Search results for "Copolymer"

Synthesis of Functional Block Copolymers Carrying One Poly(p-phenylenevinylene) and One Nonconjugated Block in a Facile One-Pot Procedure

2016

Block copolymers composed of a MEH–PPV block and a nonconjugated functional block (molecular weights between 5 and 90 kg/mol) were synthesized in a facile one-pot procedure via ROMP. This one-pot procedure permits the synthesis of numerous block copolymers with little effort. Amphiphilic block copolymers were obtained via incorporation of oxanorbornene carrying a PEG side chain as well as via postpolymerization modification of a reactive ester carrying norbornene derivative with methoxypoly(ethylene glycol)amine. These amphiphilic block copolymers can be self-assembled into micelles exhibiting different sizes (60–95 nm), morphologies (micelles or fused, caterpillar-like micelles), and optic…

Nanopattern Evolution in Block Copolymer Films: Experiment, Simulations and Challenges

2010

The present contribution reviews novel insights into block copolymer phase behavior and nanostructure formation in confined geometries. We focus on state-of-the-art experimental and theoretical progress in this area, with an emphasis on characterization methods and techniques that provide a quantitative framework for fundamental analysis. We discuss and compare basic system parameters that are readily controlled in simulations and in experiments, and present comparative stud- ies of increasing degree of complexity concerning the phase behavior and ordering dynamics of cylinder- and lamella-forming block copolymers in thin films.

Bimetallic PdAg nanoparticle arrays from monolayer films of diblock copolymer micelles

2015

MICROSCOPIE+ATARI+EEH:GMA:TBG:NSP:MAO; International audience; The self-assembly technique provides a highly efficient route to generate well-ordered structures on a nanometer scale. In this paper, well-ordered arrays of PdAg alloy nanoparticles on flat substrates with narrow distributions of particle size (6-7 nm) and interparticle spacing (about 60 nm) were synthesized by the block copolymer micelle approach. A home-made PS-b-P4VP diblock copolymer was prepared to obtain a micellar structure in toluene. Pd and Ag salts were then successfully loaded in the micellar core of the PS-b-P4VP copolymer. A self-assembled monolayer of the loaded micelles was obtained by dipping the flat substrate …

Secondary-Structure-Driven Self-Assembly of Reactive Polypept(o)ides: Controlling Size, Shape, and Function of Core Cross-Linked Nanostructures.

2017

Achieving precise control over the morphology and function of polymeric nanostructures during self-assembly remains a challenge in materials as well as biomedical science, especially when independent control over particle properties is desired. Herein, we report on nanostructures derived from amphiphilic block copolypept(o)ides by secondary-structure-directed self-assembly, presenting a strategy to adjust core polarity and function separately from particle preparation in a bioreversible manner. The peptide-inherent process of secondary-structure formation allows for the synthesis of spherical and worm-like core-cross-linked architectures from the same block copolymer, introducing a simple y…

Production of polymeric micro- and nanostructures with tunable properties as pharmaceutical delivery systems

2020

Abstract The production of novel graft copolymers based on poly-e-caprolactone (PCL) and polyaspartamide are useful to realize structures for potential biomedical applications. Here, the synthesis of pegylated PCL/polyhydroxyethyl aspartamide (PHEA) graft copolymers (PHEA-g-SUCC-PCL-g-PEG) with tunable composition, was achieved by followpling a synthetic strategy that involved first the grafting of preformed PCL on PHEA backbone, then polyethylen glycol (PEG), by using 1,1′-carbonyldiimidazole (CDI) to speed up the condensation reaction. Graft copolymers with a Derivatization Degree (DD) in PCL ranging between 1.1 and 4.4 mol% were obtained, and processable with different technologies for t…

Self-Assembly of block copolymers into internally ordered microparticles

2020

Abstract Block copolymer (BCP) self-assembly is one of the most versatile concepts for the bottom-up design of functional nanostructures in materials science, nanomedicine and nanotechnology. While BCPs have been extensively studied regarding their microphase separation in bulk and the self-assembly in solution, only recently BCPs were investigated for their ability to form internally ordered microparticles. In this review, we discuss two emerging concepts: (i) the microphase separation of BCPs in the spherical confinement of evaporating emulsion droplets and (ii) the self-assembly of highly asymmetric BCPs under concentrated conditions. While the first concept yields solid and compact mult…

Chiral helical nanostructures based on amorphous abc-triblock copolymers

1995

So far all lattices of regular microdomain structures reported in the literature, either based on binary AB, ABA or ternary ABC block copolymers, can be described using simple symmetry elements like mirror planes, symmetry centers and rotation axes. The microphase separation in a linear ternary block copolymer consisting of three immiscible components namely polystyrene, polybutadiene and polymethyl methacrylate gives rise to the formation of a chiral supramolecular assembly in which chirality is not defined on a molecular (or macromolecular) level but only by the assembly of the linear triblock copolymer molecules. The polybutadiene (7, 12 wt.-%) phase forms helical strands surrounding the…

Dual Functionalization of Nanostructures of Block Copolymers with Quantum Dots and Organic Fluorophores

2014

Selectivity of cyclodextrins as a parameter to tune the formation of pseudorotaxanes and micelles supramolecular assemblies. A systematic SANS study

2011

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich. This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. We studied the formation of polypseudorotaxanes formed with cyclodextrins (CDs) threading a copolymer chain that forms self-assembled structures in water. The size of the CD cavity was chosen such that it is block selective with respect to the formation of inclusion complexes and therefore in terms of altering the structure of the copolymer self-assemblies in a systematic fashio…

Photocleavable core cross-linked polymeric micelles of polypept(o)ides and ruthenium(II) complexes

2021

Core cross-linking of polymeric micelles has been demonstrated to contribute to enhanced stability that can improve the therapeutic efficacy. Photochemistry has the potential to provide spatial resolution and on-demand drug release. In this study, light-sensitive polypyridyl-ruthenium(II) complexes were combined with polypept(o)ides for photocleavable core cross-linked polymeric micelles. Block copolymers of polysarcosine-block-poly(glutamic acid) were synthesized by ring-opening N-carboxyanhydride polymerization and modified with aromatic nitrile-groups on the glutamic acid side chain. The modified copolymers self-assembled into micelles and were cross-linked by cis-diaquabis(2,2'-bipyridi…