INVESTIGATION OF SURFACE ANCHORING IN MESOPHASE PITCH BY IN SITU AND EX SITU OPTICAL MICROSCOPY

摘要

Surface anchoring, or preferred molecular surface orientation, is a key property of liquid crystalline systems such as mesophase pitch. The anchoring direction can determine the ultimate graphene layer orientations at interfaces (such as in carbon matrix composites), or at the external surface (gas interface) or at the inner surface of solidified bubble cavities. It also determines the proper boundary condition for mesophase flow problems, such as those that describe fiber spinning. While anchoring angles have been measured for many conventional liquid crystals in contact with a variety of technologically important surfaces, there has been little systematic study of mesophase pitch.