The flotation behavior of quartz using N-(2-aminoethyl)-octadecanamide (AEOA ) as a collector was investigated.Zeta potential and infrared spectra were conducted to investigate the mechanism of the interaction of the ...The flotation behavior of quartz using N-(2-aminoethyl)-octadecanamide (AEOA ) as a collector was investigated.Zeta potential and infrared spectra were conducted to investigate the mechanism of the interaction of the quartz surface with the collector molecules. The results show that electrostatic force and hydrogen bond play an important role in governing the mechanism of flotation in acidic and alkaline media. The recoveries of quartz are (99.0%)-99.8% in the pH range of 3-11. The recovery of quartz is less dependent on AEOA concentration, mainly due to the formation of micellae in aqueous solution,and the adsorption density of AEOA on the quartz surface nearly remains constant.展开更多
The title compound [Cu2(m-NO2)(aepy)4](ClO4)3 (Cu2C28H40N9Cl3O14, Mr = 960.12, aepy = 2-(2-aminoethyl)pyridine) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallizes in ...The title compound [Cu2(m-NO2)(aepy)4](ClO4)3 (Cu2C28H40N9Cl3O14, Mr = 960.12, aepy = 2-(2-aminoethyl)pyridine) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallizes in monoclinic, space group C2/c with cell parameters: a = 21.958(3), b = 12.205(2), c = 15.180(3) ? b = 106.06(1), V = 3909.5(12) ?, Z = 4, Dc = 1.631 g/cm3, F(000) = 1968 and m(MoKa) = 1.368 mm-1. The structure was solved by direct methods and refined by full-matrix least-squares techniques. The final R = 0.0734 and wR = 0.1954 for 1606 observed reflections with I ≥2.0s(I). The crystal structure revealed that the [Cu2(m-NO2)(aepy)4]3+ cation consists of two square-based pyramidal copper (Ⅱ) atoms bridged by one nitrate anion. The distance between the two copper atoms (Cu(1)…Cu(1A)) is 5.373 (2) ?展开更多
A new method for preparing chemically modified gold electrode by anchoring thionine to self-assembled bi - (2 -aminoethyl) -aminodithiocarboxyl acid(BANTC) monolayers through coordination with Cu2+ is described. This...A new method for preparing chemically modified gold electrode by anchoring thionine to self-assembled bi - (2 -aminoethyl) -aminodithiocarboxyl acid(BANTC) monolayers through coordination with Cu2+ is described. This thionine modified electrode exhibits two-new redox couples.Two protons were involved in the electrochemical process undergone by the couple I in the pH range of 5.0-10.0. The apparent surface electron transfer rate constant is about 0.050s-1.展开更多
The title complex [Cu(HTren)Cl2]ClO4·H2O (Tren = tris(2-aminoethyl)amine) was synthesized by the reaction of Cu(ClO4)2·6H2O with Tren.3HCl in water and methyl alcohol. The crystal (CuC6H21Cl3N4O5) ...The title complex [Cu(HTren)Cl2]ClO4·H2O (Tren = tris(2-aminoethyl)amine) was synthesized by the reaction of Cu(ClO4)2·6H2O with Tren.3HCl in water and methyl alcohol. The crystal (CuC6H21Cl3N4O5) is of triclinic, space group P1, with a = 8.2689(2), b = 8.4503(3), c = 11.6801(4) A, α= 96.9350(10), β= 108.2440(10), y = 90.7550(10)°, V= 768.32(4)A^3, Z = 2, Mr= 399.16, D,.= 1.725 g/cm^3,μ= 1.962 mm^-1, F(000) = 410, T= 293(2) K, the final R = 0.0479 and wR = 0.1339 for 2659 observed reflections with I 〉 2σ(I). X-ray single-crystal structure analysis reveals that the copper(Ⅱ) atom adopts a slightly distorted square-pyramidal geometry. The distances between Cu and N atoms (N(1), N(2), N(3)) range from 1.975(4) to 2.116(3)A,. The bond lengths of Cu-Cl(1) and Cu-Cl(2) are 2.309(10) and 2.591(10) A, respectively. The whole crystal presents a three-dimensional network structure by hydrogen bonds.展开更多
This paper reports that low-temperature heat capacities of 4-(2-aminoethyl)-phenol (C8H11NO) are measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial eq...This paper reports that low-temperature heat capacities of 4-(2-aminoethyl)-phenol (C8H11NO) are measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of heat capacities as a function of the temperature was fitted by the least square method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15K were calculated and tabulated at the interval of 5K. The energy equivalent, εcalor, of the oxygen-bomb combustion calorimeter has been determined from 0.68g of NIST 39i benzoic acid to be εcalor=(14674.69±17.49)J·K^-1. The constant-volume energy of combustion of the compound at T=298.15 K was measured by a precision oxygen-bomb combustion calorimeter to be ΔcU=-(32374.25±12.93)J·g^-1. The standard molar enthalpy of combustion for the compound was calculated to be ΔcHm = -(4445.47 ± 1.77) kJ·mol^-1 according to the definition of enthalpy of combustion and other thermodynamic principles. Finally, the standard molar enthalpy of formation of the compound was derived to be ΔfHm(C8H11NO, s)=-(274.68 ±2.06) kJ·mol^-1, in accordance with Hess law.展开更多
A commercially available chelating polymer, polystyrene tris(2-aminoethyl)amine, was used for the removal of chromium from aqueous solution. The influence of pH, contact time, adsorbent dosage and initial Cr (VI) conc...A commercially available chelating polymer, polystyrene tris(2-aminoethyl)amine, was used for the removal of chromium from aqueous solution. The influence of pH, contact time, adsorbent dosage and initial Cr (VI) concentration on adsorption was studied. The optimum pH for the removal of Cr (VI) was at pH 5, while optimum contact time and adsorbent dosage were 120 minutes and 10 g/L, respectively. Total chromium and Cr (VI) concentrations were analyzed by ICP-MS and UV-Visible. Adsorption isotherms using Langmuir and Freundlich isotherm models revealed that the data fitted Langmuir isotherm model better than Freundlich with a maximum adsorption capacity of 312.27 mg/g. FTIR spectroscopy, Scanning electron microscopy (SEM) and Energy Dispersive Spectrometry (EDS) analyses were performed on the adsorbent before and after binding Cr (VI). All analyses confirmed the complexation of Cr (VI) to the adsorbent. Desorption experiments using KCl solution indicated 89.3% release of chromium, rendering this method of high potential for adsorbent regeneration.展开更多
Recently, many attempts have been made to use carbon nanotubes in analytical chemistry, especially in adsorption of heavy metal ions from water. In this study, multiwalled carbon nanotubes (MWCNTs) were functionalized...Recently, many attempts have been made to use carbon nanotubes in analytical chemistry, especially in adsorption of heavy metal ions from water. In this study, multiwalled carbon nanotubes (MWCNTs) were functionalized with tris(2-aminoethyl) amine. The functionalized nanoparticles were characterized using Fourier transform infrared (FTIR), thermal gravimetric analyzer (TGA), elemental analysis, and Raman spectroscopy. The results revealed that the functionalization reaction was successfully accomplished. Lead adsorption from water was carried out using functionalized MWCNTs and measured by flame atomic absorption spectrometry (FAAS). The effects of pH, shaking time, initial metal ion concentration, and adsorbent dosage on the adsorption process were studied via batch method. The results obtained showed that removal of lead ions strongly depended on the pH. Desorption study revealed that lead ions adsorbed on the functionalized MWCNTs could be desorbed at pH 3 due to breakage of complexes formed on the sorbent surface. Maximum adsorption capacity of the sorbent under the optimal conditions was 43 mg/g. This favorable adsorption capacity suggests that functionalized carbon nanotubes can be applied for removal of lead from water solutions. The data obtained were fitted with the Langmuir and Freundlich isotherm adsorption models and Langmuir model showed better agreement with the experimental data.展开更多
Ruthenium loaded on activated carbon pre-treated by HNO3 was used to catalyze the reaction of 1-(2-Aminoethyl)-2-imidazolidone (AEI) synthesized from ethylenediamine, ethanolamine and CO2. Response surface methodology...Ruthenium loaded on activated carbon pre-treated by HNO3 was used to catalyze the reaction of 1-(2-Aminoethyl)-2-imidazolidone (AEI) synthesized from ethylenediamine, ethanolamine and CO2. Response surface methodology (RSM) based on Box-Behnken design (BBD) was employed to optimize the synthesis of AEI. The statistical analysis results showed that the yield of AEI was significantly affected by the CO2 pressure, reaction temperature and reaction time. According to the results of variance analysis, the value of the determination coefficient of 0.9854 was in reasonable agreement with the “Adj R-Squared” of 0.9666, which means this model can predict the yield of AEI well and can be used to optimize reaction conditions for higher AEI yield. The optimal values of AEI yield predicted by RSM was 84.9% under temperature 206.51?C, CO2 pressure 9.35 Mpa, reaction time 10.11 h, and the verification experiment yield of AEI was 83.1%.展开更多
A new ion selective electrode for salicylate based on N,N'-(aminoethyl)ethylenediamide bis(2-salicylideneimine) binuclear copper(Ⅱ) complex [Cu(Ⅱ)2-AEBS] as an ionophore was developed. The electrode has a l...A new ion selective electrode for salicylate based on N,N'-(aminoethyl)ethylenediamide bis(2-salicylideneimine) binuclear copper(Ⅱ) complex [Cu(Ⅱ)2-AEBS] as an ionophore was developed. The electrode has a linear range from 1.0 × 10^-1 to 5.0 ×10^-7 mol·L^- 1 with a near-Nemstian slope of ( - 55 ±1 ) mV/decade and a detection limit of 2.0 × 10-7 mol·L^-1 in phosphorate buffer solution of pH 5.0 at 25 ℃. It shows good selectivity for Sal^- and displays anti-Hofmeister selectivity sequence: Sal^-〉SCN^-〉 ClO4^- 〉I^-〉 NO2^- 〉Br^-〉 NO3^- 〉Cl^-〉 SO3^2- 〉 SO4^2- The proposed sensor based on binuclear copper(Ⅱ)complex has a fast response time of 5-10 s and can be used for at least 2 months without any major deviation. The response mechanism is discussed in view of the alternating current (AC) impedance technique and the UV-vis spectroscopy technique. The effect of the electrode membrane compositions and the experimental conditions were studied. The electrode has been successfully used for the determination of salicylate ion in drug pharmaceutical preparations.展开更多
文摘The flotation behavior of quartz using N-(2-aminoethyl)-octadecanamide (AEOA ) as a collector was investigated.Zeta potential and infrared spectra were conducted to investigate the mechanism of the interaction of the quartz surface with the collector molecules. The results show that electrostatic force and hydrogen bond play an important role in governing the mechanism of flotation in acidic and alkaline media. The recoveries of quartz are (99.0%)-99.8% in the pH range of 3-11. The recovery of quartz is less dependent on AEOA concentration, mainly due to the formation of micellae in aqueous solution,and the adsorption density of AEOA on the quartz surface nearly remains constant.
基金This project was financially supported by the Postdoctoral Science Foundation of China K. C. Wong Education Foundation+1 种基金 the National Natural Science Foundation of China and the Natural Science Foundation of Fujian Province and CAS
文摘The title compound [Cu2(m-NO2)(aepy)4](ClO4)3 (Cu2C28H40N9Cl3O14, Mr = 960.12, aepy = 2-(2-aminoethyl)pyridine) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallizes in monoclinic, space group C2/c with cell parameters: a = 21.958(3), b = 12.205(2), c = 15.180(3) ? b = 106.06(1), V = 3909.5(12) ?, Z = 4, Dc = 1.631 g/cm3, F(000) = 1968 and m(MoKa) = 1.368 mm-1. The structure was solved by direct methods and refined by full-matrix least-squares techniques. The final R = 0.0734 and wR = 0.1954 for 1606 observed reflections with I ≥2.0s(I). The crystal structure revealed that the [Cu2(m-NO2)(aepy)4]3+ cation consists of two square-based pyramidal copper (Ⅱ) atoms bridged by one nitrate anion. The distance between the two copper atoms (Cu(1)…Cu(1A)) is 5.373 (2) ?
文摘A new method for preparing chemically modified gold electrode by anchoring thionine to self-assembled bi - (2 -aminoethyl) -aminodithiocarboxyl acid(BANTC) monolayers through coordination with Cu2+ is described. This thionine modified electrode exhibits two-new redox couples.Two protons were involved in the electrochemical process undergone by the couple I in the pH range of 5.0-10.0. The apparent surface electron transfer rate constant is about 0.050s-1.
基金The project was supported by the Education Foundation of Jiangsu Province (03KJD150212)
文摘The title complex [Cu(HTren)Cl2]ClO4·H2O (Tren = tris(2-aminoethyl)amine) was synthesized by the reaction of Cu(ClO4)2·6H2O with Tren.3HCl in water and methyl alcohol. The crystal (CuC6H21Cl3N4O5) is of triclinic, space group P1, with a = 8.2689(2), b = 8.4503(3), c = 11.6801(4) A, α= 96.9350(10), β= 108.2440(10), y = 90.7550(10)°, V= 768.32(4)A^3, Z = 2, Mr= 399.16, D,.= 1.725 g/cm^3,μ= 1.962 mm^-1, F(000) = 410, T= 293(2) K, the final R = 0.0479 and wR = 0.1339 for 2659 observed reflections with I 〉 2σ(I). X-ray single-crystal structure analysis reveals that the copper(Ⅱ) atom adopts a slightly distorted square-pyramidal geometry. The distances between Cu and N atoms (N(1), N(2), N(3)) range from 1.975(4) to 2.116(3)A,. The bond lengths of Cu-Cl(1) and Cu-Cl(2) are 2.309(10) and 2.591(10) A, respectively. The whole crystal presents a three-dimensional network structure by hydrogen bonds.
基金supported by the National Natural Science Foundation of China (Grant No 20673050)
文摘This paper reports that low-temperature heat capacities of 4-(2-aminoethyl)-phenol (C8H11NO) are measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of heat capacities as a function of the temperature was fitted by the least square method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15K were calculated and tabulated at the interval of 5K. The energy equivalent, εcalor, of the oxygen-bomb combustion calorimeter has been determined from 0.68g of NIST 39i benzoic acid to be εcalor=(14674.69±17.49)J·K^-1. The constant-volume energy of combustion of the compound at T=298.15 K was measured by a precision oxygen-bomb combustion calorimeter to be ΔcU=-(32374.25±12.93)J·g^-1. The standard molar enthalpy of combustion for the compound was calculated to be ΔcHm = -(4445.47 ± 1.77) kJ·mol^-1 according to the definition of enthalpy of combustion and other thermodynamic principles. Finally, the standard molar enthalpy of formation of the compound was derived to be ΔfHm(C8H11NO, s)=-(274.68 ±2.06) kJ·mol^-1, in accordance with Hess law.
文摘A commercially available chelating polymer, polystyrene tris(2-aminoethyl)amine, was used for the removal of chromium from aqueous solution. The influence of pH, contact time, adsorbent dosage and initial Cr (VI) concentration on adsorption was studied. The optimum pH for the removal of Cr (VI) was at pH 5, while optimum contact time and adsorbent dosage were 120 minutes and 10 g/L, respectively. Total chromium and Cr (VI) concentrations were analyzed by ICP-MS and UV-Visible. Adsorption isotherms using Langmuir and Freundlich isotherm models revealed that the data fitted Langmuir isotherm model better than Freundlich with a maximum adsorption capacity of 312.27 mg/g. FTIR spectroscopy, Scanning electron microscopy (SEM) and Energy Dispersive Spectrometry (EDS) analyses were performed on the adsorbent before and after binding Cr (VI). All analyses confirmed the complexation of Cr (VI) to the adsorbent. Desorption experiments using KCl solution indicated 89.3% release of chromium, rendering this method of high potential for adsorbent regeneration.
文摘Recently, many attempts have been made to use carbon nanotubes in analytical chemistry, especially in adsorption of heavy metal ions from water. In this study, multiwalled carbon nanotubes (MWCNTs) were functionalized with tris(2-aminoethyl) amine. The functionalized nanoparticles were characterized using Fourier transform infrared (FTIR), thermal gravimetric analyzer (TGA), elemental analysis, and Raman spectroscopy. The results revealed that the functionalization reaction was successfully accomplished. Lead adsorption from water was carried out using functionalized MWCNTs and measured by flame atomic absorption spectrometry (FAAS). The effects of pH, shaking time, initial metal ion concentration, and adsorbent dosage on the adsorption process were studied via batch method. The results obtained showed that removal of lead ions strongly depended on the pH. Desorption study revealed that lead ions adsorbed on the functionalized MWCNTs could be desorbed at pH 3 due to breakage of complexes formed on the sorbent surface. Maximum adsorption capacity of the sorbent under the optimal conditions was 43 mg/g. This favorable adsorption capacity suggests that functionalized carbon nanotubes can be applied for removal of lead from water solutions. The data obtained were fitted with the Langmuir and Freundlich isotherm adsorption models and Langmuir model showed better agreement with the experimental data.
文摘Ruthenium loaded on activated carbon pre-treated by HNO3 was used to catalyze the reaction of 1-(2-Aminoethyl)-2-imidazolidone (AEI) synthesized from ethylenediamine, ethanolamine and CO2. Response surface methodology (RSM) based on Box-Behnken design (BBD) was employed to optimize the synthesis of AEI. The statistical analysis results showed that the yield of AEI was significantly affected by the CO2 pressure, reaction temperature and reaction time. According to the results of variance analysis, the value of the determination coefficient of 0.9854 was in reasonable agreement with the “Adj R-Squared” of 0.9666, which means this model can predict the yield of AEI well and can be used to optimize reaction conditions for higher AEI yield. The optimal values of AEI yield predicted by RSM was 84.9% under temperature 206.51?C, CO2 pressure 9.35 Mpa, reaction time 10.11 h, and the verification experiment yield of AEI was 83.1%.
基金Project supported by the National Natural Science Foundation of China (No. 29705001) and the Natural Science Foundation of Chongqing City (Nos. CSTC-2004BB4149 and CSTC-2005BB4100).
文摘A new ion selective electrode for salicylate based on N,N'-(aminoethyl)ethylenediamide bis(2-salicylideneimine) binuclear copper(Ⅱ) complex [Cu(Ⅱ)2-AEBS] as an ionophore was developed. The electrode has a linear range from 1.0 × 10^-1 to 5.0 ×10^-7 mol·L^- 1 with a near-Nemstian slope of ( - 55 ±1 ) mV/decade and a detection limit of 2.0 × 10-7 mol·L^-1 in phosphorate buffer solution of pH 5.0 at 25 ℃. It shows good selectivity for Sal^- and displays anti-Hofmeister selectivity sequence: Sal^-〉SCN^-〉 ClO4^- 〉I^-〉 NO2^- 〉Br^-〉 NO3^- 〉Cl^-〉 SO3^2- 〉 SO4^2- The proposed sensor based on binuclear copper(Ⅱ)complex has a fast response time of 5-10 s and can be used for at least 2 months without any major deviation. The response mechanism is discussed in view of the alternating current (AC) impedance technique and the UV-vis spectroscopy technique. The effect of the electrode membrane compositions and the experimental conditions were studied. The electrode has been successfully used for the determination of salicylate ion in drug pharmaceutical preparations.