New catalyst for zinc-air batteries
Scientists have synthesized a bifunctional catalyst made of a nanocarbon material that can make rechargeable zinc-air batteries used to make electric vehicle propulsion more efficient and sustainable.
India is looking for alternatives to lithium batteries, and zinc, sodium and aluminum batteries are being researched rapidly. Metal-air batteries, where air is the cathode, are gaining ground, but research is still nascent. The efficiency of such batteries, especially zinc-air, depends on the cathode material. Binary metals are essential for achieving bifunctionality in electrocatalysts to be rendered as cathode materials in rechargeable zinc-air batteries.
The major hurdle is that active metal centers are more susceptible to degradation if not properly bonded to the substrate. This leads to uncertainty in the metal-active units, which hampers the catalysts.
Scientists from India’s Institute of Nanoscience and Technology, Mohali, an autonomous institute of the Department of Science and Technology (DST), have developed an efficient bifunctional electrocatalyst. “This material could be further utilized as a cathode catalyst, which would impact the high power output of both liquid-state and solid-state rechargeable zinc-air batteries,” a DST press release said.
New way to make steel alloy powder
Researchers at the Advanced Research Center for Powder Metallurgy and New Materials International (ARCI), Hyderabad, have developed a process for making steel alloy powder that can help produce efficient cooling channels for die casting. This can improve the life and quality of castings and reduce the number of rejects during the casting process.
Die casting is used to manufacture devices ranging from medical to industrial. Manufacturing die tools with efficient cooling channels by conventional methods has been difficult. In conventional manufacturing, die tools are designed with compromised straight-line cooling channels.
The ARCI team has developed an additive manufacturing process for a steel alloy powder (called AISI H13) that can be used as a tool for efficient cooling channels or conformal cooling channels (CC) for die casting. pressure. “These DC systems hold great promise as a replacement for conventional cooling systems, as the former can provide more uniform and efficient cooling effects and thus significantly improve production quality and efficiency. The additive manufacturing process provides the freedom to give the desired shape to the cooling channels so that they can perform the cooling efficiently,” an ARCI press release reads.
Iron aluminide coatings for corrosion resistance
A team of scientists from the Center for Engineered Coatings (CEC), International Advanced Research Center for Powder Metallurgy & New Materials (ARCI), have developed low-cost iron-based intermetallic powders that can be used as a corrosion-resistant coating for materials exposed to harsh environments such as the high temperature in thermal power plants, where oxidation, corrosion and wear occur simultaneously. The coatings showed four times more corrosion resistance in aqueous corrosive media than mild steel.
Wear and corrosion cause significant damage over a range of service temperatures. Hence the need to protect the surface of the component for economic viability. Such a surface coating on a turbine blade can improve service life.
At present, thermally sprayed chromium-nickel-chromium carbide and tungsten-cobalt carbide (cermet) powder coatings are widely used for superior wear and high temperature oxidation resistance in thermal power plant turbine blades, aerospace engine blades, landing gear shafts and steel rollers. in the paper industry. This is primarily attributed to their hardness, toughness and corrosion resistance under exposure to nearly 550 degrees C in the case of tungsten-cobalt carbide coatings and up to 850 degrees C for chromium carbide coatings. -nickel-chromium. However, the powders are expensive due to the presence of cobalt and nickel. In addition, chromium is toxic. The replacement of these coatings by simple iron-based coatings with new microstructural constituents is very promising. In this regard, iron-based solid phases involving two or more metallic or semi-metallic (intermetallic) elements can play a major role due to their hardness and better corrosion resistance. However, their deployment is limited by low ductility. ARCI solved this problem by synthesizing iron-based intermetallic powders and used them to deposit the coatings using the Detonation Spray Coating (DSC) technique.
In addition, ARCI developed gas atomized iron aluminide powder and deposited it on mild steel substrates by DSC, without any cracking or peeling. The coatings have demonstrated four times more corrosion resistance in aqueous corrosive media than mild steel.
The coatings show better corrosion resistance when the chromium and aluminum are in solid solution with iron than in the iron-rich phases. Coatings have demonstrated 30-40% better wear resistance than mild steel in solid particle erosion mode, implying that they can be used for erosion resistance applications at high temperature. For further studies, ARCI has partnered with NTPC to apply this technology to improve the life of the utility’s boilers.
Scientists at the Agharkar Research Institute (ARI) have developed a handy peptide-based diagnostic tool that detects an aquaculture pathogen known as White Spot Syndrome Virus (WSSV).
Infection caused by WSSV in shrimp Penaeus vannamei results in huge crop losses. This high-value superfood is susceptible to a wide range of viral and bacterial pathogens and the likelihood of infection is high. Improved nutrition, probiotics, disease resistance, water, seed and feed quality control, immunostimulants and affordable vaccines play an important role in improving production . Early and rapid pathogen detection technologies in the field will help fish and shellfish farming, which provides significant export revenue, with the country being a major supplier to the United States.
To provide a convenient self-use diagnosis for WSSV, Dr. Prabir Kulabhusan, Dr. Jyutika Rajwade and Dr. Kishore Paknikar developed a lateral flow test using gold nanoparticles for easy visualization of results. Instead of using poly- or mono-clonal antibodies in assay development, ARI scientists selected 12 amino acid-containing peptides from a phage display library by biopanning. This was a time and cost saving approach, eliminating the need to immunize laboratory animals to obtain the antisera. With the use of peptides, cold chain requirements for storage are reduced and the assay becomes production friendly.
June 12, 2022