Grafting density induced reentrant disorder–order–disorder transition in planar di-block copolymer brushes

By means of multiscale molecular simulation, we here present a re-entrant disorder/order/disorder transition in diblock copolymer brushes.

Full parameter space exploration of microphase separation of block copolymer brushes within a single simulation framework

Block copolymer brushes where chains are grafted onto the substrate have been of special interest due to their capability to form various self-assembled nanoscale structures. The self-assembled structures depend on...

Water-dispersed fluorescence nanomaterials based on boron nitride nanotubes

Water-dispersed fluorescence nanomaterials based on boron nitride nanotubes and grafted copolymer brushes (poly(acrylic acid-co-fluorescein acrylate) were successfully fabricated in a two-step process. The functionalization of BNNTs was confirmed by spectroscopic, gravimetric and imaging techniques. In contrast to “pure” BNNTs, functionalized BNNTs demonstrate intense green fluorescence emission at 520 nm. The developed hybrid structure can potentially be used for cellular imaging, as “smart” surfaces, nanotransducers and nanocarriers.

Synthesis of Block Copolymer Brush by RAFT and Click Chemistry and Its Self-Assembly as a Thin Film

A well-defined block copolymer brush poly(glycidyl methacrylate)-graft-(poly(methyl methacrylate)-block- poly(oligo(ethylene glycol) methyl ether methacrylate)) (PGMA-g-(PMMA-b-POEGMA)) is synthesized via grafting from an approach based on a combination of click chemistry and reversible addition-fragmentation chain transfer (RAFT) polymerization. The resulting block copolymer brushes were characterized by 1H-NMR and size exclusion chromatography (SEC). The self-assembly of the block copolymer brush was then investigated under selective solvent conditions in three systems: THF/water, THF/CH3OH, and DMSO/CHCl3. PGMA-g-(PMMA-b-POEGMA) was found to self-assemble into spherical micelle structures as analyzed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The average size of the particles was much smaller in THF/CH3OH and DMSO/CHCl3 as compared with the THF/water system. Thin film of block copolymer brushes with tunable surface properties was then prepared by the spin-coating technique. The thickness of the thin film was confirmed by scanning electron microscopy (SEM). Atom force microscopy (AFM) analysis revealed a spherical morphology when the block copolymer brush was treated with poor solvents for the backbone and hydrophobic side chains. The contact angle measurements were used to confirm the surface rearrangements of the block copolymer brushes.