Influence of a long-chain alkane on the photoinduced nematic-isotropic transition

• We investigated the phenomenon of photoinduced nematic-isotropic (N-I) transition for different concentrations of a long-chain alkane, viz., octadecane ~OD!, and a host liquid crystalline material having a small quantity ~4.5 mol%! of a photoactive azo compound. As expected, the N-I transition temperature diminishes with increasing concentration of OD. Data of time-resolved measurements of the dielectric constant through both the UV-activated trans-cis transformation and the thermal back relaxation process are presented. With increasing concentration of OD, although the response time for the former process increases slightly by less than a factor of 2, the thermal back relaxation shows a greater increase by more than an order of magnitude. As a possible explanation for this surprising result, we discuss an argument based on the structural incompatibility of the constituents of the system investigated.

Ämnesord

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Nyckelord

photoinduced

nematic

isotropic

alkane

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)