嵌段共聚物PS-b-PAA自组装过程的原位小角X射线散射  

In-situ SAXS study on self-assembly of copolymer PS-b-PAA

作　　者：金鑫 王建军[1,3] 李怡雯[4] 黄达 杨春明 边风刚[1] 王劼[1] JIN Xin;WANG Jianjtm;LI Yiwen;HUANG Da;YANG Chunming;BIAN Fenggang;WANG Jie(Shanghai Synchrotron Radiation Facility,Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Zhangjiang Campus,Shanghai 201204,China;University of Chinese Academy of Sciences,Beijing 100049,China）3（East China University of Science and Technology,Shanghai 200237,China;4.Nation Center for Protein Science Shanghai,Shanghai Advanced Research Institute,Shanghai 201210,Chin)

机构地区：[1]中国科学院上海应用物理研究所上海光源张江园区,上海201204 [2]中国科学院大学,北京100049 [3]华东理工大学,上海200237 [4]中国科学院上海高等研究院国家蛋白质中心,上海201210

出　　处：《核技术》2018年第8期7-13,共7页Nuclear Techniques

基　　金：国家重点研发计划(No.2017YFA0403000);国家自然科学基金(No.11405259);上海市基础研究项目(No.17JC1400802)资助~~

摘　　要：以嵌段共聚物聚苯乙烯聚丙烯酸(PS3000-b-PAA5000)(分子数分别为PS:PAA=3 000:5 000)为研究对象,应用变温小角X射线散射(Small-angle X-ray Scattering,SAXS)技术对其自组装过程进行了原位研究。SAXS峰位被发现随着温度的升高从q≈0.73 nm^(-1)移动至低q区的q≈0.39 nm^(-1)附近,同时SAXS峰的半峰宽、积分面积和强度的最大值也发生相应的转变。结果分析表明:该嵌段共聚物在128oC附近发生相变,相变温度跨度约为5oC。应用对距离分布函数(Pair Distance Distribution Function,PDDF),对SAXS数据进行拟合分析后发现:相变前为表面带有起伏的棒状体,随着温度升高棒状体出现孔洞,且棒状体变短,随后逐渐由棒状转变为带孔的球状体,并逐渐最终长大为直径30 nm左右的类球体。[Background] Block copolymers can spontaneously self-assemble into various micro-scale morphologies under the various external fields, which have an extensive potential on the application of the electronics, information, chemistry and biology, etc. However, the self-assembly process is still a ＂black box＂, the understanding is still limited to the evolution of morphology during the varying external conditions. [Purpose] This study aims to investigate the self-assembly behavior of Poly（styrene）-block-poly（acrylic acid）（PS-b-PAA） in the temperature field by using in-situ synchrotron radiation small-angle X-ray scattering（SAXS）. [Methods] SAXS experiments were performed on the BL16 B1 beamline of Shanghai Synchrotron Radiation Facility（SSRF）. Energy was selected as 10 ke V and the wave length is 0.124 nm. 2D SAXS patterns were recorded by Mar165 CCD with pixel size of 79 μm×79 μm. A sample-to-detector distance of 1 946 mm was chosen. The temperatures of the specimens were monitored by using a Linkam thermal stage THMS600（Linkam scientific instruments）. One-dimensional integrated intensity curves were obtained from 2 D SAXS patterns by self-developed software. PS-b-PAAs（PS：PAA=3 000：5 000） were used directly as purchased from Sigma-Aldrich Inc. [Results] The in-situ SAXS experiment shows that the center of scattering peak was shifted with increasing temperature from q≈0.73 nm^-1 to q≈0.39 nm^-1, which was also accompanied by the varying of full width of half maximum, integral area, and maximum value of SAXS peak. A phase transition temperature was estimated as Tc=128 oC and the temperature width of transition is 5 oC. Pair distance distribution function was used for the analysis of SAXS data. [Conclusion] With increasing temperature, the length of particle decreased gradually and body perforated, A rod-like shape with an undulating surface exists before the phase transition. At the temperature higher than Tc, the particle was degraded from the rod-like shape changes to a nea

关 键 词：嵌段共聚物 自组装 小角X射线散射 同步辐射 

分 类 号：O562.4[理学—原子与分子物理]