Topic 13: Liquid Crystalline Systems

Question 1

describe liquid crystals

Answer 1

they are mesomorphous meaning between liquid and solid

Question 2

What are the phases of liquid crystals based on their optical properties?

Answer 2

Thermotropic and lyotropic

Question 3

What does thermotropic mean?

Answer 3

the order of components is determined by temperature

Question 4

What are the phases of thermotropic molecules?

Answer 4

nematic, smectic and cholesteric. nematic means no positional order but point in same direction (some order), smectic means aligned in layers or planes in addition to nematic alignment (more solid than nematic), cholesteric (chiral nematic) means molecules are aligned with slight angles between each other eventually making a full rotation

Question 5

What does lyotropic mean?

Answer 5

contains immiscible molecules with hydrophobic and hydrophillic properties, has order of liquid crystal when solvent is added to it

Question 6

Liposome describes the tendancy for the lipid bilayer to form a _____

Answer 6

sphere

Question 7

lamellar structure describes the tendency for lipids to form a __________

Answer 7

bilayer