Structural changes in liquid crystals doped with functionalized carbon nanotubes

• Published in: Physica. E, Low-dimensional systems & nanostructures Low-dimensional systems & nanostructures, 2018-09, Vol.103, p.53-59
• Main Authors: Bury, Peter, Veveričík, Marek, Kopčanský, Peter, Timko, Milan, Mitróová, Zuzana
• Format: Article
• Language: English
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2018.05.008

Structural changes induced by electric and weak magnetic fields in the nematic liquid crystal (6CHBT) doped with low concentration (1 × 10−3, 1 × 10−4, 1 × 10−5) of carbon nanotubes, including single-walled (SWCNT), multi-walled (MWCNT) and functionalized with Fe3O4 nanoparticles are investigated using surface acoustic waves (SAW) and magneto-optical effect. The role of temperature, concentration and functionalization on structural changes under applied electric and weak magnetic fields is investigated using measurements of the response of both SAW attenuation and light transmission. The obtained results that manifest an effective orientational coupling between electric and magnetic moments of carbon nanotubes and the LC director are compared and the effect of their functionalization by magnetic nanoparticles (SWCN/Fe3O4, MWCNT/Fe3O4) on their behavior is determined. •Structural changes induced by electric and weak magnetic fields in the nematic liquid crystal (6CHBT) doped with low concentration (1 × 10−3, 1 × 10−4, 1 × 10−5) of carbon nanotubes, including single-walled (SWCNT), multi-walled (MWCNT) and functionalized with Fe3O4 nanoparticles (SWCN/Fe3O4, MWCNT/Fe3O4) are investigated using surface acoustic waves (SAW) and magneto-optical effect. The role of temperature, concentration and functionalization on structural changes under applied electric and weak magnetic fields is investigated using measurements of the response of both SAW attenuation and light transmission.•Obtained results that manifest an effective orientational coupling between electric and magnetic moments of carbon nanotubes and the LC director are compared and the effect of their functionalization by magnetic nanoparticles on their behavior is determined. Results significantly pointed out also the role of both concentration and functionalization on the structural changes under external fields. The investigation of the switching processes validated that the orientation of the liquid crystal molecules at some distance from the surface depends on the strength of the applied external fields and the progress of switching processes is then the strong function of applied field intensities.•The functionalization of CNTs with Fe3O4 nanoparticles, however, leads to the different behavior of SWCNT/Fe3O4 and MWCNT/Fe3O4, respectively, under applied fields which means that, despite of the increasing anchoring energy, their responses are different. While in the case of MWCNTs their functionalizatio