PMID- 21189037
OWN - NLM
STAT- MEDLINE
DCOM- 20110607
LR  - 20131121
IS  - 1520-5827 (Electronic)
IS  - 0743-7463 (Linking)
VI  - 27
IP  - 5
DP  - 2011 Mar 1
TI  - Spontaneous phase transfer of thermosensitive hairy particles between water and 
      an ionic liquid.
PG  - 2019-27
LID - 10.1021/la1044706 [doi]
AB  - This article describes the temperature-induced phase transfer behavior of a 
      series of thermosensitive polymer brush-grafted particles between water and a 
      hydrophobic ionic liquid, 1-ethyl-3-methylimidazolium 
      bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]). Six samples were made by 
      surface-initiated atom transfer radical polymerization: silica particles grafted 
      with poly(methoxypoly(ethylene glycol) methacrylate) (PPEGMMA) with two different 
      molecular weights, poly(methoxytri(ethylene glycol) methacrylate) (PTEGMMA), 
      poly(methoxydi(ethylene glycol) methacrylate) (PDEGMMA), and two copolymers of 
      PEGMMA and TEGMMA with different compositions (P(PEGMMA-co-TEGMMA)-82 and 
      P(PEGMMA-co-TEGMMA)-74). The cloud points of free PPEGMMA with M(n,SEC) of 23 and 
      40 kDa, P(PEGMMA-co-TEGMMA)-82, P(PEGMMA-co-TEGMMA)-74, and PTEGMMA in 
      [EMIM][TFSI]-saturated water were 95, 94, 80, 72, and 43  degrees C, respectively. 
      PDEGMMA was not soluble in the ionic liquid-saturated water. PPEGMMA 
      brush-grafted particles moved spontaneously and completely from water to the 
      [EMIM][TFSI] phase upon heating at 80  degrees C. When cooled to 22  degrees C, all particles 
      returned to the water layer. From UV-vis absorbance measurements, the transfer 
      temperature (T(tr)) of PPEGMMA-grafted particles from water to the ionic liquid 
      was 42  degrees C. Thermodynamic analysis showed that the particle transfer was an 
      entropically driven process. P(PEGMMA-co-TEGMMA)-82, P(PEGMMA-co-TEGMMA)-74, and 
      PTEGMMA brush-grafted particles also underwent reversible and quantitative 
      transfer between the two phases upon heating at 70  degrees C and cooling at 0  degrees C; their 
      transfer temperatures from water to [EMIM][TFSI] were 36, 30, and 16  degrees C, 
      respectively. T(tr) was a linear function of the cloud point of the corresponding 
      free polymer in ionic liquid-saturated water. In contrast, PDEGMMA-grafted 
      particles moved spontaneously to the ionic liquid layer upon heating but did not 
      return to water even after prolonged stirring at 0  degrees C.
FAU - Horton, Jonathan M
AU  - Horton JM
AD  - Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, 
      United States.
FAU - Bai, Zhifeng
AU  - Bai Z
FAU - Jiang, Xiaoming
AU  - Jiang X
FAU - Li, Dejin
AU  - Li D
FAU - Lodge, Timothy P
AU  - Lodge TP
FAU - Zhao, Bin
AU  - Zhao B
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20101228
PL  - United States
TA  - Langmuir
JT  - Langmuir : the ACS journal of surfaces and colloids
JID - 9882736
RN  - 0 (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide)
RN  - 0 (Imidazoles)
RN  - 0 (Imides)
RN  - 0 (Ionic Liquids)
RN  - 0 (Polymers)
RN  - 059QF0KO0R (Water)
RN  - 7631-86-9 (Silicon Dioxide)
SB  - IM
MH  - Catalysis
MH  - Hot Temperature
MH  - Imidazoles/*chemistry
MH  - Imides/*chemistry
MH  - Ionic Liquids/*chemistry
MH  - Polymers/chemistry
MH  - Silicon Dioxide/chemistry
MH  - Surface Properties
MH  - *Temperature
MH  - Water/*chemistry
EDAT- 2010/12/30 06:00
MHDA- 2011/06/08 06:00
CRDT- 2010/12/30 06:00
PHST- 2010/12/30 06:00 [entrez]
PHST- 2010/12/30 06:00 [pubmed]
PHST- 2011/06/08 06:00 [medline]
AID - 10.1021/la1044706 [doi]
PST - ppublish
SO  - Langmuir. 2011 Mar 1;27(5):2019-27. doi: 10.1021/la1044706. Epub 2010 Dec 28.