The scaling up of nanomaterials in the broader context of materials science and engineering is the topic of a Perspective article, where the authors construct a roadmap for assembling nanoscale building blocks into bulk nanostructured materials, and define some of the critical challenges and goals. Two-dimenisonal sheets are uniquely well-suited in this roadmap for constructing dense, bulk-sized samples with scalable material performance or interesting emergent properties. But no matter what structures are used, when nanostructures with better-than-bulk material performances are used in bulk form, it is critical that those extraordinary nanoscale properties can be scaled to the macroscopic level.
In the past couple of decades, nickel-tungsten (Ni-W) amorphous and nanocrystalline materials have been drawing more and more research interest due to the superior mechanical properties such as high hardness, good mechanical performance, and excellent corrosion resistance. Striving to enhance the mechanical performance of Ni-W thin film alloys, researchers report how the annealing temperature will influence the microstructure evolution and the fracture properties of Ni-W alloys.
Here are the 10 most popular Nanowerk Nanotechnology Spotlight articles of 2015. This year, the list includes a quick and simple blood test to detect early-stage cancer; self-powered smart suits; nanomaterials for camouflage and stealth applications; nanotechnology energy applications; 3D-printing with graphene; fuzzy and Boolean logic gates based on DNA nanotechnology; a path towards self-powered electronic papers; a look at whether nanomedicine lhas ived up to its promise; smart materials that become 'alive' with living bacteria in supramolecular assemblies; and repair nanobots on damage patrol.
Applying multivariate statistical techniques to the study of nanocarbons, researchers have presented a methodology to identify nanoparticles with unique combinations of features and, in general, a feasible way of in silico characterization of intractable nanomaterial spaces. These analyses are based on structural features characterizing geometry, interatomic distances, bond angle, surface-to-volume ratio, carbon-to-hydrogen ratio, and hybridization fraction; many of which can be preselected without undertaking expensive electronic structure simulations.
The capture silk used in spider webs consists of axial fiber coated with glue droplets at regular intervals. The spider glue has a unique property that its adhesion is humidity responsive such that for some species the adhesion keeps on increasing up to 100% relative humidity. This is unlike synthetic adhesives that fail under humid conditions. From a polymer science perspective, researchers are interested in understanding the principle behind humidity responsive adhesion of spider glue to create adhesives that work in high humidity conditions.
Observations made on a fern and an insect have led researchers to develop a nanofur structure that significantly reduces fluid drag. Both have surfaces covered by high density hairs which allow them to keep an air layer under water. This enables the bug to move nimbly and swiftly through the water by reducing the drag on its surface. Based on these observations, researchers have developed a very inexpensive, highly scalable method to produce a superhydrophobic, air retaining biomimetic surface - a 'nanofur' - which shows not only a high long-term stability but also a high resistance against additional applied pressure.
According to Planck's law, the emittance of a non-reflective black object - a blackbody - defines the maximum level of thermal emittance from an arbitrary object. Planck's law has been challenged in recent decades by predictions and successful demonstrations of the radiative heat transfer between objects separated by nanoscale gaps that deviate significantly from the law predictions. Researchers have now demonstrated another way to modify the object thermal emission spectrum and to force it to deviate from the one predicted by Planck's law.
Novel materials designed and fabricated with the help of nanotechnologies offer the promise of radical technological development. Many of these will improve our quality of life, and develop our economies, but all will be measured against the overarching principle that we do not make some error, and harm ourselves and our environment by exposure to new forms of hazard. A publication explores recent developments in nanomaterials research, and possibilities for safe, practical and resource-efficient applications.