Abstract
We explore the role of nanoparticle (NP) size and loading on the kinetics of polymer crystallization, in particular, the crystal growth rate (G), under conditions where the NPs and polymers are uniformly mixed. While there are significant differences with variations in NP size and loading, the measured G data fall into an apparently universal curve when we consider them on the basis of confinement. In particular, we find that the ratio of polymer volume, VPEO, to the NP surface area, SANP, is the most appropriate confinement metric in the 10–100 nm range, which includes typical lamellar spacings in semicrystalline polymers (5–50 nm). Similarly, we find that the fraction of polymer crystallized also decreases with increasing confinement. We thus posit that the formation of a bound layer at the attractive NP interface is the key driver in these situations. Because the volume fraction of the bound polymer layer of thickness δ is (δ × SANP)/VPEO, these results support the notion that, in addition to confining the polymer and reducing its equilibrium melting point, the NPs serve to “remove” a certain fraction of the PEO from the crystallization process by binding “irreversibly” to them. Additionally, when combined with the fact that the formation of a bound layer slows down NP dynamics, we emphasize that the bound polymer critically affects crystallization kinetics from both a structural and a dynamical perspective. These results strongly parallel our earlier work on the glass transition temperature of amorphous polymers intimately mixed with NPs where material properties are critically determined by the formation of a bound layer.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.