Solubilizate reorganization in reversed micelles

Journal Article · Thu Jan 25 00:00:00 EST 1990 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100365a065· OSTI ID:6882302

Nagy, J B; Yuan, Youxin; Fendler, J H ^[1]; Jao, Tzechi ^[2]

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1. Syracuse Univ., NY (USA)
2. Texaco Research Center, Beacon, NY (USA)

Reversed micelles, freshly prepared from 2.0 {times} 10{sup {minus}3} M calcium alkylarylsulfonate surfactant (1) and 4.0 {times} 10{sup {minus}4} M TbCl{sub 3} containing 2.2 {times} 10{sup {minus}2} M water ((H{sub 2}O)/(1) = {omega} = 11.1), showed no luminescence upon excitation at 300 nm (the wavelength at which {epsilon}{sub 1} = 4,200 M{sup {minus}1} cm{sup {minus}1} and {epsilon}{sub TbCl{sub 3}} = 0.12 M{sup {minus}1} cm{sup {minus}1}). Allowing this solution to stand at room temperature for several hours resulted, however, in the appearance of a weak luminescence which grew in intensity with time and became identifiable with that corresponding to TbCl{sub 3} emission. Since fluorescence lifetimes of 1 in heptane ({tau}{sub 1} = 1.03 {plus minus} 0.02 ns, {tau}{sub 2} = 5.12 {plus minus} 0.06 ns, {tau}{sub 3} = 12.3 {plus minus} 0.11 ns, {chi}{sup 2} = 1.17) did not change upon the addition of 4 {times} 10{sup {minus}3} M TbCl{sub 3} ({tau}{sub 1} = 1.02 {plus minus} 0.02 ns, {tau}{sub 2} = 5.01 {plus minus} 0.06 ns, {tau}{sub 3} = 12.1 {plus minus} 0.12 ns, {chi}{sup 2} = 1.21), the observed luminescence (L{sub Tb}) has been attributed to energy transfer from the triplet domain of the aromatic moieties of the surfactant to ({sup 7}F)Tb(III). Plots of 1/L{sub Tb} against 1/(TbCl{sub 3}), at constant concentrations of 2.0 {times} 10{sup {minus}3} M 1 and 2.2 {times} 10{sup {minus}2} M H{sub 2}O in heptane, gave good straight lines from the intercepts and slopes of which triplet sensitization constants (K{sub s}{sup t} = rate constant for triplet energy transfer {times} triplet lifetimes) have been calculated. Increased energy transfer efficiency (decreased triplet lifetimes) thus paralleled the increased luminescence. FTIR spectroscopy indicated that TbCl{sub 3} affected most profoundly the aryl sulfonate moiety of the surfactant which formed the core of reversed micellar 1.

• OSTI ID: 6882302
• Journal Information: Journal of Physical Chemistry; (USA), Vol. 94:2; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
MICELLAR SYSTEMS
LUMINESCENCE
ORGANIZATIONAL MODELS
MICROEMULSIONS
CALCULATION METHODS
DATA ANALYSIS
ENERGY TRANSFER
EXPERIMENTAL DATA
MEASURING INSTRUMENTS
MEASURING METHODS
TERBIUM CHLORIDES
CHLORIDES
CHLORINE COMPOUNDS
COLLOIDS
DATA
DISPERSIONS
EMULSIONS
HALIDES
HALOGEN COMPOUNDS
INFORMATION
NUMERICAL DATA
RARE EARTH COMPOUNDS
TERBIUM COMPOUNDS
360603* - Materials- Properties
400201 - Chemical & Physicochemical Properties