Dynamic FT-IR spectroscopy of liquid crystals and polymer films

Step-scan and continuous-scan FT-IR methods have been used to investigate the molecular and sub-molecular dynamics of polymer and liquid crystal films in response to synchronously modulated (AC) mechanical and electric fields and to pulsed (DC) electric fields. In these experiments the relative response times of different components in copolymers and blends, and of different parts of the same liquid crystal molecule are inferred from the response times and/or phase lags observed for the characteristic functional group frequencies. The interpretation of the AC data is enhanced by two dimensional frequency correlation analysis (2D FT-IR). Examples illustrated are of the dynamic polymer rheology of the SBS triblock copolymer Kraton™ and of the electroreorientation dynamics of the nematic liquid crystal 5PCH.

Duke Scholars

Author Richard A. Palmer Chemistry