Effect of Temperature and Alkyl Chain Length on the Micellar Properties of n-Alkyltrimethylammonium Bromides in a Low pH Medium

1995 ◽  
Vol 172 (1) ◽  
pp. 137-141 ◽  
Author(s):  
J.M. del Rio ◽  
C. Pombo ◽  
G. Prieto ◽  
V. Mosquera ◽  
F. Sarmiento
Keyword(s):  
Chain Length ◽  
Alkyl Chain ◽  
Low Ph ◽  
Alkyl Chain Length ◽  
Effect Of Temperature ◽  
Micellar Properties ◽  
Alkyltrimethylammonium Bromides

Untersuchungen der elektrischen Leitfähigkeit homologer 4,4′-Di-n-alkyloxy-azoxybenzole im nematischen Phasenbereich / Investigation of the Electric Conductivity of Homologous 4,4′-Di-n-alkoxyazoxybenzenes in their Nematic Phase

1975 ◽  
Vol 30 (3) ◽  
pp. 316-322 ◽  
Author(s):  
G. Heppke ◽  
F. Schneider
Keyword(s):  
Electric Conductivity ◽  
Chain Length ◽  
Nematic Phase ◽  
Alkyl Chain ◽  
Electrolyte Concentration ◽  
Alkyl Chain Length ◽  
Effect Of Temperature ◽  
Alkyl Chains ◽  
Long Chains

The effect of temperature and concentration of the added electrolyte tetrabutylammoniumpicrate on the electric conductivity of homologous 4,4′-di-n-alkoxyazoxybenzenes (C1 to C8) in their nematic phase is investigated. In general an increase of the alkyl chain length results in a decrease of the ratio of anisotropy x∥/x⊥. At the lowest temperature of the nematic phase values between 1,6 (C2) and 0,45 (C8) are obtained. This behaviour can be explained by the formation of cybotactic groups with a smectic structure. Increasing the electrolyte concentration reduces the ratio of anisotropy for short alkyl chains, whereas for long chains the ratio rapidly increases.

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