Nematic liquid crystals have revolutionized the electro-optic display industry because their optical response can be manipulated by an applied electric field and because this response is fast.
To understand the molecular factors that determine this response we have developed a methodology, in conjunction with Professor Sugimura (Osaka), to investigate the director dynamics based on time resolved deuterium NMR spectroscopy. In these experiments the alignment of the nematic is controlled by the magnetic field intrinsic to the spectrometer and an electric field applied across a thin nematic film. This has proved to be a powerful approach and has resulted in a unique tool for exploring the fascinating physics of the alignment process. For example, the macroscopic structure of the nematic can vary from a state of uniform alignment to non-uniform depending on the angle between the aligning field and the initial orientation of the director. In addition, the nature of the aligning field whether just the magnetic field or a combination of electric and magnetic fields also affects the state of director distribution during the alignment process. Such remarkable behaviour is proving to be a challenge to understand and it seems new, unexpected physics is involved relating to thermal fluctuations of the director.