Water-Insoluble Complexes of Poly(L-Lysine) with Mixed Alkyl Sulfates: Composition-Controlled Solid State Structures
Abstract
Structures of the water-insoluble complexes of poly(L-lysine) with octyl and octadedecyl sulfates, and with the mixtures of these surfactants, were examined via X-ray diffraction, infrared spectroscopy, and differential scanning calorimetry. The solid-state structures of the complexes were shown to be governed by their compositions. In the stoichiometric poly(L-lysine) complex with octadecyl sulfate, surfactant chains crystallize on a hexagonal lattice. In the poly(L-lysine)−octyl sulfate complex of nearly stoichiometric composition, the surfactants are arranged on an alkane-type two-dimensional lattice. In the complex with 20 mol % octadecyl sulfate and about 75 mol % octyl sulfate, the longer surfactant chains form hexagonal crystalline blocks, and the shorter chains are arranged on an alkane-type two-dimensional lattice. In the poly(l-lysine) complex with 10 mol % octadecyl sulfate and about 85 mol % octyl sulfate, all surfactant chains are arranged on a two-dimensional alkane-type lattice. All complexes are organized in lamellar structures consisting of layers of poly(L-lysine) chains in β-sheet conformations, separated by layers of surfactants. Complexes with crystalline and partially crystalline surfactants adopt lamellar structures with identical long periods and with interdigitated octadecyl chains. Complexes with two-dimensional order in the surfactant arrangement also adopt lamellar structures with identical long periods and with octyl chains packed tail to tail.
Additional Information
Copyright © 1998 American Chemical Society. Received September 19, 1997; Revised Manuscript Received January 2, 1998. Publication Date (Web): February 20, 1998.Additional details
- Eprint ID
- 53437
- DOI
- 10.1021/ma971388u
- Resolver ID
- CaltechAUTHORS:PONm1998
- Created
-
2015-02-01Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field