PMID- 18433162
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20080805
LR  - 20080516
IS  - 1520-6106 (Print)
IS  - 1520-5207 (Linking)
VI  - 112
IP  - 20
DP  - 2008 May 22
TI  - Solvation dynamics in ionic liquid swollen p123 triblock copolymer micelle: a 
      femtosecond excitation wavelength dependence study.
PG  - 6350-7
LID - 10.1021/jp7118857 [doi]
AB  - Femtosecond solvation dynamics of coumarin 480 (C480) in a mixed micelle is 
      reported. The mixed micelle consists of a triblock copolymer (PEO)20-(PPO) 
      70-(PEO)20 (Pluronic P123) and an ionic liquid (IL), 1-pentyl-3-methylimidazolium 
      tetrafluoroborate ([pmim][BF4]). At a low concentration (0.3 M), the sparingly 
      water soluble IL ([pmim][BF4]) penetrates the hydrophobic PPO core of the P123 
      micelles. Thus emission maximum of C480 in the core (accessed at lambdaex=375 nm) 
      in 0.3 M IL is red-shifted by 8 nm from that in its absence and the red edge 
      excitation shift (REES) is large (19+/-1 nm). At a high concentration (0.9 M), 
      the ionic liquid [pmim][BF4] invades both the core and corona region and the 
      mixed micelle exhibits very small REES (3+/-1 nm). Anisotropy decay and solvation 
      dynamics in different regions of the mixed micelle are studied by variation of 
      excitation wavelength (lambda ex). In P123 micelle, the average rotational time 
      (<taurot>) is 2800 ps in the core (at lambdaex=375 nm) and 1350 ps in the corona 
      region (at lambdaex=435 nm). In 0.3 M [pmim][BF4], tau rot at the core of the 
      mixed micelle decreases to 1950 ps while that in the corona remains unaffected. 
      In 0.9 M IL, both the core and corona (lambda ex=375 and 435 nm) exhibit similar 
      and short <taurot> approximately 600 ps. In 0.3 M IL, solvation dynamics in the 
      core region (lambdaex=375 nm) of P123 micelle is about 2 times faster than in its 
      absence. In 0.3 M IL, solvation dynamics in the corona region (lambdaex=435 nm) 
      is approximately 100 times faster than that in the core. In 0.9 M IL, the 
      solvation dynamics in the core and in the corona is, respectively, approximately 
      9 times and 4 times faster than that in 0.3 M IL.
FAU - Adhikari, Aniruddha
AU  - Adhikari A
AD  - Department of Physical Chemistry, Indian Association for the Cultivation of 
      Science, Jadavpur, Kolkata, India.
FAU - Dey, Shantanu
AU  - Dey S
FAU - Das, Dibyendu Kumar
AU  - Das DK
FAU - Mandal, Ujjwal
AU  - Mandal U
FAU - Ghosh, Subhadip
AU  - Ghosh S
FAU - Bhattacharyya, Kankan
AU  - Bhattacharyya K
LA  - eng
PT  - Journal Article
DEP - 20080424
PL  - United States
TA  - J Phys Chem B
JT  - The journal of physical chemistry. B
JID - 101157530
EDAT- 2008/04/25 09:00
MHDA- 2008/04/25 09:01
CRDT- 2008/04/25 09:00
PHST- 2008/04/25 09:00 [pubmed]
PHST- 2008/04/25 09:01 [medline]
PHST- 2008/04/25 09:00 [entrez]
AID - 10.1021/jp7118857 [doi]
PST - ppublish
SO  - J Phys Chem B. 2008 May 22;112(20):6350-7. doi: 10.1021/jp7118857. Epub 2008 Apr 
      24.