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Keywords:

  • Columnar phase;
  • Self-assembly;
  • Ionic conductivity;
  • Liquid crystal;
  • Hemi-phasmid;
  • Crown ether Poly(ethy1ene oxide)

Abstract

Molecular packing and electrical conductivity were studied in complexes of alkali trifluoromethanesulphonates with low-molar or polymeric compounds containing both taper-shaped mesogens were esters of either 3,4,5-tris [p-(n-dodecan-l-yloxy) benzyloxy] benzoic acid (I) or 3, 4, 5-tris (n-dodecan-l-yloxy) benzoic acid (II). In the hexagonal columnar liquid crystal phase the tapered mesogens fan out from the centre of the column, with the ionic receptors forming the central channel and the aliphatic tails constituting the continuum matrix. In the case of side-chain polymethacrylates the column core also contains the backbone chain. The DC conductivity σ of unoriented samples increases greatly at the crystal-columnar transition, with only a minor further change upon columnar-isotropic transition. σ was in the range 10−9 − 10−6 in the columnar phase 40–90 °C, whilst the activation energies for conduction were between 28 kcal mol−1 for the crown ether and only 2 kcal mo−1 for the complex of LiCf3SO3 with the non-polymeric ester of tri(ethylene oxide) with I.