Thermal shock synthesis (TSS) is a method in which materials are synthesized via rapid, high-temperature heating. In the TSS process, temperatures as high as 3000 K are applied for a duration of just seconds or milliseconds, followed by rapid cooling (a TSS image shown in Fig. 1). [1] [2] [3] In this regard, TSS is distinct from conventional high-temperature syntheses that feature slow and near-equilibrium heating at limited temperature ranges (e.g., 1500 K for furnace heating) for extended periods of time (typically hours) and generally slow heating and cooling (~10 K/min).
TSS utilizes high temperature to drive reactions at extreme and non-equilibrium conditions. Additionally, the use of the ultra-high temperature can dramatically increase reaction rates for rapid material production. [1] [4] As a result of these characteristics, TSS is particularly applicable for the discovery of new reactions and materials and enabling rapid manufacturing.
The TSS method was invented by Dr. Liangbing Hu and his team at the University of Maryland, College Park. The technology is also patented. [5] [6] The TSS was first realized by Joule heating of carbon materials to a high temperature and rapidly quenched with a short duration, which are controlled by electric power with a high temporal resolution. [1] [3] The essence of TSS is the ability to precisely control the high temperature to ensure rapid “shock” heating. Generally, the temperature, duration, and ramping rate can be independently controlled for specific heating requirements.
Since high-temperature heating is ubiquitously used for reactions and materials synthesis, innovative TSS processes have been discovered and demonstrated, including microwave, laser, rapid radiative heating, and discharge flash heating, [4] [7] [8] [9] [10] [11] enabling synthesis of diverse emerging materials, such as single atom and alloyed catalysts, high entropy alloy nanoparticles, nanoscale composites, battery cathodes and anodes, and high-quality graphene, etc. [1] [4] [7] [8] [9] [10] [12] [13] [14]
Chemical vapor deposition (CVD) is a vacuum deposition method used to produce high-quality, and high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films.
Graphene is an allotrope of carbon consisting of a single layer of atoms arranged in a hexagonal lattice nanostructure. The name is derived from "graphite" and the suffix -ene, reflecting the fact that the graphite allotrope of carbon contains numerous double bonds.
As the world's energy demand continues to grow, the development of more efficient and sustainable technologies for generating and storing energy is becoming increasingly important. According to Dr. Wade Adams from Rice University, energy will be the most pressing problem facing humanity in the next 50 years and nanotechnology has potential to solve this issue. Nanotechnology, a relatively new field of science and engineering, has shown promise to have a significant impact on the energy industry. Nanotechnology is defined as any technology that contains particles with one dimension under 100 nanometers in length. For scale, a single virus particle is about 100 nanometers wide.
An artificial enzyme is a synthetic organic molecule or ion that recreates one or more functions of an enzyme. It seeks to deliver catalysis at rates and selectivity observed in naturally occurring enzymes.
Photothermal therapy (PTT) refers to efforts to use electromagnetic radiation for the treatment of various medical conditions, including cancer. This approach is an extension of photodynamic therapy, in which a photosensitizer is excited with specific band light. This activation brings the sensitizer to an excited state where it then releases vibrational energy (heat), which is what kills the targeted cells.
Magnetic nanoparticles are a class of nanoparticle that can be manipulated using magnetic fields. Such particles commonly consist of two components, a magnetic material, often iron, nickel and cobalt, and a chemical component that has functionality. While nanoparticles are smaller than 1 micrometer in diameter, the larger microbeads are 0.5–500 micrometer in diameter. Magnetic nanoparticle clusters that are composed of a number of individual magnetic nanoparticles are known as magnetic nanobeads with a diameter of 50–200 nanometers. Magnetic nanoparticle clusters are a basis for their further magnetic assembly into magnetic nanochains. The magnetic nanoparticles have been the focus of much research recently because they possess attractive properties which could see potential use in catalysis including nanomaterial-based catalysts, biomedicine and tissue specific targeting, magnetically tunable colloidal photonic crystals, microfluidics, magnetic resonance imaging, magnetic particle imaging, data storage, environmental remediation, nanofluids, optical filters, defect sensor, magnetic cooling and cation sensors.
Graphite oxide (GO), formerly called graphitic oxide or graphitic acid, is a compound of carbon, oxygen, and hydrogen in variable ratios, obtained by treating graphite with strong oxidizers and acids for resolving of extra metals. The maximally oxidized bulk product is a yellow solid with C:O ratio between 2.1 and 2.9, that retains the layer structure of graphite but with a much larger and irregular spacing.
A nanosheet is a two-dimensional nanostructure with thickness in a scale ranging from 1 to 100 nm.
In materials science, the term single-layer materials or 2D materials refers to crystalline solids consisting of a single layer of atoms. These materials are promising for some applications but remain the focus of research. Single-layer materials derived from single elements generally carry the -ene suffix in their names, e.g. graphene. Single-layer materials that are compounds of two or more elements have -ane or -ide suffixes. 2D materials can generally be categorized as either 2D allotropes of various elements or as compounds.
High-entropy alloys (HEAs) are alloys that are formed by mixing equal or relatively large proportions of (usually) five or more elements. Prior to the synthesis of these substances, typical metal alloys comprised one or two major components with smaller amounts of other elements. For example, additional elements can be added to iron to improve its properties, thereby creating an iron-based alloy, but typically in fairly low proportions, such as the proportions of carbon, manganese, and others in various steels. Hence, high-entropy alloys are a novel class of materials. The term "high-entropy alloys" was coined by Taiwanese scientist Jien-Wei Yeh because the entropy increase of mixing is substantially higher when there is a larger number of elements in the mix, and their proportions are more nearly equal. Some alternative names, such as multi-component alloys, compositionally complex alloys and multi-principal-element alloys are also suggested by other researchers.
In materials and electric battery research, cobalt oxide nanoparticles usually refers to particles of cobalt(II,III) oxide Co
3O
4 of nanometer size, with various shapes and crystal structures.
A rapidly increasing list of graphene production techniques have been developed to enable graphene's use in commercial applications.
Carbon quantum dots also commonly called carbon dots are carbon nanoparticles which are less than 10 nm in size and have some form of surface passivation.
Transparent wood composites are novel wood materials which have up to 90% transparency. Some have better mechanical properties than wood itself. They were made for the first time in 1992. These materials are significantly more biodegradable than glass and plastics. Transparent wood is also shatterproof.
Nanotech metallurgy is an emerging interdisciplinary domain of materials science and engineering, manufacturing, and nanoscience and engineering to study how nanophases can be applied to significantly improve the processing/manufacturing, micro/nano-structures, and physical/chemical/mechanical behaviors of metals and alloys. This definition was first proposed by Xiaochun Li at the University of California, Los Angeles in 2018.
High-entropy oxides (HEOs) are complex oxides that contain five or more principal metal cations and have a single-phase crystal structure. The first HEO, (MgNiCuCoZn)0.2O in a rock salt structure, was reported in 2015 by Rost et al. HEOs have been successfully synthesized in many structures, including fluorites, perovskites, and spinels. HEOs are currently being investigated for applications as functional materials.
High-entropy-alloy nanoparticles (HEA-NPs) are nanoparticles having five or more elements alloyed in a single-phase solid solution structure. HEA-NPs possess a wide range of compositional library, distinct alloy mixing structure, and nanoscale size effect, giving them huge potential in catalysis, energy, environmental, and biomedical applications.
Ashlie Martini is a tribologist and professor of mechanical engineering at University of California, Merced.
Moldable wood is a strong and flexible cellulose-based material. Moldable wood can be folded into different shapes without breaking or snapping. The patented synthesis is based on the deconstruction and softening of the wood's lignin, then re-swelling the material in a rapid "water-shock" process that produces a wrinkled cell wall structure. The result of this unique structure is a flexible wood material that can be molded or folded, with the final shape locked in plate by simple air-drying. This discovery broadens the potential applications of wood as a sustainable structural material. This research, which was a collaborative effort between the University of Maryland, Yale University, Ohio State University, USDA Forest Service, University of Bristol, University of North Texas, ETH Zurich, and the Center for Materials Innovation, was published on the cover of Science in October 2021.
Covalent adaptable networks (CANs) are a type of polymer material that closely resemble thermosetting polymers (thermosets). However, they are distinguished from thermosets by the incorporation of dynamic covalent chemistry into the polymer network. When a stimulus (for example heat, light, pH, ...) is applied to the material, these dynamic bonds become active and can be broken or exchanged with other pending functional groups, allowing the polymer network to change its topology. This introduces reshaping, (re)processing and recycling into thermoset-like materials.