Nanocomposites Based on Coil-Comb Diblock Copolymers

Abstract

Polymer chain architecture is an important factor determining the phase behavior of nanoparticle (NP) assembly in polymer matrices. Block copolymers (BCPs) containing a random copolymer (RCP) block present a convenient variation on traditional BCPs to tune the interaction parameters between the polymer blocks and the nanofillers as well as to evaluate the effect of chain architecture on the NP arrangements within BCP microdomains. Here, we synthesized BCPs with a coil polystyrene (PS) block and a comb RCP block through reversible addition-fragmentation chain transfer polymerization. The RCP block consists of methyl-and 1 lauryl acrylates, the latter which confers a long-chain alkyl moiety to favorably interact with alkyl-passivated NPs. BCPs showing lamellar, cylindrical, and mixed morphologies were obtained by varying the volume fractions of the RCP block (f RCP ). In comparison to coil-coil BCP, the coil-comb BCPs show highly asymmetric phase behavior with respect to f RCP , where lamellar morphologies were observed at f RCP from 0.31 to 0.51. NPs in the size of 4-5 nm were successfully incorporated in the RCP block of the BCPs with periodicities of 30-60 nm. An order-to-order phase transition from lamellae to PS cylinders was observed after the addition of only 1-2 vol% of 5 nm NPs into the BCP with a periodicity of 25 nm and f RCP of 0.51. Selfconsistent field theory-density functional theory simulations qualitatively described the observed morphologies and phase transitions in the nanocomposites. The current study presents a platform to fabricate nanocomposites with NP assemblies in coil-comb BCPs that contain a random copolymer block, and provides insight into how polymer chain architecture can affect the phase behavior of BCPs and nanocomposites.

Hierarchical Colloidosomes and Superlattices via Confined Assembly of Polymer-Tethered Inorganic Nanoparticles

“…Metal nanoparticles (NPs) have attracted great interest due to their unique quantum effect. − However, spatial organization of NPs into hierarchical superstructures with a highly ordered internal arrangement can derive excellent and novel collective properties compared with those of the conventional single-metal NPs, such as optical, mechanical, and catalytic properties, arising from the strong interactions between adjacent NPs. − Over the past decade, researchers have used a variety of strategies to fabricate hierarchical ordered superstructures, for example, hydrophilic–hydrophobic interactions, electric and magnetic fields, DNA templating, solvent evaporation, and emulsification. − For example, Luo et al used DNA as a “dry ligand” to mediate the self-assembly process and then obtained free-standing NP superlattices . The inter-particle spacing and plasmonic properties can be tuned by controlling the length of DNA.…”

Hybrid Dielectric Films of Inkjet‐Printable Core–Shell Nanoparticles

“…Such tuned structures of AuNPs have been reported recently by the usage of PS block and random copolymers. [47] Inkjet-printed thin film capacitors with a 17 nm thick dielectric layer and a capacitance of 2.2 ± 0.1 nF@1 kHz over 0.79 mm 2 were prepared in air at room temperature without any posttreatment of the dielectric. The polymer shells of the particles were sufficiently mobile to reliably form insulating layers.…”

“…Such tuned structures of AuNPs have been reported recently by the usage of PS block and random copolymers. [ 47 ]…”

Synthesis, Hydrophilicity and Micellization of Coil-Brush Polystyrene-b-(polyglycidol-g-polyglycidol) Copolymer—Comparison with Linear Polystyrene-b-polyglycidol

“…Recently, amphiphilic block copolymers with coil-brush (also named coil-bottle brush or coil-comb) architecture were synthesized. For instance, polystyrene coil and brush composed of methyl and lauryl acrylates and oligo(ethylene glycol) methyl ether acrylate were used to produce hierarchically structured nanocomposites [22]. Other studies revealed that self-assembly of amphiphilic copolymers composed of poly(N-methylglycine)-b-poly(Ndecyl glycine) leads to formation of nano-or microsized particles with various shape and morphology from long worm-like structures to 2D sheets, depending on N-decyl glycine content in copolymer [23].…”