Funct. Mater. 2026; 33 (2): 275-281.

A composite nematic-cholesteric liquid crystal (LC) system based on a eutectic mixture of saturated cholesterol esters designated as M29 and a non-aromatic hydrogen bond-formed nematic trans-4-butylcyclohexanecarboxylic acid (4CHCA) was studied in various DSC, optical spectroscopy and microscopic experiments. In a wide concentration range, the helical pitch vs. concentration and temperature were recorded. The general behavior was similar to classical systems with cholesteryl chloride, with the difference that the helical twisting was controlled not by the opposite twisting signs, but by the effect of specific steric interaction. An interesting feature of the system studied was the formation of the blue phase (BP) close to the isotropic transition, with the selective reflection spectra in the alleged BP region in a qualitative conformity with the Oton model for the blue phase. The fully non-aromatic character of the LC crystal mixture suggested its possible biomedical applications, with toxicity problems of cyanobiphenyl-based systems removed, and specific tuning for the physiological temperatures readily obtained in the concentration range studied.