Amphiphilic block copolymers have been recognized as effective surface active molecules with the ABA Pluronic family as a renown example. Yet, the relation between the molecular architecture, size and chemistry is not clear. Fundamental understanding of these simpler molecules may provide the tools for understanding interfacial behavior of structurally more complex biopolymers.
In this study, we examined a series of polyethyleneoxide – polydimethylsiloxane (PEO-PDMS) diblock copolymers and PEO-PDMS-PEO triblock copolymers at the water\isooctane interface. The pendent drop technique was employed to study the adsorption kinetics and oscillatory dilatational rheology to study the interfacial rheology.
In view of recent criticism of the pendant drop measurements (Alvarez et al. Phys Rev E 2010) care has been taken to examine the mpact of drop size on the measurements. Fourier Transform analysis was employed in the analysis of the rheological data to identify non-linear effects.
Results will be discussaed in terms of the effects of architecture (diblock vs. triblock), chain length, block size and block size ratio (A/B) on interfacial dynamics and rheology.
