SEM-EDS technique employed in evaluating the aggregation behaviors of amphiphilic ABC-type triblock copolymers in mixed solvents with tuned polarities

摘要

In this paper, a scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) technique has been developed for evaluating the aggregation structure of amphiphilic fluorinated ABC-type triblock copolymers MeOPEO_(16)-PSt_(220)-PFHEA_(22) in mixed solvents with different polarities. The polarities of mixed solvents can be tuned by changing volume ratios of toluene, anhydrous ethanol, and distilled water, which leads to the changes in morphology and size of self-assembled colloidal particles of the copolymers in the system. The aggregation behaviors of the copolymers are revealed by SEM, transmission electron microscopy (TEM), and corresponding SEM-EDS techniques. The variations in concentrations of O and F elements over the thickness of copolymers particles give direct evidence for a better understanding of the arrangement of each block segment of copolymers in solution. And the technique can also help to explain the aggregation structure of micro- or nanomaterial with shell-core structure.