Infrastructure and everyday materials

Cellulose nanocrystals derived from renewable resources have shown great potential for use in composites, biomedical materials, and packaging. But a major challenge in the production of cellulose nanocrystals is the energy-intensive drying process. To address this issue, a team of researchers from the University of Illinois Urbana-Champaign, Purdue University, and North Carolina Agricultural and Technical State University has introduced a novel multi-frequency ultrasonic drying technology.

Researchers at the City University of New York have experimentally demonstrated that metasurfaces (two-dimensional materials structured at the nanoscale) can precisely control the optical properties of thermal radiation generated within the metasurface itself. This work paves the way for creating custom light sources with unprecedented capabilities. Metasurfaces offer a solution for greater utility by controlling electromagnetic waves through meticulously engineered shapes of nanopillars that are arrayed across their surfaces. 

Researchers from the University of Michigan and Indiana University have shown that by combining an electron microscope, a small sample holder with microscopic channels, and computer simulations, it is possible to see how nanoscale building blocks can rearrange into different organized structures. In the study, the researchers suspended nanoparticles in tiny channels of liquid on a microfluidic flow cell.

Researchers from North Carolina State University, the Leibniz Institute of Polymer Research Dresden in Germany, Technische Universität Dresden in Germany, and Otto von Guericke University Magdeburg in Germany have embedded gold nanorods in hydrogels that can be processed through 3D printing to create structures that contract when exposed to light and expand when the light is removed. When the hydrogel structures are exposed to light, the embedded gold nanorods convert that light into heat.

Scientists from the U.S. Department of Energy’s Pacific Northwest National Laboratory have discovered that reducing graphene oxide membranes with ultraviolet light alters the oxygen functional groups on the graphene oxide surface. This modification results in a novel separation mechanism that is selective for charge rather than size. Exposure to ultraviolet light selectively removed hydroxyl groups from the graphene oxide planes, leading to enhanced interactions of metal cations with functional groups located at the edges of the graphene oxide.

Scientists from the U.S. Department of Energy's (DOE) Argonne National Laboratory (ANL) and the University of Chicago have developed a new technique to determine how nanoparticles move and interact with one another in soft matter when subjected to an applied force or temperature change. At the start, three bands of nanoparticles formed: fast moving, slow moving, and static. After 15 seconds, the fast-moving band vanished. About 40 seconds later, the three bands returned.

University of California, Irvine scientists have discovered a one-dimensional nanoscale material whose color changes as temperature changes. "We found that we can make really small and sensitive thermometers," said Maxx Arguilla, one of the scientists involved in this study. Arguilla likened the thermometers to "nano-scale mood rings," referring to the jewelry that changes color depending on the wearer's body temperature.

Researchers from Cornell University have used solubility rather than entropy to overcome thermodynamic constraints and create high-entropy oxide nanocrystals at lower temperatures. High-entropy materials are formed by mixing five or more elements within the structure of a crystal.

University of Missouri researchers have developed a novel 3D printing and laser process to manufacture multi-material, multi-layered sensors, circuit boards, and even textiles with electronic components. The researchers built a machine that has three different nozzles: one nozzle adds ink-like material, another uses a laser to carve shapes and materials, and a third nozzle adds functional materials to enhance the product’s capabilities. The manufacturing process starts by making a basic structure with a regular 3D printing filament.

Researchers from Purdue University and the University of Illinois Urbana-Champaign have created a process to develop ultrahigh-strength aluminum alloys that are suitable for additive manufacturing. The researchers produced the aluminum alloys by using several transition metals, including cobalt, iron, nickel and titanium. "These intermetallics have crystal structures with low symmetry and are known to be brittle at room temperature," said Anyu Shang, one of the researchers involved in this study.