Crystallization Behavior of Poly(ethylene oxide) in Vertically Aligned Carbon Nanotube Array

We investigate the effect of the presence of vertically aligned multiwalled carbon nanotubes (CNTs) on the orientation of poly­(ethylene oxide) (PEO) lamellae and PEO crystallinity. The high alignment of carbon nanotubes acting as templates probably governs the orientation of PEO lamellae. This templating effect might result in the lamella planes of PEO crystals oriented along a direction parallel to the long axis of the nanotubes. The presence of aligned carbon nanotubes also gives rise to the decreases in PEO crystallinity, crystallization temperature, and melting temperature due to the perturbation of carbon nanotubes to the crystallization of PEO. These effects have significant implications for controlling the orientation of PEO lamellae and decreasing the crystallinity of PEO and thickness of PEO lamellae, which have significant impacts on ion transport in PEO/CNT composite and the capacitive performance of PEO/CNT composite. Both the decreased PEO crystallinity and the orientation of PEO lamellae along the long axes of vertically aligned CNTs give rise to the decrease in the charge transfer resistance, which is associated with the improvements in the ion transport and capacitive performance of PEO/CNT composite

Chemically Modified Surface Having a Dual-Structured Hierarchical Topography for Controlled Cell Growth

This report describes a technique for fabricating dual-structured hierarchical surface topography on the surface of polydimethylsiloxane (PDMS) films through simply replicating prefabricated patterns and wrinkling PDMS films. To enhance the biocompatibility of PDMS films, we synthesize a biocompatible dopamine-glycopolymer, which is utilized to modify the chemical feature of the PDMS surface. Dopamine component in this copolymer is introduced for the formation of a carbohydrate layer on the surface of PDMS films because of its excellent adhesion. The carbohydrate component in this copolymer enhances the interactions between cells and PDMS films. We investigate the influence of the chemical and topographical surface properties of the extracellular matrix on fibroblast cell growth. The coupling of the dopamine-glycopolymer coating and hierarchical topography produces the best induction effect on the alignment of cells