SAMMON, C., LI, C., ARMES, S. P. and LEWIS, A. L. (2006). ATR-FTIR studies of a thermo-responsive ABA triblock copolymer gelator in aquaeous solution. Polymer, 47.Full text not available from this repository.
A variable temperature ATR–FTIR study of the gelation behaviour of a thermo-responsive ABA triblock copolymer (A = poly(N-isopropylacrylamide) and B = poly[2-(methacryloyloxy)ethyl phosphorylcholine]) is reported. Close inspection of selected copolymer and water bands in the temperature resolved spectra provides evidence for the dehydration of the poly(N-isopropylacrylamide) chains above a critical gelation temperature of approximately 37 °C, while the central poly[2-(methacryoyloxy)ethyl phosphorylcholine]) chains remain hydrated. A blue shift in the amide I peak and a red shift in the amide II band indicate a reduction in the hydrogen bonding between the PNIPAM amide functional group and the solvent water. This is corroborated by a decrease in the intensity of the amide I peak above the gel point. Evidence of hydrophobic interactions and an indication of the source of the gelation mechanism were observed in the form of a red shift in the antisymmetric CH vibration with increasing temperature. These findings are consistent with the formation of a micellar gel network by the copolymer chains.
|Additional Information:||Copyright © Elsevier Ltd|
|Research Institute, Centre or Group:||Materials and Engineering Research Institute > Polymers Nanocomposites and Modelling Research Centre > Polymers, Composites and Spectroscopy Group|
|Depositing User:||Ann Betterton|
|Date Deposited:||30 Jul 2008|
|Last Modified:||09 Aug 2010 13:10|
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