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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 17:58 |
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Conference: Bucharest University Faculty of Physics 2014 Meeting
Section: Polymer Physics
Title:
2D Fast Fourier Transform function for analysis of distribution of polystyrene nanoballs assembled on a substrate
Authors:
Valentina MARASCU(1,2), N. COTFAS(1), E.S. BARNA(1), M.D. IONIȚA(2), B. MITU(2), G. DINESCU(1, 2)
Affiliation:
(1) Faculty of Physics, University of Bucharest, 405 Atomistilor, 077125 Bucharest- Magurele, Romania
(2) National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Street, 077125 Bucharest– Magurele, Romania
E-mail
valentina.marascu@gmail.com
Keywords:
2D Fast Fourier Transform, power spectrum, colloidal lithography
Abstract:
In our paper we investigate the uniformity and regularity of polystyrene nanoballs distributions on a substrate by using the squared modulus of 2D Fast Fourier Transform (2D FFT). The 2D FFT is an efficient algorithm for the 2D Discrete Fourier Transform (2D DFT). To implement the 2D FFT algorithm we use the Scanning Electron Microscope (SEM) images of the materials. Particularly, in this case we have used self-assembled layers of polystyrene spheres, with size of around 500 nm diameters, distributed on surface. Low pressure oxygen plasma treatment was involved for nanoballs shrinkage down to ~200 nm. The SEM images were digitized and matrices describing the levels of grey pixels were obtained. These matrices were transformed by 2D FFT and the regularities in the appearance of the same grey levels were investigated. The existence of some narrow sharp peaks in the squared modulus of 2D FFT indicates the existence of a tendency of periodic distribution of the polystyrene spheres. More details concerning this regularity can be extracted by exploring the shape and the geometric distribution of the narrow peaks.
Acknowledgments: This work was performed in the frame of COST Action MP1101- Biomedical Applications of Atmospheric Pressure Plasma Technology. The financial support of the Romanian Ministry of Education under Nucleus project PN 09 39 04 01 is gratefully acknowledged.
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