber mats obtained from different compositions of mixtures. Depending on the ratios of the mixtures of different dyes, the luminance was balanced between blue and red emissions. Commission Internationale de L'Eclairage (CIE) measurements depict this fine-tuning of the colors' intensities, and the right composition for white-light emission of the submicronic fiber mats was found.
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Affiliation(s)
- Monica Enculescu
- Group of Functional Nanostructures, National Institute of Materials Physics, Atomistilor 405A, P.O. Box MG-7, 077125 Magurele-Bucharest, Romania.
| | - Alexandru Evanghelidis
- Group of Functional Nanostructures, National Institute of Materials Physics, Atomistilor 405A, P.O. Box MG-7, 077125 Magurele-Bucharest, Romania.
| | - Ionut Enculescu
- Group of Functional Nanostructures, National Institute of Materials Physics, Atomistilor 405A, P.O. Box MG-7, 077125 Magurele-Bucharest, Romania.
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Beregoi M, Evanghelidis A, Diculescu VC, Iovu H, Enculescu I. Polypyrrole Actuator Based on Electrospun Microribbons. ACS Appl Mater Interfaces 2017; 9:38068-38075. [PMID: 28976177 DOI: 10.1021/acsami.7b13196] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The development of soft actuators by using inexpensive raw materials and straightforward fabrication techniques, aiming at creating and developing muscle like micromanipulators, represents an important challenge nowadays. Providing such devices with biomimetic qualities, for example, sensing different external stimuli, adds even more complexity to the task. We developed electroactive polymer-coated microribbons that undergo conformational changes in response to external physical and chemical parameters. These were prepared following three simple steps. During the first step nylon-6/6 microribbons were fabricated by electrospinning. In a second step the microribbons were one side coated with a metallic layer. Finally, a conducting layer of polypyrrole was added by means of electrochemical deposition. Strips of polypyrrole-coated aligned microribbon meshes were tested as actuators responding to current, pH, and temperature. The electrochemical activity of the microstructured actuators was investigated by recording cyclic voltammograms. Chronopontentiograms for specific current, pH, and temperature values were obtained in electrolytes with different compositions. It was shown that, upon variation of the external stimulus, the actuator undergoes conformational changes due to the reduction processes of the polypyrrole layer. The ability of the actuator to hold and release thin wires, and to collect polystyrene microspheres from the bottom of the electrochemical cell, was also investigated.
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Affiliation(s)
- Mihaela Beregoi
- Functional Nanostructures Group, Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics , 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania
- Advanced Polymer Materials Group, Department of Bioresources and Polymer Science, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest , 1-7 Gh Polizu Street, 011061, Bucharest, Romania
| | - Alexandru Evanghelidis
- Functional Nanostructures Group, Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics , 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania
- Faculty of Physics, University of Bucharest , 405 Atomistilor Street, 077125, Magurele, Ilfov, Romania
| | - Victor C Diculescu
- Functional Nanostructures Group, Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics , 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania
| | - Horia Iovu
- Advanced Polymer Materials Group, Department of Bioresources and Polymer Science, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest , 1-7 Gh Polizu Street, 011061, Bucharest, Romania
| | - Ionut Enculescu
- Functional Nanostructures Group, Multifunctional Materials and Structures Laboratory, National Institute of Materials Physics , 405A Atomistilor Street, 077125, Magurele, Ilfov, Romania
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Florica C, Costas A, Kuncser A, Preda N, Enculescu I. High performance FETs based on ZnO nanowires synthesized by low cost methods. Nanotechnology 2016; 27:475303. [PMID: 27779113 DOI: 10.1088/0957-4484/27/47/475303] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Single ZnO nanowires prepared by wet and dry methods are used as channels in high performance back-gated field effect transistors working in low power operation mode, with on-off ratios up to 105 and mobilities up to 167 cm2 V-1 s-1. The nanowires' properties, generated by the growth techniques, influence the parameters of the transistors, therefore a throughout comparison is made.
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Beregoi M, Busuioc C, Evanghelidis A, Matei E, Iordache F, Radu M, Dinischiotu A, Enculescu I. Electrochromic properties of polyaniline-coated fiber webs for tissue engineering applications. Int J Pharm 2015; 510:465-73. [PMID: 26688039 DOI: 10.1016/j.ijpharm.2015.11.055] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 11/18/2015] [Accepted: 11/29/2015] [Indexed: 01/30/2023]
Abstract
By combining the electrospinning method advantages (high surface-to-volume ratio, controlled morphology, varied composition and flexibility for the resulting structures) with the electrical activity of polyaniline, a new core-shell-type material with potential applications in the field of artificial muscles was synthesized. Thus, a poly(methylmethacrylate) solution was electrospun in optimized conditions to obtain randomly oriented polymer fiber webs. Further, a gold layer was sputtered on their surface in order to make them conductive and improve the mechanical properties. The metalized fiber webs were then covered with a PANI layer by in situ electrochemical polymerization starting from aniline and using sulphuric acid as oxidizing agent. By applying a small voltage on PANI-coated fiber webs in the presence of an electrolyte, the oxidation state of PANI changes, which is followed by the device color modification. The morphological, electrical and biological properties of the resulting multilayered material were also investigated.
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Affiliation(s)
- Mihaela Beregoi
- National Institute of Materials Physics, RO-077125 Magurele, Romania; University POLITEHNICA of Bucharest, RO-011061 Bucharest, Romania
| | - Cristina Busuioc
- National Institute of Materials Physics, RO-077125 Magurele, Romania; University POLITEHNICA of Bucharest, RO-011061 Bucharest, Romania
| | | | - Elena Matei
- National Institute of Materials Physics, RO-077125 Magurele, Romania
| | - Florin Iordache
- Institute of Cellular Biology and Pathology "Nicolae Simionescu", RO-050568 Bucharest, Romania
| | - Mihaela Radu
- University of Bucharest, Department of Biochemistry and Molecular Biology, RO-050095 Bucharest, Romania
| | - Anca Dinischiotu
- University of Bucharest, Department of Biochemistry and Molecular Biology, RO-050095 Bucharest, Romania
| | - Ionut Enculescu
- National Institute of Materials Physics, RO-077125 Magurele, Romania.
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Matei E, Florica C, Costas A, Toimil-Molares ME, Enculescu I. Electrical properties of single CdTe nanowires. Beilstein J Nanotechnol 2015; 6:444-450. [PMID: 25821685 PMCID: PMC4362016 DOI: 10.3762/bjnano.6.45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 12/16/2014] [Indexed: 06/04/2023]
Abstract
Ion track, nanoporous membranes were employed as templates for the preparation of CdTe nanowires. For this purpose, electrochemical deposition from a bath containing Cd and Te ions was employed. This process leads to high aspect ratio CdTe nanowires, which were harvested and placed on a substrate with lithographically patterned, interdigitated electrodes. Focused ion beam-induced metallization was used to produce individual nanowires with electrical contacts and electrical measurements were performed on these individual nanowires. The influence of a bottom gate was investigated and it was found that surface passivation leads to improved transport properties.
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Affiliation(s)
- Elena Matei
- National Institute for Materials Physics, Magurele, Ilfov, Romania, 77125
| | - Camelia Florica
- National Institute for Materials Physics, Magurele, Ilfov, Romania, 77125
| | - Andreea Costas
- National Institute for Materials Physics, Magurele, Ilfov, Romania, 77125
| | | | - Ionut Enculescu
- National Institute for Materials Physics, Magurele, Ilfov, Romania, 77125
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Florica C, Preda N, Enculescu M, Zgura I, Socol M, Enculescu I. Superhydrophobic ZnO networks with high water adhesion. Nanoscale Res Lett 2014; 9:385. [PMID: 25136286 PMCID: PMC4131485 DOI: 10.1186/1556-276x-9-385] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 08/01/2014] [Indexed: 05/31/2023]
Abstract
UNLABELLED ZnO structures were deposited using a simple chemical bath deposition technique onto interdigitated electrodes fabricated by a conventional photolithography method on SiO2/Si substrates. The X-ray diffraction studies show that the ZnO samples have a hexagonal wurtzite crystalline structure. The scanning electron microscopy observations prove that the substrates are uniformly covered by ZnO networks formed by monodisperse rods. The ZnO rod average diameter and length were tuned by controlling reactants' concentration and reaction time. Optical spectroscopy measurements demonstrate that all the samples display bandgap values and emission bands typical for ZnO. The electrical measurements reveal percolating networks which are highly sensitive when the samples are exposed to ammonia vapors, a variation in their resistance with the exposure time being evidenced. Other important characteristics are that the ZnO rod networks exhibit superhydrophobicity, with water contact angles exceeding 150° and a high water droplet adhesion. Reproducible, easily scalable, and low-cost chemical bath deposition and photolithography techniques could provide a facile approach to fabricate such ZnO networks and devices based on them for a wide range of applications where multifunctionality, i.e., sensing and superhydrophobicity, properties are required. PACS 81.07.-b; 81.05.Dz; 68.08.Bc.
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Affiliation(s)
- Camelia Florica
- National Institute of Materials Physics, P.O. Box MG-7, Magurele, Bucharest 077125, Romania
| | - Nicoleta Preda
- National Institute of Materials Physics, P.O. Box MG-7, Magurele, Bucharest 077125, Romania
| | - Monica Enculescu
- National Institute of Materials Physics, P.O. Box MG-7, Magurele, Bucharest 077125, Romania
| | - Irina Zgura
- National Institute of Materials Physics, P.O. Box MG-7, Magurele, Bucharest 077125, Romania
| | - Marcela Socol
- National Institute of Materials Physics, P.O. Box MG-7, Magurele, Bucharest 077125, Romania
| | - Ionut Enculescu
- National Institute of Materials Physics, P.O. Box MG-7, Magurele, Bucharest 077125, Romania
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Matei E, Enculescu M, Enculescu I. Single bath electrodeposition of samarium oxide/zinc oxide nanostructured films with intense, broad luminescence. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.02.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Stan GE, Pasuk I, Husanu MA, Enculescu I, Pina S, Lemos AF, Tulyaganov DU, El Mabrouk K, Ferreira JMF. Highly adherent bioactive glass thin films synthetized by magnetron sputtering at low temperature. J Mater Sci Mater Med 2011; 22:2693-2710. [PMID: 21915698 DOI: 10.1007/s10856-011-4441-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 08/29/2011] [Indexed: 05/31/2023]
Abstract
Thin (380-510 nm) films of a low silica content bioglass with MgO, B(2)O(3), and CaF(2) as additives were deposited at low-temperature (150°C) by radio-frequency magnetron sputtering onto titanium substrates. The influence of sputtering conditions on morphology, structure, composition, bonding strength and in vitro bioactivity of sputtered bioglass films was investigated. Excellent pull-out adherence (~73 MPa) was obtained when using a 0.3 Pa argon sputtering pressure (BG-a). The adherence declined (~46 MPa) upon increasing the working pressure to 0.4 Pa (BG-b) or when using a reactive gas mixture (~50 MPa). The SBF tests clearly demonstrated strong biomineralization features for all bioglass sputtered films. The biomineralization rate increased from BG-a to BG-b, and yet more for BG-c. A well-crystallized calcium hydrogen phosphate-like phase was observed after 3 and 15 days of immersion in SBF in all bioglass layers, which transformed monotonously into hydroxyapatite under prolonged SBF immersion. Alkali and alkali-earth salts (NaCl, KCl and CaCO(3)) were also found at the surface of samples soaked in SBF for 30 days. The study indicated that features such as composition, structure, adherence and bioactivity of bioglass films can be tailored simply by altering the magnetron sputtering working conditions, proving that this less explored technique is a promising alternative for preparing implant-type coatings.
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Affiliation(s)
- G E Stan
- National Institute of Materials Physics, Bucharest-Magurele, Romania.
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Abstract
Abstract
The electrodeposition process of Eosin Y/ZnO: Mn as films and nanowires performed using a solution containing zinc and manganese nitrates + lactic acid mixture was studied by linear voltammetry. The films and wires grown by polarization at −1.1 V/SCE electrode potential were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS). Additionally, the Eosin Y presence was evidenced by optical measurements as absorption and photoluminescence spectroscopy. The manganese content in films depends on the nature of support electrode used. On the other hand, the presence of Eosin Y species in the deposition bath increased significantly the manganese concentration in the ZnO: Mn nanowires electrodeposited at −1.1 V/SCE.
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Affiliation(s)
- Mariana Sima
- National Institute of Materials Physics, Magurele, Rumänien
| | | | - Elena Matei
- National Institute of Materials Physics, Magurele, Rumänien
| | | | | | - Marian Sima
- National Institute of Materials Physics, Magurele, Rumänien
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Sima F, Axente E, Ristoscu C, Mihailescu IN, Kononenko TV, Nagovitsin IA, Chudinova G, Konov VI, Socol M, Enculescu I, Sima LE, Petrescu SM. Tailoring immobilization of immunoglobulin by excimer laser for biosensor applications. J Biomed Mater Res A 2010; 96:384-94. [DOI: 10.1002/jbm.a.32991] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Accepted: 10/05/2010] [Indexed: 11/06/2022]
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Abstract
Electrochemical deposition in nanoporous ion track membranes is used for the preparation of multisegment CdTe--homojunction diode nanowires. Our study is based on the fact that the deposition overpotential strongly influences the composition of the compound semiconductor nanowires. Therefore, the transport behavior of the nanowire devices can be tailored by appropriately choosing a certain sequence of electrodeposition potentials. The wires were characterized using scanning electron microscopy, energy dispersive x-ray analysis, optical spectroscopy and x-ray diffraction. The current-voltage characteristics measured prove that, by appropriately choosing the voltage pulse pattern, one can fabricate nanowires with ohmic or rectifying behavior. The semiconducting nanowires are sensitive to light, their spectral sensitivity being characteristic of CdTe. The preparation of functional nanostructures in such a simple approach provides, as a major advantage, an increase in the process reproducibility and opens a wide field of potential optoelectronic applications.
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Affiliation(s)
- Elena Matei
- National Institute of Materials Physics, Atomistilor Street 105 bis, Magurele, Ilfov 77125, Romania
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Sima M, Enculescu I, Sima M, Vasile E, Visan T. EIS studies of electrodeposition process of manganese and copper doped ZnO wires. SURF INTERFACE ANAL 2008. [DOI: 10.1002/sia.2721] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Enculescu I, Matei E, Sima M, Enculescu M, Sima M, Ghica C. Influence of polyvinylpyrolidone as an additive in electrochemical preparation of ZnO nanowires and nanostructured thin films. SURF INTERFACE ANAL 2008. [DOI: 10.1002/sia.2749] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Ohgai T, Enculescu I, Zet C, Westerberg L, Hjort K, Spohr R, Neumann R. Magneto-sensitive nickel nanowires fabricated by electrodeposition into multi- and single-ion track templates. J APPL ELECTROCHEM 2006. [DOI: 10.1007/s10800-006-9200-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Enculescu I, Iliescu B, Enculescu M, Covalcica I. A Model for Structures Growth by Sodium Electrodiffusion in Quartz Crystals. Zeitschrift für experimentelle und technische Kristallographie 2002. [DOI: 10.1002/1521-4079(200208)37:8<868::aid-crat868>3.0.co;2-j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Iliescu B, Enculescu I, Pera I, Alexe G, Polosan S, Stanculescu A. Chemical Composition of Structures Obtained Inside Quartz Crystals by Sodium Electrodiffusion. Cryst Res Technol 2001. [DOI: 10.1002/1521-4079(200106)36:4/5<403::aid-crat403>3.0.co;2-h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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