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Theory of steric stabilization of colloid systems by grafted polymers
Author(s) -
Ekaterina B.Zhulina,
Oleg V.Borisov
Publication year - 1991
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19910440128
Subject(s) - colloid , polymer , steric effects , hamaker constant , chemical physics , materials science , solvent , chemical engineering , molecule , polymer chemistry , chemistry , van der waals force , organic chemistry , composite material , van der waals radius , engineering
An analytical mean‐field theory of steric stabilization of dispersions by non‐charged polymer chains grafted at one end onto the surface of colloid particles has been developed. The chains were assumed to be grafted densly, so that the neighboring coils overlap and form a single stabilizing layer. In the case of low‐molecular‐weight dispersing medium and relatively loose stabilizing layers the shape of the potential curve of interparticle interaction is determined by the value ofis the Hamaker constant and Γ is the surface concentration of stabilizing polymer) and the quality of the dispersing medium as a solvent for polymer chains. Depending on the value of γ the system may exhibit the stability of both thermodynamic ( α<1 ) and kinetic ( α> 1 ) character. When the molecules of the dispersing medium are short polymer chains the increase in their length leads to a drastic decrease in the stability range of the system and to its destabilization.