Abstract
Adsorption of sodium dodecylbenzenesulfonate (SDBS) on polystyrene (PS) particles is described by the Langmuir equation only superficially: on closer look there are small but systematic differences with the expts. This is expressed here as an excess G function (GE) of the surfactant electrolyte on adsorption, which changes with increasing degree of occupation of adsorption sites (q). At low q values, GE changes in pos. direction with increasing q; at large q values, this trend levels off and may even be in the opposite direction (depending on the value assumed for total satn. of the surface with surfactants). This is explained by changes in adsorption energy of the surfactant chain on the polystyrene surface: at very low q values the chain is adsorbed in a flat configuration; at larger q values this is no longer possible, but this is partially compensated by interaction between the hydrocarbon chains of surfactant ions adsorbed on neighboring sites. This explanation is confirmed by the effect of cosurfactant mols. on the adsorption. [on SciFinder (R)]
| Original language | English |
|---|---|
| Pages (from-to) | 1284-1290 |
| Journal | Langmuir |
| Volume | 11 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 1995 |