A femtosecond study of excitation wavelength dependence of a triblock copolymer -: Surfactant supramolecular assembly:: (PEO)20-(PPO)70-(PEO)20 and CTAC

被引:31
作者
Dey, Shantanu [1 ]
Adhikari, Aniruddha [1 ]
Mandal, Ujjwal [1 ]
Ghosh, Subhadip [1 ]
Bhattacharyya, Kankan [1 ]
机构
[1] Indian Assoc Cultivat Sci, Dept Phys Chem, Kolkata 700032, India
关键词
D O I
10.1021/jp8002257
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Solvation dynamics and anisotropy decay of coumarin 480 (C480) in a supramolecular assembly containing a triblock copolymer, PEO20-PPO70-PEO20 (Pluronic P123) and a surfactant, CTAC (cetyl trimethylammonium chloride) are studied by femtosecond up-conversion. In a P123-CTAC complex, C480 displays a significant (22 nm) red edge excitation shift (REES) in the emission maximum as lambda(ex) increases from 335 to 445 nm. This suggests that the P123-CTAC aggregate is quite heterogeneous. The average rotational relaxation time (<tau(rot)>) of C480 in a P123-CTAC complex decreases by a factor of 2 from 2500 ps at lambda(ex) = 375 nm to 1200 ps at lambda(ex) = 435 nm. For lambda(ex) = 375 nm, the probe molecules in the buried core region of P123-CTAC are excited and the solvation dynamics displays three components, 2, 60, and 4000 ps. It is argued that insertion of CTAC in P123 micelle affects the polymer chain dynamics, and this leads to reduction of the 130 ps component of P123 micelle to 60 ps in P123-CTAC. For lambda(ex) = 435 nm, which selects the peripheral highly polar corona region, solvation dynamics in P123-CTAC and P123 are extremely fast with a major component of <0.3 ps (similar to 80%) and a 2 ps (similar to 20%) component.
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页码:5020 / 5026
页数:7
相关论文
共 52 条
[1]   Structure, stability, and hydration of a polypeptide in AOT reverse micelles [J].
Abel, S ;
Waks, M ;
Urbach, W ;
Marchi, M .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2006, 128 (02) :382-383
[2]   Heterogeneous dynamics and dynamic heterogeneities at the glass transition probed with single molecule spectroscopy [J].
Adhikari, Aashish N. ;
Capurso, Noah A. ;
Bingemann, Dieter .
JOURNAL OF CHEMICAL PHYSICS, 2007, 127 (11)
[3]   Structural polymorphism of poly(ethylene oxide)-poly(propylene oxide) block copolymers in nonaqueous polar solvents [J].
Alexandridis, P .
MACROMOLECULES, 1998, 31 (20) :6935-6942
[4]   A record nine different phases (four cubic, two hexagonal, and one lamellar lyotropic liquid crystalline and two micellar solutions) in a ternary isothermal system of an amphiphilic block copolymer and selective solvents (water and oil) [J].
Alexandridis, P ;
Olsson, U ;
Lindman, B .
LANGMUIR, 1998, 14 (10) :2627-2638
[5]   MICELLIZATION OF POLY(ETHYLENE OXIDE)-POLY(PROPYLENE OXIDE)-POLY(ETHYLENE OXIDE) TRIBLOCK COPOLYMERS IN AQUEOUS-SOLUTIONS - THERMODYNAMICS OF COPOLYMER ASSOCIATION [J].
ALEXANDRIDIS, P ;
HOLZWARTH, JF ;
HATTON, TA .
MACROMOLECULES, 1994, 27 (09) :2414-2425
[6]   AGGREGATION OF POLY(ETHYLENE OXIDE)-POLY(PROPYLENE OXIDE)-POLY(ETHYLENE OXIDE) TRIBLOCK COPOLYMERS IN THE PRESENCE OF SODIUM DODECYL-SULFATE IN AQUEOUS-SOLUTION [J].
ALMGREN, M ;
VANSTAM, J ;
LINDBLAD, C ;
LI, PY ;
STILBS, P ;
BAHADUR, P .
JOURNAL OF PHYSICAL CHEMISTRY, 1991, 95 (14) :5677-5684
[7]   Solvation dynamics of chromophores in polyethers [J].
Argaman, R ;
Huppert, D .
JOURNAL OF PHYSICAL CHEMISTRY A, 1998, 102 (31) :6215-6219
[8]   Sensitivity of polar solvation dynamics to the secondary structures of aqueous proteins and the role of surface exposure of the probe [J].
Bandyopadhyay, S ;
Chakraborty, S ;
Balasubramanian, S ;
Bagchi, B .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2005, 127 (11) :4071-4075
[9]   Cosurfactant impact on probe molecule in reverse micelles [J].
Corbeil, EM ;
Riter, RE ;
Levinger, NE .
JOURNAL OF PHYSICAL CHEMISTRY B, 2004, 108 (30) :10777-10784
[10]   Influence of ionic surfactants on the aggregation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers studied by differential scanning and isothermal titration calorimetry [J].
da Silva, RC ;
Olofsson, G ;
Schillén, K ;
Loh, W .
JOURNAL OF PHYSICAL CHEMISTRY B, 2002, 106 (06) :1239-1246