Size-Controlled Nanoparticle-Guided Assembly of Block Copolymers for Convex Lens-Shaped Particles

Abstract

The tuning of interfacial properties at selective and desired locations on the particles is of great importance to create the novel structured particles by breaking the symmetry of their surface property. Herein, a dramatic transition of both the external shape and internal morphology of the particles of polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) was induced by precise positioning of size-controlled Au nanoparticle surfactants (Au NPs). The size-dependent assembly of the Au NPs was localized preferentially at the interface between the P4VP domain at the particle surface and the surrounding water, which generated a balanced interfacial interaction between two different PS/P4VP domains of the BCP particles and water, producing unique convex lens-shaped BCP particles. In addition, the neutralized interfacial interaction, in combination with the directionality of the solvent-induced ordering of the BCP domains from the interface of the particle/water, generated defect-free, vertically ordered porous channels within the particles. The mechanism for the formation of these novel nanostructures was investigated systemically by varying the size and the volume fraction of the Au NPs. Furthermore, these convex lens-shaped particles with highly ordered channels can be used as a microlens, in which the light can be concentrated toward the focal point with enhanced near-field signals. And, these particles can possess additional optical properties such as unique distribution of light scattering as a result of the well-ordered Au cylinders that filled into the channels, which hold great promise for use in optical, biological-sensing, and imaging applications.

Comparative Study of Poly(4-vinylpyridine) and Polylactic Acid-block-poly (2-vinylpyridine) Nanocomposites on Structural, Morphological and Electrochemical Properties

“…Poly(4-vinylpyridine) (P4VP) as a synthetic water soluble polymer and coordinative reagent for transition metals has been paid much attention in recent years, which is often used to extract heavy metals in waste water treatment and also as a host ligand of metal-containing chromospheres (Li et al 2008(Li et al , 2007. P4VP and P2VP are also frequently co-polymerized with other polymer for block copolymers (BCPs) synthesis which made up of blocks of different polymerized monomers, where they are linked by a covalent bond at their ends (Ku et al 2014). BCPs made of blocks of different polymerized monomers linked by covalent bonds at their ends likewise attracted interest based on their structure, size and chemical composition.…”

Aspect ratio effect of nanorod surfactants on the shape and internal morphology of block copolymer particles

“…Recently, controlling the position of NPs at the interface between the BCP particle and the surrounding media led to a dramatic change in the internal morphology and overall shape of the BCP particles by tuning their interfacial properties. [33][34][35] For example, we achieved precise positioning of size-controlled Au NPs in the BCP particles and controlled the interfacial properties at selective locations on the particle surface, generating the interesting morphological transitions of the BCP particles. 33 Herein, we exploited the particles of polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) BCPs to investigate the AR effect of NRs on their location in the BCP domains and on the internal morphology and the overall shape of the BCP particles.…”

“…Figure 1 illustrates the fabrication of BCP particles from the mixture of PS 27k -b-P4VP 7k (PDP) 0.5 and ARcontrolled CuPt NRs using the "emulsion-encapsulation and evaporation process." [31][32][33]39 Depending on the AR value of the CuPt NRs, the ratio of the length of the NRs over the size of the NR-hosting P4VP(PDP) domain (l/L) was varied from 0.14 to 2.16. It was found that the l/L value was a key parameter in determining the positioning of the NRs in the Additional Supporting Information may be found in the online version of this article.…”

“…In addition, when the NRs were segregated at the surfaces of the BCP particles, significant gains of enthalpic energy were expected by reducing the unfavorable interfacial interactions between the BCP emulsion/water. 27,33 In this case, both CuPt NRs and CTAB surfactants rearranged themselves at the surface of the BCP emulsion by interacting with two different domains of the PS-b-P4VP(PDP), respectively, driven by favorable interactions between the NRs and the P4VP(PDP) domain and between the CTAB and the PS domain. 35,36 This could generate a balanced interaction between the PS/P4VP domains of the BCP particles and the surrounding water during emulsion, leading to the formation of the convex-shaped BCP particles.…”

“…[33][34][35] For example, we achieved precise positioning of size-controlled Au NPs in the BCP particles and controlled the interfacial properties at selective locations on the particle surface, generating the interesting morphological transitions of the BCP particles. 33 Herein, we exploited the particles of polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) BCPs to investigate the AR effect of NRs on their location in the BCP domains and on the internal morphology and the overall shape of the BCP particles. The lengths (l) of the CuPt NRs were tuned from 2.6 to 40 nm with a fixed width (w) of 2.6 nm, thus producing five different AR values of 1, 3, 6, 10, and 15.…”