Control of\nPolymer Crystallization by Pseudo-Polyrotaxane\nNanosheets

We present a straightforward\nyet highly efficient approach for\ncontrolling the orientations of poly(ethylene oxide) (PEO) lamellae\nby introducing pseudopolyrotaxane nanosheets (PPRNSs), a novel class\nof two-dimensional fillers featuring well-organized polymer brushes.\nGrazing-incidence wide-angle X-ray scattering reveals parallel alignments\nof uniformly flat-on PEO lamellae to the film surface, and the degrees\nof their orientations are closely linked to the PPRNS concentration.\nVia control experiments and comprehensive investigations of crystallization\nkinetics and morphological evolutions of nanocomposites with different\nPPRNS contents, we elucidate the mechanism driving lamellar orientation.\nPPRNSs provide additional nucleation sites for PEO crystallization,\nthereby influencing the crystallization kinetics. PPRNSs, acting as\nnucleating agents, accelerate crystallization rates, impacting crystal\nmorphology, crystal growth direction, and crystallinity preservation.\nControl experiments emphasize the distinct roles of polymer brushes\nin offering nucleation sites. This study lays the foundation for diverse\napplications and further explorations of PPRNS-based materials in\nthe fields of polymer nanocomposites, surface engineering, and functional\nmaterial design.