Syntheses, Characterisation And Mesophase Investigation Of A New Class Of Hydrazine-Based Liquid Crystal Dimers
| dc.contributor.author | Abd Rani, Umairah | |
| dc.date.accessioned | 2017-02-10T01:57:24Z | |
| dc.date.available | 2017-02-10T01:57:24Z | |
| dc.date.issued | 2016-02 | |
| dc.description.abstract | Four new series of non-symmetric dibenzylidenehydrazine-based liquid crystal dimers, N-{4[10-(16-decyloxyphenylimino)methyl)phenoxy] alkyloxybenzy lidene}-N'-(4'-decyloxybenzylidene)hydrazines (SB-(CH2)n-HZ), N-{4[10-(16-decyl oxyphenyldiazenyl)phenoxy]alkyloxybenzylidene}-N'-(4'-decyloxybenzylidene) hyd razines (AZ-(CH2)n-HZ), N-[4-{12-[18-((S)-(-)-23-methylbutyloxy)carbonylphenyl] phenoxy} alkyloxybenzylidene]-N'-(4'-decyloxybenzylidene) hydrazines (BP-(CH2)n -HZ) and N-(4-alkylxybenzylidene)-N'-[4'-(cholesteryloxycarbonyl)alkyloxybenzylid ene]hydrazines (Chol-(CH2)m-HZ-(CH2)n) had been synthesised and characterised. All dimers incorporated dibenzylidenehydrazine as one of the mesogenic arms and differ in terms of the other side arms and spacer parity. The molecular structures of these dimers were elucidated by CHN, FT-IR, 1D and 2D-NMR spectroscopy. Their liquid crystalline properties were investigated using POM, DSC and XRD. Phase behavior of the dimers was structure and spacer parity dependent. Various mesophases including nematic (N), cholesteric (N*), smectic A (SmA), chiral smectic A (SmA*), smectic C (SmC), chiral smectic C (SmC*) and smectic J (SmJ) were observed when one of the mesogenic side arms was changed. A pronounced odd-even effect in transitional properties (melting and clearing temperatures as well as entropy changes) were seen in SB-(CH2)n-HZ, AZ-(CH2)n-HZ and BP-(CH2)n- HZ upon varying the spacer length. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/3700 | |
| dc.language.iso | en | en_US |
| dc.publisher | Universiti Sains Malaysia | en_US |
| dc.subject | Liquid crystals dimers | en_US |
| dc.title | Syntheses, Characterisation And Mesophase Investigation Of A New Class Of Hydrazine-Based Liquid Crystal Dimers | en_US |
| dc.type | Thesis | en_US |
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