AVS 51st International Symposium
    Biomaterial Interfaces Friday Sessions
       Session BI-FrM

Paper BI-FrM5
pH Induced Conformational Behaviour of Polyelectrolytes in Bulk Solution and Grafted to Surfaces: Neutron Reflectometry and Fluorescence Studies

Friday, November 19, 2004, 9:40 am, Room 210D

Session: "Active" - Dynamic Biointerfaces
Presenter: M. Geoghegan, Univ. of Sheffield, UK
Authors: M. Geoghegan, Univ. of Sheffield, UK
L. Ruiz-Perez, Univ. of Sheffield, UK
A.J. Parnell, Univ. of Sheffield, UK
J.R. Howse, Univ. of Sheffield, UK
A.J. Pryke, Univ. of Sheffield, UK
C.J. Crook, Univ. of Sheffield, UK
P. Topham, Univ. of Sheffield, UK
S.J. Martin, Univ. of Sheffield, UK
A.J. Ryan, Univ. of Sheffield, UK
R.A.L. Jones, Univ. of Sheffield, UK
A. Menelle, Lab. Lön Brillouin, France
J.R.P. Webster, Rutherford Appleton Lab, UK
I. Soutar, Univ. of Sheffield, UK
L. Swanson, Univ. of Sheffield, UK
Correspondent: Click to Email
We present neutron reflectometry results on (deuterated) water-swollen poly[diethylamino)ethyl methacrylate] (PDEAMA, a polybase) and polymethacrylic acid (PMAA) brushes grafted from silicon substrates using atom transfer radical polymerisation. The PDEAMA data are presently the more comprehensive and reveal that the expanded brush (low pH) is some 6 to 10 times thicker than the collapsed brush at high pH. Brush data will be compared with bulk solution data of the collapse transition of PMAA in water measured by a variety of fluorescence techniques: steady state energy transfer, lifetime, and time-resolved fluorescence anisotropy measurements, which enable a correlation of this single polymer in solution collapse transition with the confinement-influenced transition which occurs when the polymers are tethered to a surface.