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RESEARCH PRODUCT
Semicarbazides as gel forming agents for common solvents and liquid crystals
Thomas GeigerDieter SchollmeyerJian Hui YePia DeindörferRudolf Zentelsubject
chemistry.chemical_classificationSemicarbazideSemicarbazidesStereochemistryInfrared spectroscopyGeneral Chemistrychemistry.chemical_compoundDifferential scanning calorimetryAzobenzenechemistryLiquid crystalPolymer chemistryMaterials ChemistryGlass transitionAlkyldescription
This paper describes the synthesis of 14 new gelling agents with semicarbazide groups as H-bonding motifs and alkyl- and/or azobenzene side groups. They gel solvents like decaline, 1,2-dichlorobenzene and toluene and liquid crystalline mixtures. X-Ray structure analysis shows that the semicarbazides are connected by H-bonds, each molecule to four neighbours. As a result a ribbon is formed with a core of H-bonded semicarbazide groups and alkyl chains sticking to the side. IR measurements show an unchanged H-bonding motif in large crystals and in the gel fibres, even in LC-mixture. During heating the gel melts (rheology), while the H-bonding motif of the crystal disappears (IR and DSC measurements). First experiments show that these gel-forming agents can be used to gel LC-phases and to stabilise the director pattern present during gel formation.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2006-01-01 | J. Mater. Chem. |