Abstract(s)
Understanding interfacial interactions in polymer systems is crucial for their applicability for
instance in adhesives and coatings. Enclosing polymers in a cylindrical volume provides a
system for studying interactions dictated by a continuous interfacial layer and a bulk-like
volume in the middle of the cylinders. Here, we describe a simple method for enclosing
polymers into boron nitride nanotubes (BNNTs) and establishing the effect of the interfacial
interactions on the glass transition temperature (Tg) of the polymers by infrared spectroscopy.
The volume of the inner channel is large in comparison to the volume of the loaded polymer
coils, allowing the polymer to expand along the inner channel, resulting in the effect of
interfacial interactions on polymer dynamics dominating over confinement effects. As
examples, we loaded poly(4-vinyl pyridine), poly(methyl methacrylate), poly(vinyl
pyrrolidone), and poly(disperse red 1 acrylate) in BNNTs. The strongest interaction between
the studied polymer and BNNTs was observed for poly(4-vinyl pyridine), which also caused a significant increase of Tg. In addition to characterizing the effect of interfacial interactions on
the thermal transitions of the polymers, this method, which is generalizable to most soluble
polymer materials, can be used for studying photoinduced transitions in photoactive polymers
thanks to the transparency of the BNNTs at visible wavelengths.