1. Conformational study on the thermal transition of chitosan- g-poly( N-vinylcaprolactam) in aqueous solution.
- Author
-
Fernández-Quiroz, Daniel, González-Gómez, Álvaro, Lizardi-Mendoza, Jaime, Vázquez-Lasa, Blanca, Goycoolea, Francisco, San Román, Julio, and Argüelles-Monal, Waldo
- Subjects
- *
CHITOSAN , *CAPROLACTAM , *HEAT transfer , *COPOLYMERS , *AQUEOUS solutions , *IONIC strength - Abstract
Conformational changes of the thermal transitions of chitosan- graft-poly( N-vinylcaprolactam) copolymers in aqueous solution were studied by varying of the length of the grafted poly( N-vinylcaprolactam) (PVCL) chains, as well as the ionic strength and the pH of the solution. The conformational properties of the copolymer were monitored by means of dynamic light scattering and ζ-potential measurements. A series of copolymers with defined molecular architecture were synthesized. Obtained results point out that hydrophobic hydration plays a crucial role on the solubility of this copolymer at neutral and slightly alkaline solutions. The evolution of the size of macromolecular aggregates indicates that, in the coil state, there is a monomodal distribution, passing through a bimodal distribution in the pre-transition region, just before the phase separation. The role of the charge of the copolymers on the cooperative transition is also analyzed. The phase transition of these amphiphilic copolymers shows a strong dependence on the ionic strength of the solution. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF