Document Type



Changes to the structure of polystyrene melt films as measured through the spectrum of density fluctuations have been observed as a function of film thickness down to the polymer radius of gyration (Rg). Films thicker than 4Rg show bulklike density fluctuations. Thinner films exhibit a peak in S(q) near q = 0, which grows with decreasing thickness. This peak is attributed to a decreased interpenetration of chains resulting in an enhanced compressibility. Measurements were made using small angle x-ray scattering in a standing wave geometry designed to enhance scattering from the interior of the film compared to interface scattering.



Publication Date


Original Citation

M.K. Mukhopadhyay, X. Jiao, L.B. Lurio, J. Stark, M. Sprung, S. Narayanan, A. Sandy, S.K. Sinha, "Thickness induced structural changes in polystyrene films." Phys. Rev. Lett. 101, 115501

Legacy Department

Department of Physics


This work is supported by NSF Grant No. DMR-0209542. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.






American Physical Society


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