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Clarification of Order Structure Peculiar to the Near-surface Region of Crystalline Polymer Films and Dynamics on their Structural Formation

结晶聚合物薄膜近表面区域特有的有序结构的澄清及其结构形成的动力学

基本信息

批准号：
15550109
负责人：
SASAKI Sono
金额：
$ 2.37万
依托单位：
Japan Synchrotron Radiation Research Institute (JASRI/SPring-8) (2004-2005)Kyushu University (2003)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

We have successfully investigated chain and lamellar packing structures peculiar to crystalline polymers confined to narrow space, such as the surface and the thin film, by synchrotron grazing-incidence X-ray diffraction (SR-GIXD) and grazing-incidence small-angle X-ray scattering (SR-GISAXS) measurements. Thin films with a thickness of ca. 400 nm were prepared on silicon wafers from a p-xylene solution of high-density polyethylene (HDPE) by a dip-coating method. The dip-coated films and HDPE bulk samples were isothermally crystallized from the melt or annealed at various temperatures under nitrogen atmosphere.In order to detect Bragg diffractions from the near-surface and bulk regions of the thin films, in-plane GIXD measurements were carried out at incident angles (α_i) of X-rays smaller and lager than the critical angle (α_c) at the BL13XU beamline of SPring-8 (Hyogo, Japan). It was revealed that the lattice constants a and b of orthorhombic unit cell in the near-surface region of t … More he thin film were smaller than those in the bulk region but larger than those of the bulk samples. This implied that the unit cell especially in the interfacial region between PE and silicon was distorted during sample preparation due to large mismatching between their thermal expansion coefficients. On the other hand, pracrystalline lattice analysis for the thin films indicated that long and short-range lattice distortion was larger in the near-surface region than in the bulk region. This might be related with the surface free energy of the film and/or releasing the latent heat from the surface.SR-GISAXS measurements were carried out at α_i of X-rays smaller and lager than the α_c at the BL40B2 beamline of SPring-8. The 2D-GISAXS patterns from the films placed in a vacuum cell were detected at 300K with an imaging intensifier and a CCD detector or an imaging plate. Strong scattering in the in-plane direction near Yoneda peak were detected for all of the films. From the peak position of the scattering, it was found that the long period, the average distance between stacked crystalline lamellae, was ca.25-30 nm. From the GIXD data, it was implied that chains were relatively oriented parallel to the surface in the lamellae. Combination of GIXD and GISAXS data indicated that relatively edge-on oriented lamellae were stacked in the parallel direction to the surface. By annealing, partial melting and recrystallization might occur remarkably in the near-surface region. Less

我们已经成功地研究了链和层状堆积结构所特有的结晶聚合物局限于狭窄的空间，如表面和薄膜，通过同步辐射掠入射X射线衍射（SR-GIXD）和掠入射小角X射线散射（SR-GISAXS）测量。薄膜的厚度约为。400 nm的高密度聚乙烯（HDPE）的对二甲苯溶液通过浸涂法在硅片上制备。在氮气保护下，对浸渍涂膜和HDPE块体样品进行了等温结晶或不同温度退火，在SPring-8（Hyogo，Japan）的BL 13 XU光束线上，分别在小于和大于临界角α c的X射线入射角α i下进行了面内GIXD测量，以检测薄膜近表面和块体区域的Bragg衍射。结果表明，在近表面区域，正交晶胞的晶格常数a和B随温度的升高而增大， ...更多信息薄膜的尺寸小于体区域的尺寸，但大于体样品的尺寸。这意味着，在样品制备过程中，特别是在PE和硅之间的界面区域的单元电池是扭曲的，由于它们的热膨胀系数之间的大的失配。另一方面，对薄膜的实晶晶格分析表明，在近表面区域的长、短程晶格畸变比体区域大。在SPring-8的BL 40 B2光束线上，在α_i小于α_c和大于α_c的X射线下进行了SR-GISAXS测量。在300 K下用成像增强器和CCD检测器或成像板检测来自置于真空室中的膜的2D-GISAXS图案。所有的膜在米田峰附近的面内方向上检测到强散射。从散射的峰值位置，发现长周期，即堆叠的晶体薄片之间的平均距离，为约25 -30 nm。从GIXD数据，这是暗示，链相对平行于表面的层片取向。GIXD和GISAXS数据的结合表明，相对边缘上取向的薄片堆叠在平行于表面的方向。通过退火，部分熔化和再结晶可能会发生显着的近表面区域。少