Depth Profiling of Block Copolymer Nanostructures in Films by Small‐Angle X‐Ray Scattering Using an X‐Ray Microbeam. Issue 1 (29th May 2013)

• Record Type: Journal Article
• Authors: Sakurai, Shinichi; Kimura, Go; Mizuno, Yohei; Masunaga, Hiroyasu; Ogawa, Hiroki; Ohta, Noboru; Yagi, Naoto; Adhikari, Rameshwar
• Is Part Of: Macromolecular symposia. Volume 327:Issue 1(2013)
• Page Start: 121
• Page End: 127
• Publication Date: 2013-05-29
• Subjects: Macromolecules -- Congresses; Polymers -- Congresses; Polymerization -- Congresses; Macromolecules -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1002/masy.201350515
• Languages: English
• ISSNs: 1022-1360

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Summary</title> <sec id="masy201350515-sec-0001" sec-type="section"> <p>We applied the microbeam two‐dimensional small‐angle X‐ray scattering (2d‐<italic>µ</italic>SAXS) technique in order to characterize orientation of polystyrene (PS) microdomains as a function of the distance from the free surface of a sample sheet down to the surface facing to the substrate, for depth profiling for spontaneous perpendicular orientation of PS cylinders in the matrix of polyethylenebutylene (PEB) in a PS‐<italic>b</italic>‐PEB‐<italic>b</italic>‐PS triblock copolymer thick sheet as thick as ∼0.5 mm. It has been revealed that near the free surface the cylinders were randomly oriented down to ∼70 µm in depth. Although this might indicate that the surface effect, which preferentially dictates cylinders to be oriented parallel to the surface, can propagate for such a long distance, 70 µm is unusually huge as compared to the general knowledge of the surface effect propagating at most for 1 µm. Experimentally examining further, we finally conclude that the 2d‐<italic>µ</italic>SAXS depth profiling overestimates the surface effect. This unfavorable conclusion may be ascribed to surface roughness of the sample sheet subjected to the measurement, and in order to obtain a good result a big effort is required to prepare the surface as flat as possible.</p> </sec> </abstract>