We here describe a bottom-up approach to control the composition of solid/solid interfaces in nanostructured materials, and we test its effectiveness on tetragonal ZrO2, an inorganic phase of great technological significance. Colloidal nanocrystals capped with trioctylphosphine oxide (TOPO) or oleic acid (OA) are deposited, and the organic fraction of the ligands is selectively etched with O2 plasma. The interfaces in the resulting all-inorganic colloidal nanocrystal assemblies are either nearly bare (for OA-capped nanocrystals) or terminated with phosphate groups (for TOPO-capped nanocrystals) resulting from the reaction of phosphine oxide groups with plasma species. The chemical modification of the interfaces has extensive effects on the thermodynamics and kinetics of the material. Different growth kinetics indicate different rate limiting processes of growth (surface diffusion for the phosphate-terminated surfaces and dissolution for the "bare" surfaces). Phosphate termination led to a higher activation energy of growth, and a 3-fold reduction in interfacial energy, and facilitated significantly the conversion of the tetragonal phase into the monoclinic phase. Films devoid of residual ligands persisted in the tetragonal phase at temperatures as high as 900 °C for 24 h.

Fabrication of bio‐templated metallic structures is limited by differences in properties, processing conditions, packing, and material state(s). Herein, by using undercooled metal particles, differences in modulus and processing temperatures can be overcome. Adoption of autonomous processes such as self‐filtration, capillary pressure, and evaporative concentration leads to enhanced packing, stabilization (jamming) and point sintering with phase change to create solid metal replicas of complex bio‐based features. Differentiation of subtle differences between cultivars of the rose flower with reproduction over large areas shows that this biomimetic metal patterning (BIOMAP) is a versatile method to replicate biological features either as positive or negative reliefs irrespective of the substrate. Using rose petal patterns, we illustrate the versatility of bio‐templated mapping with undercooled metal particles at ambient conditions, and with unprecedented efficiency for metal structures.

This paper describes the creation of mesoporous inorganic films based on the plasma processing of ligand-capped nanocrystals. We use nanorods of HfO2 as a model system and report an extensive characterization of the chemistry, structure, mechanical properties, and reactivity to show that (i) the aspect ratio of the nanorods regulates the pore size and pore volume of the films in a predictable manner and yields an increase in porosity over spherical nanocrystals of up to 60%, (ii) the modulus (>25 GPa) and hardness (>1.1 GPa) are sufficient to tolerate chemical–mechanical planarization, and (iii) the catalytic activity can be finely controlled by the choice of ligands, which regulate the surface chemistry and water adsorption in the final product. This approach is an attractive route to createin two simple and scalable stepscrack-free inorganic mesoporous films for applications in catalysis, energy storage, energy harvesting, and more.

Fabrication of bio‐templated metallic structures is limited by differences in properties, processing conditions, packing, and material state(s). Herein, by using undercooled metal particles, differences in modulus and processing temperatures can be overcome. Adoption of autonomous processes such as self‐filtration, capillary pressure, and evaporative concentration leads to enhanced packing, stabilization (jamming) and point sintering with phase change to create solid metal replicas of complex bio‐based features. Differentiation of subtle differences between cultivars of the rose flower with reproduction over large areas shows that this biomimetic metal patterning (BIOMAP) is a versatile method to replicate biological features either as positive or negative reliefs irrespective of the substrate. Using rose petal patterns, we illustrate the versatility of bio‐templated mapping with undercooled metal particles at ambient conditions, and with unprecedented efficiency for metal structures.

Fabrication of tunable fine textures on solid metal surfaces often demands sophisticated reaction/processing systems. By exploiting in situ polymerization and self‐assembly of inorganic adducts derived from liquid metals (the so‐called HetMet reaction) with concomitant solidification, solid metal films with tunable texture are readily fabricated. Serving as a natural dimensional confinement, interparticle pores and capillary‐adhered thin liquid films in a pre‐packed bed of undercooled liquid metal particles lead to the expeditious surface accumulation of organometallic synthons, which readily oligomerize and self‐assemble into concentration‐dictated morphologies/patterns. Tuning particle size, particle packing (flat or textured), and reactant concentration generates diverse, autonomously organized organometallic structures on a metal particle bed. Concomitant solidification and sintering of the underlying undercooled particle bed led to a multiscale patterned solid metal surface. The process is illustrated by creating tunable features on pre‐organized metal particle beds with concomitant tunable wettability as illustrated through the so‐called petal and lotus effects.