We report on the preparation of a well-defined star-shaped tricationic ionic liquid possessing three arms of poly（ethylene glycol） functionalized imidazolium rings. Remarkable solubility was found in most of the org...We report on the preparation of a well-defined star-shaped tricationic ionic liquid possessing three arms of poly（ethylene glycol） functionalized imidazolium rings. Remarkable solubility was found in most of the organic solvents we used. Thermogravimetric analysis（TGA） exhibited excellent thermal stability and two distinct decomposition temperatures were attributed to two kinds of chemical degradation. Differential scanning calorimetry（DSC） was further employed to investigate the thermal phase transitions, that three different signals（Tg, Tc, and Tm） were shown upon the second heating process. Moreover, CH2Cl2 solution of the ionic liquid expressed an excitation-wavelength dependent fluorescence response, leading to the facile modulation of photoluminescence behavior. This work represents an example of utilizing molecular design to construct novel ionic liquids and endow further potential to be used in the engineering materials.展开更多
An overview of science and technology of pretreatment process suitable for automotive finishing with cathodic electrodeposition primer is presented in details in this paper. Both the theoretical principles and practic...An overview of science and technology of pretreatment process suitable for automotive finishing with cathodic electrodeposition primer is presented in details in this paper. Both the theoretical principles and practical aspects of tricationic phosphating process that are used in automotive industry are discussed in details. The characteristic features of phosphate coatings of both conventional high zinc phosphating formulations and modern tricationic phosphating formulations on steel surface are compared in details by SEM, EDX and XRD techniques. The corrosion protection of the phosphated and painted steel panels were evaluated by both salt spray test and electrochemical impedance spectroscopy (EIS). The analysis of impedance data in terms of pore resistance (Rpo), coating capacitance (Cc) and breakpoint frequency (fb) as a function of salt spray exposure time provides a clear insight into the mechanism of superior corrosion resistance provided by the modern tricationic phosphating formulations compared with conventional high zinc phosphating formulations.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.50973025,51373045 and 51303044)Fundamental Research Funds for the Central Universities(2013HGCH0013)+2 种基金Specialized Research Fund for the Doctoral Program of Higher Education(SRFDP,20130111120013)Research Foundation for Returned Overseas Chinese Scholars of the Ministry of Education of ChinaAnhui Province’s Natural Scientific Foundation(1408085QE80)
文摘We report on the preparation of a well-defined star-shaped tricationic ionic liquid possessing three arms of poly（ethylene glycol） functionalized imidazolium rings. Remarkable solubility was found in most of the organic solvents we used. Thermogravimetric analysis（TGA） exhibited excellent thermal stability and two distinct decomposition temperatures were attributed to two kinds of chemical degradation. Differential scanning calorimetry（DSC） was further employed to investigate the thermal phase transitions, that three different signals（Tg, Tc, and Tm） were shown upon the second heating process. Moreover, CH2Cl2 solution of the ionic liquid expressed an excitation-wavelength dependent fluorescence response, leading to the facile modulation of photoluminescence behavior. This work represents an example of utilizing molecular design to construct novel ionic liquids and endow further potential to be used in the engineering materials.
文摘An overview of science and technology of pretreatment process suitable for automotive finishing with cathodic electrodeposition primer is presented in details in this paper. Both the theoretical principles and practical aspects of tricationic phosphating process that are used in automotive industry are discussed in details. The characteristic features of phosphate coatings of both conventional high zinc phosphating formulations and modern tricationic phosphating formulations on steel surface are compared in details by SEM, EDX and XRD techniques. The corrosion protection of the phosphated and painted steel panels were evaluated by both salt spray test and electrochemical impedance spectroscopy (EIS). The analysis of impedance data in terms of pore resistance (Rpo), coating capacitance (Cc) and breakpoint frequency (fb) as a function of salt spray exposure time provides a clear insight into the mechanism of superior corrosion resistance provided by the modern tricationic phosphating formulations compared with conventional high zinc phosphating formulations.
