Different factors affecting formation of blue phases

The effect of different factors (chirality, pretransition phenomena, surfac e conditions, and external electric field) on the polymorphism and the opti cal characteristics of blue phases (BP) has been studied. It is shown that at low concentrations of the chiral component of many systems with induced chirality, the formation of BP I and BP II phases is preceded by the format ion of amorphous blue phase BP A. It is assumed that this phase is incomple tely formed BP I. Phase BP III seems to be characterized by a disordered cu bic structure. There are indications to an important role played by surface forces in the formation of supercooled blue phase, BP S.