Chiral recognition of tryptophan enantiomers based on a polypyrrole-flake graphite composite electrode column

2012 ◽  
Vol 126 (1) ◽  
pp. 226-231 ◽  
Author(s):  
Yong Kong ◽  
Xueying Li ◽  
Chao Yao ◽  
Jingxuan Wei ◽  
Zhidong Chen
2010 ◽  
Vol 22 (20) ◽  
pp. 2460-2466 ◽  
Author(s):  
Afsaneh Safavi ◽  
Norooz Maleki ◽  
Fariba Tajabadi

2015 ◽  
Vol 15 (1) ◽  
pp. 61-66
Author(s):  
Ranjan Nepal ◽  
Raja Ram Pradhananga

Lead oxide-graphite composite electrode for pH measurement had been fabricated with different percentage of PbO2 in the composite. The proportions of lead oxide affected the sensitivity of the electrode. The electrode composed of 50% lead oxide and 50% graphite gave reproducible result and behaved in Nernstian manner with a potential gradient of -58.8±0.3 mV per unit change in pH. Metal ions such as iron (II), iron (III) and lead (II) interfered in the measurement of pH, while silver (I), copper (II), oxidizing agents such as dichromate and permanganate do not interfere. In absence of interfering ion, the lead oxide-graphite composite electrode could be used for the measurement of pH from 2 to 11. This electrode can also be used as an indicator electrode for acid base titrations. Low cost, quick response, easy to fabricate are some of the advantages of the lead oxide-graphite composite electrode. This electrode is also found to be sensitive to Pb2+ -ions and can be used as a Pb2+-ion sensor up to 10-4M.DOI: http://dx.doi.org/10.3126/njst.v15i1.12015  Nepal Journal of Science and TechnologyVol. 15, No.1 (2014) 61-66


2018 ◽  
Vol 2017 (3) ◽  
pp. 752-761
Author(s):  
Dan Jia ◽  
Jian Yu ◽  
Stephen M. Long ◽  
Hao L. Tang

Abstract A novel ZnFe2O4/TiO2/flake graphite composite material was synthesized and used as particle electrodes in a photoelectrocatalytic (PEC) system to investigate the degradation of rhodamine B as a model dye pollutant in water. Results showed that a PEC process with the new composite evidently led to enhanced degradation of rhodamine B due to a synergistic effect of photocatalysis and electrocatalysis. Operating variables including electrolyte concentration, applied cell voltage, air flow, composite dosage, solution pH, and dye concentration were also found to play important roles in rhodamine B removal. A 99.0% removal efficiency was observed within 30 min of treatment under optimum conditions of 0.01 mol/L Na2SO4, applied cell voltage of 15 V, air flow of 20 mL/min, composite dosage of 10 g/L, solution pH of 2, and rhodamine B concentration of 20 mg/L, with a pseudo-first-order rate constant of 0.278 min−1. These findings could provide new insights into the development of efficient PEC technologies on degradation of residual dyes in water.


2020 ◽  
Vol 26 (4) ◽  
pp. 126-132
Author(s):  
Su-Yong Nam ◽  
Shinyoung Kim ◽  
Se-Hoon Park ◽  
Hyun Jin Nam

2015 ◽  
Vol 12 (12) ◽  
pp. 44-47
Author(s):  
Suchi Srivastava ◽  
Raja Ram Pradhananga

A solid Fe2O3-graphite composite electrode was prepared and investigated for use as a potentiometric pH sensor. The electrode was constructed by mixing iron (III) oxide, oxidized graphite and wax that was put over silver disc onto a polypropylene rod. The response of the electrode was investigated by measuring electrode potential as a function of pH.The effect of composition of the electrode material (Fe2O3 and oxidized graphite ration) on the electrode response was investigated. The electrode with 40% Fe2O3, 30% graphite and 30% wax by mass was found to give the best potentiometric response. This electrode behaves in Nernstian manner with a potentiometric gradient of 56.6±0.4 mV per unit change in pH at 25?C within the working range of pH 2-9.The electrode was also used for the end-point detection in potentiometric acid-base titrations and found to be an excellent electrode for pH-metric titration. The effect of oxidation of electrode on pH response was investigated by dipping electrode in 0.1N KMnO4, 1:1HNO3 and 0.1N Ce4+ solutions for different interval of time. This treatment of the electrode with oxidizing agents increased the standard electrode potential of the electrode however potential gradient per unit change in pH remains unaltered. Low cost, quick response and easy to prepare are the advantages of the iron oxide - graphite composite electrode as a pH sensor. However some metal ions and oxidising agents interfered in the determination of pH using this electrode which is the limitation of using these electrodes.Scientific World, Vol. 12, No. 12, September 2014, page 44-47


2020 ◽  
Vol 10 (2) ◽  
pp. 214-224 ◽  
Author(s):  
Songyang Liu ◽  
Jie Han ◽  
Qingjie Gao ◽  
Wenze Kang ◽  
Ruichen Ren ◽  
...  

The main purpose of this paper was to synthesize a novel form-stable composite phase change material (PCM). Herein, bentonite-based PCMs were synthesized by impregnating Na-bentonite clay with lauric acid (LA) through a vacuum impregnation method. Flake graphite (FG) was used to enhance the thermal conductivity of the composite PCMs. In addition, FG also helped block the leakage of the PCMs. It is worth noting that with the addition of FG, the period of melting and solidifying of composite PCMs were decreased to some extent. Meanwhile, the thermal conductivity of the PCMs has been obviously improved. Moreover, the synthesized composite PCM exhibited a favorable performance of reliability after 200 thermocycling test. Hence, this study showed that the developed composite PCM has the potential to be applied in thermal energy storage systems.


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