TY - JOUR
T1 - Urea-induced demicellization of Pluronic L64 in water
AU - Bharatiya, B.
AU - Guo, C.
AU - Ma, J. H.
AU - Kubota, O.
AU - Nakashima, K.
AU - Bahadur, P.
PY - 2009/1/1
Y1 - 2009/1/1
N2 - The micellar behavior of a polyethylene oxide block-polypropylene oxide block-polyethylene oxide copolymer Pluronic L64 in aqueous urea solutions (urea concentrations 0, 1, 2, 3, 4, and 6 M) by physical methods, viz. cloud point and viscosity, spectral techniques (Fourier transform infrared, fluorescence, and nuclear magnetic resonance), differential scanning calorimetry, and dynamic light scattering is reported. The presence of urea causes an increase in the clouding temperature, critical micellization temperature, and the structural transition (spherical micelles to ellipsoid/rod) temperature; different methods showed good agreement. Urea induces demicellization of L64, enhancing accumulation of water molecules surrounding micelles. L64 micelles show growth at high temperatures, but this micellar transition is suppressed by urea, as proven by calorimetric and viscometric methods. The results are discussed in terms of the molecular mechanism underlying the effects of urea.
AB - The micellar behavior of a polyethylene oxide block-polypropylene oxide block-polyethylene oxide copolymer Pluronic L64 in aqueous urea solutions (urea concentrations 0, 1, 2, 3, 4, and 6 M) by physical methods, viz. cloud point and viscosity, spectral techniques (Fourier transform infrared, fluorescence, and nuclear magnetic resonance), differential scanning calorimetry, and dynamic light scattering is reported. The presence of urea causes an increase in the clouding temperature, critical micellization temperature, and the structural transition (spherical micelles to ellipsoid/rod) temperature; different methods showed good agreement. Urea induces demicellization of L64, enhancing accumulation of water molecules surrounding micelles. L64 micelles show growth at high temperatures, but this micellar transition is suppressed by urea, as proven by calorimetric and viscometric methods. The results are discussed in terms of the molecular mechanism underlying the effects of urea.
KW - Aggregation number
KW - Critical micellization temperature (CMT)
KW - Demicellization
UR - http://www.scopus.com/inward/record.url?scp=58149101837&partnerID=8YFLogxK
U2 - 10.1007/s00396-008-1953-4
DO - 10.1007/s00396-008-1953-4
M3 - Article (Academic Journal)
AN - SCOPUS:58149101837
VL - 287
SP - 63
EP - 71
JO - Colloid and Polymer Science
JF - Colloid and Polymer Science
SN - 0303-402X
IS - 1
ER -