Molla Islam - Unexpected Cononsolvency Behavior of Poly (N-isopropylacrylamide)-Based Microgels.

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      Publication Details (including relevant citation   information): Heppner, Ian N., Islam, Molla R., Serpe,   Michael J., Macromol. Rapid Commun.,   2013, 34 (21), pp 1708-1713

      Abstract: Poly (N-isopropylacrylamide)   (pNIPAm)-based microgels undergo a transition from fully water   swollen (solvated) to deswollen (desolvated) as the temp. of the   water they are dissolved in is increased >32 °C. In this   submission, we examine how the temp. of this transition, i.e.,   the vol. phase transition temp. (VPTT), depends on the concn. of   methanol (MeOH) in water the microgels are dissolved in. To   accomplish this, pNIPAm-based etalons are utilized, and it is   shown that the VPTT for the microgels is much less than that   previously obsd. for linear pNIPAm and pNIPAm-based microgels.   Furthermore, and most interestingly, it is detd. that the   microgels can collapse in solns. contg. high MeOH (>∼65% MeOH)   concn. This is in contrast to previous studies, which show that   no VPTT is obsd. for pNIPAm in aq. solns. contg. >∼65% MeOH.   [on SciFinder(R)]

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