Temperature induced formation of strong gels of acrylamide-based polyelectrolyte

• Very strong physical gels have been formed by moderate temperature increases in aqueous dispersions of acrylamide-based beads and dissolved polymeric molecules. Rheometry, confocal laser scanning microscopy,  and differential scanning calorimetric studies of acrylamide-based copolymers with acrylic acid, [Poly(AM-co-AA)], and 2-acrylamido-2-methylpropane acid, [Poly(AM-co-NaAMPS)], suggest that the temperature induced swelling of the polymer beads and chains, create strongly entangled polymer networks, above the upper critical solution temperature. Analyses of the viscoelastic response showed that the time-scale for the gelation process is about minutes to hours. The addition of high concentrations of Ca2+ resulted in a significant decrease in the gel strength

Keyword

polyelectrolyte

UCST

rheology

storage modulus

salt stability

gelation

Publication and Content Type

ref (subject category)

art (subject category)