Nanomaterials & Nanotechnology
Huda Abdullah; Norshafadzila Mohammad Naim; Mohamad Aiman Arif Awang Omar; Jian Xian Kang; Iskandar Yahya; Noorfazila Kamal; Norazreen Abd Aziz; Atiqah Mohd Afdzaluddin; Noraziah Mohammad Zin; Mohd Hafiz Dzarfan Othman; Wing Fen Yap
Abstract
Carbon nanotubes (CNTs) are particularly attractive for use in sensors for environmental and health monitoring. This study proposes a new approach in developing polymer-metal-based sensor for E. coli detection by using CNTs incorporation. PANI-SnO2 nanocomposite thin films were combined with CNTs to ...
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Carbon nanotubes (CNTs) are particularly attractive for use in sensors for environmental and health monitoring. This study proposes a new approach in developing polymer-metal-based sensor for E. coli detection by using CNTs incorporation. PANI-SnO2 nanocomposite thin films were combined with CNTs to be fabricated as biosensing devices. PANI-(SnO2)1-x-CNTx nanocomposite thin films were synthesized using sol-gel method and deposited on a glass substrate by spin coating technique. The prepared thin films were characterized by X-ray diffraction (XRD), field scanning electron microscopy (FESEM), atomic field microscopy (AFM) and ultraviolet-visible (UV-vis) spectroscopy. The sensitivity performance of PANI-(SnO2)1-x-CNTx nanocomposite thin films were conducted by using current-voltage (I-V) measurements. From the results, XRD patterns show the appearance of PANI, SnO2 and C peaks and the increasing crystallite size with the increasing of CNT concentration. FESEM images show the spherical shape of SnO2 and the nanotubes of carbon in the diameter size range 30 – 100 nm and 150 – 220 nm respectively. AFM analysis has found out the roughness parameter has increased when CNT percentage was increased. The peaks from UV-Vis absorbance bands indicated the presence of CNT and SnO2 at wavelength 270 nm and 370 nm respectively. From I-V measurement of the sensor, PANI-(SnO2)1-x-CNTx with x = 0.03 performed the highest sensitivity which is 16.32%. The results demonstrate that the increasing of CNT concentrations was increasing the sensitivity of PANI-(SnO2)1-x-CNTx thin films towards E. coli.
Sandip Maiti; Ranadip Bera;Bhanu B. Khatua; Sumanta K. Karan; Amit K. Das
Abstract
Renewable energy is very much demanding in modern time. Herein, we have discussed energy storage performance of polyaniline (PANI) and carbon nanohorn (CNH) decorated titanium dioxide (TiO2) nanoparticle, high-performance electrode material. This high-performance energy storage material was prepared ...
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Renewable energy is very much demanding in modern time. Herein, we have discussed energy storage performance of polyaniline (PANI) and carbon nanohorn (CNH) decorated titanium dioxide (TiO2) nanoparticle, high-performance electrode material. This high-performance energy storage material was prepared through simple and cost-effective method via in-situ polymerization of aniline in presence of CNH and TiO2 nanoparticles. Thus, as prepared active electrode material provides high specific capacitance value of 1068 F/g at current density of 3 A/g. The existence TiO2 nanoparticle in the ternary hybrid leads to enhancement of capacitance value through synergistic effect compared to the pure components (e.g., PANI and CNH are 335 F/g and 240 F/g, respectively at same current density). As morphological analysis says, TiO2 nanoparticles are observed to be coated by CNH nanofiller and PANI fiber in the hybrid, which plays a key role to enhance the capacitance value of hybrid making it highly promising electrode material for energy storage in the next-generation power supply.
Hemlata J. Sharma; Bhaskar M. Bahirwar; Subhash B. Kondawar
Abstract
Metal oxide nanofibers showed keen interest in chemical gas sensing due to their unique chemical and electrical properties at operating temperature more than 200 o C. Their sensitivity can be improved at low operating temperature closed to room temperature by using conducting polymers. In this paper, ...
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Metal oxide nanofibers showed keen interest in chemical gas sensing due to their unique chemical and electrical properties at operating temperature more than 200 o C. Their sensitivity can be improved at low operating temperature closed to room temperature by using conducting polymers. In this paper, Al doped tin oxide/polyaniline composite nanofibers detected H2 molecules at room temperature. A simple versatile electrospinning technique is used for the fabrication of Aluminium (Al) doped (tin oxide) SnO2 nanofibers and polyaniline was encapsulated using chemical oxidative polymerization (COP) of aniline monomer using ammonium persulfate as redox initiator. The structure and morphology of Al-doped SnO2/PANI composite nanofibers were investigated by SEM-EDX, UV-VIS and XRD spectroscopy. Structural changes of SnO2/PANI crystal due to the incorporation of Al 3+ ions have been explained. Al-doped SnO2/PANI composite nanofiber is very much selective towards H2 gas molecules in terms of high sensitivity, rapid response and recovery around room temperature compared to that of Al-doped SnO2. The present sensing mechanism systematically explained the existence of PN junction which is formed by p-type and n-type semiconductors in Al-doped SnO2/PANI hybrid composite material.
Aviraj A. Jatratkar; Jyotiprakash B. Yadav; R.R. Deshmukh; Harish C. Barshilia; Vijaya Puri; R.K. Puri
Abstract
In this work, glow discharge continuous wave plasma polymerization technique was used to deposit nanostructured polyaniline (PANI) thin film by varying input power. The radio frequency (RF) used for plasma polymerization was 13.56 MHz and working pressure was 0.15 mbar. It was found that, changes in ...
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In this work, glow discharge continuous wave plasma polymerization technique was used to deposit nanostructured polyaniline (PANI) thin film by varying input power. The radio frequency (RF) used for plasma polymerization was 13.56 MHz and working pressure was 0.15 mbar. It was found that, changes in the input power can be used to control the properties of the plasma polymerized PANI thin films. Highly cross-linked structure with an increase in chain length was observed from FTIR spectra with input RF power, whereas the film surface morphology was found to be highly uniform, densely packed and smooth from FE-SEM images. The surface roughness of the film was found to increase with RF power. The refractive index and adhesion of the film was found to be increased while the optical band gap and surface energy decreased with input RF power. The plasma polymerized PANI film showed outstanding optical transmission loss properties and proved itself as excellent optical waveguide.
M. Sivaprasad; N. Y. Sreedhar; M. R. Jayapal; Li Yang; Hongwei Ni
Abstract
Herein we reported graphene (Gr) was firstly fabricated on glassy carbon electrode (GCE) by drop casting method, subsequently polyaniline (PAN) and Palladium (Pd) nanocomposite were fabricated by two-step electrochemical depositing process on graphene dispersed glassy carbon electrode (Gr/GCE) ...
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Herein we reported graphene (Gr) was firstly fabricated on glassy carbon electrode (GCE) by drop casting method, subsequently polyaniline (PAN) and Palladium (Pd) nanocomposite were fabricated by two-step electrochemical depositing process on graphene dispersed glassy carbon electrode (Gr/GCE) and used as an electrochemical sensor for determination of Tetrachlorvinphos (TCP < /span>) pesticide in vegetables. Here most of the work has been focused on the preparation and characterization of modified electrode with cyclic voltammetry (CV) and scanning electron microscopy (SEM). The modified composite electrode unveiled significantly good voltammetric response on TCP. Square wave voltammetry (SWV) was used for determination of TCP at optimized conditions such as square wave frequency, step potential, pH of buffer, applied sample volume, accumulation potential and accumulation time. The well-defined reduction (C=C) peaks were acquired over the potential maximum around at -1.3V in acidic medium in Briton-Robinson (B-R) buffer solution at low current values. The low current peaks were obtained over the concentration of TCP at 1.5×10 -6 M with lower detection limit and limit of quantifications are 5.62×10 -10 M and 2.65×10 -8 respectively. The composite modified electrode showed good stability and reproducibility. The proposed method was successfully applied for the present investigation with a great assure as an economical and simple sensor with furthermore a shorter analysis time and further the sensor also used for heavy metal detection in real samples.
Divya P. R; P. M. Sabura Begum; Rani Joseph; Indu Sebastian
Abstract
Herein, we have prepared Polyaniline (PANI) nanofibers by interfacial polymerization in the presence of co-oxidant and surfactant. The additives are found to have a profound impact on the polymers morphology and improved room temperature conductivity. It was found that PANI nanofibers prepared in the ...
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Herein, we have prepared Polyaniline (PANI) nanofibers by interfacial polymerization in the presence of co-oxidant and surfactant. The additives are found to have a profound impact on the polymers morphology and improved room temperature conductivity. It was found that PANI nanofibers prepared in the presence of aqueous sodium hypochlorite solution (NaOCl) and cetyl trimethyl ammonium bromide (CTAB) were of shorter diameter (30 nm) and high conductivity (6.59Scm -1 ) than those formed in the absence of those chemicals. The diameter of the fibers was intricately tuned by changing the ratio of NaOCl to aniline. The effect of co-oxidant and surfactant concentration in the nanofibers has been investigated with the help of SEM, IR, XRD, UV and conductivity studies. A comparative investigation with other surfactant sodium dodecyl sulphate (SDS) has been done and the variations in diameter were noted. We also studied the third-order optical nonlinearity and optical limiting properties of polyaniline nanofibers using a single-beam z-scan technique. The experiments were performed with a Nd-YAG laser at wavelength of 532 nm The mechanism behind nonlinear absorption could be predicted as two photon absorption. The results show that the polyaniline nanofibers have useful applications in futuristic nonlinear optics.
Milind D. Deshpande; Subhash B. Kondawar
Abstract
In this paper, we report the influence of functionalized multi-walled carbon nanotubes (MWCNTs) on transport properties of conducting polymers polythiophene (PTH) and polyaniline (PANI). Nanocomposites based on multi-walled carbon nanotubes were synthesized by in-situ oxidative polymerization of thiophene/aniline ...
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In this paper, we report the influence of functionalized multi-walled carbon nanotubes (MWCNTs) on transport properties of conducting polymers polythiophene (PTH) and polyaniline (PANI). Nanocomposites based on multi-walled carbon nanotubes were synthesized by in-situ oxidative polymerization of thiophene/aniline monomer in the presence of functionalized MWCNTs. These nanocomposites have been characterized by SEM, UV-VIS, FTIR, and XRD to study the effect of incorporation of MWCNTs on the morphology, structure and crystalline of the conducting polymers. Nanocomposites have shown high electrical conductivity compared to that of pure PTH/PANI. The enhancement in conductivity of the nanocomposites is due to the charge transfer effect from the quinoid rings of the PTH/PANI to the MWCNT. The effect of MWCNT on the transport properties of PTH and PANI was systematically studied and compared in terms of transport parameters. Charge localization length and most probable hopping distance were found to be decreased with wt % of CNT, whereas the charge hopping energy was found to be increased in nanocomposites. The improved transport properties of both the types of nanocomposites due to incorporation of CNT in conducting polymer matrix can be utilized for solar cells, capacitors, electronic devices as well as chemical sensors.
Franco D.R. Amado;Satheesh Krishnamurthy
Abstract
Over the past decade or so, alternative energy plays a pivotal role in addressing challenges posed by nature. Polymer electrolyte membrane fuel cell is one of the promising alternative energy and there has been significant research and technological investments done in this field. The key information ...
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Over the past decade or so, alternative energy plays a pivotal role in addressing challenges posed by nature. Polymer electrolyte membrane fuel cell is one of the promising alternative energy and there has been significant research and technological investments done in this field. The key information and future prospective of the field is energy conversion and storage, both of which are essential in order to meet the challenges of global warming and the limited fossil fuel supply. However, polymer membrane in particular plays a crucial role in advancing this technology further. The utilization of conducting polymers in manufacturing membranes combining their electrochemical properties along with mechanical properties is of primary importance to enhance the efficiency of this system. In the present study blends of high impact polystyrene (HIPS) and polyaniline (PAni) were obtained with the aim of producing membranes for fuel cell. HIPS and PAni were dissolved in tetrachloroethylene, a common solvent for both materials. After dissolution, PAni was dispersed in an HIPS polymeric matrix. The membranes were molded on to glass plates using a laminator to keep thickness constant, and the solvent evaporated slowly for 24 h under room temperature. The amount of polyaniline used was 10 and 20 % weight. The electronic and structural properties were carried out using X-ray photoelectron spectroscopy (XPS), Thermogravimetric Analysis (TGA) Raman spectroscopy, Scanning electronic microscopic (SEM). The analysis indicate that PAni incorporation and its dispersion into the polymeric matrix modifies the membranes properties and show improvement in efficiency.
Tatiana N. Myasoedova; Eugeniya N. Shishlyanikova; Tatiana A. Moiseeva; Maria Bzerzinskaya
Abstract
In the present work, the PANI and PANI/Zr composite powders were synthesized by the method of chemical polymerization in the inorganic acid medium. The morphology of prepared composites demonstrates fiber-like structure revealed by scanning electron microscopy. The value of the specific surface area ...
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In the present work, the PANI and PANI/Zr composite powders were synthesized by the method of chemical polymerization in the inorganic acid medium. The morphology of prepared composites demonstrates fiber-like structure revealed by scanning electron microscopy. The value of the specific surface area estimated by the BET technique depends on the type of the composite powder and was found to be 66.8 and 142.05 m 2 /g for PANI and PANI/Zr respectively. UV–Vis spectroscopy was employed to characterize the optical properties of the synthesized powder composites. The incorporation of zirconium gives rise to the red shift of π– π* transition of pristine PANI. The synthesized composite powders were used for preparation of PANI/PVA and PANI/Zr/PVA composites which electrochemical properties were compared in different electrolytes: 0.5 M KOH, 0.5 M NaCl and 0.5 M H2SO4. Excellent electrochemical reversibility was found out for both PANI/PVA and PANI/Zr/PVA composites. Effect of electrolyte type and current value on the specific capacitance of the prepared composites was observed.
Sonika Thakur; Anupinder Singh; Lakhwant Singh
Abstract
Self-standing polyaniline (Pani) films modified with gold nanoparticles (Au NP’s), where Au NP’s are added in different successive weight percents, have been synthesized by conventional chemical polymerization technique. An in-depth investigation of the structural and electrical characteristics ...
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Self-standing polyaniline (Pani) films modified with gold nanoparticles (Au NP’s), where Au NP’s are added in different successive weight percents, have been synthesized by conventional chemical polymerization technique. An in-depth investigation of the structural and electrical characteristics of prepared films has been conducted using various characterizations. The X-ray diffraction (XRD) validates the presence of Au NP’s in Pani and the results are supported well by energy dispersive X-ray analyzer (EDX). The field emission scanning electron microscopy (FESEM) clearly shows thorough dispersion of Au NP’s in the amorphous host matrix with minor aggregation. The Fourier transform infrared red (FTIR) studies give the information of possible chemical interaction between the nanoparticles and polymer which is in good agreement with charge transfer mechanism proposed in the manuscript. The temperature dependent dc electrical conductivity has been observed to depend strongly on the nanoparticle loading and follows Mott’s three-dimensional variable range hopping (3D VRH) conduction mechanism. Parameters obtained from Hall Effect measurements are of same order as is calculated by dc measurements which indicates a very good corroboration of results. Higher ac conductivity, dielectric constant and dielectric loss of nanocomposites have also been observed as compared to that of pure Pani.
Keisham Radhapyari; Raju Khan
Abstract
Electrochemical biosensor is an effective tool for pharmaceutical analysis due to its simplicity, specificity, sensitivity, fast, cost-effective and repetitive measurements with miniaturized and portable devices. The paper illustrates the detail methodology for development of an amperometric biosensor ...
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Electrochemical biosensor is an effective tool for pharmaceutical analysis due to its simplicity, specificity, sensitivity, fast, cost-effective and repetitive measurements with miniaturized and portable devices. The paper illustrates the detail methodology for development of an amperometric biosensor based on polyaniline-gold nanocomposite film modified horseradish peroxidase for anticancer drug gemcitabine in bulk and in parenteral formulation. Scanning Electron Microscopy, Cyclic Voltammetry, Fourier Transform Infra Red Spectroscopy and Electrochemical Impedance Spectroscopic studies of the electrodes and after immobilizing of HRP shows the successful formation of a selectivity of the electrode. The proposed polyaniline-gold nano-composite based biosensor allow quantitation over the range 0.10 to 1.10 ngmL −1 with detection limit of 0.031 ngmL −1 , biosensor sensitivity of 2.934 µAng mL -1 has distinct advantages over other existing methods. Precision and accuracy were also checked and were within the limits. The procedure has been applied to the assay of the drug in dosage form with mean percentage recoveries of 99.00±0.08%. The suggested biosensor method can be successfully applied to the detection and determination of anticancer drug gemcitabine in different drug formulations.
Suyog M. Pethe; Subhash B. Kondawar
Abstract
One dimensional conducting polymer nanostructures have been the focus of quite extensive studies worldwide due to their high aspect ratio, high porosity apart from high surface area to volume ratio. Conducting polyaniline nanofibers can be synthesized by various methods. In this paper, we report the ...
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One dimensional conducting polymer nanostructures have been the focus of quite extensive studies worldwide due to their high aspect ratio, high porosity apart from high surface area to volume ratio. Conducting polyaniline nanofibers can be synthesized by various methods. In this paper, we report the preparation of polyaniline nanofibers with an average diameter of 40–70 nm by two different simple approach rapid mixing and interfacial polymerization. The key to producing polyaniline nanofibers is to suppress secondary growth. Based on this, interfacial polymerization and rapidly mixed reactions have been developed that can readily produce nanofibers by slightly modifying the conventional chemical synthesis of polyaniline without the need for any template or structural directing agent. Synthesized polyaniline (PANI) nanofibers were characterized by FTIR spectroscopy, X-ray diffraction, transmission electron microscopy for their structural and UV-Vis absorption spectroscopy for optical properties. Direct and indirect transition energy gaps were determined from their Tauc plots. The absorption spectra show a linear fit for the transition. Electrical properties of the synthesized polyaniline nanofibers have been studied and the Arrhenius plots of electrical conductivity for the samples synthesized by rapid mixing and interfacial polymerization method show an approximate equal in their activation energy. The results obtained from optical and electrical properties are well compared, correlated and explained with respect to interfacial and rapid mixing polymerization techniques.
Keisham Radhapyari; Raju Khan
Abstract
An amperometric sensor for detection of toxin aflatoxin B1 from aspergillus flavus based on conducting polyaniline probe using monoclonal anti-aflatoxin B1 (Mc-IgGs-a-AFB1) antibodies after activation with 3% Bovine Serum Albumin (BSA) through electrochemical polymerization has been proposed. The electrode ...
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An amperometric sensor for detection of toxin aflatoxin B1 from aspergillus flavus based on conducting polyaniline probe using monoclonal anti-aflatoxin B1 (Mc-IgGs-a-AFB1) antibodies after activation with 3% Bovine Serum Albumin (BSA) through electrochemical polymerization has been proposed. The electrode was fabricated by immobilizing Mc-IgGs-a-AFB1 antibodies molecules onto electrode surface and characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM) and fourier transform infrared spectroscopic (FT-IR) etc. The proposed amperometric immune-sensor has demonstrated excellent electro-analytical properties relative to Aflatoxin B1 in a linear range from 0.20 to 1.30 AngmL -1 with a relatively low detection limit of 0.059 AngmL -1 . The present study will help in improving for quantitative determination of mycotoxins in food samples may provide significant improvements in quality control of food safety through a simple, rapid, and sensitive testing system for agricultural products monitoring.
Subhash B. Kondawar; Arti I. Nandapure; Bharti I. Nandapure
Abstract
Nanocrystalline nickel ferrite (NiFe2O4) powder of crystallite size ~20 nm was synthesized by refluxing method. Electrically conductive polyaniline-nickel ferrite (PANI/NiFe2O4) nanocomposites have been synthesized by an in-situ polymerization of aniline monomer in the presence of as-prepared NiFe2O4 ...
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Nanocrystalline nickel ferrite (NiFe2O4) powder of crystallite size ~20 nm was synthesized by refluxing method. Electrically conductive polyaniline-nickel ferrite (PANI/NiFe2O4) nanocomposites have been synthesized by an in-situ polymerization of aniline monomer in the presence of as-prepared NiFe2O4 in different weight percentage (5%, 10%, and 15%). These nanocomposites were subsequently characterized for morphological, crystalline, structural, electrical and magnetic properties by Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), Four Probe Resistivity (FPR) and Vibrating Sample Magnetometer (VSM). Existence of NiFe2O4 in the nanocomposites was confirmed by XRD, FTIR and TEM analysis. The change in morphology with crystallite size ? 50 nm was observed for the nanocomposites clearly indicate the coating of PANI on NiFe2O4 . Nanocomposites showed increase in saturation magnetization as compared to that of PANI and increase in electrical conductivity as compared to that of NiFe2O4 indicating the synergistic effect of individual components. The saturation magnetization drastically increased as nickel ferrite content changed from 5 to 15% in nanocomposites. The conductivity of nanocomposites increased with temperature, exhibiting typical semiconductor behavior. The nanocomposites show semiconducting and ferromagnetic behaviour. The electrical conductivity of nanocomposites decreased from 1.089 to 0.268 S/cm, but saturation magnetization increased from 0.97 to 2.803 emu/g, when ferrite content changed from 5 to 15 wt%, indicates such nanocomposites are good for electromagnetic devices.
Subhash B. Kondawar; A. D. Dahegaonkar; V. A. Tabhane; D. V. Nandanwar
Abstract
With more than 100 million tonnes of fly ash produced in India, use of fly ash for the preparation of polyaniline – fly ash composites will in no way help in its bulk utilization. Still the authors have made an effort towards the better utility of fly ash by synthesizing polyaniline –fly ...
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With more than 100 million tonnes of fly ash produced in India, use of fly ash for the preparation of polyaniline – fly ash composites will in no way help in its bulk utilization. Still the authors have made an effort towards the better utility of fly ash by synthesizing polyaniline –fly ash composites for electronic devices where the requirement of dielectric materials with good electrical conductivity. There is great challenge to use the waste of thermal power stations in the form of fly ash as reinforcement for the conducting polymers to be good dielectric materials. In this paper, we report the use of fly ash to prepare conducting polymer composite materials. In-situ polymerization of aniline was carried out in the presence of fly ash (FA) to synthesize conducting polyaniline–fly ash composites (PANI-FA) by chemical oxidation method. The PANI-FA composites have been synthesized with various compositions (10, 20, 30, 40 and 50 wt %) of fly ash in conducting polymer matrix. The surface morphology of these composites was studied by scanning electron microscopy (SEM). These composites were characterized by Scanning Electron Microscopy (SEM), X-Ray Diffractometry (XRD), Fourier Transform Infra-Red (FTIR) Spectroscopy to investigate surface morphology and structure of the composites. Thermal and frequency dependence dielectric properties of all the synthesized composites have been studied with the help of impedance analyzer. By incorporating fly ash into conducting polymers, dielectric constant of the composites was found to be improved as compared to that of pure conducting polymers. It was also noticed that the dielectric constant of all the composites found to be decreased with increasing frequency but increased with increasing temperature. The results obtained for these composites are of greater scientific and technological interest for good quality capacitors.
Ameena Parveen; Aashis S. Roy
Abstract
Polyaniline/TiO2 nanocomposites have been prepared by sol-gel technique using citric acid and saturated solution of α-dextrose as a surfactant in presence of hydroxyl group at an anomeric position in sugar chain. The FTIR spectrum indicates the benzenoid, quinoid and MO peaks confirm the formation ...
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Polyaniline/TiO2 nanocomposites have been prepared by sol-gel technique using citric acid and saturated solution of α-dextrose as a surfactant in presence of hydroxyl group at an anomeric position in sugar chain. The FTIR spectrum indicates the benzenoid, quinoid and MO peaks confirm the formation of PANI/TiO2 nanocomposites. The XRD studies show the monoclinic structure and the TEM study of nano TiO2 reveals that the average particles size is 9 ±2 nm whereas the composite size is 13 ± 2 nm and further it is observed that the TiO2 nanoparticles are intercalated to form a core shell of PANI. The formation of core shell is significant up to 30wt% observed from the SEM. The TGA-DSC curves show the thermal stability of polyaniline and its nanocomposites at 660 °C of temperature.
Abstract
Nickel oxide (NiO) nanoparticles were prepared by the simple approach of co-precipitation method using nickel carbonate as precursor. Novel electrically conducting composite materials consisting of nickel oxide nanoparticles dispersed in a polyaniline (PANI) are prepared by an in-situ polymerization ...
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Nickel oxide (NiO) nanoparticles were prepared by the simple approach of co-precipitation method using nickel carbonate as precursor. Novel electrically conducting composite materials consisting of nickel oxide nanoparticles dispersed in a polyaniline (PANI) are prepared by an in-situ polymerization method in the presence of different weight percentage of NiO (5, 10, 15 and 20%) at room temperature using ammonium persulphate (NH4)2S2O8 as an oxidant in acidic medium. The synthesized PANI/NiO nanocomposites have been characterized by means of XRD, FTIR, UV-VIS, TEM and VSM for structural and magnetic investigation. NiO has single phase cubic structure with average crystallite size of 23nm and is intercalated to form a core shell of PANI due to which nanocomposites show the peaks of NiO as well as PANI. PANI/NiO nanocomposites showed semiconducting as well as ferromagnetic nature. It was also observed that the conductivity of the PANI/NiO nanocomposites decreased and the magnetization increased with the increase in weight percentage of NiO in PANI. We studied first time the effect of NiO on transport properties of PANI/NiO nanocomposites in terms of transport parameters such as electrical conductivity (s), charge localization length (a-1), most probable hopping distance (R) and charge hopping energy (w) using variable range hoping (VRH) of charge model as described by Ziller to conducting polymers.Copyright © 2013 VBRI press.
S. B. Kondawar; S. W. Anwane; D. V. Nandanwar; S. R. Dhakate
Abstract
Conducting polymer nanocomposites (PANI-CNT and POAS-CNT) have been synthesized by polymerization of aniline (ANI)/ o-anisidine (OAS) in the presence of functionalized multiwall carbon nanotubes (MWCNTs). These nanocomposites have been characterized by UV-VIS, FTIR and SEM to study the effect of incorporation ...
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Conducting polymer nanocomposites (PANI-CNT and POAS-CNT) have been synthesized by polymerization of aniline (ANI)/ o-anisidine (OAS) in the presence of functionalized multiwall carbon nanotubes (MWCNTs). These nanocomposites have been characterized by UV-VIS, FTIR and SEM to study the effect of incorporation of MWCNTs on the morphology, structure and crystalline of the conducting polyaniline and its substitute derivate poly(o-anisidine). UV-VIS spectra shows that polaron-π* and π-π* transition bands of the PANI/POAS chain shifted to longer wavelengths, indicating the interaction between quinoid rings and MWCNTs. FTIR spectra shows that the interaction between the MWCNTs and PANI/POAS may result in ‘charge transfer’, whereby the sp2 carbons of the MWCNTs compete with dopant ions [Cl – ] and perturb the H-bond, resulting an increase in the N-H stretching intensity. Electron microscopy reveals that the interaction between the quinoid ring of PANI/POAS and the MWCNTs causes PANI and POAS polymer chains to be adsorbed at the surface of MWCNTs, thus forming a tubular core surrounding the MWCNTs. The nanocomposites showed high electrical conductivity compared to pure PANI/POAS. Further, PANI-CNT showed high electrical conductivity compared to that of POAS-CNT.
Y.B. Wankhede; S.B. Kondawar; S.R. Thakare; P.S. More
Abstract
Conducting polyaniline/silver nanoparticles (PANI-Ag) nanocomposite was synthesized by in-situ polymerization of aniline in the presence of silver nitrate as precursor. Nanocomposite was characterized by UV-VIS, PL, XRD, FTIR, SEM and TGA to study the effect of silver nanoparticles embedded into PANI ...
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Conducting polyaniline/silver nanoparticles (PANI-Ag) nanocomposite was synthesized by in-situ polymerization of aniline in the presence of silver nitrate as precursor. Nanocomposite was characterized by UV-VIS, PL, XRD, FTIR, SEM and TGA to study the effect of silver nanoparticles embedded into PANI on the morphology, structure, crystalline and thermal stability of the conducting polyaniline. The optical studies show that the absorption edge of PANI-Ag nanocomposite exhibits the significant blue shift. The photoluminescence studies show that the emission peak shifted towards the blue when compared to that of bulk PANI-Ag. The broadening sharp peaks in the XRD pattern indicate that the synthesized PANI-Ag nanocomposite is nanocrystalline. FTIR reveals the presence of silver metal ions uniformly embedded into PANI. SEM reveals the rod structure surface morphology of PANI-Ag nanocomposite. Thermogravimetric analysis suggests the presence of silver and also an oligomeric component in the nanocomposite. The combination of PANI as a semiconducting polymer with silver as a noble metal may produce hybrid material that behaves as semiconductor at low temperature and as metal at high temperature.
Yasir Ali; R G Sonkawade;A S Dhaliwal; Vijay Kumar
Abstract
We have electrochemically synthesized polyaniline nano fibers with optimized process parameters (viz. concentration of monomer and dopant, applied current density, deposition time, etc.) on ITO coated glass substrate. The nano fibers of polyaniline were subjected to UV Visible, SEM and Raman spectroscopy. ...
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We have electrochemically synthesized polyaniline nano fibers with optimized process parameters (viz. concentration of monomer and dopant, applied current density, deposition time, etc.) on ITO coated glass substrate. The nano fibers of polyaniline were subjected to UV Visible, SEM and Raman spectroscopy. UV Vis spectra show two prominent peaks at 317 and 418 nm, which confirm the presence of different forms of polyaniline. Raman spectra confirm the formation of polyaniline. SEM image of synthesized nano fibers showed a flower like structure with an isotropic growth rate.
S. B. Kondawar; S. P. Agrawal; S. H. Nimkar; H. J. Sharma; P. T. Patil
Abstract
Tin oxide (SnO2) nanoparticles have been synthesized by simple route of sol-gel method. Polyaniline-tin oxide (PANI/SnO2) nanocomposite (sample A) was prepared by an in-situ polymerization of aniline in the presence of as-synthesized SnO2 nanoparticles. Similarly, tin oxide-intercalated polyaniline nanocomposite ...
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Tin oxide (SnO2) nanoparticles have been synthesized by simple route of sol-gel method. Polyaniline-tin oxide (PANI/SnO2) nanocomposite (sample A) was prepared by an in-situ polymerization of aniline in the presence of as-synthesized SnO2 nanoparticles. Similarly, tin oxide-intercalated polyaniline nanocomposite (sample B) was prepared using tin chloride (SnCl4.5H2O) as precursor during polymerization of aniline. Morphology and structure of both the nanocomposites have been studied using XRD pattern, FTIR spectra and SEM images which reveals that SnO2 was uniformly mixed within the PANI matrix. In this paper we report the comparison of polyaniline-tin oxide (PANI/SnO2) nanocomposites sample A and B for the response to ammonia. A laboratory set up for sensing ammonia has been built up using four probe resistivity unit and the response of the prepared PANI/SnO2 nanocomposites to ammonia vapour for different concentration (5, 10, and 15%) was tested. PANI/SnO2 nanocomposites were found to be good materials for NH3 detection even at room temperature as compared to that of pure SnO2. By comparing the response of sample A and B to the ammonia vapour, the sample A was found to be more sensitive than sample B due to highly porosity and surface activity of sample A. The results were reproducible and checked by repeating observations. Synthesis route for the preparation of PANI/SnO2 nanocomposites is an important factor while selecting the materials for ammonia sensing.
Ashok K. Sharma; Yashpal Sharma; Rajesh Malhotra; J.K. Sharma
Abstract
Composites of polyaniline and multiwalled carbon nanotube were prepared by in- situ chemical oxidative polymerization of the aniline monomer in 1M HCl and 1M HCl with 20% ethanol as solvent. The PANI-CNT composites were characterized by FTIR and XRD method. The surface morphology characterization of ...
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Composites of polyaniline and multiwalled carbon nanotube were prepared by in- situ chemical oxidative polymerization of the aniline monomer in 1M HCl and 1M HCl with 20% ethanol as solvent. The PANI-CNT composites were characterized by FTIR and XRD method. The surface morphology characterization of the composites was done by using scanning electron microscopy (SEM). Electrochemical behavior of prepared PANI-CNT composites was investigated by means of cyclic voltammetry. Specific capacitance of PANI-CNT composite using 0.02M aniline in 1M HCl (20% ethanol) and 1M HCl was 597.82 and 484.49 F/g respectively at scan rate of 2mV/s in 1M H2SO4.
Subhash B. Kondawar; Smita A. Acharya; Sanjay R. Dhakate
Abstract
ZnO in different nanostructures were synthesized by microwave assisted hydrothermal route. Different experimental conditions such as microwave irradiation power, exposure time have been investigated to reveal the process of formation of the ZnO nanostructures. It was revealed that the microwave exposure ...
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ZnO in different nanostructures were synthesized by microwave assisted hydrothermal route. Different experimental conditions such as microwave irradiation power, exposure time have been investigated to reveal the process of formation of the ZnO nanostructures. It was revealed that the microwave exposure time plays a vital role in determining the diameter of the rods. The interaction of microwaves with the growth units of ZnO was systematically investigated to explain formation of different structural geometry of ZnO on nanoscale. ZnO nanostructures consisted of flower-like, sword-like, needle-like and rods-like structures were prepared by microwave assisted hydrothermal process at different conditions of microwave power and irradiation time. The ZnO nanostructures are in hexagonal phase. It is considered that microwave can interact with growth units of ZnO to generate active centers on the surface of ZnO nuclei so that needle-like ZnO rods are created on those sites, resulting in the formation of the flower-like ZnO nanostructures. Polyaniline - ZnO nanocomposites (PZ) in various weight % of nanostructure ZnO were synthesized by the chemical oxidation method in sulphuric acid medium using ammonium persulphate as oxidant at 276K. The synthesized polymer nanocomposites were characterized by XRD, FTIR and UV-VIS spectroscopy.
B.S. Kushwah; S.C. Upadhyaya; Shipra Shukla; Apurva Singh Sikarwar; R.M.S. Sengar; Seema Bhadauria
Abstract
The Laccases are oxidoreductases belonging to the multinuclear copper-containing oxidases; they catalyse the monoelectronic oxidation of substrates at the expense of molecular oxygen. These essentially ecofriendly enzymes work with air and produce water as the only by-product. Their uses span from the ...
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The Laccases are oxidoreductases belonging to the multinuclear copper-containing oxidases; they catalyse the monoelectronic oxidation of substrates at the expense of molecular oxygen. These essentially ecofriendly enzymes work with air and produce water as the only by-product. Their uses span from the textile to the pulp and paper industries, and from food applications to bioremediation processes. Laccases also have uses in organic synthesis, where their typical substrates are phenols and amines, and the reaction products are dimers and oligomers derived from the coupling of reactive radical intermediates. Laccase from Pleurotus ostreatus was extracted from the Shaken flask cultures of Pleurotus ostreatus and grown at 25°C with continuous agitation (110 rpm) in baffled Erlenmeyer flasks (1000 mL) containing 200 mL medium. The basal glucose yeast extract peptone agar medium (GYP medium) used for cultures unless otherwise stated contained 20 g glucose L -1 , 5 g yeast extract L -1 , 5 g peptone L −1 and 1 g MgSO4.7H2O L −1 . The pH was adjusted to 5±0 with H3PO4 prior to sterilization. The kinetics of oxidation reactions catalyzed by laccase was studied using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS). The laccase showed lower specific activity. Enzyme modified electrodes were fabricated with polyaniline. Electrochemical polymerization of aniline was performed to get the film of polymer on the surface of glass electrode. First, ITO/PANI electrode was reduced by a 15 min cathodic polarization of the sensor at -500 mV in 0.1 M acetate buffer, pH 5.5. After cathodic polarization, the film was immersed in 0.1 M of acetate buffer, pH 5.5 containing enzyme solution for the deposition of enzyme in polymer layer at +650 mV for 20 min. During this oxidation process laccase become electrostatically attached to polymer film. The ITO/PANI/LAC electrode was rinsed with deionised water to remove any loosely bounded enzyme, and stored in buffer solution at 4 o C, when not in use. Conducting polymer/enzyme modified electrodes prepared by immobilization of enzyme were tested for electrocatalytic activities towards amperometric sensing of phenol in industrial effluent.
S.K. Shukla; Anand Bharadvaja; Ashutosh Tiwari; G.K. Parashar; G.C. Dubey
Abstract
Polyaniline (PANI) was prepared in emeraldine via chemical oxidation method using CuSO4 as initiating agent. The chemical characterizations were made using UV-vis (ultraviolet-visible spectrophotometry), FT-IR (Fourier transform spectroscopy), TG-DTA (thermo-gravimetric/differential thermal analysis), ...
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Polyaniline (PANI) was prepared in emeraldine via chemical oxidation method using CuSO4 as initiating agent. The chemical characterizations were made using UV-vis (ultraviolet-visible spectrophotometry), FT-IR (Fourier transform spectroscopy), TG-DTA (thermo-gravimetric/differential thermal analysis), ESI-MS (electrospray ionization mass spectrometry), XRD (X-ray diffraction), SEM (scanning electron microscopy) techniques. The results revealed the formation of homogeneous, crystalline PANI with sub-micron size particles. The PANI thin film of 0.5 µm thickness has been fabricated using spin coating technique. The resulting PANI film was exposed to controlled humid condition and change in resistance has been recorded. The resistance was continuously decreased from 13.5 to 3.75 MΩ with a linear change in humidity ranging from 3 to 95%. The result was reproducible and checked by repeating observation.
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