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The wide accessibility to nanostructures with high uniformity and controllable sizes and morphologies provides great opportunities for creating complex superstructures with unique functionalities. Employing anisotropic nanostructures as the building blocks significantly enriches the superstructural phases, while their orientational control for obtaining long-range orders has remained a significant challenge. One solution is to introduce magnetic components into the anisotropic nanostructures to enable precise control of their orientations and positions in the superstructures by manipulating magnetic interactions. Recognizing the importance of magnetic anisotropy in colloidal assembly, we provide here an overview of magnetic field-guided self-assembly of magnetic nanoparticles with typical anisotropic shapes, including rods, cubes, plates, and peanuts. The Review starts with discussing the magnetic energy of nanoparticles, appreciating the vital roles of magneto-crystalline and shape anisotropies in determining the easy magnetization direction of the anisotropic nanostructures. It then introduces superstructures assembled from various magnetic building blocks and summarizes their unique properties and intriguing applications. It concludes with a discussion of remaining challenges and an outlook of future research opportunities that the magnetic assembly strategy may offer for colloidal assembly.

A new procedure where Pd triangular or hexagonal nanoplates could be selectively synthesized by manipulating the reduction kinetics of the polyol process is described. The introduction of an oxidant into the synthesis of metal nanoparticles could effectively control their nucleation and growth into well-defined sizes and shapes.

A one-pot solution process is devised for preparing colloidal [Bi.sub.2][Te.sub.3]-Te heterogeneous nanostructures (HNs) that comprise [Bi.sub.2][Te.sub.3] nanoplates and Te nanorods. The synthesis of [Bi.sub.2][Te.sub.3]-Te HNs has provided opportunities for producing thermoelectric materials with enhanced performance.

Magnetochromatic microspheres are prepared through instant assembly of superparamagnetic (SPM) colloidal particles inside emulsion droplets of ultraviolet (UV) curable resin followed by an immediate UV curing process to polymerize the droplets and fix the ordered structures. A display unit is prepared that has on/off bistable states by embedding the magnetochromatic micropheres in a matrix that can thermally switch between solid and liquid phases.

Superparamagnetic colloids are assembled into ordered structures with magnetically tunable photonic properties in nonpolar solvents by establishing long-range electrostatic repulsive forces by using charge control agents. The system has a fast and fully reversible optical response to the external magnetic fields, long-term stability in performance and good diffraction intensity.

A synthetic route is described that is based on the nanoscale Kirkendall effect in order to produce colloidal solutions of monodisperse iron/iron oxide core-void-shell nanostructures and hollow maghemite nanoparticles with controllable particle size and shell thickness. A limitation on the size of the hollow nanostructures has depended on the iron diffusivities and the growth of the crystal size domains in the polycrystalline oxide shells.

The analysis presents the IR spectroscopic observation of the molecular transport through the yolk-shell nanostructures forming CO/Pt species. The results show that the transport of CO occurs only because of the surface diffusion of the weakly adsorbed molecule at low temperature.

Synthesis of Ag nanocrystals with reduced sizes and improved monodispersity using a modification of the polyol process in an organic solvent and at high temperature is presented. It is shown that surface-mediated shape control and achievement of a hollow morphology can be combined in a one-pot, single-step procedure, leading to finer tuning of particle morphology.

The physical constraint and capillary force can be combined to provide a generic approach for the self-assembly of achiral building blocks like spherical colloids into helical mesostructures having well-controlled handedness. The ability to process an achiral material into helical structures having well-controlled handedness must allow to obtain new functionalities like optical activity that the material otherwise does not exhibit.

A unified set of emulsion polymerization processes for the synthesis of a series of spherical and nonspherical magnetite-polystyrene composite colloids is reported. It presents the uniform size, complex shapes and structures, and superparamagnetic properties make these colloidal particles ideal building blocks for the fabrication of novel functional devices and materials.

A template-directed reaction, in which single-crystalline nanowires of trigonal Se (t-Se) are quantitatively converted into single-crystalline nanowires of Ag2Se by reacting with aqueous AgNO3 solutions at room temperature, is described. The single-crystalline one-dimensional morphology of the wire-like templates was retained in the final products with high fidelity.

Stimuli-responsive materials can sense specific environmental changes and adjust their physical properties in a predictable manner, making them highly desired components for designing novel sensors, intelligent systems, and adaptive structures. Magnetically responsive structures have unique advantages in applications, as external magnetic stimuli can be applied in a contactless manner and cause rapid and reversible responses. In this Perspective, we discuss our recent progress in the design and fabrication of nanostructured materials with various optical responses to externally applied magnetic fields. We demonstrate tuning of the optical properties by taking advantage of the magnetic fields' abilities to induce magnetic dipole--dipole interactions or control the orientation of the colloidal magnetic nanostructures. The design strategies are expected to be extendable to the fabrication of novel responsive materials with new optical effects and many other physical properties. [ABSTRACT FROM AUTHOR]

Research developing a technique of combining capillary forces and physical templates with the aim of assembling monodispersed colloids of spherical form is presented. Particular attention is given to ways of generating aggregates of colloids.

Develops a procedure for generating asymmetric dimers from two types of monodispersed, spherical colloids. Advantages and disadvantages of spherical colloids; Chemical methods developed to synthesize spherical colloids; Use of geometrical confinement and capillary forces to self-assemble two types of spherical colloids.