Nanocomposites, composed of organic and inorganic building blocks, can combine the properties from the parent constituents and generate new properties to meet current and future demands in functional materials. Recent developments in nanoparticle synthesis provide a plethora of inorganic building blocks, building the foundation for constructing hybrid nanocomposites with unlimited possibilities. The properties of nanocomposite materials depend not only on those of individual building blocks but also on their spatial organization at different length scales. Block copolymers, which microphase separate into various nanostructures, have shown their potential for organizing inorganic nanoparticles in bulk/thin films. Block copolymer-based supramolecules further provide more versatile routes to control spatial arrangement of the nanoparticles over multiple length scales. This review provides an overview of recent efforts to control the hierarchical assemblies in block copolymer-based hybrid nanocomposites.

Anisotropic nanoparticles are ideal building blocks for a variety of functional materials due to their unique and anisotropic optical, electronic, magnetic and mechanical properties. Precise control over the orientation and spatial arrangement of these nanomaterials is often requisite to achieve coupling between nanoparticles and thereby translate the properties of individual nanoparticles to macroscopic material properties. The physics and thermodynamics involved in the self-assembly are inherently more complex than isotropic nanoparticles due to the anisotropy within the system. However, the anisotropy also introduces anisotropic nanoparticle surface chemistry and stronger interparticle interactions which could be leveraged to achieve selfassembly. To address these challenges and opportunities, a plethora of strategies have been conceived and developed to induce the self-assembly of anisotropic nanoparticles into desired nanostructures over macroscopic areas and volumes. These strategies involve manipulation of interparticle physical interactions, modification of nanoparticle surface chemistry, application of external fields, and utilization of physically or chemically patterned templates to achieve the required level of spatial and orientational control over the assembly of anisotropic nanoparticles. The resulting ordered anisotropic nanoparticle assemblies display strong plasmonic, electronic, and excitonic coupling, which render these assemblies as ideal materials for chemical and biological sensing, energy harvesting, and many other technological applications. Considering the rapid advancement in this field of research, this review aims to provide an overview of the assembly, applications, and opportunities of anisotropic nanomaterials.

Functional nanocomposites containing nanoparticles of different chemical compositions may exhibit new properties to meet demands for advanced technology. It is imperative to simultaneously achieve hierarchical structural control and to develop rapid, scalable fabrication to minimize degradation of nanoparticle properties and for compatibility with nanomanufacturing. Here we show that the assembly kinetics of supramolecular nanocomposites in thin films are governed by the energetic cost arising from defects, the chain mobility and the activation energy for inter-domain diffusion. By optimizing only one parameter, the solvent fraction in the film, the assembly kinetics can be precisely tailored to produce hierarchically structured thin films of supramolecular nanocomposites in one minute. Moreover, the strong wavelength-dependent optical anisotropy in the nanocomposite highlights their potential applications for light manipulation and information transmission. The present study may open a new avenue in designing manufacture-friendly continuous processing for the fabrication of functional nanocomposite thin films.

Hybrid nanoparticle (NP) arrays based on particles of different sizes and chemistries are highly desirable to obtain tunable properties for nanodevices. A simple approach to control the spatial organization of NP mixtures within supramolecular frameworks based on NP size has been developed. By varying the ratio of the NP size to the periodicity of the block-copolymer-based supramolecule, a range of hybrid NP assemblies in thin films, ranging from 1D chains to 2D lattices and 3D arrays and networks of NPs, can be readily generated.

We demonstrated a versatile approach to obtain layered nanoparticle sheets with in-plane hexagonal order and 3-D ordered arrays of single nanoparticle chains in thin films upon blending nanoparticles with block copolymer (BCP)-based supramolecules. Basic understanding on the thermodynamic and kinetic aspects of the assembly process paved a path to manipulate these assemblies to meet demands in nanoparticle-based device fabrication and understand structure-property correlations.