Homogeneous Bulk, Surface, and Edge Nucleation in Crystalline Nanodroplets

Abstract

The birth of a crystal is initiated by a nucleus from which the crystal grows--a dust grain in a snowflake is a familiar example. These nuclei can be heterogeneous defects, like the dust grain, or homogeneous nuclei which are intrinsic to the material. Here we study homogeneous nucleation in nanoscale polymer droplets on a substrate which itself can be crystalline or amorphous. We observe a large difference in the nucleating ability of the substrate. Furthermore, the scaling dependence of nucleation on the size of the droplets proves that the birth of the crystalline state can be directed to originate predominantly within the bulk, at the substrate surface, or at the droplets' edge, depending on how we tune the substrate.

Crystallization of polymer chains confined in nanodomains

“…On the other hand, the crystallinity of confined blocks increases abruptly at the beginning of crystallization with no induction time, followed by an asymptotical increase at the late stage of crystallization (Fig. 3), where a large super-cooling is generally necessary (i.e., typically, the crystallizable temperature is close to the glass transition temperature of crystalline blocks), by which this crystallization can be distinguished from that starting by surface nucleation observed in some homopolymers [35][36][37]. This characteristic crystallization behavior can be successfully explained in terms of a nucleation-controlled crystallization mechanism.…”

Ion-specific ice propagation behavior on polyelectrolyte brush surfaces

“…The correlation diagram of T 1 and T 2 was plotted during cooling runs. 37 As shown in Fig. 3c, freezing temperatures of T 1 and T 2 on the PMETA-Cl brush surface are well correlated, and all data points lay on the line with a slope of 1.…”

In situ polymerization of poly(styrene- alt -maleic anhydride)/organic montmorillonite nanocomposites and their ionomers as crystallization nucleating agents for poly(ethylene terephthalate)

“…Similar to PE, strong interface effects on the orientation of crystalline structures were found in nanocomposites of polyester and single-wall carbon nanotubes (SWCNTs) obtained from highly diluted solutions [45]. A clear example of a substrate affecting crystallization was that of epitaxy, where a particular crystalline orientation was induced by the substrate [46,47]. As for the nanocomposites of PET and IMs, large interface was provided by OMMT nanoplatelets, resulting in improvement of crystallization rate of PET.…”