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Determination of Phase Transitions of <i>p</i>,<i>n</i>-Alkyloxy Benzoic Acid Mesogens Using Legendre Moments and Image Analysis
Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, India
Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, India
Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, India
Department of Electronics and Communcation Engineering, K. L. University, Greenfields, Vaddeswaram, India
Department of Chemical Science, Faculty of Science, UniversitiTunku Abdul Rahman, Jalan Universiti, Bandar Barat, Kampar, Malaysia
- 1 Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, India
- 2 Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, India
- 3 Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, India
- 4 Department of Electronics and Communcation Engineering, K. L. University, Greenfields, Vaddeswaram, India
- 5 Department of Chemical Science, Faculty of Science, UniversitiTunku Abdul Rahman, Jalan Universiti, Bandar Barat, Kampar, Malaysia
World Journal of Condensed Matter Physics·Volume 03 (2013)·Pages 54–61·Published 27 February 2013·DOI10.4236/wjcmp.2013.31010
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Abstract
Phase transition temperatures of p , n - alkyloxy benzoic acids ( n OBA, n = 3 to 10 and 12) are investigated basing on the textural image analysis of liquid crystal. The analysis is carried out by the computation of Legendre moments. Textures of the homeotropically aligned compounds are recorded as a function of temperature using POM in arthroscopic mode attached to the hot stage and high resolution camera. A recurrence formula is used to compute the liquid crystal textures based on Legendre polynomial. The discontinuities and fluctuations in the values of Legendre moments as a function of temperature are related to the phase transition temperatures of the sample. This method is successful in conforming or detecting the phase transition temperatures and the present findings are comparable with literature.
KeywordsAlkyloxybenzoic AcidsHomeotropic AlignmentPhase TransitionsTexturesLegendre MomentsImage Analysis
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