Effects on molecular orientation and phase transition of addition of carbon nanotubes into liquid crystalline matrix


Akman A., Akkurt F., Alicilar A.

Liquid Crystals, cilt.41, sa.4, ss.603-609, 2014 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 41 Sayı: 4
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1080/02678292.2013.868054
  • Dergi Adı: Liquid Crystals
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.603-609
  • Anahtar Kelimeler: order parameter, dichroic ratio, azo dye, guest-host systems, nanotube, nematic liquid crystal, BENZANTHRONE DYES, FLUORESCENT DYES, DICHROIC DYE, ALIGNMENT
  • Gazi Üniversitesi Adresli: Evet

Özet

For practical guest-host applications, it is important to choose dyes with a high ability of orientation in the liquid crystal (LC) matrix. In this experimental work, two different azo-structured dyes (disperse yellow 3 and 7) were separately doped to each of two different nematic LCs (E7 and ZLI-1132). Their solubilities, textures, phase transition temperatures and order parameters were determined. At the second stage, single-walled carbon nanotubes (SWCNTs) in a small amount were separately added to each of these solutions, and the experiments were repeated as similar to the previous ones. The solubilities of dyes in the LC E7 were lower than those of ZLI-1132. Moreover, the highest order parameter value was attained with yellow 7 dye in ZLI-1132 nematic host. Co-use of nanoparticles (CNTs) as dopant resulted in notable increases in order parameters. These dyes and CNTs did not significantly destabilise the mesomorphic phase of nematic hosts. An appreciable change in textures was not monitored with addition of dopant(s). In addition, it was observed that the narrowing on the temperature range of the LC did not take place with the addition of dopants to the crystal; on the contrary, an increase was recorded. © 2013 © 2013 Taylor & Francis.