Growth of spherulitic crystal patterns in a Belousov–Zhabotinski type reaction system
摘要:
据报道,以乙酰丙酮(AA)-丁二酸(SA)为双有机基质,在贝洛索夫-扎博金斯基(BZ)型反应体系中生长出了球状晶体图案。研究发现,液相中的反应体系呈现出同心环状波纹。在反应过程中还观察到由无数细小颗粒组成的胶体相。在胶体相中发现了固相成核现象,从而形成了一些稳定的核中心。随着反应的进行,固相核以对称的晶体模式生长,呈现球状形态。此外,还讨论了球晶的可能生长行为。通过扫描电子显微镜(SEM)技术,观察到了由从共同中心发散的细小晶体纤维组成的球状结构。晶体材料的热表征(TGA/DTA)和 X 射线衍射(XRD)图也证实了球晶中发现的多晶体相。
Temperature-Dependent Rate Coefficients for the Reactions of Br(<sup>2</sup>P<sub>3/2</sub>), Cl(<sup>2</sup>P<sub>3/2</sub>), and O(<sup>3</sup>P<sub>J</sub>) with BrONO<sub>2</sub>
作者:R. Soller、J. M. Nicovich、P. H. Wine
DOI:10.1021/jp001947q
日期:2001.3.8
fluorescence technique has been employed to investigate the kinetics of reactions of the important stratospheric species bromine nitrate (BrONO2) with ground-state atomic bromine (k1), chlorine (k2), and oxygen (k3) as a function of temperature (224−352 K) and pressure (16−250 Torr of N2). The rate coefficients for all three reactions are found to be independent of pressure and to increase with decreasing
Bromineoxides have been generated by passing a mixture of Br(2)/O(2)/Ar through a microwave discharge. The products were stabilized at 6.5 K in an excess amount of argon. Infrared spectroscopy was used to analyze the species formed; experiments with enriched (18)O(2) and abinitio calculations were carried out to assist in the assignment of the spectra. Besides the known species BrO, OBrO, and BrBrO
Vacuum ultraviolet (VUV) light photolysis of an HBr/O-2 mixture in a Ne matrix has produced HO2Br isomers (HOOBr and HOBrO), which are important reaction intermediates in atmospheric chemistry. The observed bands have been assigned with an aid of a quantum chemical calculation at CCSD/aug-cc-pVDZ. These assignments have been confirmed by the experimental results using isotopic species of O-18(2) or DBr. Their characteristic bands are discussed in comparison with those of HOOCl and HOClO from an HCl/O-2 mixture [7]. Both HOOBr and HOBrO are found to be photolyzed with the UV light below 385 nm. (c) 2010 Elsevier B. V. All rights reserved.
Kinetics of the IO Radical. 2. Reaction of IO with BrO
作者:Mary K. Gilles、Andrew A. Turnipseed、James B. Burkholder,、A. R. Ravishankara、Susan Solomon
DOI:10.1021/jp9709159
日期:1997.7.1
The rate coefficient for the IO + BrO --> products (1) reaction was measured using pulsed laser photolysis with a discharge flow tube for radical production and pulsed laser-induced fluorescence and UV absorption for detection of IO and BrO radicals, respectively. Reaction 1 was studied under pseudo-first-order conditions in IO with an excess of BrO between 204 and 388 K at total pressures of 6-15 Torr. The Arrhenius expression obtained for non-iodine atom producing channels is k(la)(T) = (2.5 +/- 1.0) x 10(-11) exp[(260 +/- 100)/T] cm(3) molecule(-1) s(-1) independent of pressure. The rate coefficient for the reaction BrO + BrO --> products (2) and the UV absorption cross sections of BrO as a function of temperature were also determined as part of this study. The implications of these results to the loss rate of stratospheric ozone are discussed.