ISSN:
1572-8900
Keywords:
Levan
;
liquid crystal
;
nematic
;
polysaccharide
;
starch
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Energy, Environment Protection, Nuclear Power Engineering
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Transmitted light measurements performed with a UV-visible spectrophotometer were used to characterize how starch affects the position of boundaries on the phase diagram for dilute aqueous solutions of levan (a branched polymer of fructose). Data were collected in the range 15 to 70°C; the minimum concentrations required for separation of a nematic phase and the minimum concentration required for a fully nematic solution were identified within this range. While “hard” interactions (repulsion between rod-like molecular segments) dictate the formation of a liquid crystalline phase at and above ambient temperature in the absence of starch, “soft” interactions become more significant as solutions are cooled toward ambient when starch is present. Small amounts of starch might be used as a filler to modify the mechanical properties (while retaining the process-related benefits) of levan films cast from liquid crystalline solution.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02067445
Permalink