Thermoresponsive solubility

Water-soluble thermoresponsive PNIPAM and PMVE blocks have been associated to hydrophobic blocks [140,141], Micelles have been prepared in water in which the hydrophobic core is surrounded by PMVE or PNIPAM... 

On the other hand, poly(AT-isopropylacrylamide), poly(NIPAM), has a lower critical solution temperature (LOST) at 32 °C in water it is water-soluble below LOST but precipitates above LOST. The thermoresponsive... 

Materials that typify thermoresponsive behavior are polyethylene- polyethylene glycol) copolymers that are used to fiinchonalize the surfaces of polyethylene films (smart surfaces). When the copolymer is immersed in water, the poly(elhylene glycol) functionalities at the surfaces have solvation behavior similar to poly(ethylene glycol) itself. The ability to design a smart surface in these cases is based on the observed behavior of inverse temperature-dependent solubility of poly(alkene oxidejs in water. 

Another approach involves the covalent attachment of a metal complex to a (water-) soluble polymer [41]. By using thermoresponsive, smart , polymers the reaction can be performed in a homogeneous liquid phase and, after completion, the polymer-enlarged catalyst can be precipitated by adjusting the temperature [42]. 

Thermoresponsive enhances decomplexation below critical solubility temperature Environmentally sensitive disulfide bonds... 

Arotcarena M, Heise B, Ishaya S, Laschewsky A. 2002. Switching the inside and the outside of aggregates of water soluble block copolymers with double thermoresponsivity. J Am Chem Soc 124 3787 3793. 

Jiang, X., Smith, M. R., Baker, G. L. Water-soluble thermoresponsive polylactides. cromolecul 2007, 41, 318-324. 

Furthermore, polymers such as PDMAEMA combine a weak polybase character with thermoresponsive properties at high pH and low temperatures PDMAEMA is not ionized, but, nevertheless, is soluble in water. An increase in temperature, however, leads to an increase in the hydrophobicity of the monomers and, at T > LCST, the unionized polymers collapse, lose solubility, and precipitate from aqueous solution [47]. 

Finally, the solution behavior of thermoresponsive multiblock copolymers has been reported [50]. Multiblocks of PDMA and PNIPAM with sequences of different molecular weights were studied upon increasing the solution temperature. At elevated temperatures the PDMA block is water soluble, while the PNIPAM block becomes insoluble. Depending on the molecular weight of the sequences, the multiblock copolymer ean adopt imimolecular flower-like micelle conformation or can aggregate through intermoleeular interactions. 

Figure 5.S Water-soluble thermoresponsive polymethacrylates obtained by living anionic polymerization.

Thermoresponsive polymers containing short oligo(ethy-lene glycol) side chains have been proposed as an attractive alternative to PNIPAAm. PEG is an uncharged, water-soluble, nontoxic polymer used to prepare biocompatible materials, such as biosensors and dmg delivery systems.Lutz ... 

As discussed previously, zwitterionic polymers such as poly (sulfobetaine)s have thermoresponsive UCST properties. The water solubility of poly(sulfobetaine) depends on salt concentration. The site-binding ability of the cation and the anion allows polymer chains to preferentially complex the... 

Hybrid hyperbranched stmctures can be prepared, for instance, comprising a hyperbranched portion and also linear arms. Such hyperbranched star structures exhibit properties intermediate to those of well-defined star polymers and neat hyperbranched stmctures. The solubility and self-assembly of these polymers can be modified by changing the chemical composition and size of both the core and arms. For example, stmctures prepared from thermoresponsive arms exhibit... 

LUZ Luzon, M., Boyer, C., Peinado, C., Corrales, T., Whittaker, M., Tao, L., and Davis, T.P., Water-soluble, thermoresponsive, hyperbranched copolymers based on PEG-methacrylates Synthesis, characterization, and LCST behavior, J. Polym. Sci. Part A Polym. Chem., 48, 2783, 2010. 

SU1 Sun, J., Peng, Y., Chen, Y., Liu, Y., Deng, J., Lu, L., and Cai, Y., Effect of molecular stracture on thermoresponsive behaviors of pyrrolidone-based water-soluble polymQt, Macromolecules, 43, 4041, 2010. 

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