Formation of well-organized, concentric-ringed spherulites of four-arm star symmetric PEO-b-PCL via confined evaporative crystallization

Toluene solvent-assisted topology confinement facilitates PCL block templated rhythmic crystallization into concentric-ringed spherulites of star symmetric P(EO_2.5k-b-CL_2.7k)₄.

Nonbirefringent bands in thin films of a copolymer melt: rapid rhythmic crystal growth with an unusual crystal–melt interface

Rhythmic-growth-induced nonbirefringent bands that are comprised of repetitive stacks of discrete flat-on lamellae along the growth directions are reported in a thin film of an asymmetric PCL-b-PEO during isothermal melt crystallization.

In situ dynamic observations of perovskite crystallisation and microstructure evolution intermediated from [PbI6]4- cage nanoparticles

Hybrid lead halide perovskites have emerged as high-performance photovoltaic materials with their extraordinary optoelectronic properties. In particular, the remarkable device efficiency is strongly influenced by the perovskite crystallinity and the film morphology. Here, we investigate the perovskites crystallisation kinetics and growth mechanism in real time from liquid precursor continually to the final uniform film. We utilize some advanced in situ characterisation techniques including synchrotron-based grazing incident X-ray diffraction to observe crystal structure and chemical transition of perovskites. The nano-assemble model from perovskite intermediated [PbI₆]⁴⁻ cage nanoparticles to bulk polycrystals is proposed to understand perovskites formation at a molecular- or nano-level. A crystallisation-depletion mechanism is developed to elucidate the periodic crystallisation and the kinetically trapped morphology at a mesoscopic level. Based on these in situ dynamics studies, the whole process of the perovskites formation and transformation from the molecular to the microstructure over relevant temperature and time scales is successfully demonstrated.

The photovoltaic performances of perovskite materials are strongly influenced by their crystallinity and film morphology. Here, the authors investigate the formation and morphology evolution mechanisms of lead halide perovskites and reveal that bulk polycrystals grow from intermediate [PbI6]⁴⁻ cage nanoparticles.

Enhance understanding of rhythmic crystallization in confined evaporating polymer solution films: from environment to solution film and then to one period

An enhanced understanding of rhythmic crystallization in an evaporating polymer solution is explored from the environment to the film and to within one period.

Structures and morphologies of biocompatible and biodegradable block copolymers

Biocompatible and biodegradable block copolymers (BBCPs) have become increasingly important in polymer science, and have many potential applications in polymer materials.