Direct deposition of chitosan macromolecules on a substrate from solutions in supercritical carbon dioxide: Solubility and conformational analysis

• Published in: European polymer journal 2012-05, Vol.48 (5), p.906-918
• Main Authors: Chaschin, Ivan S., Grigorev, Timofei E., Gallyamov, Marat O., Khokhlov, Alexei R.
• Format: Article
• Language: English
• Subjects: Atomic force microscopy; Chitosan macromolecules; Deposition; Solubility; Substrate; Supercritical carbon dioxide
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2012.03.003

[Display omitted] ► Isolated chitosan chains are deposited from solutions in SC CO2 on a substrate. ► Macromolecular conformation is revealed using atomic force microscopy. ► Good mechanical properties of the coatings as deposited from SC CO2 are expected. ► Solubility of chitosan materials in SC CO2 is roughly estimated. Chitosan and its derivatives are promising materials for coating medical devices because this procedure improves their bio- and haemocompatibility. It is known that supercritical carbon dioxide attracts significant scientific interest in biomedical applications as well. Coatings deposited directly from solutions in supercritical carbon dioxide are expected to have particularly smooth and uniform morphology that should enhance their stability. We have tested the possibility of obtaining chitosan films using direct deposition from solutions in this fluid. In order to reveal benefits of this approach we modelled and studied the initial stage of formation of chitosan coatings with prototype system of depositing pioneer single polymer chains directly from such solutions on a model ultrasmooth mica substrate. We estimated achievable solubility of the chitosan materials in supercritical carbon dioxide and performed conformational analysis of the deposited chitosan chains on a substrate. AFM imaging directly demonstrated that the pioneer macromolecules adsorb as rather extended 2D coils from such solutions.