Abstract: (8228 Views)
Single crystals of double crystalline block copolymers of poly(ethylene glycol) (PEG)-b-poly(ε-caprolactone) (PCL) and PEG-b-poly(L-lactide) (PLLA) were grown from dilute solution in homo- and mixed-brush systems. Crystallization behavior of biodegradable one end-restricted crystallizable PCL and PLLA chains in homo- and mixed-brush nanostructures were investigated. Chemical and physical circumstances of crystallizable brushes were altered. Physical environment was adjusted by amorphism/crystallinity and rigidity/flexibility of neighboring brushes. Chemical environment was manipulated by interaction and miscibility of various brushes. Distinct single crystals were grown with mixed-brushes of amorphous-crystalline (polystyrene (PS), poly(methyl methacrylate) (PMMA), PCL and PLLA, double crystalline (PCL/PLLA), and rod-crystalline polyaniline (PANI)/PCL or PLLA. Surrounding was only effective on hindrance or nucleation commencement of crystallization for crystallizable brushes and had no effect on crystallization features. Novel three-layer fully single crystalline nanostructures, whose characteristics were fixed via changing the crystallization temperature, were also developed. For long crystallizable tethers, crystallization increased both brush and substrate thicknesses.
Type of Study:
Research Paper |
Subject:
Ceramics