Controlled Assembly of Block Copolymer Coated Nanoparticles in 2D Arrays

Abstract

The defined assembly of nanoparticles (NPs) in polymer matrices is an important prerequisite for next‐generation functional materials. A promising approach to control NP positions in polymer matrices at the nanometer scale is the use of block copolymers. It allows the selective deposition of NPs in nanodomains, but the final defined and ordered positioning of the NPs within the domains has not been possible. This can now be achieved by coating NPs with block copolymers. The self‐assembly of block copolymer‐coated NPs directly leads to ordered microdomains containing ordered NP arrays with exactly one NP per unit cell. By variation of the grafting density, the inter‐nanoparticle distance can be controlled from direct NP surface contact to surface separations of several nanometers, determined by the thickness of the polymer shell. The method can be applied to a wide variety of block copolymers and NPs and is thus suitable for a broad range of applications.

Spin crossover in Fe(triazole)–Pt nanoparticle self-assembly structured at the sub-5 nm scale

“…31 By this strategy, we obtained a hybrid system, consisting of lamellae where the NPs aligned with a periodicity of 3 nm. Specific lamellar SA of nanoparticles have already been reported, with liquid crystals, 32 diblock copolymers, [33][34][35] or peptidic polymers. 36 But to our knowledge, even if demonstrated for molecular clusters, 37 no work has described organization of ultra-small NPs in quasi perfect linear assemblies with a periodicity lower than 5 nm, so far.…”

3D‐Positioning of Nanoparticles in High‐Curvature Block Copolymer Domains

“…The scattering curve at the lowest grafting density shows an increased intensity at the onset of the Porod-regime at q % 1.3 nm À1 indicating nanoparticle multiplet formation similar as reported in 2D for low grafting densities. [20] Forthe nanocomposite with the highest grafting density of s = 0.76 nm À2 the ratios for the positions of the 9o bserved reflections is 1:1.73( p…”

“…This is on first instance counter intuitive,since lower grafting densities correspond to larger nanoparticle volume fractions. Forahomogeneous distribution of nanoparticles this would lead to smaller inter-particle distances,l eading to peak shifts to higher q-values.Inthe present case the nanoparticles form alinear array within cylindrical domains.Itisalready known from 2D-studies [14,20] that lower ligand grafting densities reduce the distance between the nanoparticles.T his is accompanied by ar edistribution of ligand polymers from the inter particle region to the peripheral region of the cylindrical domains,w hich increases the inter cylinder distance.Asthe first order peak position is directly related to the inter cylinder distance,aconcomitant shift to lower q-values is…”

“…This has been demonstrated for polymer-coated Au-nanoparticles in thin films of bottle brush copolymers, [15] for block copolymer-coated iron oxide nanoparticles in micellar monolayers, [16][17][18] as well as for CuS nanoplatelets in PS-P4VP [19] and two-dimensional assemblies. [20] Fora lmost all applications of nanocomposites the 3Dassembled structure is most relevant. Yet, the ordered and stoichiometric localization of nanoparticles within 3D-block copolymer domains is still achallenge without the guidance of planar substrates or interfaces.F urthermore,i tc an have considerable complexity,a st he incorporation of nanoparticles in diblock copolymers can lead to ternary phase systems with as tructural variability comparable to ABC triblock copolymers.…”

Self-assembly for electronics

“…An additional layer of information content can be added if the polymeric ligand is a block copolymer chain. 47…”