Conducting Polyaniline Composites Research Articles

Radiation-induced synthesis, electrical and optical characterization of conducting polyaniline of PANI/ PVA composites

This study employs the gamma radiation technique to produce conducting polyaniline from an aqueous solution. The solution comprises four materials: ANI, PVA, CaCl2 and distilled H2O, which serve as a binder or film support, precursor, Cl ions provider, and a solvent. To obtain the conducting polyaniline (PANI/PVA) composite, a film of ANI/ PVA/ CaCl2 was subjected to gamma radiation under ambient conditions. Conducting polyaniline composite was seen to form once the colour began to change from white to green in accordance with the doses of radiation. The results demonstrated that the level of gamma radiation increased to 30 KGy, thereby confirming that the electrical insulation ANI/ PVA/ CaCl2 film was converted into electrically conductive polyaniline composite film. In addition, the measurements of UV–Visible spectrophotometer revealed an absorption band of 795 nm rises alongside the radiation dose which produced PANI/PVA with a green hue that increases in intensity in accordance with rises in the doses of radiation.

Synthesis of novel conducting polyaniline composites based on seaweed Enteromorpha compressa macro-alga powder

New bio-composites were successfully synthesized from Enteromorpha compressa macro-alga (ECMA) and polyanilic matrix (PANI) through oxidative polymerization. To examine the ECMA effect on the PANI’s characteristics, different weights (5, 10, 15, 20 and 50%) of ECMA powder were incorporated into the polymer matrix. The in situ polymerization of aniline was confirmed by FTIR and UV–Vis spectroscopies which lead to the formation PANI emeraldine base. The XRD analysis showed that the crystallinity of PANI becomes more conspicuous with addition of ECMA as evidenced by the increased peaks intensities. The electrical conductivity measured by the four-probe method averages 10−2 S cm−1. The results showed that ECMA powder has a high ability as reinforcing material in the polymer matrix. As application, PANI–20% ECMA presents the best efficiency for the removal of yellow quinoline from aqueous solutions with an uptake yield of 85%. The adsorption isotherm is well described by the Freundlich model with a capacity of 118.906 mg g−1, and the experimental data were fitted with the pseudo-second-order kinetic models.

Synthesis and Characterization of Conducting Polyaniline Based on ANI-PVA-MgCl2Composites Using Gamma Radiation Technique

Conducting polymer composites such as conducting polyaniline composites have numerous attractive physical properties which could be used in several vital applications. In order to give composite materials unique physical and chemical properties that can have broad application potential in various areas, it requires appropriate adding of metal chloride through conductive polymer composites. This study employs the gamma radiation technique to produce conducting polyaniline from an aqueous solution. The solution comprises four materials, including: ANI, PVA, MgCl2 and distilled H2O, which serve as a binder or film support, precursor, Cl ions provider, and a solvent. To attain the conducting polyaniline composite, a film of ANI-PVA-MgCl2 was subjected to gamma radiation under ambient conditions. Conducting polyaniline composite has been formed once the colour began to change from white to green following the doses of radiation. The results have demonstrated that the level of gamma radiation increased to 40 KGy, thereby confirming that the electrical insulation ANI-PVA-MgCl2 film was converted into an electrically conductive polyaniline composite film. The production of conducting polyaniline composite has been observed since the colour has been changed from white to green colour alongside radiation doses.

Polyaniline/silver decorated‐MWCNT composites with enhanced electrical and thermal properties

Conducting polyaniline (PANI) composites reinforced with pristine Multi‐walled carbon nanotubes (MWCNTs) and silver decorated MWCNTs (Ag‐MWCNTs) were fabricated via in situ polymerization method. These composites were characterized by Fourier transform infrared (FTIR) spectroscopy, ultraviolet‐visible (UV‐Vis) spectroscopy, scanning electron microscopy (SEM), conductivity measurements and thermogravimetric analysis (TGA). FTIR and UV‐Vis spectra confirmed the successful polymerization of aniline on the surface of Ag‐MWCNTs. SEM showed uniform dispersion of MWCNTs into PANI matrix with a few coarse patches. Studies of electrical conductivity revealed that Ag‐MWCNT, as filler, is more effective in enhancing the electrical conductivity of PANI. The maximum conductivity of PANI/Ag‐MWCNTs composites was almost two times, i.e., 11.9 Scm−1 for composites having only 2% fillers as compared to that of PANI/MWCNTs having 4% filler, i.e., 5.7 Scm−1. Thus, PANI/Ag‐MWCNTs composites are thermally more stable than PANI/MWCNTs composites due to better interaction between PANI and Ag‐MWCNTs. The results of TGA suggest that PANI‐MWCNTs composites showed 12 to 15% higher weight loss than that of PANI/Ag‐MWCNTs composites. Also, PANI had lower thermal stability than its composites with MWCNTs and Ag‐MWCNTs. POLYM. COMPOS., 39:E1346–E1353, 2018. © 2016 Society of Plastics Engineers

Conductive composites of polyaniline–polyacid complex and graphene nanostacks

Nanocomposites based on graphene and polyaniline–polyacid complexes with tunable electrical conductivity are elaborated. An influence of graphene oxidation degree on conductivity of the nanocomposites is investigated. The change of optical and electrical properties after graphene introduction into polyaniline–polyacid complexes is explained by the formation of graphene nanostacks of different size and their different distribution in the film bulk. The role of (i) internal interactions between graphene sheets revealed by high-resolution TEM and AFM and (ii) external interactions between graphene and polyaniline or polyacid of different hydrophobicity elucidated by UV–vis, FTIR-spectroscopies and pH-measurements is discussed. In case of uniform distributed graphene sheets having a low oxidation degree, the electrical conductivity of the nanocomposites based on polyaniline complexed with more hydrophilic polyacid increases up to 20 times in respect to initial polyaniline complex.

The effect of molecular structure, band gap energy and morphology on the dc electrical conductivity of polyaniline/aluminium oxide composites

Conducting composites of polyaniline have successfully synthesised with different weight percentages of aluminium oxide (0–40%) dispersed during polymerisation of polyaniline. These composites were characterised by X-ray diffraction analysis, UV–visible absorption spectroscopy, scanning electron microscopy and standard two probe method to study the influence of doping on their structure, effect of band gap energy and surface morphology on conductivity of polyaniline. It was perceived that dispersion of aluminium oxide in polyaniline matrix has introduced good structural and conducting properties. The percolation threshold for conductivity was observed at 10 wt-% of metal oxide content in polyaniline matrix owing to semicrystalline behaviour, small band gap energy, homogeneous dispersion and reduction in grain boundary volume as inferred from X-ray diffraction, ultraviolet and scanning electron microscopy studies.

Active corrosion protection by conductive composites of polyaniline in a UV-cured polyester acrylate coating

Polyaniline doped with phosphoric acid (PANI-PA) was synthesized and characterized by impedance and Raman spectroscopy. Exposure to UV-light resulted in a slight decrease in the PANI's electrical c ...

Graphene oxide-filled conducting polyaniline composites as methanol-sensing materials

Polyaniline/graphene oxide (PANI/GO) composites were prepared by polymerization of aniline monomer in the presence of GO under acidic conditions. The synthesized samples were characterized by Fourier transform infra red spectroscopy, ultraviolet–visible absorption, Raman spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and thermogravimetric analysis. The direct current electrical conductivity of the composite was calculated by a four-probe technique. It is found that the conductivity dramatically increased to 241 S m−1 for PANI/GO (5 wt%) composite at 110 °C compared to pure PANI (7.5 S m−1). The composite material was investigated as a methanol vapour sensor and compared with pure PANI. The methanol-sensing characteristics of the prepared composite was monitored by measuring the change in electrical resistivity on exposure to methanol vapour at different concentrations. The resistivity of PANI increases on exposure to methanol vapour because of strong hydrogen bonding between methanol with the polymer chain. A density functional theory study was carried out to verify the proposed concept of hydrogen bonding between the polymer chains and methanol. The presence of GO in PANI/GO composite increases the sensitivity towards methanol as compared with the pure PANI.

Template synthesis of conducting polyaniline composites based on honeycomb ordered polycarbonate film

This paper describes the synthesis of polyaniline (PANI) layers by a simple one-step chemical oxidative polymerization, based on the surface of a honeycomb ordered porous polycarbonate (PC) film prepared via water-assisted method from PC/CHCl3 solutions. The surface and cross-section morphology of the PANI/PC composite film was characterized by environmental scanning electron microscopy, indicating that the honeycomb ordered PC film plays the role as template in controlling the morphology of the PANI/PC composite film. The results of thermogravimetric analysis of the PANI/PC composite film showed higher thermal stability than PANI itself. The electrical conductivity of the PANI/PC composite film was also determined by the four-probe technique.

Conducting polyaniline composites as microwave absorbers

AbstractConducting polymers are excellent microwave absorbers and they show technological advantage when compared with inorganic electromagnetic absorbing materials, being light weight, easily processable, and the ability of changing the electromagnetic properties with nature and amount of dopants, synthesis conditions, etc. In this paper we report the synthesis, dielectric properties, and expected application of conducting composites based on polyaniline (PAN). Cyclohexanone soluble conducting PAN composites of microwave conductivity 12.5 S/m was synthesized by the in situ polymerization of aniline in the presence of emulsion grade polyvinyl chloride. The dielectric properties of the composites, especially the dielectric loss, conductivity, dielectric heating coefficient, absorption coefficient, and penetration depth, were studied using a HP8510 vector network analyzer. The microwave absorption of the composites were studied at different frequency bands i.e, S, C, and X bands (2–12 GHz). The absorption coefficient was found to be higher than 200 m−1 and it can be used for making microwave absorbers in space applications. POLYM. COMPOS., 28:588–592, 2007. © 2007 Society of Plastics Engineers

Conductive Composites of Lignophenol and Polyaniline

Conductive Composites of Lignophenol and Polyaniline

Intricate relation between the content and interactive roles of β‐cyclodextrin in fixing the characteristics of conducting polyaniline composites

AbstractThis work is an investigation of the influence of β‐cyclodextrin (CD) on the synthesis and characteristics of conducting polyaniline composites (PCDs). In a systematic way, this influence was studied with two different approaches for five PCDs: (1) increasing the initial CD content under identical preparation conditions (three composites: PCD1, PCD2, and PCD3) and (2) using the same initial CD content (as in PCD2) under different preparation conditions (two composites: PCD4 and PCD5). The quite unexpected order of the electrical conductivity (PCD2 < PCD3 < PCD1 < PCD4 < PCD5), the IR and ultraviolet–visible spectroscopy features, and the scanning electron microscopy characteristics (the particle size decreased from PCD1 to PCD3 but increased for PCD4 and PCD5) all exposed and confirmed the markedly different physicochemical characteristics associated with the two groups of composites. PCD5 remained unique among the five (prepared in i‐PrOH–H2O–acid; the other four were prepared in H2O–acid). Differences in the characteristics existed within the group also. The development of all these characteristics in an unrelated order was found to originate from the amount of CD in its two roles as encapsule and dopant toward polyaniline. The interrelation between the content and roles of CD was, however, intricate in combination with the experimental conditions employed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 281–294, 2006

Conductive composites of polyaniline and polypyrrole with MoO3

Composites of polyaniline and polypyrrole with MoO3 were prepared via polymerization of the respective monomer by ammonium vanadate (AV)/H2SO4 oxidant system in presence of an aqueous suspension of MoO3. Formation of PANI and PPY and their subsequent incorporation in the PANI–MoO3 and PPY–MoO3 composite systems was endorsed by FTIR spectral analyses. Thermogravimetric analyses (TGA) revealed the overall thermal stability upto 1000 °C as follows: MoO3> PANI–MoO3> PANI and MoO3> PPY–MoO3> PPY. Differential thermal analyses (DTA) of PANI–MoO3 and PPY–MoO3 composites indicated occurrence of oxidative degradation characteristic of the corresponding homopolymers. XRD scans of PANI–MoO3 and PPY–MoO3 composites suggested that crystalline structure of MoO3 remained undisturbed upon incorporation of PANI or PPY moieties in the MoO3 matrix. Dc conductivity values of PANI–MoO3 and PPY–MoO3 composites were in the order of 10−2 and 10−3 S/cm, respectively.

Electromagnetic shielding behaviour of conducting polyaniline composites

The paper reports the designing and development of conducting polyaniline composites which show a shielding effectiveness of 4–58 dB against electromagnetic interference at 101 GHz range, depending upon the loading of the conducting polyaniline in polystyrene and polymethylmethaacrylate matrix. The composites can be used for the dissipation of static charge. A static decay time of the order of 0.11–0.02 s for the conducting polyaniline composites is observed when thecharge is reduced from 5000 to 500 V.

Broadband Electromagnetic Shields Using Polyaniline Composites

Electromagnetic interference behaviour of conducting polyaniline composites in the radio frequency range X, Ku, and Ka bands is presented. Methods for determining the conductivity and the shielding effectiveness are discussed. The conducting composites are made from CSA-doped polyaniline blended with the styrene acrylonitrile host polymer. The samples exhibit high conductivities, up to 104 S.m−1, and therefore are compatible with an electromagnetic shielding application. The percolation threshold is very low—below 1% of mass fraction of polyaniline in the blend—and the shielding effectiveness is up to 70 dB, depending on the sample.

Estudo das Propriedades de Compósitos de Polianilina e Resina Epoxídica

Compósitos condutores de eletricidade envolvendo polianilina e resina epoxídica foram preparados utilizando-se o método da polimerização in situ. O método consiste da polimerização em emulsão da anilina na presença da resina epoxídica. Ácido dodecilbenzenossulfônico foi utilizado como agente dopante, que age também como surfactante da polimerização em emulsão. A condutividade elétrica do sistema Pani/resina epoxídica alcançou valores tão altos quanto 2 x 10-3 S/cm, com uma concentração de Pani correspondente a 7% em peso. O conteúdo de Pani na mistura foi determinado por análise elementar. O efeito do método de cura da resina epoxídica na condutividade elétrica, temperatura de transição vítrea e propriedades mecânicas do sistema foi também investigado.

Preparation of conductive polyaniline/chlorosulfonated polyethylene composites viain situ emulsion polymerization and study of their properties

The conductive composites of polyaniline (PAn) and chlorosulfonated polyethylene (CSPE) were prepared by polymerization of aniline in the presence of CSPE, using a direct, one-step in situ emulsion polymerization method. The polymerization of aniline was performed in an emulsion comprising water and xylene containing CSPE in the presence of dodecylbenzene sulfonic acid, which acts both as a surfactant and a dopant for PAn. The composites can be processed by either melt method (MP) or solution method (SP). Conductivity of the composites obtained by different processing methods shows different percolation thresholds: 14 wt % for MP samples and 22 wt % for SP samples. At the same content of PAn, the conductivity of MP composites is higher than that of SP composites. The relationships between mechanical properties and PAn content obtained by the two different processing methods were also investigated. When PAn content of MP samples is between 12 and 18 wt %, the composites behave like a thermoplastic elastomer with tensile strength at 6–8 MPa, ultimate elongation > 400% and permanent set < 30%. The conductivity of composites obtained by SP method after secondary doping with m-cresol is about 6 orders of magnitude higher than the original at below 18 wt % PAn content and the percolation threshold for conductivity is lowered to 3 wt % PAn content. The composite shows no electrochromic activity in acidic solution of LiClO4 in propylene carbonate, but after secondary doping exhibits electrochromic activity even in neutral electrolyte. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 845–850, 2000

Secondary doping phenomena of conductive polyaniline composite

Secondary doping phenomena of conductive polyaniline composite

Highly conductive composites of polyaniline with plasticized cellulose acetate

Highly transparent, conductive blends can be prepared from plasticized cellulose acetate and polyaniline protonated with sulphonic acids, phosphonic acids and phosphoric acid diesters. Films cast from m-cresol solution exhibit percolation threshold below 0.5 wt% and excellent mechanical properties of plasticized cellulose acetate.

Novel preparation and properties of conductive polyaniline/nafion ® film

A unique method was employed for making a composite with polyaniline and Nafion ®, a strong-acid-containing polymer. The composite was made by reacting aqueous HCl/aniline and oxidizing agent solutions which were diffused in a Nafion ® film. The method should be applicable to other insoluble, acid containing polymers. The highest conductivity achieved from the composite films was 0.01 S/cm. The conductive polyaniline composite was more stable thermally than HCl-doped polyaniline and it retained the same level of conductivity after immersion in water for six hours. Although ammonium hydroxide deactivated the conductive polyaniline, the conductivity could be recovered by immersing the ammonium hydroxide treated composite film in water.