Linear and nonlinear viscoelasticity of concentrated thermoresponsive microgel suspensions

Role of Charge Content in the Two-Step Deswelling of Poly(N-isopropylacrylamide)-Based Microgels

“…In fact, although the effective potential for swollen microgels can be described as a soft repulsion, 74 at high temperatures both hydrophobic and electrostatic interactions should become important. 75,76 Therefore, it will be necessary to appropriately assess their relative contribution to the collective and rheological behavior of dense microgel suspensions. Last but not least, polyelectrolyte and/or nanoparticle adsorption onto soft colloids, such as microgels, is very often determined by electrostatic forces that are closely related to the swelling state of the adsorbing substrate.…”

“…Finally, the outcomes of this work are relevant for future investigations of the collective behavior and dynamics of PNIPAm-based microgels, especially at high temperatures and for near-critical conditions, where numerical/theoretical works are still lacking. In fact, although the effective potential for swollen microgels can be described as a soft repulsion, at high temperatures both hydrophobic and electrostatic interactions should become important. , Therefore, it will be necessary to appropriately assess their relative contribution to the collective and rheological behavior of dense microgel suspensions. Last but not least, polyelectrolyte and/or nanoparticle adsorption onto soft colloids, such as microgels, is very often determined by electrostatic forces that are closely related to the swelling state of the adsorbing substrate. , Understanding how randomly distributed charges and the enhanced two-step deswelling influence the adsorption of oppositely charged objects onto soft ionic microgels represents another important open question having potential important implications in applications such as water-remediation protocols and sensors.…”

The role of charge content in the two-step deswelling of Poly(N-isopropylacrylamide)-based microgels

“…Finally, the outcomes of this work are relevant for future investigations of the collective behavior and dynamics of PNIPAm-based microgels, especially at high temperatures and for near-critical conditions, where numerical/theoretical works are still lacking. In fact, though the effective potential for swollen microgels can be described as a soft repulsion, 68 at high temperatures both hydrophobic and electrostatic interactions should become important 69,70 . It will be therefore necessary to appropriately assess their relative contribution to the collective and rheological behavior of dense microgel suspensions.…”

Stress-independent delay time in yielding of dilute colloidal gels

“…[28][29][30] The aqueous suspensions at high T above the VPT can undergo colloidal gelation even at extremely low particle concentrations, while the gelation requires a balance of the short-range hydrophobic attraction and the electrostatic repulsion. [31][32][33][34][35][36][37][38][39][40] Strong short-range attraction results in a complete phase separation of the microgel aggregates and the water-rich phase. When the short-range attraction is considerably screened by the electrostatic repulsion, the microgel dispersion is stabilized.…”