Design and functionality of colloidal-crystal-templated materials—chemical applications of inverse opals

Abstract

Templating with colloidal crystals composed of monodisperse spheres is a convenient chemical method to obtain porous materials with well-ordered periodicity and interconnected pore systems. The three-dimensionally ordered macroporous (3DOM) products or inverse opals are of interest for numerous applications, both for the optical properties related to structural color of these photonic crystal materials and because of their bicontinuous nanostructure, i.e., a continuous nanostructured skeleton with large interfacial area and a three-dimensionally interconnected pore system with low tortuosity. This review outlines various synthetic methods used to control the morphology of 3DOM materials with different compositions. It highlights aspects of the choice of colloidal particles, assembly of the colloidal crystal template, infiltration and processing, template removal, and other necessary modifications to enhance the functionality of the materials. It also considers syntheses within the confinement of 3DOM materials and summarizes characterization methods that are particularly useful in the analysis of 3DOM materials. The review then discusses chemical applications of 3DOM materials, namely sorption and controlled release, optical and electrochemical sensors, solar cells, lithium ion batteries, supercapacitors, fuel cells, and environmental and chemical fuel catalysis. A focus is on structural features and materials properties that enable these applications.

A colloidoscope of colloid-based porous materials and their uses

“…The inversion of a colloidal crystal, by backfilling the interstitial sites with a matrix material followed by removal of the templating colloids, produces materials with interconnected pores with uniform, defined neck sizes and long-range order inherited from the colloid templates ( Figure 3C). 57,58 These inverse opals are the subject of extensive research and will be discussed in depth in the following chapters. Direct opals are also porous and interconnected, although the pores are not spherical and the degree of porosity much lower.…”

“…CBPM can be made with high surface area, interconnected porosity, and control over material composition, all of which are important for developing catalysts having high activity and selectivity, thermal stability, and superior mass transport (Figure 23). 58,79 CBPM possess many advantageous characteristics and degrees of freedom that enable them to be designed for a wide range of catalytic applications (Figure 23). They exhibit architectural tunability easily achievable via hierarchical templating and characterized by a porous network where many factors can be controlled, including wall thickness, pore size, pore interconnectivity, and shape.…”

Colloidal crystals and water: Perspectives on liquid–solid nanoscale phenomena in wet particulate media

“…from condensation of a surrounding gas atmosphere) affects their performance, although historically this issue has barely received attention. Other applications of CCs as membranes [55], nanostructured platforms [56,57] and templates [58,59] depend on flow and diffusion processes of liquids in nanoconfinements such as the opal interstices. Any advance in the comprehension of these features is also beneficial for fields such as colloidal assembly or capillary/evaporation-assisted lithography [60,61].…”

Silica core–polystyrene shell nanoparticle synthesis and assembly in three dimensions

“…A large number of attempts have been made to fabricate 3D colloidal crystals. 27,[33][34][35] Despite improvements in the process of self-assembly, fabricated CCs typically suffer from a large number of defects. [36][37][38][39][40][41][42][43][44] A suspension of spherical silica nanoparticles grafted with concentrated polymer brushes, first observed by Ohno et al, 34,45 has advantages over hard and soft colloidal particles in terms of size manipulation and interparticle distancing.…”