Activation Energy for Dissociation of Hydrogen-Bonding Crosslinkers in Phase-Change Salogels: Dynamic Light Scattering versus Rheological Studies Academic Article uri icon

abstract

  • AbstractDissociation energy of dynamic bonds in thermoresponsive phasechange salogels is explored using rheology and dynamic light scattering (DLS). The salogels are formed by polyvinyl alcohol (PVA) reversibly crosslinked by hydrogenbonding amineterminated molecules in an inorganic phasechange materiallithium nitrate trihydrate (LNH) saltas a solvent. The crosslinker geometry (linear vs branched) has a strong effect on both the gelation temperature (Tgel) and the crosslinker to polymer ratio at which the gelation occurs. Due to their higher functionality, dendritic crosslinkers are more efficient gelators as compared to their linear counterparts, inducing PVA gelation at a lower concentration of a crosslinker and resulting in salogels with higher Tgel. Both stress relaxation and DLS data can be fitted by the exponential functions with temperatureindependent exponents of 0.5 and 2, respectively. For the first time, it is reported that the crosslinker dissociation activation energy determined from the rheological stress relaxation time and DLS slow mode decay time are in very good agreement, comprising 130140 kJ mol1 for salogels with both linear and dendritic crosslinkers.

published proceedings

  • MACROMOLECULAR CHEMISTRY AND PHYSICS

altmetric score

  • 1.6

author list (cited authors)

  • Karimineghlani, P., & Sukhishvili, S. A.

citation count

  • 3

complete list of authors

  • Karimineghlani, Parvin||Sukhishvili, Svetlana A

publication date

  • November 2019

publisher