PMID- 20452568
OWN - NLM
STAT- MEDLINE
DCOM- 20100910
LR  - 20161125
IS  - 1873-3727 (Electronic)
IS  - 0001-8686 (Linking)
VI  - 158
IP  - 1-2
DP  - 2010 Jul 12
TI  - Polyelectrolyte brushes studied by surface forces measurement.
PG  - 130-8
LID - 10.1016/j.cis.2010.03.004 [doi]
AB  - Brush layers of polyelectrolytes, ionized chains of poly(glutamic acid) (PLGA) 
      and poly(lysine) (PLL), prepared by the Langmuir-Blodgett method, were 
      characterized using the surface forces measurements at various pHs, salt 
      concentrations and chain densities. This paper reviews the major results: (1) the 
      effective charge density of the brush layer calculated from the force profiles 
      was much lesser than the density of the ionized groups of the polyelectrolyte 
      brushes, indicating that nearly all the ionized groups were neutralized by the 
      counterions in the brush layer; (2) the thickness of the brush layers agreed with 
      the length of the extended polyelectrolytes and was practically independent of 
      the salt concentrations studied (0.43-10mM). The thickness was proportional to 
      the polymerization degree of polyelectrolytes; (3) the initial elastic 
      compressibility modulus of the brush layer of PLGA or PLL increased with 
      increasing ionization degree, while it decreased with increasing salt 
      concentration because of a decrease in the osmotic pressure of the counterions; 
      (4) stress profiles between the brush layers were scaled for polyelectrolytes of 
      various polymerization degrees according to the contour length of the 
      polyelectrolyte. Similar scaling was also found for stress profiles obtained at 
      various salt concentrations (0.43-10mM) and pHs; (5) the "osmotic pressure of 
      counterion" model reproduced well the steric components of the stress profiles, 
      thus supporting that the steric repulsion was mainly due to the osmotic pressure 
      of the counterions; and (6) a density-dependent jump in the properties of 
      polyelectrolyte brushes such as transfer ratio, compressibility and surface 
      potential has been found, indicating the existence of the density (interchain 
      distance)-dependent transition of polyelectrolytes in solutions. We have proposed 
      a counterion model to account for this transition.
CI  - Copyright 2010 Elsevier B.V. All rights reserved.
FAU - Kurihara, Kazue
AU  - Kurihara K
AD  - Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku 
      University, Katahira, Aoba-ku, Sendai 980-8577, Japan. 
      kurihara@tagen.tohoku.ac.jp
LA  - eng
PT  - Journal Article
DEP - 20100411
PL  - Netherlands
TA  - Adv Colloid Interface Sci
JT  - Advances in colloid and interface science
JID - 8706645
RN  - 0 (Bromides)
RN  - 0 (Potassium Compounds)
RN  - 0 (Solutions)
RN  - 25104-18-1 (Polylysine)
RN  - 25513-46-6 (Polyglutamic Acid)
RN  - OSD78555ZM (potassium bromide)
SB  - IM
MH  - Bromides/chemistry
MH  - Chemical Phenomena
MH  - Hydrogen Bonding
MH  - Hydrogen-Ion Concentration
MH  - Osmolar Concentration
MH  - Polyglutamic Acid/*chemistry
MH  - Polylysine/*chemistry
MH  - Potassium Compounds/chemistry
MH  - Solutions
MH  - Static Electricity
MH  - Surface Properties
EDAT- 2010/05/11 06:00
MHDA- 2010/09/11 06:00
CRDT- 2010/05/11 06:00
PHST- 2009/11/23 00:00 [received]
PHST- 2010/03/31 00:00 [revised]
PHST- 2010/03/31 00:00 [accepted]
PHST- 2010/05/11 06:00 [entrez]
PHST- 2010/05/11 06:00 [pubmed]
PHST- 2010/09/11 06:00 [medline]
AID - S0001-8686(10)00075-8 [pii]
AID - 10.1016/j.cis.2010.03.004 [doi]
PST - ppublish
SO  - Adv Colloid Interface Sci. 2010 Jul 12;158(1-2):130-8. doi: 
      10.1016/j.cis.2010.03.004. Epub 2010 Apr 11.