Effect of comonomer ratio and ionic strength on the thermo-induced conformational changes in N-isopropylacrylamide based copolymers: An ATR-FTIR spectroscopic study
作者： Mihaela Avadanei , Ovidiu Avadanei , Gheorghe Fundueanu
DOI: 10.1016/J.VIBSPEC.2012.03.001
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摘要: Abstract The phase transition behavior of thermo-sensitive linear copolymers based on N-isopropylacrylamide (NIPAAm) and acrylamide (AAm) have been studied by means ATR-FTIR spectroscopy. temperature dependence was as a function the NIPAAm:AAm molar ratio. investigations were carried out in de-ionized water two different phosphate buffer systems (pH = 7.4), containing mono- and/or divalent anions. Increasing ratio AAm copolymer composition produced shifting lower critical (LCST) toward higher values, well broadening domain, regardless solvent type. Spectral decomposition amide I band area allowed investigating more detailed manner thermal evolution C O groups involved various interactions. results compared with dehydration process methyl from isopropyl moieties. Due to Hofmeister effect, shifted values systems. sub-bands ionic strength suggests that there is synergistic effect anions conformational changes copolymers.
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