Standalone Block Copolymer Nanoballoons: Decoupling Self-Assembly from Implementation in Nanomanufacturing

We report a facile method to produce isolatable block copolymer self-assembly in a polymer blend. Poly(isopreneblock-dimethylsiloxane) (PI-PDMS) diblock copolymers are blended with PDMS homopolymers (h-PDMS) as a solvent phase to template the self-assembly of PDMS-tethered vesicles with PI walls. The walls are subsequently crosslinked to yield mechanically stabilized elastomeric vesicles. The h-PDMS inner core and matrix are separated from the vesicles by dialysis to yield the matrix-free nanoballoons. These objects, 0.3-1 mu m in diameter, can be further reincorporated into a crosslinkable PDMS. Throughout the self-assembly, recovery, and reincorporation processes we apply several techniques including solvent spectroscopy (EDS), and small-angle X-ray scattering (SAXS) to provide a consilient body of evidence that the nanoballoon morphology is retained. This work presents advanced nanomanufacturing schema that illustrate the decoupling of the thermodynamic and dynamic factors that govern macromolecular self-assembly from the environment in which the self-assembled objects are deployed.

Automated summary

This paper presents a facile method to produce isolatable block copolymer self-assembly in a polymer blend. By using PDMS homopolymers as a solvent phase, PDMS-tethered vesicles with PI walls are formed through self-assembly. The walls are subsequently crosslinked to yield mechanically stabilized elastomeric vesicles. The h-PDMS inner core and matrix are separated from the vesicles by dialysis to yield matrix-free nanoballoons. These nanoballoons can be further reincorporated into a crosslinkable PDMS.