Stabilization of blue phases by solvent effect using n-octadecane with a simple linear molecular structure

¹ Department of Physics, Graduate School of Science, Kyoto University - Kitashirakawa, Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
² Department of Physics, Kyoto Prefectural University of Medicine - 1-5, Shimogamohangi-cho, Sakyo, Kyoto 606-0823, Japan
³ Japan Science and Technology Agency, CREST - 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan

Received: 5 October 2025
Accepted: 23 January 2026

Abstract

We investigated how mixing a n-octadecane with a simple linear molecular structure affects the stability of a liquid-crystalline blue phase (BP). It was found that the addition of the solvent reduces the appearance temperature of the BPs and expands the temperature range over which the BPs are seen. From our measurement, we confirmed that the solvent molecules were dispersed uniformly throughout the liquid-crystal phase. Also, we found that the solvent molecules reduce the splay and bend elastic constants K₁ and K₃, as well as the ratio K₃/K₁. We propose that the reduction of K₃/K₁ by mixing solvent molecules contributes to the stabilization of the BPs, in agreement with existing theoretical predictions.