Health & Environmental Research Online (HERO)


Print Feedback Export to File
6604675 
Journal Article 
CHOLESTERIC PITCH OF AQUEOUS HYDROXYPROPYLCELLULOSE IN THE PRESENCE OF SYNTHETIC POLYELECTROLYTES 
Okubo, T; , 
1991 
Yes 
Journal of the Chemical Society. Faraday Transactions
ISSN: 0956-5000 
ROYAL SOC CHEMISTRY 
CAMBRIDGE 
87 
4 
607-609 
English 
WOS:A1991FA72600016 
Cholesteric pitches (D) of mesophases of aqueous hydroxypropyl cellulose (HPC) have been measured by the reflection spectrum method in the presence of simple-and poly-electrolytes. The simple electrolytes used were sodium chloride and sodium sulphate, the polyelectrolytes were sodium poly(ethene sulphonate) (NaPES), sodium poly(styrene sulphonate (NaPSS), polybrene (PB), poly(4-vinyl-N-benzylpyridinium chloride) (BzPVP), and a copolymer of 4-vinyl-N-hexadecylpyridinium bromide and 4-vinyl-N-benzylpyridinium chloride (C16BzPVP). NaCl and Na2SO4 decrease D values, explained by the desolvation effect of the salts upon HPC molecules. Cationic macro-ions also decrease D values, and the strength of the effect is in the order PB > BzPVP > C16BzPVP. This is due to the shrinkage of the HPC helicoid by the association of HPC with the macrocations. On the other hand, anionic polyelectrolytes increase D values in the order NaPSS > NaPES, which is ascribed to the intercalation of the macro-anions into the intra-chain space of the helicoidal HPC by the hydrophobic interaction.