Para-sulfonatocalix[n]arene-based biomaterials: Recent progress in pharmaceutical and biological applications.

Thermal decomposition kinetics of polypropylene composites filled with graphene nanoplatelets

The thermal behaviour of three ester derivatives of p-tert-butyl calix[n]arene (n = 4, 6 and 8) in comparison with the parent calixarene was investigated by means of the thermogravimetric (TG) and differential thermogravimetic (DTG) analysis and differential scanning calorimetry (DSC). The thermal stability domains, the composition of the pyrolysis products and the thermal effects, were determined on the basis of TG, DTG and DSC plots registered in nitrogen flow. Attempts to analyse the evolved gases by TG-FTIR coupling were also performed. It was demonstrated that the stability of the calix[n]arene derivatives depends on both the size of the hydrophobic cavity and number of the substituting groups grafted on the calix[n]arene skeleton.

Thermal behaviour of some ester derivatives of p - tert -butyl calix[ n ]arene

Glucose is one of the most important monosaccharides found in the food, as a part of more complex structures, which is a primary energy source for the brain and body. Thus, the monitoring of glucose concentration is more important in food and biological samples in order to maintain a healthy lifestyle. Herein, an electrochemical glucose biosensor was fabricated by immobilization of glucose oxidase (GOX) onto poly(3,4-ethylenedioxythiophene):4-sulfocalix [4]arene (PEDOT:SCX)/MXene modified electrode. For this purpose, firstly, PEDOT was synthesized in the presence of SCX (counterion) by the chemical oxidative method. Secondly, MXene (a 2D layered material) was synthesized by using a high-temperature furnace under a nitrogen atmosphere. After that, PEDOT:SCX/MXene (1:1) dispersion was prepared by ultrasonication which was later utilized to prepare PEDOT:SCX/MXene hybrid film. A successful formation of PEDOT:SCX/MXene film was confirmed by HR-SEM, Fourier transform infrared (FT-IR), and Raman spectroscopies. Due to the biocompatibility nature, successful immobilization of GOX was carried out onto chitosan modified PEDOT:SCX/MXene/GCE. Moreover, the electrochemical properties of PEDOT:SCX/MXene/GOX/GCE was studied through cyclic voltammetry and amperometry methods. Interestingly, a stable redox peak of FAD-GOX was observed at a formal potential of –0.435 V on PEDOT:SCX/MXene/GOX/GCE which indicated a direct electron transfer between the enzyme and the electrode surface. PEDOT:SCX/MXene/GOX/GCE also exhibited a linear response against glucose concentrations in the linear range from 0.5 to 8 mM. The effect of pH, sensors reproducibility, and repeatability of the PEDOT:SCX/MXene/GOX/GCE sensor were studied. Finally, this new biosensor was successfully applied to detect glucose in commercial fruit juice sample with satisfactory recovery.

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Electrochemical Sensing of Glucose Using Glucose Oxidase/PEDOT:4-Sulfocalix [4]arene/MXene Composite Modified Electrode

Polyguaiacol was successfully synthesized by enzyme-catalyzed polymerization in an aqueous micelle system with horseradish peroxidase (HRP) as the catalyst. As-synthesized polyguaiacol was characterized by infrared spectrometry and gel permeation chromatography, and its thermal stability was evaluated by thermogravimetric analysis. Besides, the thermal antioxidant behavior of the as-synthesized phenolic polymer as an antioxidant in polypropylene was evaluated by differential scanning calorimetry and accelerated aging test, and the apparent activation energies of thermal decomposition of polypropylene (PP) were calculated by Friedman method. Results show that the as-synthesized polyguaiacol as an antioxidant is able to significantly increase the oxidation induction time of virgin PP, and it exhibits better antioxidative performance than corresponding monomer. Moreover, polyguaiacol, the as-synthesized phenolic polymer, exhibits good resistance against aging of polypropylene.

Enzymatic synthesis of polyguaiacol and its thermal antioxidant behavior in polypropylene

Study on thermal decomposition of calix[4]arene and its application in thermal stability of polypropylene

Thermal decomposition mechanism of p-tert-butyl-calix(n)arenes

Zeta potential of calixarenes has been reported for the first time The water-soluble calixarenes has been used as dispersion media in solid/liquid interface p-sulfonato-calix[4]arene (PSC4) and p-sulfonato-calix[8]arene (PSC8) were synthesized and characterized by FTIR, NMR, mass spectrometry, and HPLC techniques It was proved that the zeta potential is a fast and simple measurement to know the adsorption behavior of sufonato calixarnes on calcite The chemisorption of p-sulfonato-calix[n]arene was confirmed by shift in iso electric point, adsorption studies and FTIR The calculated free energy of adsorption value and its sign suggests the chemical interaction between the calcite surface and p-sulfonato calix[4]and[8]arene

Studies on the Zetapotential of Calcite/p-Sulfonato-calix[4,8]arenes

The interaction of p-sulfonatocalix[6]arene (PSC6) with o-arsanilic acid (OASA) and p-arsanilic acid (PASA) was studied by UV–Visible spectroscopy, high-performance liquid chromatography (HPLC) ana...

Study on interaction of p-sulfonato calix[6]arene with arsanilic acid

The electrokinetic behavior of fluorite mineral was studied under various partical sizes and different concentrations of oleic acid at constant pH. The particle size has been reduced with an increase in activation time. The surface energies of milled fluorite minerals were calculated theoretically and experimentally. The zeta potential of the fluorite/water system has shifted to lower side with an increase in particle size. The isoelectric point (iep) of fluorite minerals has been shifted to lower side with increase in oleic acid concentration. This indicates the chemisorbed oleate formation on fluorite. A sharp decrease in zeta potential in the pH range of 6.5–8.4 and the decrease in calculated free energy of adsorption shows the formation of calcium dioleate precipitate on fluorite.

P. Sreedevi

Papers

Study on thermal decomposition of calix[4]arene and its application in thermal stability of polypropylene

Thermal decomposition mechanism of p-tert-butyl-calix(n)arenes

Studies on the Zetapotential of Calcite/p-Sulfonato-calix[4,8]arenes

Study on interaction of p-sulfonato calix[6]arene with arsanilic acid

Electrokinetic Behavior of Fluorite