Figure 1

Graphical overview of the characteristics and current utilization of CNC chiral nematic phases with helical nanorod arrangement. (a) Shows the formation of a chiral nematic liquid crystal phase and its coexistence with an isotropic phase in a CNC suspension of 5 wt% (upper image). The helical arrangement of the nanorods is illustrated schematically next to a scanning electron microscopy image of an actual CNC helix (reproduced with permission from Majoinen et al.,²⁹ Copyright © 2012, Springer). Currently explored utilization schemes are exemplified by (b) the iridescence revealing the photonic crystal character of the film (reproduced with permission from Zhang et al.,¹⁵ Copyright © 2012, SPIE) and (c) templating of the CNC-derived helical structure into inorganic materials (here, titanium dioxide) (reproduced with permission from Shopsowitz et al.⁸⁴ Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).