Liquid Crystals an Applications
Code
10201
Academic unit
Faculdade de Ciências e Tecnologia
Department
Departamento de Ciências dos Materiais
Credits
6.0
Teacher in charge
Maria Helena Figueiredo Godinho
Weekly hours
5
Total hours
70
Teaching language
Português
Objectives
Concerning the formative aspect this curricular unit aims to provide the students with scientific and technological knowledge on new mesomorphic materials. The students will also be acquainted with new concepts in various branches of knowledge (elasticity, fluid mechanics, crystal defects, phase transitions, and others) and will develop their reasoning ability on an interdisciplinary basis and their skills to create scientific and technological innovation. In the informational aspect the UC aims to acquaint the students with different applications of liquid crystals and the latest technological developments, and future prospects in this field of materials science.
Subject matter
1. Introduction. Technological and biological relevance of liquid crystals (LC) and liquid-crystalline polymers.
2. Classification, molecular organization and optical properties. Degree of order. Textures and defects of orientation (disclinations).
3. Elasticity of curvature. Free energy of deformation. Equilibrium equations.
4. Molecular orientation at the solid-nematic interface. Effects of the surface roughness.
5. Introduction to nematodynamics. Director’s response to applied fields.
6. Electro-optical effects in nematics. Alphanumeric displays and liquid crystal display (LCD). Flexible displays. Digital paper.
7. Polymer-liquid crystal composites (PDLC, PSLC). Controlled transparency windows.
8. Applications of liquid-crystalline polymers in structural materials. Other technological applications of liquid crystals and liquid-crystalline polymers.
Bibliography
A.F. Martins, Os Cristais Líquidos, Fundação Calouste Gulbenkian, Colóquio "Ciências", 7, 253, 1991.
P.J. Collings and M. Hird, Introduction to Liquid Crystals, Taylor & Francis, 1997.
P.G. de Gennes and J. Prost, The Physics of Liquid Crystals, Osford University Press (UK), 2nd, 1993.
P. Oswald, P. Pieranski, Nematic and Cholesteric Liquid Crystals: Concepts and Physical Properties illustrated by Experiments (Liquid Crystals Book Series), Taylor & Francis, 2005.
Evaluation method
The assessment of laboratory work will be done through an individual questionnaire, to be held at the end of the semester. The laboratory classification (NL) will be calculated using the expression:
NL = 0.8 Nq + 0.2 Nc (1)
with
Nq - classification of the questionnaire
Nc - classification of work performed, outside school hours, by the student, in accordance with the requested in the lab protocol
The final note (NF) of the course will be calculated using the expression:
NF = 0:50 NT + 0:40 NL + 0:10 Ni (2)
with
NT - classification of the two tests (average), or of the exam
Ni - mark given by the student''''s participation in class, namely, the number of classes attended and participation during the session itself.
Students may waive examination if they have obtained NF with a minimum of equal or higher than 9.5 val, with a minimum of 8.0 val in each test and with NT equal or higher than 9.0 val.
Students who have not obtained approval in the continuous evaluation may perform an examination provided they have obtained frequency in the discipline, with the frequency given by the weighted average rating of the laboratory, NL, and participation grade, Ni, which must be equal or higher than 9.5 val.