Undulation textures at the phase transitions of some alkyloxybenzoic acids

TL;DR

This paper reports the observation of undulated textures at phase transitions in certain alkyloxybenzoic acids, revealing new surface phenomena associated with smectic phase changes.

Contribution

It is the first to document undulated textures at phase transitions in 4,n-alkyloxybenzoic acids, including binary mixtures, expanding understanding of surface textures in liquid crystals.

Findings

Undulated textures appear at smectic-isotropic and smectic-nematic transitions.

Binary mixtures exhibit unique fingerprint patterns.

Undulations overlay typical Schlieren textures.

Abstract

We observed undulated smectic textures for some compounds of the 4,n-alkyloxybenzoic (nOBAC) acid series, at transitions between the smectic and the isotropic phase and between the smectic and nematic phase. Studied compounds were 12OBAC, 16OBAC and a binary mixture of 12- and 16OBAC. The undulations are dressing a usual Schlieren texture. In the case of the binary mixture, an interesting fingerprint pattern is observed too.