An interesting transition is the texture transition inside the nematic phase. We observe in some liquid crystalline compounds a transition from a low-temperature nematic texture which looks like a texture of a smectic phase to a high temperature nematic Schlieren texture. Compounds that have the texture transition are the alkyloxybenzoic acids. Here, you can see a movie of the texture transtion inside the nematic phase of 6OBAC. The sample is heated from the crystal phase. We can see the smectic pahse and then the two following nematic subphases. Click on the image to see the movie.
More details in my papers:
Texture transitions in binary mixtures of 6OBAC with compounds of its homologous series A. Sparavigna; A. Mello; B. Montrucchio Phase Transitions: A Multinational Journal, 1029-0338 Volume 80, Issue 3, 2007, Pages 191 – 201 Abstract | |
Texture transitions in the liquid crystalline alkyloxybenzoic acid 6OBAC A. Sparavigna; A. Mello; B. Montrucchio Phase Transitions: A Multinational Journal, 1029-0338 Volume 79, Issue 4, 2006, Pages 293 – 303 Abstract | |
A new image processing method for enhancing the detection sensitivity of smooth transitions in liquid crystals Liquid Crystals, 1366-5855, Volume 24, Issue 6, 2001, Pages 841 – 852 Abstract | |
A novel order transition inside the nematic phase of trans -4-hexylcyclohexane-1-carboxylic acid discovered by image processing Liquid Crystals, 1366-5855, Volume 25, Issue 5, 2001, Pages 613 – 620 Abstract | |
In the following, three movies show a transition on cooling from the nematic to the smectic phase of an oxadiazole compound. We see a transition from the nemtic to a smectic phase with toric domains.
Clink on images to launch the movies.
For more details, these are my articles: | |
Growth of toric domains in mesophases of oxadiazoles A. Sparavigna; A. Mello; B. Montrucchio Phase Transitions: A Multinational Journal 1029-0338, Volume 81, Issue 5, 2008, Pages 471 – 477 Abstract | |
Fan-shaped, toric and spherulitic textures of mesomorphic oxadiazoles A. Sparavigna; A. Mello; B. Montrucchio Phase Transitions: A Multinational Journal 1029-0338, Volume 80, Issue 9, 2007, Pages 987 – 998 Abstract |
Amelia Carolina Sparavigna
