Easy,operable ionic polymer metal composite actuator based on a platinum‐coated sulfonated poly(vinyl alcohol)–polyaniline composite membrane

In this study, an electric‐stimulus‐responsive bending actuator based on a platinum (Pt)‐coated sulfonated poly(vinyl alcohol) (SPVA)–polyaniline (PANI) composite membrane was developed. The SPVA–PANI membrane was prepared by a solution casting method; it showed good electrochemical properties and an adequate ion‐exchange capacity of 1.6 mequiv/g of dry membrane. The water uptake by the membrane with 4 h of immersion time at 45 °C was found to be 425%. The SPVA–PANI composite membrane based ionic polymer metal composite (IPMC) actuator prepared by the coating of Pt metal layers on both sides of the membrane by an electroless plating process showed a good proton conductivity of 1.75 × 10^?3 S/cm. The smooth and uniform coating of Pt on both surfaces of the membrane, as indicated by scanning electron micrographs, seemed to be responsible for the slow water loss that is necessary for the long life of an IPMC actuator. The maximum water loss was 48% at 6 V for 12 min. This indicated the better performance of the IPMC membrane when an electric potential was applied. According to electromechanical characterization, the maximum tip displacement was 14.5 mm at 5.25 V. A multifinger IPMC membrane based microgripping system was developed, and it showed potential for microrobotics application. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43787.     

Synthesis and characterization of a thermally stable strongly acidic Cd(II) ion selective composite cation-exchanger: Polyaniline Ce(IV) molybdate

A polymer supported organic-inorganic composite and strongly acidic cation-exchanger polyaniline Ce(IV) molybdate was chemically synthesized and demonstrated to be an excellent ion-exchange material due to its high selectivity for Cd(II), thermal stability and fast elution of an exchangeable H⁺ ion. The material was characterized for its ion exchange properties to study its cation-exchange behavior. Cd(II) selectivity depends upon the distribution coefficient in several solvent systems. The selectivity of this material varied depending upon its composition and the composition of the eluting solvent. Its selectivity was examined and some important binary separations such as Cd(II)-Pb(II), Cd(II)-Hg(II), Cd(II)-Zn(II) and Cd(II)-Ni(II) were also achieved. The physico-chemical properties of the material were also studied using C, H, N elemental analysis, ICP-MS, FTIR, TGA-DTA, X-ray and SEM studies.     

Optimization of glassy carbon electrode based graphene/ferritin/glucose oxidase bioanode for biofuel cell applications

A glassy carbon (GC)/graphene/ferritin/glucose oxidase (GOx) anode was developed by using graphene/ferritin biocomposite as an electron transfer enhancer and mediator, respectively. The electrode exhibited good electrocatalytic activity towards the oxidation of glucose. The electrocatalytic oxidation of glucose using GOx modified electrode increased with increasing the concentration of glucose upto 45 mM. The results showed that the graphene/ferritin biocomposite mediator provides enhancement in electron transfer generated at the active cites of GOx to the electrode. All electrochemical measurements were carried out by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). A saturation current density of 66.5 ± 2 mA cm⁻² at scan rate 100 mV s⁻¹ for the oxidation of 45 mM glucose was achieved.     

Thorium (IV) phosphate‐polyaniline composite‐based hydrophilic membranes for bending actuator application

In the present study, ionic polymer metal composite (IPMC) membrane actuator based on triple‐layered thorium(IV) phosphate/polyaniline/Pt (ThP‐PANI‐Pt) was prepared via consecutive solution recasting and electroless plating methods. The triple‐layered membrane is composed of thorium(IV) phosphate (ThP) inorganic cation exchanger layer in the middle section, two layers of polyaniline deposited through in situ polymerization and finally Pt electrode layers on both the surfaces on the outer section. The water uptake capacity of the ThP‐PANI composite polymer membrane was found to be 95.40% at 45ºC for 10 h of immersion time. The ion exchange capacity and proton conductivity was found to be 1.6 meq g^?1of dry membrane and 1.12 × 10^?3 S cm^?1, respectively. Maximum water loss from IPMC was 38% at 4 V for a time period of 12 min. Scanning electron micrographs shows the smooth and uniform coating of Pt on both side of composite polymer membrane surfaces. Cyclic voltammetry, linear sweep voltammetry, transmission electron microscopy, Fourier transforms infrared spectroscopy, thermal gravimetric analysis, X‐ray diffraction, and tip displacement of ThP‐PANI‐Pt IPMC membrane actuator was also examined. POLYM. ENG. SCI., 57:258–267, 2017. © 2016 Society of Plastics Engineers     

Synthesis and characterization of electrically conducting poly-o-methoxyaniline Zr(1V) molybdate Cd(II) selective composite cation-exchanger

In this study a composite cation-exchanger poly-o-methoxyaniline Zr(1V) molybdate was prepared and the ion-exchange properties like ion-exchange capacity for different metal ions, elution behavior, pH titration and a temperature dependent study of ion-exchange capacity were explored. The physical properties of the material were also determined using TGA-DTA, FTIR, X-ray and SEM studies. The results of physical properties were found progressive in terms of their specific properties. Electrical conductivity of this composite determined by four-in-line probe method was found to be in semi-conducting range i.e. 10^− 4-10^− 2 S cm^− 1. The adsorption efficiency towards heavy metal ions was determined by distribution studies and material was found highly selective for cadmium a heavy toxic metal ion indicating the utility for the removal from waste stream.     

Synthesis and characterization of a new inorganic cation-exchanger-Zr(IV) tungstomolybdate: analytical applications for metal content determination in real sample and synthetic mixture

An amorphous sample of inorganic cation-exchanger Zr(IV) tungstomolybdate was prepared by mixing varying ratios of 0.1M aqueous solution of sodium tungstate and 0.1M aqueous solution of sodium molybdate into 0.1M aqueous solution of zirconium oxychloride at pH 1. This cation-exchanger was found to have a good ion-exchange capacity (2.40 mequiv.g(-1) for Na(+)), high thermal and chemical stability. A tentative structural formula was proposed on the basis of chemical composition, FTIR and thermogravimetric analysis. Distribution coefficients (K(d)) values of metal ions in various solvent systems were determined. Some important and analytically difficult quantitative binary separations viz. Ni(II)-Pb(II), Ni(II)-Zn(II), Ni(II)-Cd(II), Mg(II)-Al(III), etc. were achieved. The practical applicability of the cation-exchanger was demonstrated in the separation of Cu(II)-Zn(II) from a synthetic mixture as well as from real samples of pharmaceutical formulation and brass alloy.     

A conducting polymer/ferritin anode for biofuel cell applications

An enzyme anode for use in biofuel cells (BFCs) was constructed using an electrically connected bilayer based on a glassy carbon (GC) electrode immobilized with the conducting polymer polypyrrole (Ppy) as electron transfer enhancer, and with horse spleen ferritin protein (Frt) as electron transfer mediator. The surface-coupled redox system of nicotinamide adenine dinucleotide (NADH) catalyzed with diaphorase (Di) was used for the regeneration of NAD⁺ in the inner layer and the NAD⁺-dependent enzyme catalyst glucose dehydrogenase (GDH) in the outer layer. The outer layer of the GC-Ppy-Frt-Di-NADH-GDH electrode effectively catalyzes the oxidation of glucose biofuel continuously; using the NAD⁺ generated at the inner layer of the Di-catalyzed NADH redox system mediated by Frt and Ppy provides electrical communication with enhancement in electron transport. The electrochemical characteristics of the electrodes were investigated by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). This anode provides a current density of 1.2 mA cm⁻² in a 45 mM glucose solution and offers a good possibility for application in biofuel cells.     

Fabrication of bioanode by using electrically conducting polythiophene via entrapment technique

A glassy carbon electrode (GCE) was tailored with conducting polymer polythiophene and further immobilized by an enzyme glucose oxidase (GOx). A thin film of polymer was developed by electrochemical polymerization of thiophene monomer. During electrochemical polymerization of the monomer the enzyme GOx and the redox active mediator ferritin (Frt) were entrapped within this polymer matrix. In this novel approach, the entrapment of enzyme and mediators within a polymer matrix occurs without chemical reaction that could affect their activity. The entrapment of enzyme and mediator within the conducting polymer matrices increases the surface area of the electrode. The tailored GCE/Ptp/Frt/GOx electrode showed a high catalytic activity. The increased surface area causes a high rate of electron transfer between the electrode and Frt engaged as an electron transfer mediator. The electrochemical properties of the electrode were determined by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The fabricated bioanode showed a current density of 3.9mA cm^?2 at 1.0 V vs. Ag/AgCl in a 45 mM glucose solution and suggests proficient chances in biofuel cells (BFCs) applications.     

Fabrication and optimization of Cu(II) ion selective membrane electrode

In this study, the fabrication, performance characteristics and application of a Cu(II) ion selective pyridine based thorium(IV) phosphate membrane electrode are studied. The membrane electrode exhibited a fast response time of 10 s, the wide linear response in the concentration of 1 × 10^–1 to 1 × 10^–7 M of Cu (II) ions with a slope of 27.60 mV/decade change in concentration and a lifetime of 4 months. The potentiometric response revealed that the potentials are independent of pH in the wide range of 3.0–6.5. It was also used as an indicator electrode in the potentiometric titration of Cu(II) ions using ethylenediamine tetraacetic acid, disodium salt.