Bhavna H. Meshram; Subhash B. Kondawar
Abstract
Fabrication of nanocomposite film of electrically conducting polypyrrole (PPy) and functionalized multi-walled carbon nanotubes (MWCNTs) on a stainless steel electrode by electro-deposition method and immobilization of urease onto the nanocomposite film to obtain a nanobiocomposite electrode as a sensitive ...
Read More
Fabrication of nanocomposite film of electrically conducting polypyrrole (PPy) and functionalized multi-walled carbon nanotubes (MWCNTs) on a stainless steel electrode by electro-deposition method and immobilization of urease onto the nanocomposite film to obtain a nanobiocomposite electrode as a sensitive electrochemical urease biosensor is reported. Cross-linking by glutaraldehyde (0.1%) method for the immobilization of urease (2 mg/mL) in a phosphate buffer solution of 0.1 molarity at a pH of 7.0 was used. The Characterization of the nanocomposite and nanobiocomposite film thus obtained was done by Scanning Electron Microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS). The increased size of the Cyclic voltammogram and shifting of anionic peaks towards the lower voltage indicates the incorporation of MWCNTs into the growing film during the electro-deposition of PPy on electrode. Reduction of the oxidation potential due to MWCNTs leads to lowering of potential for the electro-catalytic reduction of urea. The incorporation of functionalized MWCNT also made possible increased amount of enzyme concentration, an extended lifetime, long time stability and improved response times of the enzyme electrode. This modified nanobiocomposite electrode showed a good linear response to the urea concentration change in the range of 10 mM to 50 mM. The results obtained from Michaelis–Menten constant K´m, maximum current (Imax), detection limit, sensitivity, response time and shelf-life of electrochemical biosensor indicating good sensing for urea detection.
Xiaoyan Tang; Yusuf Khan; Cato T. Laurencin
Abstract
Conducting polymers are emerging as highly attractive materials since they can be used alone or in combination with other biomaterials to provide electrical stimulus for tissue regeneration. Here, we report the fabrication of a novel stimuli-responsive conducting polymer scaffold, which can be used to ...
Read More
Conducting polymers are emerging as highly attractive materials since they can be used alone or in combination with other biomaterials to provide electrical stimulus for tissue regeneration. Here, we report the fabrication of a novel stimuli-responsive conducting polymer scaffold, which can be used to regulate muscle cell adhesion, proliferation and differentiation. Our goal in this study was to develop electroconductive nanofiber polymer scaffolds that can modulate the cellular physical microenvironment to increase electrical communication between cells and ultimately generate a more robust and functional construct for muscle regeneration. Matrices such as those designed here could have a significant impact in the clinical setting, where muscle atrophy and fatty infiltration prevent healing of common injuries such as rotator cuff tears. The bio-interface consists of a conducting polymer, poly (3,4ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT: PSS), with a dopamine-polymerized biodegradable substrate made from poly (ε-carprolactone) (PCL) that is rationally assembled together based on the native structure of muscle fibers. XPS analysis confirmed that poly (dopamine) deposition on the PCL scaffolds was successful. The coating of PEDOT: PSS on the poly(dopamine) modified PCL scaffolds was stable as both representative peaks were shown. C2C12 cells, a myoblast cell line was cultured on conductive substrates with different concentrations. Biocompatibility and cellular proliferation of the conducting polymer scaffolds were assessed. It was found that conducting polymers scaffolds of all groups were biocompatible. PEDOT:PSS coating of a low and medium concentration(1% and 10%) showed stimulatory effect on C2C12 growth compared to the control groups. These results showed that the presence of PEDOT:PSS at optimum concentration might enhance C2C12 cell growth and proliferation. These conducting polymer scaffolds hold great promise as biomimetic platforms for skeletal muscle regeneration.
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 ...
Read More
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.
Ashok Kumar Sharma; Preetam Bhardwaj; Sundeep Kumar Dhawan; Yashpal Sharma
Abstract
A novel study on conducting polymers based composites involving hybrid carbon nanostructure assemblage of graphene, amine functionalized multiwalled carbon nanotubes and poly(aniline-co-pyrrole) has been done. The composites were synthesized by oxidative polymerization of 1:1 mixture of aniline and pyrrole ...
Read More
A novel study on conducting polymers based composites involving hybrid carbon nanostructure assemblage of graphene, amine functionalized multiwalled carbon nanotubes and poly(aniline-co-pyrrole) has been done. The composites were synthesized by oxidative polymerization of 1:1 mixture of aniline and pyrrole monomer with ammonium per sulphate and ferric chloride oxidants. UV-vis Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy were used to identify the chemical structure of the obtained composites. Thermal studies indicate that the composites are stable in comparison to poly (aniline-co-pyrrole) alone showing that the hybrid carbon assemblage contributes towards thermal stability in the composites. Crystalline properties of the composites were investigated by X-ray diffraction (XRD). Scanning electron microscopy (SEM) was used to characterize the surface morphology of the composites. The specific capacitance of the composites was characterized by cyclic voltammogram (CV). The capacitive studies reveal that the composite has synergistic effect and highest specific capacitance of 337.35F/g at scan rate of 10mV/sec and 193.06F/g at scan rate of 50 mV/sec was obtained for the composite having thinnest layer of co-polymer over hybrid carbon assemblage i.e., 02-PANI-co-PPY-C.
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 ...
Read More
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.
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 ...
Read More
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 ...
Read More
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 ...
Read More
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.
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 ...
Read More
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.
M. Roy; J. Bajpai;A. K. Bajpai; R. G. Mahloniya
Abstract
Novel electrically conducting nanocomposite materials comprising of poly (pyrrole) (PPy) nanoparticles dispersed homogeneously in a poly (vinyl alcohol)-g-poly (2-acrylamido-2-methyl-1-propanesulphonic acid-co-acrylonitrile) matrix were prepared by in situ polymerization of pyrrole. Radiation shielding ...
Read More
Novel electrically conducting nanocomposite materials comprising of poly (pyrrole) (PPy) nanoparticles dispersed homogeneously in a poly (vinyl alcohol)-g-poly (2-acrylamido-2-methyl-1-propanesulphonic acid-co-acrylonitrile) matrix were prepared by in situ polymerization of pyrrole. Radiation shielding potential of so designed polypyrrole based nanocomposites was studied by exposure of polymer materials to gamma radiation under varying experimental conditions and structural and morphological changes in irradiated materials were examined by FTIR and SEM techniques.
)