Based on thermal analysis, the isothermal and nonisothemal crystallization kinetics of Ziegler-Natta catalyzed linear low density polyethylene (Z-N LLDPE) and metallocene catalyzed LLDPE (m-LLDPE) were studied. Treati...Based on thermal analysis, the isothermal and nonisothemal crystallization kinetics of Ziegler-Natta catalyzed linear low density polyethylene (Z-N LLDPE) and metallocene catalyzed LLDPE (m-LLDPE) were studied. Treating the results with the Avrami equation and the Ozawa equation, the crystallization constant Igk and the Avrami exponent n were obtained. Some other crystallization parameters were also discussed. According to the different characteristics of the chain structures of Z-N LLDPE and metallocene LLDPE, their crystallization behaviors were analyzed. It is indicated that the homogeneity and heterogeneity of the two polymers act in different way during the crystallization process of polymers, including the nucleation and the growth of crystals under various conditions.展开更多
Electrostatic layer-by-layer self-assembly multilayer films were successfully fabricated from C-60-ethylenediamine adduct (C-60-EDA) and DNA. Under visible light irradiation, DNA is ready to be cleaved and the films a...Electrostatic layer-by-layer self-assembly multilayer films were successfully fabricated from C-60-ethylenediamine adduct (C-60-EDA) and DNA. Under visible light irradiation, DNA is ready to be cleaved and the films are destroyed.展开更多
基金This work was supported by the National Natural Science Foundation of China (No. B040504), and the Science Foundation of State Key Laboratory of Polymer Physics and Chemistry, Chinese Academy of Sciences (00-B-15).
文摘Based on thermal analysis, the isothermal and nonisothemal crystallization kinetics of Ziegler-Natta catalyzed linear low density polyethylene (Z-N LLDPE) and metallocene catalyzed LLDPE (m-LLDPE) were studied. Treating the results with the Avrami equation and the Ozawa equation, the crystallization constant Igk and the Avrami exponent n were obtained. Some other crystallization parameters were also discussed. According to the different characteristics of the chain structures of Z-N LLDPE and metallocene LLDPE, their crystallization behaviors were analyzed. It is indicated that the homogeneity and heterogeneity of the two polymers act in different way during the crystallization process of polymers, including the nucleation and the growth of crystals under various conditions.
基金The National Natural Science Foundation of China (Grant No. 29774036 and 29904007) and PPLAS Foundation of Chinese Academy of Sciences (Grant No. 01-B-06) are gratefully acknowledged for their financial support of this work.
文摘Electrostatic layer-by-layer self-assembly multilayer films were successfully fabricated from C-60-ethylenediamine adduct (C-60-EDA) and DNA. Under visible light irradiation, DNA is ready to be cleaved and the films are destroyed.
