Cloning polymer single crystals through self-seeding

Abstract

In general, when a crystal is molten, all molecules forget about their mutual correlations and long-range order is lost. Thus, a regrown crystal does not inherit any features from an initially present crystal. Such is true for materials exhibiting a well-defined melting point. However, polymer crystallites have a wide range of melting temperatures, enabling paradoxical phenomena such as the coexistence of melting and crystallization. Here, we report a self-seeding technique that enables the generation of arrays of orientation-correlated polymer crystals of uniform size and shape ('clones') with their orientation inherited from an initial single crystal. Moreover, the number density and locations of these cloned crystals can to some extent be predetermined through the thermal history of the starting crystal. We attribute this unique behaviour of polymers to the coexistence of variable fold lengths in metastable crystalline lamellae, typical for ordering of complex chain-like molecules.

A design strategy for the hierarchical fabrication of colloidal hybrid mesostructures

“…The fibre-like petals of these sunflowers are all similar in length, with L n ¼ 204 nm (PDI TEM ¼ 1.04). This protocol is conceptually related to 'self-seeding' in which heating leads to the selective dissolution of the most soluble crystallites 34 . Upon cooling, the solution becomes supersaturated in BCP, which then deposits epitaxially on the remaining seed crystallites in solution.…”

Two-dimensional assemblies from crystallizable homopolymers with charged termini

“…Such a "memory" effect is a likely consequence of identical crystal packing in these 2D structures and also the preference for similar growth rates in the different crystallographic directions (see further discussions below and in the Supplementary Information page S10). 29 We envisaged that if the 2D seeds possess a "memory" of the shape of the "parent" platelets, it should be possible to prepare 2D platelets using 2D seeds derived from platelets of different shape. We therefore explored the use of 2D seeds derived from the rectangular platelets (Fig.…”

“…13,29 Furthermore, to our knowledge, the use of different seeds from the same polymer to induce the formation of 2D platelets of different shape via seeded growth in solution is unprecedented. Analysis by selected area electron diffraction (SAED) analysis revealed that the quasi-hexagonal disk-like and rectangular platelets (grown from 2D seedHD and 2D seedR1, respectively) have near identical ED patterns with three pairs of diffraction spots, confirming the presence of a single crystalline PFS core with monoclinic symmetry (Fig.…”

Equilibrium Melting Temperature of Poly(ferrocenyl dimethylsilane) in Homopolymers and Lamellar Diblock Copolymers with Polystyrene

“…At this T max , the crystalline order vanishes to an extent that the material appears isotropically from the macroscopic point of view; crystalline regions cannot be detected, neither by calorimetry, nor by nuclear magnetic resonance, nor by microscopic techniques. [37][38][39][40][41] It is still a matter of controversy whether some local chain orientation or even tiny crystallites survive under the applied melting conditions. In any case, these remaining structural entities considerably support nucleation when the material is subsequently cooled down to the respective crystallization temperature.…”