Cononsolvency of thermoresponsive polymers: where we are now and where we are going

Abstract

Cononsolvency is an intriguing phenomenon where a polymer collapses in a mixture of good solvents. This cosolvent induced modulation of the polymer solubility has been observed in solutions of several...

Co-nonsolvency Transition in Polymer Solutions: A Simulation Study

“…Other qualitative or semianalytical models for co-nonsolvency address aspects of specific systems such as methanol–water mixtures . For a recent review of co-nonsolvency, we refer the reader to ref .…”

Cononsolvency of the responsive polymer poly(N-isopropylacrylamide) in water/methanol mixtures: a dynamic light scattering study of the effect of pressure on the collective dynamics

“…− the preferential adsorption of the cosolvent leads to an overall weaker solvation of the chains [18]. At 130 MPa, the preferential adsorption is less pronounced, causing the temperaturedependences relative to the respective cloud points to become very similar.…”

“…The addition of a cosolvent, e.g., short-chain alcohol such as methanol, was shown to reduce the cloud point and to alter the hydration behavior of the PNIPAM chain in aqueous solution [14][15][16][17][18]. In dilute solution, the chain conformation in water/alcohol (methanol or ethanol) mixtures changes from expanded to collapsed, as cosolvent is added successively to the aqueous PNIPAM solution up to a certain volume fraction, where demixing sets in [19][20][21].…”

Distinctly different solvation behaviors of poly(N,N-diethylacrylamide) gels in water/acetone and water/DMSO mixtures

“…[1][2][3][4] PNIPAM is famous for its cononsolvency phenomenon in a series of binary solvents. 5,6 One of the best characterized examples is in water/ methanol mixtures, [7][8][9][10] where a mixture of two good solvents results in a poor one for PNIPAM at a certain temperature. This phenomenon is normally characterized by the decrease of LCST upon the addition of methanol in the water-rich region.…”

“…6,27 Actually, the preferential cosolvent adsorption was observed widely in cononsolvency systems, especially in PNIPAM-wateradditive ternary systems via both experiments and molecular dynamics simulation. 8,10,[28][29][30][31][32][33][34][35][36][37][38][39] Based on the widely existing preferential cosolvent adsorption, Mukherji et al 40 attempted to interpret the cononsolvency phenomenon in a universal way irrespective of specific intermolecular interactions, declaring that polymer collapse in miscible good solvents is a generic phenomenon driven by preferential adsorption. Unfortunately, this universality was denied by both theoretical and experimental research, for example, the preferential methanol adsorption on PDEA does not induce the cononsolvency phenomenon, and the cononsolvency effect occurred in water/DMSO mixtures but DMSO was preferentially excluded out of the PNIPAM network.…”