Ag nanoparticles were synthesized on the surface of a glassy carbon electrode modified with p‐tert‐butylcalix[4]arene and p‐tert‐butylcalix[6]arene by the deposition of Ag+ at an open circuit potential followed by...Ag nanoparticles were synthesized on the surface of a glassy carbon electrode modified with p‐tert‐butylcalix[4]arene and p‐tert‐butylcalix[6]arene by the deposition of Ag+ at an open circuit potential followed by the electrochemical reduction of the Ag+.The presence of the calixarene layer on the electrode surface controlled the particle size and prevented agglomeration.Cyclic voltam‐metry showed that the Ag nanoparticles on the modified glassy carbon electrode had good catalytic ability for the reduction of flutamide.The effects of calixarene concentration,potential applied for the reduction of Ag+,number of calixarene layers,and p H value on the electrocatalytic activity of the Ag nanoparticles were investigated.The modified electrode had a linear range in differential pulse voltammetry of 10-1000 μmol/L with a detection limit of 9.33 μmol/L for flutamide at an S/N = 3.The method was applied to the detection of flutamide in practical samples.展开更多
A series of new polycalixesters （PCES） were synthesized by polyesterification of calixarene dicarboxylic acid derivatives having tertiary butyl pendant groups at the upper rim using five different diols. All polyest...A series of new polycalixesters （PCES） were synthesized by polyesterification of calixarene dicarboxylic acid derivatives having tertiary butyl pendant groups at the upper rim using five different diols. All polyesters were readily soluble in polar solvents such as NMP （N-methylpyrrolidone）, DMF （dimethylformamide）, DMSO （dimethylsulfoxide）, pyridine, THF （tetrahydrofurane）, HMPA （hexamethylenephosphoramide） and DMAC （dimethylacetamide）. The PCES were also partially soluble in TCE （tetrachloroethane） and ethanol and they were unsoluble in aceton. The glass transition temperatures of polyesters were between 80-184 ℃, the crystallinity temperatures of polyesters were between 130-212 ℃ and the melting temperatures of polyesters were between 185-234 ℃, as determined by differential scanning calorimeter （DSC）. The inherent viscosities of polyesters were obtained from 0.55 dL/mg to 0.61 dL/mg. The temperatures at 10% weight loss of polyesters ranged from 182 ℃ to 237 ℃. The temperatures at 25% weight loss of polyesters ranged from 258 ℃ to 331 ℃. The half weight loss （50%） temperatures of polyesters were among 315 ℃ to 371 ℃ and the char yields at 600 ℃ were determined within 13% to 22.3% in N2 atmosphere, as determined by thermo gravimetric analysis （TGA）. The polyester, PES3, has the higher melting point （234 ℃） and higher inherent viscosity （molecular weight） than the other polyesters.展开更多
文摘Ag nanoparticles were synthesized on the surface of a glassy carbon electrode modified with p‐tert‐butylcalix[4]arene and p‐tert‐butylcalix[6]arene by the deposition of Ag+ at an open circuit potential followed by the electrochemical reduction of the Ag+.The presence of the calixarene layer on the electrode surface controlled the particle size and prevented agglomeration.Cyclic voltam‐metry showed that the Ag nanoparticles on the modified glassy carbon electrode had good catalytic ability for the reduction of flutamide.The effects of calixarene concentration,potential applied for the reduction of Ag+,number of calixarene layers,and p H value on the electrocatalytic activity of the Ag nanoparticles were investigated.The modified electrode had a linear range in differential pulse voltammetry of 10-1000 μmol/L with a detection limit of 9.33 μmol/L for flutamide at an S/N = 3.The method was applied to the detection of flutamide in practical samples.
文摘A series of new polycalixesters （PCES） were synthesized by polyesterification of calixarene dicarboxylic acid derivatives having tertiary butyl pendant groups at the upper rim using five different diols. All polyesters were readily soluble in polar solvents such as NMP （N-methylpyrrolidone）, DMF （dimethylformamide）, DMSO （dimethylsulfoxide）, pyridine, THF （tetrahydrofurane）, HMPA （hexamethylenephosphoramide） and DMAC （dimethylacetamide）. The PCES were also partially soluble in TCE （tetrachloroethane） and ethanol and they were unsoluble in aceton. The glass transition temperatures of polyesters were between 80-184 ℃, the crystallinity temperatures of polyesters were between 130-212 ℃ and the melting temperatures of polyesters were between 185-234 ℃, as determined by differential scanning calorimeter （DSC）. The inherent viscosities of polyesters were obtained from 0.55 dL/mg to 0.61 dL/mg. The temperatures at 10% weight loss of polyesters ranged from 182 ℃ to 237 ℃. The temperatures at 25% weight loss of polyesters ranged from 258 ℃ to 331 ℃. The half weight loss （50%） temperatures of polyesters were among 315 ℃ to 371 ℃ and the char yields at 600 ℃ were determined within 13% to 22.3% in N2 atmosphere, as determined by thermo gravimetric analysis （TGA）. The polyester, PES3, has the higher melting point （234 ℃） and higher inherent viscosity （molecular weight） than the other polyesters.
