Abstract
We report here the transition phenomenon with unrecognized interpretation thus far; the bulk transition occurs before surface nematic layer is formed in an aerosil-LC system. The high-sensitivity heat-flux differential scanning calorimetry (HS-DSC) and optical retardation have been precisely measured in binary mixtures consisting of rod-like LC 7CB and silica nanoparticle aerosil300. The two heat anomaly peaks are pronounced and two-step retardation change is observed in both the cooling and heating processes. Combining with the macroscopic polarizing microscopy observation, these results allow us to safely conclude that the high- and low-temperature peak appeared in HS-DSC are attributed to the Iso-N transition in the bulk and at the surface, respectively.
