Experimental techniques

Abstract

Abstract In this chapter we discuss some of the most employed experimental techniques in the study of the properties of lyotropic liquid crystals. We start with Polarized Optical Microscopy that is, probably, the one firstly used to observe the outstanding optical properties of these materials. Laser Conoscopy is used to precisely measure optical birefringences and the nature of phase transitions in nematic lyotropic liquid crystals. Differential Scanning Calorimetry is employed to investigate thermal behaviour of the different mesophases and phase transitions. X-ray and neutron diffraction and scattering techniques are employed to study structure and molecular nanosegregation in the basic units of the mesophases. Nuclear Magnetic Resonance is a powerful and complementary tool to investigate molecular structure and dynamics in these materials. Finally, Cryogenic Transmission Electron Microscopy for direct imaging is a technique that allows the observation of the specimen thermally fixed in its natural state.