Cononsolvency of poly(carboxybetaine methacrylate) in water–ethanol mixed solvents

Cononsolvency-Induced Microphase Separation of Double Hydrophilic Poly(2-ethyl-2-oxazoline)–Polycarboxybetaine Diblock Copolymers in Water–Ethanol Mixtures

“…PEtOx 39 and PCB2 44 homopolymers were soluble in water and ethanol; however, PCB2 44 exhibited cosolvent-induced aggregation in water−ethanol mixed solvents with specific f EtOH = 0.76−0.96 (Figure S1). 37 Thus, the unique solvent composition-dependent re-entrant aggregation of PEtOx 39 -b-PCB2 53 in water−ethanol mixed solvents is driven by the cononsolvency of PCB2 chains. Considering the aggregation characteristics of PEtOx 39 and PCB2 32 homopolymers, core− shell-type polymer micelles, where PCB2 is the core and PEtOx is the shell, would be produced.…”

“…PCB2 67 was soluble in water and ethanol at a low polymer concentration of 1.0 mg mL −1 (Figure S1). 37 However, PCB2 67 became insoluble as ϕ increased, providing an opaque dispersion in water and a phase-separated viscous fluid in ethanol (Figure 7b). The interface between the upper transparent phase and the bottom fluid became clear at f EtOH = 0.5, while the bottom fluid volume reduced with increasing f EtOH .…”

“…DHBCs with PNIPAM blocks exhibited temperature-responsive aggregation, where the formation of polymer micelles and/or vesicles is controlled by temperature. – In contrast, the molecular assembly of DHBCs controlled by a cosolvent has been reported. – Cononsolvency is an intriguing phenomenon in that polymer chains collapse in a mixture of good solvents with a specific composition range . The cosolvent-induced re-entrant coil-to-globule-to-coil transition has been observed in PNIPAM, , poly­( n -propyl-2-oxazoline), an elastin-like peptide, poly­(2-methacryloyloxyethyl phosphorylcholine) (PMPC), , poly­(2-(( N -2-methacryloyloxyethyl- N,N -dimethyl)­ammonio)­acetate) (PCB2), etc. The molecular mechanism of cononsolvency has been explained by Flory–Huggins ternary solution theory, , water–ethanol complexation, and competitive hydration; however, it has remained controversial.…”

“…27−29 Cononsolvency is an intriguing phenomenon in that polymer chains collapse in a mixture of good solvents with a specific composition range. 30 The cosolvent-induced reentrant coil-to-globule-to-coil transition has been observed in PNIPAM, 31,32 poly(n-propyl-2-oxazoline), 33 an elastin-like peptide, 34 poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), 35,36 poly(2-((N-2-methacryloyloxyethyl-N,Ndimethyl)ammonio)acetate) (PCB2), 37 etc. The molecular mechanism of cononsolvency has been explained by Flory− Huggins ternary solution theory, 38,39 water−ethanol complexation, 40 and competitive hydration; 41 however, it has remained controversial.…”

Solution Properties of Amphiphilic Alternating Copolymers of N-Ethylmaleimide and 2-Hydroxyethyl Vinyl Ether: Thermoresponsiveness in Alcohols and Cosolvency Phenomenon in Binary Ethanol/Water Solutions

“…Another intriguing approach for achieving unique polymer solution properties is the use of binary solvent systems. When the solubility of polymers varies depending on the composition of a mixture of solvents, cononsolvency or cosolvency phenomena can be observed. − Cononsolvency is a phenomenon in which a polymer collapses in a mixture of good solvents due to disruption of solvation in the presence of a cosolvent. − A notable example is poly­( N -isopropylacrylamide), which is insoluble in a binary water/alcohol system at a certain composition, although soluble in each solvent at room temperature. − On the other hand, cosolvency in which the solubility of solutes is improved in a mixed solvent compared to that in the single solvent, is relatively limited in polymer systems. , Poly­(methyl methacrylate) has been investigated as the representative case, exhibiting solubility in a binary ethanol/water system despite being insoluble in either water or ethanol at room temperature. − To the best of our knowledge, other polymers that undergo an insoluble–soluble transition upon mixing with solvents at room temperature are limited to poly­(methyl acrylate), poly­(2-phenyl-2-oxazoline), poly­( N -(6-acetamidopyridin-2-yl)­acrylamide), and chitin propionate . As a broader definition of cosolvency, scarce examples have been reported: a decrease in the insoluble-to-soluble transition temperature in a high temperature range in a binary system; and the increased swelling degree of a polymer gel by mixing solvents. , Since such cononsolvency and cosolvency phenomena are likely to result from the structure formation of the solute polymer and the two solvent molecules, a unique solution property would be observed with amphiphilic alternating copolymers in a binary solvent system (Figure a).…”