One of the best ways to learn the art of texture analysis is to look at known materials. Over the past few days, I've been revisiting some venerable mesogens: the azoxybenzenes. Today, I'll share some photos of the bis(hexyloxy)azoxybenzene (right).
This mesogen forms only a nematic phase; you'll note the similarity between the textures shown here and those of PCH-5 from a previous post.
These patterns are known as schlieren textures:
These textures were all obtained on untreated glass substrates. Occasionally, you also find some more unusual schlieren textures, like the one to the right.