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Abstract Polyindole–tin (IV) molybdophosphate (PIn-SMP), an organic-inorganic nanocomposite ion exchanger, was synthesized by a sol-gel process and exhibited excellent ion exchange capacity (2.1 meq g−1). A heterogeneous ion exchange membrane of PIn-SMP (ion exchange capacity 0.95 meq g−1) was also prepared by a solution casting method. The materials were characterized by various instrumental methods, such as scanning electron microscopy, transmission electron microscopy, Fourier transform IR spectroscopy, and thermogravimetric analysis. PIn-SMP exhibits high electrical conductivity (6.1 × 10−2 S/cm) and is stable up to 120 °C under ambient conditions. A Cu2+-selective membrane electrode was fabricated, and its linear working range (1.8 × 10−7–1.0 × 10−1 M), response time (20 s), Nernstian slope (24.07 mV dec−1), and working pH range (4–7) were calculated. Moreover, it was used as an indicator electrode in the potentiometric titration of Cu2+. Graphical abstract Image 1 Highlights • Polyindole–tin (IV) molybdophosphate nanocomposite ion exchanger (IEC-2.1 meq g−1), was synthesized by a sol-gel process. • The nanocomposite displayed high DC electrical conductivity (6.1 × 10−2 S cm−1) at room temperature. • A heterogeneous ion exchange membrane (IEC-0.95 meq g−1) was prepared by a solution casting method. • The materials were characterized by various instrumental methods, such as SEM, TEM, FT-IR, and TGA analysis. • A Cu2+-selective membrane electrode was fabricated and exhibited a wide linear response range (1.8 × 10−7–1.0 × 10−1 M). [ABSTRACT FROM AUTHOR]

We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active paper and its hybrid composites such as blends or coatings with synthetic polymers, biopolymers, carbon nanotubes, chitosan, and metal oxides, are explained. In addition, the integration of cellulose electro-active paper is highlighted to form various functional devices including but not limited to bending actuators, flexible speaker, strain sensors, energy harvesting transducers, biosensors, chemical sensors and transistors for electronic applications. The frontiers in cellulose paper devices are reviewed together with the strategies and perspectives of cellulose electro-active paper and cellulose nanocomposite research and applications. [ABSTRACT FROM AUTHOR]

In the present study, a novel electrically conductive polypyrrole–titanium(iv)sulphosalicylophosphate (PPy–TSCP) cation exchange nanocomposite was synthesized by an in situ chemical oxidative polymerization of pyrrole in the presence of titanium(iv)sulphosalicylophosphate (TSCP). The PPy–TSCP cation exchange nanocomposite was characterized by various instrumentation techniques such as FTIR, FE-SEM, XRD, TGA, DTA, DTG and EDXA. The composite exhibited good ion-exchange capacity (IEC) (2.10 meq g−1) as well as electrical conductivity (0.756 S cm−1) and isothermal stability in terms of DC electrical conductivity retention under ambient conditions up to 100 °C. The PPy–TSCP cation exchange nanocomposite based sensor was fabricated for the detection of acetaldehyde vapours, and it was found that the resistivity of the nanocomposite increases on exposure to a high concentration of acetaldehyde vapors at room temperature (25 °C). The rate of reaction for acetaldehyde vapour sensing on PPy–TSCP was observed to be first order. [ABSTRACT FROM AUTHOR]

Electrically conductive Polypyrrole-zirconium(IV)selenoiodate (PPy/ZSI) cation exchange nanocomposite have been synthesized by chemical oxidative polymerization of polypyrrole (PPy) in the presence of zirconium(IV)selenoiodate (ZSI) by sol-gel method. The formation of PPy/ZSI nanocomposite was characterized by fourier transform infra-red spectroscopy (FTIR), x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive x-ray (EDX) and thermogravimetric analysis (TGA). The ion exchange capacity (IEC) and electrical conductivity of the nanocomposite was found to be 2.49 meq/g and 0.436 S/cm respectively. The nanocomposite showed appreciable isothermal stability in terms of DC electrical conductivity retention under ambient condition up to 130 °C. In addition, the cation exchange nanocomposite based sensor for detection of formaldehyde vapors was fabricated at room temperature. It was revealed that the resistivity of the nanocomposite increases on exposure to higher percent concentration of formaldehyde at room temperature (25 °C), also the sensor exhibited good reversible response towards formaldehyde vapors ranging from 5 to 7%. The present study may serve as a basis for designing other smart materials for formaldehyde sensors. [ABSTRACT FROM AUTHOR]

Highlights: [•] Kinetics studies envisage the mechanism of ion exchange on the surface of nanocomposite PANI-ZTP. [•] Exchange process governed by particle controlled diffusion phenomenon which is faster than the film diffusion. [•] Self-diffusion co-efficient of Ba2+ is highest because of greater ionic size. [•] Activation energy is calculated by using verified and validated Arrhenius equation. [•] Negative values of ΔS° indicate the presence of more active exchangeable sites in the proposed nanocomposite. [ABSTRACT FROM AUTHOR]

Abstract: Electrically conductive poly(3-methythiophene) cerium(IV)phosphate cation exchange nanocomposites have been synthesized for the first time by in situ chemical oxidative polymerization of 3-methythiophene in the presence of cerium(IV)phosphate. FTIR, SEM, TEM and XRD analysis were used to characterize P3MTh cerium(IV)phosphate cation exchange nanocomposites. The characterization results confirmed that there is a strong interaction between poly(3-methythiophene) and cerium(IV)phosphate particles. The thermal behavior of poly(3-methythiophene), cerium(IV)phosphate and poly(3-methythiophene) cerium(IV)phosphate nanocomposite were also investigated by thermogravimetric analysis (TGA), differential thermal analysis (DTA) and differential thermal gravimetry (DTG) at heating rate 10°Cmin−1 under nitrogen atmosphere and the P3MTh cerium(IV)phosphate nanocomposite was found thermally more stable than pure P3MTh. Isothermal stability of P3MTh and P3MTh cerium(IV)phosphate nanocomposite in terms of direct-current electrical conductivity retention was also studied in ambient air. The P3MTh cerium(IV)phosphate nanocomposite showed better ion-exchange capacity, electrical conductivity and isothermal stability in terms of direct-current electrical conductivity retention under ambient condition than pure poly(3-methythiophene). [Copyright &y& Elsevier]

Abstract: The separation of Hg(II) from aqueous solutions was studied using Poly-o-anisidine Sn(IV) tungstate nano-composite cation exchanger. This nano-composite material was synthesized via sol–gel mixing of Poly-o-anisidine with the inorganic precipitate of Sn(IV) tungstate, providing a new class of organic–inorganic nano-composite cation exchanger with good ion-exchange capacity, better chemical and thermal stability than most of the Poly-o-anisidine based exchanger reported so far. The ion-exchange capacity and ion-exchange behaviors of the nano-composite were also carried out to understand the ion-exchange capabilities. Its selectivity was examined by achieving some important binary and tertiary separations of metal cations on its column indicating its utility in environmental pollution control. This new exchanger was successfully applied for quantitative determination and separation of Hg(II) from a synthetic mixture of metal ions. [Copyright &y& Elsevier]

Abstract: An organic–inorganic nano-composite poly-o-anisidine Sn(IV) tungstate was chemically synthesized by sol–gel mixing of the incorporation of organic polymer o-anisidine into the matrices of inorganic ppt of Sn(IV) tungstate in different mixing volume ratios. This composite material has been characterized using various analytical techniques like XRD (X-ray diffraction), FTIR (Fourier transform infrared), SEM (Scanning electron microscopy), TEM (Transmission electron microscopy) and simultaneous TGA (Thermogravimetric analysis) studies. On the basis of distribution studies, the material was found to be highly selective for Hg(II). Using this nano-composite cation exchanger as electro-active material, a new heterogeneous precipitate based on ion-sensitive membrane electrode was developed for the determination of Hg(II) ions in solutions. The membrane electrode was mechanically stable, with a quick response time, and can be operated within a wide pH range. The electrode was also found to be satisfactory in electrometric titrations. [Copyright &y& Elsevier]

An advanced cation-exchange nano-composite poly- o-toluidine Ce(IV) phosphate was synthesized by sol-gel technique by incorporating Ce(IV) phosphate precipitate with the matrix of poly- o-toluidine. The material showed good ion-exchange behavior and used successfully in separation of metal ions. The conductivity of the composite was found within the range of 10 to 10S/cm; measured by four-in-line probe DC electrical conductivity measuring technique. The conductivity is at the border of metallic and semiconductor region. Ion-exchange kinetics for few divalent metal ions was evaluated by particle diffusion-controlled ion-exchange phenomenon at four different temperatures. The particle diffusion mechanism is confirmed by the linear τ (dimensionless time parameter) versus t (time) plots. The exchange processes thus controlled by the diffusion within the exchanger particle for the systems studies herein. Some physical parameters like self-diffusion coefficient ( D), energy of activation ( E), and entropy of activation (∆ S°) have been evaluated under conditions favoring a particle diffusion-controlled mechanism. [ABSTRACT FROM AUTHOR]

Abstract: The objective of the present research was to synthesize, characterize and to investigate the efficiency of an advanced class of hybrid nano-composite cation exchanger for the detection of mercury(II) ion in aqueous solution. In the present study the cation exchanger ployaniline–zirconium titanium phosphate (PANI–ZTP) nanocomposite, was synthesized via sol–gel mixing of organic polymer polyaniline (PANI) into the matrices of the inorganic precipitate of zirconium titanium phosphate (ZTP), having extraordinary ion exchange capacity, thus used as electroactive component for the construction of an ion-selective membrane electrode. The proposed electrode shows fairly good discrimination of mercury ion over several other inorganic ions. The membrane electrode was mechanically stable, having wide dynamic range of 10−10 mol/m3 to 10−1 mol/m3 of Hg2+ ions, with quick response time and could be operated for at least 4months without any considerable divergence in the potential response characteristics. The electrode was successfully applied for direct determination of mercury ions in some real sample with satisfactory results and acts as indicator electrode in complexation titrations. [Copyright &y& Elsevier]

Abstract: Composites are 21st century material used to meet the demand of improved materials and possess a combination of several desirable properties. Present study focussed on the conducting behavior of ‘polymeric–inorganic’ nanocomposite of conducting polymer polyaniline and polypyrrole. ‘Polymeric–inorganic’ nanocomposite cation-exchangers, i.e., polyaniline zirconium titanium phosphate (PANI-ZTP) and polypyrrole zirconium titanium phosphate (PPy-ZTP), were synthesized via sol–gel mixing of electrical conducting polymers into the matrices of inorganic precipitate of zirconium titanium phosphate (ZTP) having excellent ion exchange properties. The proposed nanocomposite possessed DC electrical conductivity in the semi-conducting range, i.e., 10−5–10−3 Scm−1. The stability in terms of DC electrical conductivity retention was also studied in an oxidative environment by two slightly different techniques viz. isothermal and cyclic techniques. The DC electrical conductivity of composite material was found stable upto 110°C under ambient conditions. [Copyright &y& Elsevier]

Abstract: In this study, the electrically conducting polyaniline–titanium(IV)phosphate (PANI–TiP) cation exchange nanocomposite was synthesized by sol–gel method. The cation exchange nanocomposite based sensor for detection of ammonia vapors was developed at room temperature. It was revealed that the sensor showed good reversible response towards ammonia vapors ranging from 3 to 6%. It was found that the sensor with p-toluene sulphonic acid (p-TSA) doped exhibited higher sensing response than hydrochloric acid doped. This sensor has detection limit ≤1% ammonia. The response of resistivity changes of the cation exchange nanocomposite on exposure to different concentrations of ammonia vapors shows its utility as a sensing material. These studies suggest that the cation exchange nanocomposite could be a good material for ammonia sensor at room temperature. [Copyright &y& Elsevier]

Abstract: A ‘polymeric-inorganic’ advanced nano-composite cation-exchanger has been synthesized via sol–gel technique by incorporating polyaniline into inorganic ion-exchanger, zirconium titanium phosphate, a class of mixed material of tetravalent bimetallic acid salts (TMA). The composite shows extraordinary high ion-exchange capacity of 4.52meqg−1 as well as good chemical and thermal stability than other polyaniline composites prepared so far. The physico-chemical property of the composite, polyaniline zirconium titanium phosphate (PAZTP) was determined using AAS, TEM, SEM, FTIR and TGA-DTA studies. Ion-exchange behavior was also observed to characterize the material. On the basis of distribution studies, the material was found to be highly selective for toxic heavy metal ions Hg(II) and Pb(II). The analytical applications of the material have been explored by achieving some binary as well as ternary separations of heavy metal ions. A comparative study of the ion-exchange properties of PAZTP with other polyaniline composites has been done. [ABSTRACT FROM AUTHOR]

Poly-o-anisidine Sn(IV) arsenophosphate is a newly synthesized nanocomposite material and has been characterized on the basis of its chemical composition, ion exchange capacity, TGA-DTA, FTIR, X-RAY, SEM, and TEM studies. On the basis of distribution studies, the exchanger was found to be highly selective for lead that is an environmental pollutant. For the detection of lead in water a heterogeneous precipitate based ion-selective membrane electrode was developed by means of this composite cation exchanger as electroactive material. The membrane electrode is mechanically stable, with a quick response time, and can be operated over a wide pH range. The selectivity coefficients were determined by mixed solution method and revealed that the electrode is sensitive for Pb(II) in presence of interfering cations. The practical utility of this membrane electrode has been established by employing it as an indicator electrode in the potentiometric titration of Pb(II). [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of polypyrrole–titanium(IV)phosphate (PPy–TiP) nanocomposite as a synthetic adsorbent for the adsorptive removal of Cr(VI) ions from aqueous solutions. Facile in situ chemical oxidative polymerization of pyrrole in presence of titanium(IV)phosphate (TiP) formed PPy–TiP nanocomposite. The prepared PPy–TiP nanocomposite was characterized by FT-IR, FE-SEM, TEM, EDAX and BET analysis. A strong interaction between PPy and TiP particles was observed, and the nanocomposite showed remarkable adsorption of Cr(VI) ions from aqueous solutions. In order to optimize the conditions for maximum adsorption of Cr(VI) ions, batch process was used and the effects of contact time, initial concentration, pH, point of zero charge measurement and adsorbent doses were investigated. The equilibrium isotherm data were fitted using Langmuir and Freundlich isotherms. The adsorption process based on the thermodynamic parameters was spontaneous and endothermic. Dubinin–Radushkevich (D–R) isotherm was used to calculate the mean free energy, which showed that the adsorption process involves chemical forces, hence chemical in nature. The kinetics data were evaluated using the pseudo-first-order and pseudo-second order kinetics model, and it was found that data was best fitted by the pseudo-second-order model for adsorption of Cr(VI) supporting that the adsorption mainly consisted of chemisorption. The desorption studies were also performed by batch process and ∼100% desorption of Cr(VI) ions was achieved using 0.5 M NaOH solution as eluent. [ABSTRACT FROM AUTHOR]