Orthogonal Templating Control of the Crystallisation of Poly(ε-Caprolactone)

Abstract

Abstract:The crystal growth of poly(ε-caprolactone) can be very effectively directed through the use of small amounts of dibenzylidene sorbitol in conjunction with modest flow fields to yield extremely high levels of the preferred polymer crystal orientation. We show that by introducing small quantities of a terpolymer, based on polyvinyl butyral we can switch the symmetry axis of the final lamellar orientation from parallel to perpendicular to the melt flow direction. During shear flow of the polymer melt, the dibenzylidene sorbitol forms highly extended nanoparticles which adopt a preferred alignment with respect to the flow field and on cooling, polymer crystallisation is directed by these particles. The presence of the terpolymer, based on polyvinyl butyral, limits the aspect ratio of the dibenzylidene sorbitol (DBS) particles, such that the preferred orientation of the particles in the polymer melt changes from parallel to normal to the flow direction. The alignment of lamellar crystals perpendicular to the flow direction has important implications for applications such as scaffolds for tissue engineering and for barrier film properties.

Comparative AFM Studies on the Morphology of Conducting Polymers/DNA Templated Nanowires

“…DNA is an effective template for the conformation of nanowires (NWs) by wet chemical styles because it's available as extremely monodisperse samples with exceptional control over the length and it's chemically robust. It will retain its introductory structural integrity under the response conditions necessary to form conductive polymers and metals in as much as high temperature or strong acid are not required (Mitchell and Olley 2018). Conductive polymers are attractive materials to template on DNA because together they form smooth, conductive nanowires (NWs) which provide access to a wide range of chemical functionality for subsequent applications.…”