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Polypyrrole-Sn(IV)arsenotungstate (Ppy-SnAT) nanocomposite cation exchanger membrane was prepared by solution casting method of Polypyrrole in the presence of Sn(II)arsenotungstate gel and polyvinyl chloride (PVC) as a binder. The formation of Polypyrrole-Sn(IV)arsenotungstate nanocomposite cation exchanger membrane was characterized by Fourier Transform Infra-Red spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Scanning electron microscopy (SEM) and Energy dispersive X-ray (EDX). The membrane having a composition of 4.5:1 (composite:PVC) shows best results for water content, porosity, thickness and swelling. Our studies show that the present ion selective membrane electrode is selective for Ba(II) metal, having detection limit (1 × 10 − 8 M to 1 × 10 − 1 M), response time (35 s) and working pH range (3–5). The selectivity coefficient values for interfering ions indicate good selectivity for Ba(II) over interfering cations. The analytical utility of this electrode was established by employing it as an indicator electrode in potentiometric titration. The dielectrical constants (ε′, ε″), dielectric loss (tanδ) and AC conductivity (σ ac ) were studied as a function of frequency. [ABSTRACT FROM AUTHOR]

Treatment methodologies and precautionary measures are the topmost priority for sustainable development. Mesoporous silicates MCM-41, SBA-15 and its hybrid SBA-PMDA were directly employed to remove the textile reactive dyes from water at room temperature and neutral pH. These nanostructured materials were prepared and characterized by using FTIR spectroscopy, Nitrogen adsorption/desorption, NMR spectroscopy, X-rays diffraction, Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA) and Zeta potential. The cationic reactive dye brilliant green (BG) removal capacity of silicas SBA-15 and MCM-41 was found 119.0 mg g−1 133.20 mg g−1, respectively and zero affinity was observed for anionic dye reactive blue (RB 15) by these materials. In comparison, modified silica with PMDA bridged polysilsesquioxane SBA-PMDA, showed 25.66 mg g−1 of removal capacity for anionic dye RB 15. Kinetic studies showed that about 70% of the dye was removed within 4–5 h. To predict the system efficiency, the experimental data was treated with mathematical models such as Langmuir, Freundlich, Sips and Dubinin–Radushkevich isotherms, pseudo-first-order and pseudo-second-order. The obtained results suggest that nanostructured silicates could be simple, efficient, inexpensive and convenient adsorbents for the direct and selective removal of reactive dyes from water at room temperature. • Mesoporous silicas MCM-41, SBA-15 and its derivative SBA-PMDA with different pore sizes and surfaces were synthesized. • The synthesized materials showed high adsorption capacities. • These materials could be potential candidates for selective removal of cationic or anionic species from wastewater. [ABSTRACT FROM AUTHOR]

Mesoporous silica based drug carriers were synthesized and characterized by FTIR, NMR spectroscopy, elemental analysis, nitrogen adsorption, thermogravimetry, scanning and transmission electron microscopy and X-rays diffraction. Zeta potential was measured with zetasizer. The synthesized materials were tested as a drug carrier for ibuprofen, ibuprofen sodium dihydrate and 5‑fluorouracil. Silica with long organic surface chains and ordered mesoporous network showed a high loading capacity for ibuprofen (22.0 wt%), ibuprofen sodium dehydrate (48.0 wt%) and 5‑fluorouracil (9.4 wt%). The long hydrophobic chains enhanced the drug adhesion to the silica surface which eventually delayed the release of the drug and hence presented a sustained and controlled release profiles. The study suggests that the synthesized materials have potential as controlled drug release systems where prolonged drug therapeutic effects are required. This study also suggests that the 5‑fluorouracil loaded nano-carriers in the form of films, mats or cream could be a potential candidate for skin cancer treatment formulations. [ABSTRACT FROM AUTHOR]

[Display omitted] • Green chemistry sample preparation concept by means of Deep Eutectic Solvents (DES). • Novel DES based approach for pre-concentration of Niclosamide. • Effective method dedicated to determination of Niclosamide in pharmaceutical and wastewater samples. • Step forward for trace analysis of Niclosamide in environmental samples. The paper presents a simple, but very effective and sensitive spectrophotometric method for trace analysis of Niclosamide based on liquid–liquid microextraction using deep eutectic solvents (DESs) prior to its quantification. Here, different DES systems, such as Choline chloride (ChCl) + Urea, ChCl + Citric acid, ChCl + Ethylene glycol and ChCl + Phenol, were synthesized and evaluated at different molar ratios, selecting ChCl + Phenol 1:2 as an extractive DES system. Optimization studies revealed that best performance were obtained at pH 8 with optimum volume of THF and DES as 0.3 mL and 0.4 mL, respectively. The developed method is characterized by good analytical performance, e.g., a recovery of 99.26% and precision described by RSD value as <2%. The inter-assay precision was 0.51% while intermediate precision was 0.0323%. The method was found linear from 4.8 to 48 µg/L. LOD and LOQ were found as 0.112 and 0.374 µg/L, respectively. The paper presents also examples of the application of the proposed method for the determination of Niclosamide in different pharmaceutical and wastewater samples. This alternative method reveals a better performance in respect to the British pharmacopoeia procedure, providing concurrently ease of operation and simplicity. [ABSTRACT FROM AUTHOR]