Aggregation of inclusion complexes formed by noncovalent columnar structures based on α- and γ-cyclodextrins and poly(alkylene glycols)

• Published in: Colloid journal of the Russian Academy of Sciences Vol. 71; no. 4; pp. 550 - 558
• Main Authors: Topchieva, I. N., Panova, I. G., Spiridonov, V. V., Matukhina, E. V., Kurganov, B. I.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01-08-2009
• Subjects: Chemistry; Chemistry and Materials Science; Polymer Sciences; Surfaces and Interfaces; Thin Films; Ethylene Oxide; Cyclodextrin; Inclusion Complex; Kinetic Curve; Macrocycle
• ISSN: 1061-933X; 1608-3067
• DOI: 10.1134/S1061933X09040188

Kinetic analysis of the aggregation of complexes formed by columnar types of α- and γ-cyclodextrins (α-CD
col
and γ-CD
col
) and poly(alkylene glycols) is performed by the dynamic light scattering method. For comparison, analogous studies were conducted for systems containing initial α- and γ-cyclodextrins (α-CD and γ-CD). Upon the aggregation of systems containing α-CD, the number of nuclei with critical sizes slowly increases at the initial part of kinetic curve throughout the solution bulk; when some limiting concentration and sizes of formed aggregates are achieved, the system is transformed into the gel-like state. The aggregation of γ-CD
col
-poly(ethylene glycol) system proceeds into two stages. At the first fast stage, aggregates are formed by particles representing single-strand inclusion complexes composed of one γ-CD
col
molecule and two units of ethylene oxide. At the second, much slower stage, aggregates are formed by two-strand complexes composed of one γ-CD
col
molecule and four units of ethylene oxide. It follows from the comparison of aggregative properties of γ-CD
col
-poly(ethylene glycol) and γ-CD
col
-poly(propylene glycol) systems that the rate of aggregation is much higher in the second case.