2004-10-25 8CB Layers at Different Temperature

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8CB Layers at Different Temperature

“Formation of Liquid Crystalline Phases from a Langmuir Monolayer”

By K.A. Suresh and A. Bhattacharyya

Langmuir 1997, 13, 1377-1380

2004-10-25 8CB Layers at Different Temperature

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Phase Transition of 8CB in Bulk (3D)

Crystal

20.5 oC

Smectic A

33.3 oC

Nematic

41.5 oC

Isotropic

Temperature

2004-10-25 8CB Layers at Different Temperature

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Typical Isotherm at 25 oC

(T < 28 oC)

2004-10-25 8CB Layers at Different Temperature

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Isotherm at 30 oC

(28 oC < T < 36 oC)

2004-10-25 8CB Layers at Different Temperature

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Isotherm at 40 oC

(36 oC < T < 36 oC)

2004-10-25 8CB Layers at Different Temperature

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Images under Fluorescence Microscope

25 oC 30 oC

Area/Molecule = 10 A2

1~40 um

2004-10-25 8CB Layers at Different Temperature

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Images under Reflection Microscope

25 oC 30 oC ~28 oC

Area/Molecule = 10 A2 Thickness = Nλ/(2n)

2004-10-25 8CB Layers at Different Temperature

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Images under Polarized Microscope

30 oC, 10 A2 A/M

Nematic PhaseSchlieren Textures

Boojum-like Textures

2004-10-25 8CB Layers at Different Temperature

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