| 15927574 |
Norman AI, Ho DL, Karim A, Amis EJ: Phase behavior of block co-poly (ethylene oxide-butylene oxide), E18B9 in water, by small angle neutron scattering. J Colloid Interface Sci. 2005 Aug 1;288(1):155-65.
We present a small angle neutron scattering (SANS) study into the micellar structures of diblock copolymer E18B9 (where E denotes a ethylene oxide unit and B denotes a butylene oxide unit, 18 and 9 being the number of repeat units respectively) in aqueous solution over a range of five different concentrations (0.2, 1.0, 10.0, 20.0, and 40.0% (by mass fraction)) and eight temperatures (10 to 90 degrees C). The NG7 30 m SANS instrument provides a q range of 0.0009 to 0.5548 A (-1), thus probing the structure over a very broad length scale. At low temperature and low concentration, spherical micelles exist, elongating into worm-like structures at higher temperatures. This transition is observed by the scaling of the scattered intensity at low q and confirmed upon fitting to an appropriate model. Upon increasing concentration, the micelles pack into ordered arrays of either hexagonally packed rod-like micelles or lamellar sheets, again dependent on temperature. Both concentration and temperature effects of this block copolymer have been discussed. |
7(0,0,1,2) |