The microstructure of aqueous CuCl2 has been studied through lots of technologies for many years; however, it remains a controversial subject. In this study, a new spectroscopic method has been proposed to analyze the...The microstructure of aqueous CuCl2 has been studied through lots of technologies for many years; however, it remains a controversial subject. In this study, a new spectroscopic method has been proposed to analyze the UV-visible spectra of thin fihn of CuCl2/H2O solutions at different concentrations. This method is the combination of ratio spectra, difference spectra and second order difference spectra. By using this method, two new bands at -230 and -380 nm are obviously observed. The bands are assigned as the contacted ion pairs [CuCl3（H2O）n]- or [CuCl4（H2O）n]2-, which demonstrates that ion pairs exist in the CuCl2/H2O solution. Such finding agrees with the recent theoretical spectra obtained by time-dependent density functional theory. Furthermore, the populations of the contacted ion pairs are discussed. This study not only offers the direct spectroscopic evidence of [CuCl3（H2O）n]- or [CuCl4（H2O）n]2- in aqueous CuCl2, but also suggests that the spec- troscopic analysis method is powerful to extract the weak bands in a strong overlapping spectrum.展开更多
Photoresponsive behavior and self assembly properties of three side chain azo polyelectrolytes, poly (2 (4 phenylazophenoxy) ethanol co acrylic acid) (PPAPE), poly (2 (4 (4′ nitrophenylazo) phenoxy) ethanol...Photoresponsive behavior and self assembly properties of three side chain azo polyelectrolytes, poly (2 (4 phenylazophenoxy) ethanol co acrylic acid) (PPAPE), poly (2 (4 (4′ nitrophenylazo) phenoxy) ethanol co acrylic acid) (PNAPE), and poly (2 (4 (4′ ethoxyphenylazo) phenoxy) ethanol co acrylic acid) (PEAPE), were studied. These polyelectrolytes with different degrees of functionalization of azo chromophores were fabricated into nano composite multilayers using two types of dipping solutions through a layer by layer electrostatic self assembling process. Results show that the ratio between tetrahydrofuran (THF) and H 2O significantly influences the photoresponsive behavior of PNAPE in THF H 2O mixture. The THF H 2O dipping solution, used in this work for self assembly of hydrophobic polyelectrolytes, is proved to be as applicable as aqueous dipping solution for normal self assembly of hydrophobic polyelectrolytes. However, significant differences in the multilayer growth between the two systems were also observed, which resulted from the remarkable difference of the existing forms of the polyelectrolytes in these two dipping solutions.展开更多
文摘The microstructure of aqueous CuCl2 has been studied through lots of technologies for many years; however, it remains a controversial subject. In this study, a new spectroscopic method has been proposed to analyze the UV-visible spectra of thin fihn of CuCl2/H2O solutions at different concentrations. This method is the combination of ratio spectra, difference spectra and second order difference spectra. By using this method, two new bands at -230 and -380 nm are obviously observed. The bands are assigned as the contacted ion pairs [CuCl3（H2O）n]- or [CuCl4（H2O）n]2-, which demonstrates that ion pairs exist in the CuCl2/H2O solution. Such finding agrees with the recent theoretical spectra obtained by time-dependent density functional theory. Furthermore, the populations of the contacted ion pairs are discussed. This study not only offers the direct spectroscopic evidence of [CuCl3（H2O）n]- or [CuCl4（H2O）n]2- in aqueous CuCl2, but also suggests that the spec- troscopic analysis method is powerful to extract the weak bands in a strong overlapping spectrum.
基金the National Natural Science Foundationof China(No.5 992 5 30 9)
文摘Photoresponsive behavior and self assembly properties of three side chain azo polyelectrolytes, poly (2 (4 phenylazophenoxy) ethanol co acrylic acid) (PPAPE), poly (2 (4 (4′ nitrophenylazo) phenoxy) ethanol co acrylic acid) (PNAPE), and poly (2 (4 (4′ ethoxyphenylazo) phenoxy) ethanol co acrylic acid) (PEAPE), were studied. These polyelectrolytes with different degrees of functionalization of azo chromophores were fabricated into nano composite multilayers using two types of dipping solutions through a layer by layer electrostatic self assembling process. Results show that the ratio between tetrahydrofuran (THF) and H 2O significantly influences the photoresponsive behavior of PNAPE in THF H 2O mixture. The THF H 2O dipping solution, used in this work for self assembly of hydrophobic polyelectrolytes, is proved to be as applicable as aqueous dipping solution for normal self assembly of hydrophobic polyelectrolytes. However, significant differences in the multilayer growth between the two systems were also observed, which resulted from the remarkable difference of the existing forms of the polyelectrolytes in these two dipping solutions.
