pH sensitive adsorption of polypeptide/sodium dodecyl sulfate mixtures.
Neutron reflectivity and surface tension have been used to investigate the pH sensitivity of the adsorption of poly-L-lysine hydrobromide and sodium dodecyl sulfate mixtures at the air-solution interface. The surface tension variation with surfactant concentration is complex, and between the critical aggregation concentration and critical micellar concentration there is a marked increase in the surface tension. The neutron reflectivity results show that this is associated with a depletion of the surface of polypeptide/surfactant complexes. The variations in the adsorption and surface tension with pH are attributed to changes in the polypeptide conformation at the interface and in solution.
Penfold
J
J
ISIS, Rutherford Appleton Laboratory, Didcot, OXON, OX11 0QX. j.penfold@rl.ac.uk
Tucker
I
I
Thomas
R K
RK
Taylor
D J F
DJ
Zhang
X L
XL
D000327:Adsorption; D006863:Hydrogen-Ion Concentration; D009502:Neutrons; D011107:Polylysine / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*; D012996:Solutions; D014867:Water / Q000737:chemistry
D012996:Solutions; D014867:Water; D011107:Polylysine; D012967:Sodium Dodecyl Sulfate