By David L. Chandler, Massachusetts Institute of Technology May 17, 2024MIT scientists have actually developed a novel gas detection system that combines metal-organic structures with a resilient polymer to enable constant and sensitive tracking of toxic gases like nitrogen dioxide. The group used a product called a metal-organic framework, or MOF, which is extremely sensitive to tiny traces of gas however whose efficiency quickly degrades, and integrated it with a polymer product that is extremely long lasting and easier to process, however much less sensitive.The results are reported today in the journal Advanced Materials, in a paper by MIT teachers Aristide Gumyusenge, Mircea Dinca, Heather Kulik, and Jesus del Alamo, graduate student Heejung Roh, and postdocs Dong-Ha Kim, Yeongsu Cho, and Young-Moo Jo.Researchers at MIT have actually developed a detector that might provide constant tracking for the presence of toxic gases, at low cost. With their sponge-like form, they are effective at recording molecules of various gases, and the sizes of their pores can be tailored to make them selective for specific kinds of gases. “If you are using them as a sensing unit, you can recognize if the gas is there if it has a result on the resistivity of the MOF,” says Gumyusenge, the papers senior author and the Merton C. Flemings Career Development Assistant Professor of Materials Science and Engineering.The disadvantage for these products use as detectors for gases is that they easily become saturated, and then can no longer spot and quantify brand-new inputs. The group demonstrated that this brand-new composite might spot, reversibly, the gas at concentrations as low as 2 parts per million.Applications and Future DirectionsWhile their presentation was particularly intended at nitrogen dioxide, Gumyusenge says, “We can definitely tailor the chemistry to target other unpredictable particles,” as long as they are small polar analytes, “which tend to be many of the hazardous gases.
By David L. Chandler, Massachusetts Institute of Technology May 17, 2024MIT researchers have developed an unique gas detection system that combines metal-organic structures with a long lasting polymer to make it possible for delicate and continuous monitoring of poisonous gases like nitrogen dioxide. This new sensor can discover lowA advancement in gas detection technology at MIT integrates high level of sensitivity and constant monitoring. The product could be made as a thin coating to examine air quality in industrial or home settings.Most systems developed to spot toxic gases in domestic or industrial environments are restricted to single or very little usages. Scientists at MIT, nevertheless, have developed a detector efficient in providing continuous, low-cost tracking of these gases.The new system integrates two existing technologies, bringing them together in a manner that protects the advantages of each while avoiding their limitations. The team used a product called a metal-organic framework, or MOF, which is highly conscious small traces of gas but whose performance quickly breaks down, and integrated it with a polymer product that is highly durable and easier to process, but much less sensitive.The outcomes are reported today in the journal Advanced Materials, in a paper by MIT professors Aristide Gumyusenge, Mircea Dinca, Heather Kulik, and Jesus del Alamo, graduate student Heejung Roh, and postdocs Dong-Ha Kim, Yeongsu Cho, and Young-Moo Jo.Researchers at MIT have actually developed a detector that could offer constant monitoring for the presence of toxic gases, at low expense. The group utilized a product called a metal-organic framework, or MOF (envisioned as the black lattice), which is extremely conscious small traces of gas but whose performance quickly breaks down. They combined the MOF with a polymer material, shown as the teal clear strands, that is highly resilient however much less delicate. Credit: Courtesy of the researchersInnovative Material CombinationHighly porous and with big surface areas, MOFs come in a range of compositions. Some can be insulators, however the ones used for this work are extremely electrically conductive. With their sponge-like form, they work at capturing molecules of various gases, and the sizes of their pores can be customized to make them selective for specific type of gases. “If you are using them as a sensing unit, you can acknowledge if the gas exists if it has an impact on the resistivity of the MOF,” states Gumyusenge, the papers senior author and the Merton C. Flemings Career Development Assistant Professor of Materials Science and Engineering.The drawback for these materials use as detectors for gases is that they readily become saturated, and after that can no longer identify and quantify new inputs. “Thats not what you desire. You wish to be able to recycle and detect,” Gumyusenge states. “So, we decided to utilize a polymer composite to achieve this reversibility.”The team utilized a class of conductive polymers that Gumyusenge and his co-workers had previously shown can respond to gases without permanently binding to them. “The polymer, although it doesnt have the high surface location that the MOFs do, will at least offer this recognize-and-release type of phenomenon,” he says.Researchers demonstrated the products capability to spot nitrous oxide, a harmful gas produced by numerous sort of combustion, in a small lab-scale gadget. After 100 cycles of detection, the material was still maintaining its baseline efficiency within a margin of about 5 to 10 percent, demonstrating its long-lasting use potential. Here is the layout of the sensing setup. Credit: Courtesy of the researchersEnhanced Sensing CapabilitiesThe group integrated the polymers in a liquid option in addition to the MOF product in powdered form, and deposited the mixture on a substrate, where they dry into a uniform, thin finishing. By combining the polymer, with its fast detection ability, and the more delicate MOFs, in a one-to-one ratio, he says, “unexpectedly we get a sensor that has both the high sensitivity we obtain from the MOF and the reversibility that is allowed by the presence of the polymer.”The material alters its electrical resistance when particles of the gas are momentarily trapped in the material. These modifications in resistance can be constantly kept an eye on by simply connecting an ohmmeter to track the resistance in time. Gumyusenge and his students showed the composite materials capability to find nitrogen dioxide, a poisonous gas produced by many kinds of combustion, in a small lab-scale gadget. After 100 cycles of detection, the product was still maintaining its standard efficiency within a margin of about 5 to 10 percent, demonstrating its long-term usage potential.In addition, this material has far greater level of sensitivity than a lot of presently utilized detectors for nitrogen dioxide, the team reports. This gas is frequently identified after making use of stove ovens. And, with this gas just recently connected to numerous asthma cases in the U.S., trustworthy detection in low concentrations is necessary. The team showed that this new composite might discover, reversibly, the gas at concentrations as low as 2 parts per million.Applications and Future DirectionsWhile their demonstration was specifically intended at nitrogen dioxide, Gumyusenge states, “We can definitely tailor the chemistry to target other unpredictable molecules,” as long as they are little polar analytes, “which tend to be the majority of the toxic gases.”Besides being suitable with a basic hand-held detector or a smoke-alarm type of gadget, one advantage of the material is that the polymer enables it to be deposited as an extremely thin uniform film, unlike regular MOFs, which are typically in an ineffective powder kind. Due to the fact that the movies are so thin, there is little product needed and production product expenses could be low; the processing approaches might be common of those used for commercial covering processes. “So, maybe the restricting element will be scaling up the synthesis of the polymers, which weve been synthesizing in little amounts,” Gumyusenge says.”The next steps will be to examine these in real-life settings,” he says. For instance, the material might be applied as a covering on chimneys or exhaust pipelines to constantly keep track of gases through readings from an attached resistance tracking device. In such settings, he states, “we require tests to examine if we really distinguish it from other potential pollutants that we may have neglected in the laboratory setting. Lets put the sensors out in real-world circumstances and see how they do.”Reference: “Robust Chemiresistive Behavior in Conductive Polymer/MOF Composites” by Heejung Roh, Dong-Ha Kim, Yeongsu Cho, Young-Moo Jo, Jesús A. del Alamo, Heather J. Kulik, Mircea Dincă and Aristide Gumyusenge, 17 April 2024, Advanced Materials.DOI: 10.1002/ adma.202312382 The work was supported by the MIT Climate and Sustainability Consortium (MCSC), the Abdul Latif Jameel Water and Food Systems Lab (J-WAFS) at MIT, and the U.S. Department of Energy.
