Morphology Evolution of PS-b-P2VP Diblock Copolymers via Supramolecular Assembly of Hydroxylated Gold Nanoparticles

Abstract

ABSTRACT:We report on the strong segregation of core− shell Au nanoparticles, with a shell layer consisting of a random copolymer brush of styrene and vinylphenol (PS-rPVPh-SH), in poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) diblock copolymer. Because of the formation of multiple hydrogen bonds between the hydroxyl groups within the shell of the nanoparticles and the pyridine group in PS-b-P2VP, the Au nanoparticles were strongly localized into P2VP domains with a very high volume fraction of nanoparticles (ϕ p ∼ 0.53). The spatial distribution of Au nanoparticles, observed by transmission electron microscopy (TEM), is compared with results of previous experiments where homopolymers were blended with block copolymers. If the diameter d of the nanoparticles is much less than the width D of the P2VP lamellar domains, these nanoparticles are more uniformly distributed across the P2VP domain than if d is comparable to D, in which case the nanoparticles are pushed toward the center of the P2VP domains. This behavior is similar to that observed when homopolymers are blended with block copolymers. Novel morphological transitions from spherical to cylindrical P2VP morphologies and from lamellae to cylindrical PS morphologies were observed during coassembly of these functional nanoparticles with block copolymers.

Improving Faraday rotation performance with block copolymer and FePt nanoparticle magneto-optical composite

“…BCPs can microphase segregate into versatile periodic structures at the nanoscale, with facile control over the volume fraction and chemical nature of the two blocks [59][60][61][62][63]. Strong NP/BCP interactions have been shown to selectively integrate functional NPs into specific domains with desired size, filling fractions, and building block directions [64][65][66][67][68][69][70]. Resulting hybrid materials, with improved electric and optical properties, have been utilized in organic field effect transistor [71] and polymeric Bragg mirrors [72,73].…”

Colloidal Nanocrystal Frameworks

“…[41][42][43][44][45] It is possible to manipulate their interfacial interactions with colloidal nanocrystal building units further, through additional synthetic manipulations or the use of additives. [46][47][48][49][50][51] In the end, any imposed set of interactions needs to be quite favorable so that order is retained during CNF thermal processing, and framework collapse is avoided. [52][53][54][55][56][57] Those that do allow ordered CNFs to be reliably assembled have been carefully confi gured so as to provide access to the greatest range of framework architectures with respect to pore dimension (ca.…”

“…For ligand-coated nanocrystals, poly(4-vinyl pyridine) (P4VP) microdomains have been shown to interact favorably with noble metal and semiconductor nanocrystals bearing hydroxylterminated organic ligands or interfacial additives; [46][47][48][49][50][51] here, the fundamental interaction is based on hydrogen bonding at the ligand-ADA interface. While mesostructured composites have been generated using this strategy, there have been no further reports indicating that stable CNFs can be derived therefrom.…”

“…Interestingly, most examples of CNF assembly under thermodynamic control have been reported using ligand-coated nanocrystals. [ 21,22,[46][47][48][49][50][51] In these instances, the mesostructural organization of the block copolymers ADAs in thin fi lms provides the dominant organizational scaffold; [52][53][54][55][56][57] to support CNF architectures, nanocrystals should be arranged in the continuous BCP-derived mesophase, or along a continuous interface (e.g., as in a gyroidal phase-segregated BCP morphology). Thermodynamic control generally requires extensive thermal annealing to physically arrange components in the composite, which can be time-consuming owing to the slow diffusion of nanoscale components (i.e., relative to a small molecule).…”

Phase Behavior of Copolymers Confined in Multi-Walled Nanotubes: Insights from Simulations

“…Two-dimensional (2D) confinement in the form of cylindrical pores with curved surfaces presents a more tightly confined geometry than that of thin films, and 2D confinements have been demonstrated to provide rich, varied structures. The use of cylindrical nanotubes produces 2D confinement with varying diameters for diblock copolymers as-studied in theory [16][17][18], simulation [19][20][21][22][23][24][25], and experiments [26][27][28][29][30][31]. Previous studies have also shown that the combined effects of confinement and curvature significantly influence the morphologies of copolymers in self-assembled systems.…”