Distinguishing channel-type crystal structure from dispersed structure in 13-cyclodextrin based polyrotaxanes via FTIR spectroscopy  

作　　者：Jin WANG Pei-Jing WANG Peng GAO Lan JIANG Shuo LI Zeng-Guo FENG 

机构地区：[1]School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China

出　　处：《Frontiers of Computer Science》2011年第3期329-334,共6页中国计算机科学前沿（英文版）

基　　金：Acknowledgements We acknowledge the support from the National Natural Science Foundation of China （Grant No. 209740150） and the Doctoral Program Foundation of Ministry of Education of China （Grant No. 20091101110029）.

摘　　要：Combining with XRD analysis, Fourier transform infrared （FTIR） spectroscopy is employed to discern the self-assembled structures of β-cyclodextrins （β-CDs） threaded onto the polymer backbone in the polyrotaxanes （PRs） by means of the relative changes of absorption intensity of the characteristic peaks of β-CDs at 1153 and 1025 cm^-1. For quantitative analysis, six parameters are proposed to describe the relative absorption intensity variations of these peaks associated with a channel-type crystal structure or a dispersed structure of β-CDs entrapped. Among them, absorbance ratio （AR）, relative absorbance difference （RAD） and transmittance difference （TD） values are suitable. When the AR, RAD and TD data get below 1.04, 4.8 and 1.27, respectively, the PRs obtained would possess a dispersed structure. If these values go beyond 1.32, 34,5 and 9.47, respectively, they would hold a channel-type crystal structure. This finding provides a useful judgment to distinguish the self-assembled structures of β-CDs residing along the polymer backbone in the PRs.Combining with XRD analysis, Fourier transform infrared （FTIR） spectroscopy is employed to discern the self-assembled structures of β-cyclodextrins （β-CDs） threaded onto the polymer backbone in the polyrotaxanes （PRs） by means of the relative changes of absorption intensity of the characteristic peaks of β-CDs at 1153 and 1025 cm^-1. For quantitative analysis, six parameters are proposed to describe the relative absorption intensity variations of these peaks associated with a channel-type crystal structure or a dispersed structure of β-CDs entrapped. Among them, absorbance ratio （AR）, relative absorbance difference （RAD） and transmittance difference （TD） values are suitable. When the AR, RAD and TD data get below 1.04, 4.8 and 1.27, respectively, the PRs obtained would possess a dispersed structure. If these values go beyond 1.32, 34,5 and 9.47, respectively, they would hold a channel-type crystal structure. This finding provides a useful judgment to distinguish the self-assembled structures of β-CDs residing along the polymer backbone in the PRs.

关 键 词：FTIR POLYROTAXANE Β-CYCLODEXTRIN self-assembled structure 

分 类 号：O657.33[理学—分析化学] O614.121[理学—化学]