Adsorbed layer structure of cationic surfactants on quartz - art. no. 041604

Recent atomic force microscopy (AFM) surface images of surfactant adsorbed at solid and solution interfaces have shown apparent micellar aggregates fa miliar from bulk self-assembly. This contradicts the classical picture of l aterally unstructured bilayers within which neutron reflectometry (NR) meas urements have previously been analyzed. Applying both techniques to surfact ant adsorption on quartz, we show that film thickness and coverage paramete rs derived from NR results are generally consistent with those from AFM and bulk self-assembly. NR by itself allows us to distinguish between actual b ilayer and probable aggregate adsorption, which will be of particular impor tance when a solution's rheology makes AFM imaging impractical.