Chronopotentiometric and electroanalytical studies of Ni(II) selective polyaniline Zr(IV) molybdophosphate ion exchange membrane electrode

A new route to select the referable values of property indicators for normalization and its application in screening polymeric membrane heavy metal (Co, Ni, and Cr)-ion-selective electrodes with multiple high-response performances

Distance to target normalization may not be suitable to select the referable values, (RC)_refer, and responsive characteristic (RC) indicators, for the electrode comprehensive quality index (I_ECQ). (RC)_refer is selected as an excellent response property value in alliance with corresponding constants (e.g., 1.8 or 2.5) in this method. It is recently found that these constants are not appropriate to normalize indicators for other ion-selective electrodes (ISEs). The present study aimed to report a new and universal route to select good (RC)_refer values for the normalization without additional constants by only controlling the mean value ([Formula: see text]) being 0.90 < [Formula: see text] < 1.1. The route provided reliable results of both (RC)_refer for indicator normalization and I_ECQ values. It has been successfully applied to select the referable values (RC)_refer of each indicator for the I_ECQ of three heavy metal (HM) (Co, Ni, and Cr)-ISEs. The second aim of the work is to screen these heavy metal-ion-selective electrodes (HM-ISEs) with highly multiple response properties by using the I_ECQ. Twenty-four HM-ISEs with the top 3 I_ECQ values have been recommended. For example, the largest I_ECQ for three indicators, [Formula: see text], P_S, and P_RT, which was used as the main indicator (MI), was 1.461 for Co²⁺-ISE, 1.385 for Ni²⁺-ISE, and 1.561 for Cr³⁺-ISE, respectively. The results will be beneficial to meeting the special requirements to monitor/analyze HM ions in different water samples.

Fabrication of a lead ion selective membrane based on a polycarbazole Sn(iv) arsenotungstate nanocomposite and its ion exchange membrane (IEM) kinetic studies

A polycarbazole-Sn(iv) arsenotungstate (Pcz-SnAT) nanocomposite cation exchanger membrane (CEM) was prepared via the casting solution technique utilizing polycarbazole-Sn(iv) arsenotungstate and PVC (polyvinyl chloride) as a binder. The synthesis of the Pcz-SnAT membrane was confirmed via various characterization methods such as EDX, SEM, TGA, XRD, and FTIR spectroscopy. This membrane having a 4.5 : 1 composition ratio of composite by PVC exhibited the most effective outcomes for swelling, thickness, porosity, and water content. Our research indicates that the present ion selective membrane electrode is selective towards Pb(ii) ions, with the detection limit ranging from 1 × 10-7 mol L-1 to 1 × 10-1 mol L-1 where 20 s is the response time and 3-7 is the working value pH. The mechanism of the Pcz SnAT ion exchange membrane was obtained by kinetic studies by utilizing the equation given by Nernst Planck at 40-80 °C. As a result, activation energy and thermodynamic studies were done. The analytical utility of this electrode is conventional by utilizing it as an electrode indicator within the potentiometric titration.

Electrochemical behavior of a membrane based on zirconium(iv) phosphoborate nanocomposite and its application in dye removal

A new hybrid ion-exchange membrane was prepared from a novel composite obtained by dispersion of polyaniline into an inorganic matrix of zirconium(iv) phosphoborate employing a sol–gel method.

Preparations and characterizations of poly-o-toluidine/multiwalled carbon nanotubes/Sn(iv) tungstate composite ion exchange thin films and their application as a Pb(ii) selective electrode

Poly-o-toluidine (POT), poly-o-toluidine (POT)/multiwalled carbon nanotubes (MWCNTs), and poly-o-toluidine (POT)/multiwalled carbon nanotubes (MWCNTs)/Sn(iv) tungstate (ST) thin films were prepared by a solution casting method using polystyrene as a binder.