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Pasha A, Khasim S, Al-Hartomy OA, Lakshmi M, Manjunatha KG. Highly sensitive ethylene glycol-doped PEDOT-PSS organic thin films for LPG sensing. RSC Adv 2018; 8:18074-18083. [PMID: 35542062 PMCID: PMC9080499 DOI: 10.1039/c8ra01061g] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 05/03/2018] [Indexed: 01/31/2023] Open
Abstract
In this study, for the first time we report the fabrication of low-cost ethylene glycol (EG)-doped PEDOT-PSS (poly 3,4-ethylenedioxythiophene:polystyrene sulfonate) organic thin film sensors for the detection of LPG at room temperature. The prepared thin films were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-Vis) spectroscopy and thermogravimetric analysis (TGA) techniques for the analysis of their structural and morphological features. The doping of EG strongly improved the conductivity of pure PEDOT-PSS films by three orders of magnitude. The gas sensing responses of pristine and doped PEDOT-PSS thin films were investigated at room temperature by fabricating a sensor device on an ITO-coated glass substrate. The gas sensing characteristics of the prepared thin films were investigated for liquified petroleum gas (LPG), dimethyl propane, methane and butane test gases. The EG-doped PEDOT-PSS thin films exhibited excellent sensitivity for all the test gases, especially towards LPG, at room temperature. The sensitivity of the doped PEDOT-PSS films was recorded to be >90% for LPG with improved response and recovery time. The stability study indicated that the sensing response of doped PEDOT-PSS thin films was highly stable over a period of 30 days. Due to enhanced sensitivity, stability and fast response and recovery times, these EG-doped PEDOT-PSS thin films can be used in gas sensor technology, especially towards the detection of LPG at room temperature.
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Affiliation(s)
- Apsar Pasha
- Department of Physics, Ghousia College of Engineering Ramanagaram-562159 Karnataka India
| | - Syed Khasim
- Department of Physics, Faculty of Science, University of Tabuk Tabuk 71491 Kingdom of Saudi Arabia
- Department of Physics, PES University Bangalore-560100 India
| | - Omar A Al-Hartomy
- Department of Physics, Faculty of Science, King Abdul Aziz University Jeddah-21599 Kingdom of Saudi Arabia
| | - Mohana Lakshmi
- Department of Physics, PES University Bangalore-560100 India
| | - K G Manjunatha
- Department of Chemistry, Ghousia College of Engineering Ramanagaram-562159 Karnataka India
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Kim T, Fu X, Warther D, Sailor MJ. Size-Controlled Pd Nanoparticle Catalysts Prepared by Galvanic Displacement into a Porous Si-Iron Oxide Nanoparticle Host. ACS NANO 2017; 11:2773-2784. [PMID: 28195692 DOI: 10.1021/acsnano.6b07820] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Porous silicon nanoparticles containing both Pd and iron oxide nanoparticles are prepared and studied as magnetically recoverable catalysts for organic reductions. The Pd nanoparticles are generated in situ by electroless deposition of Pd(NH3)42+, where the porous Si skeleton acts as both a template and as a reducing agent and the released ammonia ligands raise the local pH to exert control over the size of the Pd nanoparticles. The nanocomposites are characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy, nitrogen adsorption, X-ray diffraction, superconducting quantum interference device magnetization, and dynamic light scattering. The nanocomposite consists of a porous Si nanoparticle (150 nm mean diameter) containing ∼20 nm pores, uniformly decorated with a high loading of surfactant-free Pd nanoparticles (12 nm mean diameter) and superparamagnetic γ-Fe2O3 nanoparticles (∼7 nm mean diameter). The reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride is catalyzed by the nanocomposite, which is stable through the course of the reaction. Catalytic reduction of the organic dyes methylene blue and rhodamine B is also demonstrated. The conversion efficiency and catalytic activity are found to be superior to a commercial Pd/C catalyst compared under comparable reaction conditions. The composite catalyst can be recovered from the reaction mixture by applying an external magnetic field due to the existence of the superparamagnetic iron oxide nanoparticles in the construct. The recovered particles retain their catalytic activity.
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Affiliation(s)
- Taeho Kim
- Department of Chemistry and Biochemistry and ‡Department of Nanoengineering, University of California, San Diego , La Jolla, California 92093, United States
| | - Xin Fu
- Department of Chemistry and Biochemistry and ‡Department of Nanoengineering, University of California, San Diego , La Jolla, California 92093, United States
| | - David Warther
- Department of Chemistry and Biochemistry and ‡Department of Nanoengineering, University of California, San Diego , La Jolla, California 92093, United States
| | - Michael J Sailor
- Department of Chemistry and Biochemistry and ‡Department of Nanoengineering, University of California, San Diego , La Jolla, California 92093, United States
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Rudakovskaya PG, Beloglazkina EK, Majouga AG, Klyachko NL, Kabanov AV, Zyk NV. Synthesis of magnetite-gold nanoparticles with core-shell structure. ACTA ACUST UNITED AC 2015. [DOI: 10.3103/s0027131415030104] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kawamura G, Muto H, Matsuda A. Hard template synthesis of metal nanowires. Front Chem 2014; 2:104. [PMID: 25453031 PMCID: PMC4233916 DOI: 10.3389/fchem.2014.00104] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 10/31/2014] [Indexed: 11/13/2022] Open
Abstract
Metal nanowires (NWs) have attracted much attention because of their high electron conductivity, optical transmittance, and tunable magnetic properties. Metal NWs have been synthesized using soft templates such as surface stabilizing molecules and polymers, and hard templates such as anodic aluminum oxide, mesoporous oxide, carbon nanotubes. NWs prepared from hard templates are composites of metals and the oxide/carbon matrix. Thus, selecting appropriate elements can simplify the production of composite devices. The resulting NWs are immobilized and spatially arranged, as dictated by the ordered porous structure of the template. This avoids the NWs from aggregating, which is common for NWs prepared with soft templates in solution. Herein, the hard template synthesis of metal NWs is reviewed, and the resulting structures, properties and potential applications are discussed.
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Affiliation(s)
- Go Kawamura
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology Toyohashi, Japan
| | - Hiroyuki Muto
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology Toyohashi, Japan
| | - Atsunori Matsuda
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology Toyohashi, Japan
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Kubickova S, Plocek J, Mantlikova A, Vejpravova J. Nanocomposites of monodisperse nanoparticles embedded in high-K oxide matrices – a general preparation strategy. RSC Adv 2014. [DOI: 10.1039/c3ra44840a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Uusimäki T, Margaris G, Trohidou K, Granitzer P, Rumpf K, Sezen M, Kothleitner G. Three dimensional quantitative characterization of magnetite nanoparticles embedded in mesoporous silicon: local curvature, demagnetizing factors and magnetic Monte Carlo simulations. NANOSCALE 2013; 5:11944-11953. [PMID: 24132251 DOI: 10.1039/c3nr02922k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Magnetite nanoparticles embedded within the pores of a mesoporous silicon template have been characterized using electron tomography. Linear least squares optimization was used to fit an arbitrary ellipsoid to each segmented particle from the three dimensional reconstruction. It was then possible to calculate the demagnetizing factors and the direction of the shape anisotropy easy axis for every particle. The demagnetizing factors, along with the knowledge of spatial and volume distribution of the superparamagnetic nanoparticles, were used as a model for magnetic Monte Carlo simulations, yielding zero field cooling/field cooling and magnetic hysteresis curves, which were compared to the measured ones. Additionally, the local curvature of the magnetite particles' docking site within the mesoporous silicon's surface was obtained in two different ways and a comparison will be given. A new iterative semi-automatic image alignment program was written and the importance of image segmentation for a truly objective analysis is also addressed.
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Affiliation(s)
- Toni Uusimäki
- Graz University of Technology, Institute for Electron Microscopy and Nanoanalysis (FELMI), Steyrergasse 17, 8010, Graz, Austria.
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Yang WJ, Lee JH, Hong SC, Lee J, Lee J, Han DW. Difference between Toxicities of Iron Oxide Magnetic Nanoparticles with Various Surface-Functional Groups against Human Normal Fibroblasts and Fibrosarcoma Cells. MATERIALS 2013; 6:4689-4706. [PMID: 28788355 PMCID: PMC5452863 DOI: 10.3390/ma6104689] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 10/14/2013] [Accepted: 10/17/2013] [Indexed: 01/09/2023]
Abstract
Recently, many nanomedical studies have been focused on magnetic nanoparticles (MNPs) because MNPs possess attractive properties for potential uses in imaging, drug delivery, and theranostics. MNPs must have optimized size as well as functionalized surface for such applications. However, careful cytotoxicity and genotoxicity assessments to ensure the biocompatibility and biosafety of MNPs are essential. In this study, Fe3O4 MNPs of different sizes (approximately 10 and 100–150 nm) were prepared with different functional groups, hydroxyl (–OH) and amine (–NH2) groups, by coating their surfaces with tetraethyl orthosilicate (TEOS), 3-aminopropyltrimethoxysilane (APTMS) or TEOS/APTMS. Differential cellular responses to those surface-functionalized MNPs were investigated in normal fibroblasts vs. fibrosarcoma cells. Following the characterization of MNP properties according to size, surface charge and functional groups, cellular responses to MNPs in normal fibroblasts and fibrosarcoma cells were determined by quantifying metabolic activity, membrane integrity, and DNA stability. While all MNPs induced just about 5% or less cytotoxicity and genotoxicity in fibrosarcoma cells at lower than 500 μg/mL, APTMS-coated MNPs resulted in greater than 10% toxicity against normal cells. Particularly, the genotoxicity of MNPs was dependent on their dose, size and surface charge, showing that positively charged (APTMS- or TEOS/APTMS-coated) MNPs induced appreciable DNA aberrations irrespective of cell type. Resultantly, smaller and positively charged (APTMS-coated) MNPs led to more severe toxicity in normal cells than their cancer counterparts. Although it was difficult to fully differentiate cellular responses to various MNPs between normal fibroblasts and their cancer counterparts, normal cells were shown to be more vulnerable to internalized MNPs than cancer cells. Our results suggest that functional groups and sizes of MNPs are critical determinants of degrees of cytotoxicity and genotoxicity, and potential mechanisms of toxicity.
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Affiliation(s)
- Won Jun Yang
- World Class University Program, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Korea.
| | - Jong Ho Lee
- World Class University Program, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Korea.
| | - Seong Cheol Hong
- World Class University Program, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Korea.
| | - Jaewook Lee
- World Class University Program, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Korea.
| | - Jaebeom Lee
- World Class University Program, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Korea.
| | - Dong-Wook Han
- World Class University Program, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Korea.
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Hofmann T, Kumar P, Enderle M, Wallacher D. Growth of highly oriented deuterium crystals in silicon nanochannels. PHYSICAL REVIEW LETTERS 2013; 110:065505. [PMID: 23432273 DOI: 10.1103/physrevlett.110.065505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 12/10/2012] [Indexed: 06/01/2023]
Abstract
The structure of solid deuterium confined in 9 nm wide tubular silicon nanochannels has been studied by means of elastic neutron scattering techniques. As a result we report the formation of fcc D(2) as the stable solid phase in confinement in contrast to the hcp bulk structure. Further, a preferred alignment of D(2) nanocrystals with respect to the surrounding crystalline silicon matrix is discussed in terms of heteroepitaxial growth of solid D(2) on crystalline pore walls.
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Affiliation(s)
- T Hofmann
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.
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