Self-Assembled Nano-Needles of Polyaniline, Efficient Structures in Controlling Electrical Conductivity

2011 ◽  
Vol 1312 ◽  
Author(s):  
Michael I. Ibrahim ◽  
Maria J. Bassil ◽  
Umit B. Demirci ◽  
Georges El Haj Moussa ◽  
Mario R. El Tahchi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Oxidative Polymerization ◽  
Weight Ratio ◽  
High Mobility ◽  
Average Diameter ◽  
Xrd Analysis ◽  
Visible Range ◽  
Mobility Of Charge Carriers ◽  
Vis Spectroscopy ◽  
Size And Morphology

ABSTRACTPolyaniline (PANI) is one of the most interesting conducting polymers with a wide and controllable conductivity range, synthesized easily via chemical or electrical route, stable chemically and environmentally, having high absorption in the visible range and high mobility of charge carriers. Under different conditions, PANI morphology can be controlled yielding to the creation of nano-tubes, belts, rods, fibers and particles.In this study, the chemical oxidative polymerization which consists of mixing aniline hydrochloride (A-HCl) with ammonium peroxydisulfate (APS) was used to synthesize HCl doped PANI. Fixing the weight ratio A-HCl/APS defined by the IUPAC while varying their quantities leads to the formation of PANI nanoparticles with variable diameters. In addition, PANI nano-needles of 60 nm average diameter at the center are also obtained. Different methods are used to investigate of 1-D morphologies. The electrical conductivity of bulk PANI pellets is measured using the four-point probe technique. The absorption in the visible range of PANI particles and nano-needles is determined by UV-Vis spectroscopy. XRD analysis was performed to study the effect of PANI particle size and morphology on the crystallinity of the powder. Such structures could be used in hybrid solar cells for higher conversion efficiencies.

Study on the Preparation of PAMAS/PEO Fibrous Membranes by Electrospinning

2016 ◽  
Vol 852 ◽  
pp. 1039-1045
Author(s):  
Hai Jun Zhou ◽  
Ting Ting Zhang ◽  
Yu Zhang ◽  
Jiao Xia Zhang ◽  
Wei Jie Guo
Keyword(s):  
Molecular Weight ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Sulfonic Acid ◽  
Oxidative Polymerization ◽  
Average Diameter ◽  
Vis Spectroscopy ◽  
Fibrous Morphology ◽  
Fibrous Membranes ◽  
Poly Aniline

Poly (aniline-co-2-methoxy aniline-5-sulfonic acid) (PAMAS) was synthesized by an oxidative polymerization in this paper. The resulted copolymer was characterized by Fourier transform infrared spectroscopy and UV-vis spectroscopy, respectively. The PAMAS fibrous membranes and PAMAS/PEO fibrous membranes were prepared via electrospinning. The influence of the molecular weight of PEO and the ratio of PAMAS/PEO in spinning solution on the fibrous morphology was studied. The results showed that PAMAS has fiber-forming ability separately. The addition of PEO was helpful to the the electrospinning of PAMAS. With the increasing of PEO’s molecular weight, the average diameter of the PAMAS/PEO fibers increased. With the increasing of PAMAS content, the fibrous average diameter has an increasing tendency.

High Mobility IGZO/ITO Double-layered Transparent Composite Electrode: A Thermal Stability Study

2013 ◽  
Vol 1577 ◽  
Author(s):  
Aritra Dhar ◽  
T. L. Alford
Keyword(s):  
Thin Film ◽  
Thermal Stability ◽  
Electrical Properties ◽  
Indium Tin Oxide ◽  
High Mobility ◽  
Bottom Layer ◽  
Optoelectronic Device ◽  
Stability Study ◽  
Visible Range ◽  
Vis Spectroscopy

ABSTRACTThe fabrication of a thin film optoelectronic device involves the exposure of the transparent conductive oxide (TCO) to a high process temperature. Indium gallium zinc oxide (InGaZnO4 or IGZO) is a well known TCO with high optical transparency, moderate conductivity and high mobility. However, its electrical properties deteriorate after subsequent high temperature processes in air atmosphere. On the other hand indium tin oxide (ITO) has higher conductivity than IGZO and better thermal stability. Therefore, IGZO/ITO bilayers have been deposited on glass by radio frequency magnetron sputtering at room temperature and subsequently annealed at high temperatures in order to study their thermal stability. In the present work, a-IGZO layers with a thickness ranging from 10 nm to 100 nm were deposited over a 50 nm thick ITO layer. Results are compared with those from a single IGZO layered thin film without the ITO bottom layer. The structural, optical and electrical properties of the multilayers are studied with the use of scanning electron microscopy, UV–Vis spectroscopy and Hall measurement. An IGZO optimal thickness of 50 nm is found to improve the bilayer thermal stability at temperatures upto 400 °C keeping good opto-electrical properties. The sheet resistance for the optimized IGZO/ITO composite films is about 22 Ohm/sq, and the transmittance in the visible range is about 90%. The composite shows an excellent mobility above 40 cm2 /V-s and thus can be potentially applied as channel layer in thin film transistors (TFTs)

scholarly journals Structural, Optical, Electrical, and Magnetic Properties of PVA:Gd3+ and PVA:Ho3+ Polymer Films

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
M. Obula Reddy ◽  
B. Chandra Babu
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Properties ◽  
Polymer Films ◽  
High Mobility ◽  
Magnetic Characteristic ◽  
Xrd Analysis ◽  
Spectroscopy Analysis ◽  
Electrical And Magnetic Properties ◽  
Ferromagnetic Nature ◽  
Solution Casting Method

Polymer films of PVA:Gd3+ and PVA:Ho3+ have been synthesized by a solution casting method in order to study their structural, optical, electrical, and magnetic properties. The semicrystalline nature of the polymer films has been confirmed from XRD analysis. The FTIR analysis confirms the complex formation of the polymer with the metal ions. Dielectric studies of these films have also been carried out at various set temperatures in the frequency from 100 Hz to 1 MHz for carrying out impedance spectroscopy analysis to evaluate the electrical conductivity which arises due to a single conduction mechanism and thus to have a single semicircle pattern from these polymer films. The DC electrical conductivity increases with an increase in the temperature and it could be due to high mobility of free charges (polarons and free ions) at higher temperatures. The conductivity trend follows the Arrhenius equation for PVA:Gd3+ and for PVA:Ho3+ polymer films. PVA:Gd3+ polymer films show ferromagnetic nature, and PVA:Ho3+ polymer films have revealed paramagnetic nature based on the trends noticed in the magnetic characteristic profiles.

Synthesis and Characterization of Nanocomposite of Copolymer of N-Methyl Pyrrole (NMPy) and N, N-Dimethyl Aniline (NDMA)

2019 ◽  
pp. 124-129
Author(s):  
R. Rathore ◽  
Soni Sharma
Keyword(s):  
Electrical Conductivity ◽  
Surface Morphology ◽  
Oxidative Polymerization ◽  
Polymer Nanocomposite ◽  
Xrd Analysis ◽  
Probe Method ◽  
Synthesis And Characterization ◽  
Chemical Oxidative Polymerization ◽  
Amorphous Nature

Nanocomposite of copolymer of N-Methyl pyrrole (NMPy) and N, N-Dimethyl aniline (NDMA) doped with HCl was synthesized by chemical oxidative polymerization. APS was used as oxidant. The sample was characterized by FTIR, TGA, XRD and four probe method. FTIR confirms the formation of copolymer and its structure. XRD analysis shows the amorphous nature of polymer nanocomposite. The electrical conductivity of sample was measured by using four probe method. Size and surface morphology were demonstrated by SEM.

Charge-transport in Organic Semiconductors: Probing High Mobility with Light

2013 ◽  
Vol 1568 ◽  
Author(s):  
Demetrio A da Silva Filho ◽  
Pedro Henrique de Oliveira Neto ◽  
M. Carmen Ruiz Delgado ◽  
Juan T. Lopez Navarrete ◽  
Juan Casado
Keyword(s):  
Charge Transport ◽  
Organic Semiconductors ◽  
High Mobility ◽  
Charge Carriers ◽  
Experimental Result ◽  
Mobility Of Charge Carriers ◽  
Vis Spectroscopy ◽  
Efficient Charge ◽  
Processing Techniques ◽  
Improve Device

ABSTRACTEfficient charge transport is key to the operation of the various devices based on organic semiconductors, such as OLEDs, OPVs and OFETs. Both academia and industry are investing heavily in the development of new organic materials and processing techniques to improve device performance. An important parameter to tweak is the mobility of charge carriers. Triggered by an experimental result, here we investigate whether this parameter can be probed indirectly using UV-VIS spectroscopy. This would simplify the process of characterization and optimization of the mobility in amorphous molecular films, for example.

Wet Chemistry Synthesis of Semiconductor Gold/Cu1.96S Nanorod and Study of its Photoluminescence Properties

2012 ◽  
Vol 21 ◽  
pp. 51-56 ◽  
Author(s):  
Nazanin Farhadyar ◽  
M.S. Sadjadi ◽  
Farzad Farhadyar ◽  
Ali Farhadyar
Keyword(s):  
Green Emission ◽  
Optical Filters ◽  
Average Diameter ◽  
Xrd Analysis ◽  
Electron Microscopic ◽  
Wet Chemistry ◽  
Materials Research ◽  
Semiconductor Nanocomposites ◽  
Size And Morphology ◽  
Low Dimensional

In the past decade, preparation of low-dimensional semiconductor nanostructures has become a hotspot of materials research because of their attractive optical and electrical properties. Semiconductor nanoparticles have found wide spread application in varied fields of engineering. Since, p-type semiconductors, copper sulfides (Cu1.96S) were used in solar cells, optical filters and supersonic materials. In this work, we report on the synthesis of Cu1.96S semiconductor nanocomposites in the presence of PVP via a wet chemistry process and then covered by a layer of gold nanoparticles. Formation of a pure CuS phase, in the presence of a PVP nanostructure was confirmed by X-ray diffraction (XRD) analysis. Size and morphology of as-prepared nanostructure were studied using Transmission Electron Microscopic (TEM) images. The results revealed the formation of a dense Cu1.96S and roughly spherical nanoparticles with an average diameter of about 25-35 nm coated homogeneously with gold nanoparticle. Room temperature photoluminescence (PL) measurements of the prepared samples showed enhanced blue-green emission (350 to 600) nm and red emission from 600 to 800nm.

scholarly journals Biosynthesis of silver nanoparticles using Pomegranate juice extract and its antibacterial activity

2016 ◽  
Vol 4 (3) ◽  
pp. 254-258 ◽  
Author(s):  
Mona Hussein Ibraheim ◽  
A.A. Ibrahiem ◽  
T. R. Dalloul
Keyword(s):  
Silver Nanoparticles ◽  
Fourier Transforms ◽  
Average Diameter ◽  
Xrd Analysis ◽  
Pomegranate Juice ◽  
Face Centered Cubic ◽  
Vis Spectroscopy ◽  
Face Centered ◽  
Biosynthesized Agnps ◽  
High Level

Green synthesis of silver nanoparticles (AgNPs) from silver nitrate was carried out using aqueous Pomegranate juice extract (PJE) as a reducing agent. The formation of AgNPs was characterized by UV-visible (UV–vis) spectroscopy, transmission electron microscopy (TEM), Fourier transforms infrared spectroscopy and X-ray diffraction (XRD). Surface Plasmon resonance (SPR) of ∼420-423 nm confirmed the earlier formation of AgNPs. TEM and XRD analysis showed that the AgNPs with an average diameter of 23 nm are crystalline in nature and have face-centered cubic geometry. The antibacterial efficiency of AgNPs against Escherchia coli and Staphylococcus aureus showed high level of inhibition. Further, the zone of inhibition increased with the increase in the concentration of silver nanoparticles. These studies are quite useful as it shows the utility of green nanotechnology for the synthesis of silver nanoparticles without any toxic residuals and byproducts. The efficient antimicrobial activity of biosynthesized AgNPs proves the application potential in the area of nano-medicine.Int J Appl Sci Biotechnol, Vol 4(3): 254-258

Green Synthesis of Monodispersity Gold Nanoparticles with Dextran

2017 ◽  
Vol 727 ◽  
pp. 365-368 ◽  
Author(s):  
Jun Qi Tang ◽  
Ning Zhang ◽  
Shi Qing Man
Keyword(s):  
Gold Nanoparticles ◽  
Biomedical Application ◽  
Average Diameter ◽  
Xrd Analysis ◽  
Plasmon Band ◽  
Stabilizing Agents ◽  
Green Approach ◽  
Transmission Electron ◽  
Relative Standard ◽  
Vis Spectroscopy

A green approach to synthesize stable gold nanoparticles (AuNPs) employing dextran as a reducing and stabilizing agents at different temperature was described. The obtained dextran-coated gold nanoparticles (Dex-AuNPs) were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis and UV-Vis spectroscopy. The average diameter of those resultant AuNPs at boiling bath was 12.1 nm with a relative standard deviation of less than 5.6%. UV–Vis spectra showed the presence of a surface plasmon band at 518 nm. These results suggested that the prepared Dex-AuNPs complexes had excellent monodispersity and acted as a candidate for further biomedical application.

Green synthesis of iron nanoparticles using flower extract of Piliostigma thonningii and their antibacterial activity evaluation

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Antibacterial Activity ◽  
Environmental Remediation ◽  
Iron Nanoparticles ◽  
Reduction Process ◽  
Xrd Analysis ◽  
Visible Range ◽  
Magnetic Storage ◽  
Ferrous Chloride ◽  
Flower Extract ◽  
Piliostigma Thonningii

Iron nanoparticles have gained tremendous attention due to their application in magnetic storage media, ferrofluids, biosensors, catalysts, separation processes, environmental remediation and antibacterial activity. In the present paper, iron nanoparticles were synthesized using aqueous flower extract of Piliostigma thonningii, a natural nontoxic herbal infusion. Iron nanoparticles were generated by reaction of ferrous chloride solution with the flower extract. The reductants present in the flower extract acted as reducing and stabilizing agents. UV-vis analysis of the iron nanoparticles showed continuous absorption in the visible range suggesting the iron nanoparticles were amorphous. This was confirmed by X-ray diffraction (XRD) analysis which did not have distinct diffraction peaks. Scanning electron microscopy (SEM) analysis revealed that the synthesized iron nanoparticles were aggregated as irregular clusters with rough surfaces. FT-IR studies showed the functional groups that participated in the bio-reduction process to include a C-H stretch (due to alkane CH3, CH2 or CH), C=O stretch (due to aldehydes), O-H bend (due to tert-alcohol or phenol), C-O stretch (due to aldehydes or phenols) and C-O stretch (due to alcohols) corresponding to absorptions at 2929.00, 1721.53, 1405.19, 1266.31 and 1030.02 cm-1 respectively. The iron nanoparticles showed significant antibacterial activity against Escharichia coli and Staphylococcus aureus suggesting potential antibacterial application.

scholarly journals Fast Dissolving Electrospun Nanofibers Fabricated from Jelly Fig Polysaccharide/Pullulan for Drug Delivery Applications

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 241
Author(s):  
Thangavel Ponrasu ◽  
Bei-Hsin Chen ◽  
Tzung-Han Chou ◽  
Jia-Jiuan Wu ◽  
Yu-Shen Cheng
Keyword(s):  
Drug Delivery ◽  
Water Vapor Permeability ◽  
Electrospun Nanofibers ◽  
Average Diameter ◽  
Xrd Analysis ◽  
Water Soluble ◽  
Vapor Permeability ◽  
Uv Spectrum ◽  
Sem Images ◽  
Triton X

The fast-dissolving drug delivery systems (FDDDSs) are developed as nanofibers using food-grade water-soluble hydrophilic biopolymers that can disintegrate fast in the oral cavity and deliver drugs. Jelly fig polysaccharide (JFP) and pullulan were blended to prepare fast-dissolving nanofiber by electrospinning. The continuous and uniform nanofibers were produced from the solution of 1% (w/w) JFP, 12% (w/w) pullulan, and 1 wt% Triton X-305. The SEM images confirmed that the prepared nanofibers exhibited uniform morphology with an average diameter of 144 ± 19 nm. The inclusion of JFP in pullulan was confirmed by TGA and FTIR studies. XRD analysis revealed that the increased crystallinity of JFP/pullulan nanofiber was observed due to the formation of intermolecular hydrogen bonds. The tensile strength and water vapor permeability of the JFP/pullulan nanofiber membrane were also enhanced considerably compared to pullulan nanofiber. The JFP/pullulan nanofibers loaded with hydrophobic model drugs like ampicillin and dexamethasone were rapidly dissolved in water within 60 s and release the encapsulants dispersive into the surrounding. The antibacterial activity, fast disintegration properties of the JFP/pullulan nanofiber were also confirmed by the zone of inhibition and UV spectrum studies. Hence, JFP/pullulan nanofibers could be a promising carrier to encapsulate hydrophobic drugs for fast-dissolving/disintegrating delivery applications.

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