METHOD TO MEASURE ANISOTROPIC COEFFICIENTS OF VISCOSITY OF LIQUID CRYSTALS AND DEVICE FOR ITS REALISATION

摘要

FIELD: measurement equipment.;SUBSTANCE: method to measure anisotropic coefficients of viscosity of liquid crystals, includes a procedure of measured substance pumping from one reservoir to another one under action of excessive pressure via a flat capillary, to the walls of which there are transparent electrodes applied, and aligning layers from a light-sensitive material, which may set for molecules of liquid crystals (LC) serially 3 different orientations relative to direction of the flow, when the light-sensitive material is exposed to actinic linearly polarised light with three directions of the polarisation plane (PP). The fourth orientation of LC required to measure the fourth viscosity coefficient is created by application of electric voltage. When excessive pressure is developed in one of reservoirs, the LC flow arises, slowly dropping exponentially. The LC meniscus height reduction speed is measured related to time under various orientations, the exponential curve is built, the characteristic time of flow is found under one of LC orientations, and using it, one of viscosity coefficients is calculated. For measurements of other viscosity coefficients, light sensitive layers are exposed to light with other PP directions without removal of the LC from the capillary. Again excessive pressure is created, new drop curves are built, new characteristic times are found, and other viscosity coefficients are calculated.;EFFECT: increased accuracy of measurements and reduced consumption of a measured substance.;2 cl, 7 dwg