Predicting the Mesophases of Copolymer-Nanoparticle Composites

Abstract

The interactions between mesophase-forming copolymers and nanoscopic particles can lead to highly organized hybrid materials. The morphology of such composites depends not only on the characteristics of the copolymers, but also on the features of the nanoparticles. To explore this vast parameter space and predict the mesophases of the hybrids, we have developed a mean field theory for mixtures of soft, flexible chains and hard spheres. Applied to diblock-nanoparticle mixtures, the theory predicts ordered phases where particles and diblocks self-assemble into spatially periodic structures. The method can be applied to other copolymer-particle mixtures and can be used to design novel composite architectures.

Control of Nanoparticle Location in Block Copolymers

“…Localizing particles near the center of the compatible domain thus sacrifices translational entropy of the particles but avoids an even larger chain stretching penalty incurred by distributing particles throughout the domain. 1 In contrast to particles that are coated with either PS or PVP, particles that are coated with a mixture of PS and PVP thiols are localized at the interfaces between the PS-PVP blocks, as can be seen in Figure 2c. Analysis of the particle center locations in Figure 2d shows a sharp peak at the interface of the PS and PVP blocks, indicating strong adsorption of particles.…”

Controlled Ordering of Block Copolymer Thin Films by the Addition of Hydrophilic Nanoparticles

“…In Figure 6, it is evident that the majority of Au-PEO nanoparticles reside within the PMMA domains, which is consistent with the theoretical prediction by Balazs and coworkers. [5][6][7] In this system, the d/L ratio is ∼0.4, which is estimated from the overall diameter of Au-PEO nanoparticles and the size of the PMMA domains. Therefore, one can expect that the Au-PEO nanoparticles should be localized at the center of PMMA domains.…”

“…In terms of nanoparticles, Balazs and co-workers have recently suggested that the nanoparticle position can be simply controlled by the ratio d/L, where d is the particle size and L is the size of block copolymer domain. [5][6][7] When d/L g 0.3, they predict that the particles are localized around the center of domain due to the chain stretching penalty, while the particles move outward to the interface when d/L becomes smaller. Several experimental approaches have been developed to confirm this prediction, [8][9][10] and more recent work has examined the effect of chemistry where the surface of nanoparticle is tuned to allow favorable interactions between nanoparticles and block copolymers, which in turn allows their location to be influenced.…”

Selective Doping of Block Copolymer Nanodomains by Sputter Deposition of Iron

“…Therefore, templates of such long-range hexagonal array of upright cylindrical domains, in a thin film of a block copolymer, can serve as advanced host materials for metal nanostructures. 1,[24][25][26][27][28][29][30][31][32] So far, there have been several methods used to install metal nanostructures inside of the block copolymer domains. Among them, one common method is to remove the minor block from the film and refill the produced pores with the desired metallic materials.…”