Browse Topic: Chemicals
This specification establishes the requirements for chemical-film (conversion) coatings on aluminum alloys.
This specification covers a biodegradable deodorant in the form of a liquid concentrate, solid, or gel.
A Northwestern University-led team of researchers has developed a new fuel cell that harvests energy from microbes living in dirt. About the size of a standard paperback book, the completely soil-powered technology could fuel underground sensors used in precision agriculture and green infrastructure. This potentially could offer a sustainable, renewable alternative to batteries, which hold toxic, flammable chemicals that leach into the ground, are fraught with conflict-filled supply chains and contribute to the ever-growing problem of electronic waste.
This foundation specification (AMS1424T) and its associated category specifications (AMS1424/1 and AMS1424/2) cover a deicing/anti-icing material in the form of a fluid.
Optical sensors serve as the backbone of numerous scientific and technological endeavors, from detecting gravitational waves to imaging biological tissues for medical diagnostics. These sensors use light to detect changes in properties of the environment they’re monitoring, including chemical biomarkers and physical properties like temperature. A persistent challenge in optical sensing has been enhancing sensitivity to detect faint signals amid noise.
Composite materials are created by combining two or more different materials, such as a filler or fibrous reinforcement dispersed in a polymer matrix. The primary goal of developing composites is to improve properties while reducing weight, making them ideal for the sustainable development of the automotive industry. Poly(lactic acid) (PLA) has emerged as a promising polymer matrix for composites due to its ecological and biodegradable nature, as well as its good mechanical properties (tensile strength and modulus of elasticity), though it remains limited when compared to engineering polymers such as acrylonitrile butadiene styrene (ABS) and acrylonitrile styrene acrylate (ASA). Cotton fibers have gained visibility in recent years as reinforcement in various matrices due to their low cost, renewable origin, and relative abundance. Incorporating cotton fibers into PLA can improve its mechanical properties, enhancing attributes such as tensile strength and stiffness, which makes the
This specification covers the requirements of uncoated aluminum alloy foil for core materials required for structural sandwich construction.
Over the past two decades, microfluidic devices, which use technology to produce micrometer-sized droplets, have become crucial to various applications. These span chemical reactions, biomolecular analysis, soft-matter chemistry, and the production of fine materials. Furthermore, droplet microfluidics has enabled new applications that were not possible with traditional methods. It can shape the size of the particles and influence their morphology and anisotropy. However, the conventional way of generating droplets in a single microchannel structure is often slow, limiting production.
A team led by Emily Davidson has reported that they used a class of widely available polymers called thermoplastic elastomers to create soft 3D printed structures with tunable stiffness. Engineers can design the print path used by the 3D printer to program the plastic’s physical properties so that a device can stretch and flex repeatedly in one direction while remaining rigid in another. Davidson, an assistant professor of chemical and biological engineering, says this approach to engineering soft architected materials could have many uses, such as soft robots, medical devices and prosthetics, strong lightweight helmets, and custom high-performance shoe soles.
The properties of organic nitrate ester that inhibit scale formation were investigated in order to acquire a better understanding of ferrous carbide precipitation from supersaturated solutions. When the scale inhibitor was present, precipitation rates were much lower than when it was missing, even at very low concentrations. When the temperature and time are increased simultaneously, more scale is deposited. The effect of nitrate ester on scale deposition demonstrates that the inhibitory dosage is relatively low at low temperatures but rapidly increases when exposed to high temperatures. The inhibitor is thought to alter the shape of the first crystals by binding to dynamic growth sites and inhibiting the threshold level of development.
This specification defines limits of variation for determining acceptability of the composition of cast or wrought titanium and titanium alloy parts and material acquired from a producer.
Researchers and engineers at the U.S. Army Combat Capabilities Development Command Chemical Biological Center have developed a prototype system for decontaminating military combat vehicles. U.S. Army Combat Capabilities Development Command, Aberdeen Proving Ground, MD The U.S. Army Combat Capabilities Development Command Chemical Biological Center (DEVCOM CBC) is paving the way and helping the Army transform into a multi-domain force through its modernization and priority research efforts that are linked to the National Defense Strategy and nation's goals. CBC continues to lead in the development of innovative defense technology, including autonomous chem-bio defense solutions designed to enhance accuracy and safety to the warfighter.
The U.S. Army Combat Capabilities Development Command Chemical Biological Center (DEVCOM CBC) is paving the way and helping the Army transform into a multi-domain force through its modernization and priority research efforts that are linked to the National Defense Strategy and nation’s goals. CBC continues to lead in the development of innovative defense technology, including autonomous chem-bio defense solutions designed to enhance accuracy and safety to the warfighter.
This specification covers disinfectants or chemicals for use in disinfecting aircraft after carrying livestock.
This specification covers a shampoo type carpet cleaner in the form of a liquid.
This specification covers insecticides for use in disinsection of aircraft as required on international passenger flights.
Details of combustion — the chemical reactions that take place when, for example, a flame is lit — are fleeting and therefore, difficult to study. But scientists would like to better understand the complex processes that occur in those billionths of seconds, not only to make engines more efficient but also to shed light on how candle flames, cars, and airplanes produce gases and particles that are harmful to humans and the environment.
Nylon, Teflon, Kevlar. These are just a few familiar polymers — large-molecule chemical compounds — that have changed the world. From Teflon-coated frying pans to 3D printing, polymers are vital to creating the systems that make the world function better.
In physical chemistry, time-resolved spectroscopy is the study of dynamic processes in materials or chemical compounds. Within this field, various techniques including transient absorption spectroscopy are used to study the mechanistic and kinetic details of chemical processes that occur within just a few picoseconds to a femtosecond — the equivalent of one millionth of one billionth of a second.
Silicone elastomers have become a vital material in the medical device industry due to their unique properties, including biocompatibility, durability and chemical inertness. Silicone materials are categorized based on their unvulcanized consistency, which significantly affects their processability and their physical properties. This article compares high consistency silicone rubbers (HCRs), liquid silicone rubbers (LSRs), and low consistency elastomers (LCEs), analyzing their characteristics and the implications in selecting each during different phases in the development of silicone medical devices.
University of Waterloo Chemical Engineering Researcher Dr. Elisabeth Prince teamed up with researchers from the University of Toronto and Duke University to design the synthetic material made using cellulose nanocrystals, which are derived from wood pulp. The material is engineered to replicate the fibrous nanostructures and properties of human tissues, thereby recreating its unique biomechanical properties.
Researchers at Tufts School of Engineering have developed a method to detect bacteria, toxins, and dangerous chemicals in the environment with a biopolymer sensor that can be printed like ink on a wide range of materials — including wearables.
Unlike glass, which is infinitely recyclable, plastic recycling is challenging and expensive because of the material’s complex molecular structure designed for specific needs. New research from the lab of Giannis Mpourmpakis, Associate Professor of Chemical and Petroleum Engineering at the University of Pittsburgh, focuses on optimizing a promising technology called pyrolysis, which can chemically recycle waste plastics into more valuable chemicals.
A unique wristwatch contains multiple modules, including a sensor array, a microfluidic chip, signal processing, and a data display system to monitor chemicals in human sweat. It can continuously and accurately monitor the levels of potassium (K+), sodium (Na+), and calcium (Ca2+) ions.
This specification covers a rust removing compound in the form of a solid, generally powdered, to be dissolved in water, and heated.
A commonplace chemical used in water treatment facilities has been repurposed for large-scale energy storage in a new battery design by researchers at the Department of Energy’s Pacific Northwest National Laboratory. The design provides a pathway to a safe, economical, water-based, flow battery made with Earth-abundant materials. It provides another pathway in the quest to incorporate intermittent energy sources such as wind and solar energy into the nation’s electric grid.
Remember that party where you were swinging glow sticks above your head or wearing them as necklaces? Fun times, right? Science times, too. Turns out those fun party favors are now being used by a University of Houston researcher to identify emerging biothreats for the United States Navy.
Recycling of advanced composites made from carbon fibers in epoxy resins is required for two primary reasons. First, the energy necessary to produce carbon fibers is very high and therefore reusing these fibers could greatly reduce the lifecycle energy of components which use them. Second, if the material is allowed to break down in the environment, it will contribute to the growing presence of microplastics and other synthetic pollutants. Currently, recycling and safe methods of disposal typically do not aim for full circularity, but rather separate fibers for successive downcycling while combusting the matrix in a clean burning process. Breakdown of the matrix, without damaging the carbon fibers, can be achieved by pyrolysis, fluidized bed processes, or chemical solvolysis. The major challenge is to align fibers into unidirectional tows of real value in high-performance composites.
Robots and cameras of the future could be made of liquid crystals, thanks to a new discovery that significantly expands the potential of the chemicals already common in computer displays and digital watches. The findings are a simple and inexpensive way to manipulate the molecular properties of liquid crystals with light exposure.
Researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have invented and patented a new cathode material that replaces lithium ions with sodium and would be significantly cheaper. The cathode is one of the main parts of any battery. It is the site of the chemical reaction that creates the flow of electricity that propels a vehicle.
The aim of this study is to examine the effects of chemical treatments on the performance of composites that are reinforced with natural fibres. Natural fibres have several advantages, such as low density, low cost, and environmental friendliness, as they can be biodegraded or recycled. However, natural fibre composites also have some limitations, such as their poor compatibility with the matrix material and the reinforcement material. This leads to weak interfacial bonding and poor mechanical properties. Another problem with natural fibres is that they absorb more moisture than other materials, which can affect their dimensional stability and durability. Therefore, this research compares the compatibility of different chemical treatments that can modify the surface properties of natural fibres and improve their adhesion with the matrix and reinforcement.
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