| Summary: | Electrohydrodinamic (EHD) effects of nematic liquid crystal MBBA (4�-
methoxy-benzylidene-4-butyl-aniline) homeotropic sample with different thickness 50
μm and 100 μm have been observed. EHD could be observed by polarizing
microscope connected to CCD camera. Liquid crystal gave an active respond in the
applied electric field. Various convection patterns were considered. Stripe periodic
pattern called Williams Domain (WD) with stripe direction perpendicular to the initial
unperturbed orientation of director n was appeared at VWD. An unstable pattern called
Fluctuating Williams Domain (FWD) appeared at VFWD>VWD. Another typical pattern
which was more stationer than FWD was formed at VGP>VFWD. Critical voltage, VWD,
VFWD and VGP, for sample 1 and sample 2, had the same values. The thickness did not
affect critical voltage. It affected the stripe line width in patterns. Phase diagram was
showed in frequency-voltage plane. Increasing frequency caused increasing critical
voltage but the relation was not linear
|
|---|