Physical alginate hydrogels based on hydrophobic and ionic interactions : bead formation, structure and stability - Archive ouverte HAL
Article Dans Une Revue Journal of Colloid and Interface Science Année : 2004

Physical alginate hydrogels based on hydrophobic and ionic interactions : bead formation, structure and stability

Résumé

Hydrophobically associating alginate (AA) derivatives were prepared by covalent fixation of dodecyl or octadecyl chains onto the polysaccharide backbone (AA-C12/AA-C18). In semidilute solution, intermolecular hydrophobic interactions result in the formation of physical hydrogels, the physicochemical properties of which can be controlled through polymer concentration, hydrophobic chain content, and nonchaotropic salts such as sodium chloride. The mechanical properties of these hydrogels can then be reinforced by the addition of calcium chloride. The combination of both calcium bridges and intermolecular hydrophobic interactions leads to a decrease in the swelling ratio accompanied by an increase of elastic and viscous moduli. Beads made of hydrophobically modified alginate were obtained by dropping an aqueous solution of alginate derivative into a NaCl/CaCl2 solution. As compared to unmodified alginate beads, modified alginate particles proved to be stable in the presence of nongelling cations or calcium-sequestering agents. However, evidence is presented for a more heterogeneous structure than that of plain calcium alginate hydrogels with, in particular, an increase in the effective gel mesh size, as determined by partition and diffusion coefficient measurements.

Dates et versions

hal-00077501 , version 1 (31-05-2006)

Identifiants

Citer

M. Rastello de Boisseson, Michèle Leonard, Patrick Hubert, Philippe Marchal, A. Stequert, et al.. Physical alginate hydrogels based on hydrophobic and ionic interactions : bead formation, structure and stability. Journal of Colloid and Interface Science, 2004, 271 (1), pp.131-139. ⟨10.1016/j.jcis.2003.12.064⟩. ⟨hal-00077501⟩
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