PMID- 24410288
OWN - NLM
STAT- MEDLINE
DCOM- 20140922
LR  - 20140204
IS  - 1520-5827 (Electronic)
IS  - 0743-7463 (Linking)
VI  - 30
IP  - 4
DP  - 2014 Feb 4
TI  - Microheterogeneity and microviscosity of F127 micelle: the counter effects of 
      urea and temperature.
PG  - 1012-21
LID - 10.1021/la4049192 [doi]
AB  - F127 is the most widely studied triblock copolymer and due to the presence of 
      very long polypropylene oxide (PPO) and polyethylene oxide (PEO) groups, F127 
      micelle has different microenvironments clearly separated into core, corona, and 
      peripheral regions. Urea has been known to have adverse effects on the micellar 
      properties and causes demicellization and solvation; on the other hand, rise in 
      temperature causes micellization and solvent evacuation from the core and corona 
      regions. In the present study, we have investigated the microheterogeneity of the 
      core, corona, and peripheral regions of the F127 micelle using red edge 
      excitation shift (REES) at different temperatures and urea concentrations and 
      correlated the effect of both on the micellar system. It was found that the 
      temperature counteracts the effect of urea and also that the counteraction is 
      more prominent in the core region with respect to corona, and the peripheral 
      region is least affected. Also, the core and corona regions are very much 
      heterogeneous, while the peripheral region is more of a homogeneous nature. Using 
      time-resolved fluorescence anisotropy, we found that the microviscosity within 
      the micelles vary in the order of core > corona > peripheral region, and urea has 
      a general tendency to reduce the microviscosity, especially for core and corona 
      regions. On the other hand, rise in temperature initially increases and then 
      decreases the microviscosity throughout, and at elevated temperatures the effect 
      of urea is being dominated by the effect of temperature, thereby establishing the 
      counter effects of temperature and urea on the F127 micellar system.
FAU - Anand, Uttam
AU  - Anand U
AD  - Department of Chemistry, Indian Institute of Science Education and Research 
      Bhopal , Indore By-Pass Road, Bhauri, Bhopal 462 066, Madhya Pradesh, India.
FAU - Mukherjee, Saptarshi
AU  - Mukherjee S
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20140117
PL  - United States
TA  - Langmuir
JT  - Langmuir : the ACS journal of surfaces and colloids
JID - 9882736
RN  - 0 (Micelles)
RN  - 0 (Polyethylenes)
RN  - 0 (Polypropylenes)
RN  - 8W8T17847W (Urea)
RN  - 9038-95-3 (UCON 50-HB-5100)
SB  - IM
MH  - Fluorescence Polarization
MH  - *Micelles
MH  - Polyethylenes/*chemistry
MH  - Polypropylenes/*chemistry
MH  - Spectrometry, Fluorescence
MH  - Temperature
MH  - Urea/*chemistry
MH  - Viscosity
EDAT- 2014/01/15 06:00
MHDA- 2014/09/23 06:00
CRDT- 2014/01/14 06:00
PHST- 2014/01/14 06:00 [entrez]
PHST- 2014/01/15 06:00 [pubmed]
PHST- 2014/09/23 06:00 [medline]
AID - 10.1021/la4049192 [doi]
PST - ppublish
SO  - Langmuir. 2014 Feb 4;30(4):1012-21. doi: 10.1021/la4049192. Epub 2014 Jan 17.