title: Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives.
abstract: A facile method for the preparation of polycarbodiimide-based secondary structures (e.g., nano-rings, "craters," fibers, looped fibers, fibrous networks, ribbons, worm-like aggregates, toroidal structures, and spherical particles) is described. These aggregates are morphologically influenced by extensive hydrophobic side chain-side chain interactions of the singular polycarbodiimide strands, as inferred by atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques. Polycarbodiimide-g-polystyrene copolymers (PS-PCDs) were prepared by a combination of synthetic methods, including coordination-insertion polymerization, copper(I)-catalyzed azide alkyne cycloaddition (CuAAC) "click" chemistry, and atom transfer radical polymerization (ATRP). PS-PCDs were found to form specific toroidal architectures at low concentrations in CHCl3. To determine the influence of a more polar solvent medium (i.e., THF and THF/EtOH) on polymer aggregation behavior, a number of representative PS-PCD composites have been tested to show discrete concentration-dependent spherical particles. These fundamental studies are of practical interest to the development of experimental procedures for desirable architectures by directed self-assembly in thin film. These architectures may be exploited as drug carriers, whereas other morphological findings represent certain interest in the area of novel functional materials.
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Dallas; oleg.kulikov.chem@gmail.com.
authors.forename: Oleg V
authors.initials: OV
authors.lastname: Kulikov
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Dallas.
authors.forename: Dumindika A
authors.initials: DA
authors.lastname: Siriwardane
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Dallas.
authors.forename: Gregory T
authors.initials: GT
authors.lastname: McCandless
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Dallas.
authors.forename: Samsuddin F
authors.initials: SF
authors.lastname: Mahmood
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Dallas; bxn111230@utdallas.edu.
authors.forename: Bruce M
authors.initials: BM
authors.lastname: Novak
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D001386:Azides / Q000737:chemistry; D002384:Catalysis; D057930:Click Chemistry / Q000379:methods*; D061565:Cycloaddition Reaction; D004337:Drug Carriers; D018625:Microscopy, Atomic Force; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D014230:Triazoles / Q000737:chemistry*
chemical_list: D000480:Alkynes; D001386:Azides; D004337:Drug Carriers; D011108:Polymers; D014230:Triazoles