Ultrafast FRET to Study Spontaneous Micelle-to-Vesicle Transitions in an Aqueous Mixed Surface-Active Ionic-Liquid System
DSpace at IIT Bombay
View Archive InfoField | Value | |
Title |
Ultrafast FRET to Study Spontaneous Micelle-to-Vesicle Transitions in an Aqueous Mixed Surface-Active Ionic-Liquid System
|
|
Creator |
MANDAL, S
KUCHLYAN, J BANIK, D GHOSH, S BANERJEE, C KHORWAL, V SARKAR, N |
|
Subject |
FRET
ionic liquids micelles self-assembly vesicles RESONANCE ENERGY-TRANSFER 1-BUTYL-3-METHYLIMIDAZOLIUM OCTYL SULFATE PHOTOINDUCED ELECTRON-TRANSFER ROTATIONAL-RELAXATION AGGREGATION BEHAVIOR FLUORESCENT DYES FORSTER THEORY MOLTEN-SALTS DYNAMICS MECHANISM |
|
Description |
The spontaneous micelle-to-vesicle transition in an aqueous mixture of two surface-active ionic liquids (SAILs), namely, 1-butyl-3-methylimidazolium n-octylsulfate ([C(4)mim][C8SO4]) and 1-dodecyl-3-methylimidazoium chloride ([C(12)mim]Cl) is described. In addition to detailed structural characterization obtained by using dynamic light scattering, transmission electron microscopy (TEM), and cryogenic TEM techniques, ultrafast fluorescence resonance energy transfer (FRET) from coumarin 153 (C153) as a donor (D) to rhodamine 6G (R6G) as an acceptor (A) is also used to study micelle-vesicle transitions in the present system. Structural transitions of SAIL micelles ([C(4)mim][C8SO4] or [C(12)mim] Cl micelles) to mixed SAIL vesicles resulted in significantly increased D-A distances, and therefore, increased timescale of FRET. In [C(4)mim][C8SO4] micelles, FRET between C153 and R6G occurs on an ultrafast timescale of 3.3 ps, which corresponds to a D-A distance of about 15 angstrom. As [C(4)mim][C8SO4] micelles are transformed into mixed micelles upon the addition of a 0.25 molar fraction of [C(12)mim] Cl, the timescale of FRET increases to 300 ps, which suggests an increase in the D-A distance to 31 angstrom. At a 0.5 molar fraction of [C(12)mim] Cl, unilamellar vesicles are formed in which FRET occurs on multiple timescales of about 250 and 2100 ps, which correspond to D-A distances of 33 and 47 angstrom. Although in micelles and mixed micelles the obtained D-A distances are well correlated with their radius, in vesicles the obtained D-A distance is within the range of the bilayer thickness.
|
|
Publisher |
WILEY-V C H VERLAG GMBH
|
|
Date |
2014-12-28T11:58:01Z
2014-12-28T11:58:01Z 2014 |
|
Type |
Article
|
|
Identifier |
CHEMPHYSCHEM, 15(16)3544-3553
1439-4235 1439-7641 http://dx.doi.org/10.1002/cphc.201402372 http://dspace.library.iitb.ac.in/jspui/handle/100/16418 |
|
Language |
English
|
|