Gazala Ruhi; Haritma Chopra;Sundeep K. Dhawan; Pradeep Sambyal; Hema Bhandari
Abstract
In a novel approach, Polypyrrole/Gum Acacia composites (PPy/GA) were synthesized by in-situ oxidative polymerization of pyrrole on the Gum Acacia (GA) surface by using FeCl3 as oxidant. The 1 HNMR and FTIR confirms the presence of peaks of Polyprrole and Gum Acacia in the composite. The microstructural ...
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In a novel approach, Polypyrrole/Gum Acacia composites (PPy/GA) were synthesized by in-situ oxidative polymerization of pyrrole on the Gum Acacia (GA) surface by using FeCl3 as oxidant. The 1 HNMR and FTIR confirms the presence of peaks of Polyprrole and Gum Acacia in the composite. The microstructural analysis of the composite reveals uniform layer of Polypyrrole on the surface of GA particles. The X-ray Diffraction pattern reveals the amorphous nature of the composite. Powder coating technique was used to design the composite coatings. The electrochemical studies like Open Circuit Potential (OCP) variation with time, Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy (EIS) were conducted in 3.5% NaCl solution to evaluate the corrosion resistance of the coatings. The composite coatings demonstrated superior corrosion resistance in salt spray fog of 5.0% NaCl (under accelerated test conditions in salt spray chamber). The synergistic combination of the corrosion inhibition properties of Gum Acacia and the redox properties of Polypyrrole is the reason for the occurrence of high corrosion resistance of the composite coatings. The present coating composition has shown excellent corrosion resistance and can be a potential coating formulation for mild steel substrate used in various applications under saline conditions.
Somit Kumar Singh; Ananda Murthy H. C; Vandana Singh
Abstract
In the present investigation, the remediation of mercury by using the gum acacia-silica composite as an adsorbent has been studied. Experiments revealed optimum parameters which were found to be pH 6, contact time 2 hours, Hg(II) concentration of 100 ppm, reflux temperature 30 0 C and adsorbent dosage ...
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In the present investigation, the remediation of mercury by using the gum acacia-silica composite as an adsorbent has been studied. Experiments revealed optimum parameters which were found to be pH 6, contact time 2 hours, Hg(II) concentration of 100 ppm, reflux temperature 30 0 C and adsorbent dosage of 50 mg. The experimental data was subjected to modeling using the Langmuir and Freundlich isotherms. It was found that the data very well fitted to the Freundlich model. The pseudo second order kinetics confirms chemisorption with rate constant 3.1 × 10-4 gmg-1min-1. The calculated thermodynamic parameters (?G 0 , ?S 0 , ?H 0 ) revealed the exothermic and spontaneous nature of adsorption process at the solid–solution interface. The adsorbent could be recycled for six successive cycles with 31.5% loss in its efficiency. The adsorbent is found to be highly effective and economical for mercury remediation from water.
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