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ACS DFW Virtual Meeting
ers, but it also had extreme stretchability up to 800% without the nanosheets cracking. It maintained approximately 90% of its energy storage capacity after being stretched 1,000 times, or after being bent or twisted. The researchers say their supercapacitor’s excellent energy storage and electrical stability is attractive for stretchable energy storage devices and wearable electronic systems. The authors acknowledge funding from the Key Research and Development Program of Jiangsu Provincial Department of Science and Technology of China, China Postdoctoral Science Foundation and HighLevel Entrepreneurial and Innovative Talents Program of Jiangsu Province.
2021 DFW Section Officers
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Chair: Trey Putnam Chair-elect: Mihaela C. Stefan Past Chair: Mihaela C. Stefan Treasurer: Martha Gilchrist
Secretary: Heidi Conrad Councilors: Mary Anderson, Linda Schultz, E. Thomas Strom, and Jason McAfee
Alternate Councilors: Michael Bigwood, John McIlroy, Daniela Hutanu, and Danny Tran
The ACS-DFW Local Section will host a virtual meeting on Fri, September 24 at 6:30 pm.
ACS DFW Local Section is happy to host a virtual talk by Dr. Eric Simanek
Dr. Simanek is the Robert A. Welch Professor of Chemistry and the Chair of the Department of Chemistry & Biochemistry at Texas Christian University. His research focuses on the development of nanomedicines and nanodiagnostics, but on September 24th he will be discussing another area of passion. Dr. Simanek spent 12 years at Texas A&M before moving his lab to Texas Christian University in 2010.
Dr. Simanek will present a talk entitled, “The Science and History of Whiskey.”
Date: Friday, September 24, 2021 – Talk beginning at 6:30 PM No Registration Required
Location: Zoom (https://us02web.zoom.us/j/7176687551
From the ACS Press Room Firefighter Exposure to Wildfire Smoke Compounds Varies, Depending on Duties
“Exposure to Particulate Matter and Estimation of Volatile Organic Compounds across Wildland Firefighter Job Tasks” Environmental Science & Technology
Every summer, wildfires rage across the western U.S., and wildland firefighters are tasked with putting them out. But in the process, they inhale smoke and all the compounds in it, which can be harmful at high amounts. Now, researchers reporting in ACS’ Environmental Science & Technology have evaluated the presence of particulate matter and volatile organic compounds (VOCs) around firefighters actively combating blazes, finding the highest exposures among hotshot crews and those creating firebreaks. Most images of wildland firefighters show them covered from head to toe in black soot, or particulate matter, which they’re breathing in along with a mixture of other compounds in smoke. Inhaling particulate matter is associated with respiratory problems, such as asthma and chronic obstructive pulmonary disease, and researchers suspect that VOCs in wildfire smoke could exacerbate these conditions. However, getting accurate estimates of firefighters’ exposures to these pollutants is tough because of the extreme work environment, the different crew types and the variety of fire suppression tasks. For example, elite hotshot crews are on the front lines battling the hottest zones, while other crews may perform tasks in less intense parts of the fire’s edge or use long hoses to deliver water and
foam, usually to remote areas. So, Kathleen Navarro and colleagues wanted to evaluate particulate matter and VOC exposures of different types of firefighters. The researchers attached air samplers to wildland firefighters’ equipment, which they used when responding to large fires in many locations across the western U.S. Then the team measured the amount of particulate matter collected over one shift, averaging 14 hours, and used that data to estimate exposures to three potentially hazardous VOCs — acrolein, benzene and formaldehyde. Their results showed the single-shift exposures to these substances were below Occupational Safety and Health Administration limits for all subjects. However, the amounts of partic-
ulate matter and formaldehyde were above the shift-averaged recommendations of the National Wildfire Coordinating Group and National Institute for Occupational Safety and Health for some of the firefighters. Hotshot crews, firefighters creating firebreaks
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From the ACS Press Room Whiter Teeth, without the Burn
“Photothermal-Enhanced Fenton-like Catalytic Activity of Oxygen-Deficient Nanotitania for Efficient and Safe Tooth Whitening”
ACS Applied Materials & Interfaces
Most people would like to flash a smile of pearly whites, but over time teeth can become stained by foods, beverages and some medications. Unfortunately, the high levels of hydrogen peroxide in dentists’ bleaching treatments can damage enamel and cause tooth sensitivity and gum irritation. Now, researchers reporting in ACS Applied Materials & Interfaces have developed a gel that, when exposed to near infrared (NIR) light, safely whitens teeth without the burn. The growing demand for selfie-ready smiles has made tooth whitening one of the most popular dental procedures. Treatments at a dentist’s office are effective, but they use high-concentration hydrogen peroxide (30–40%). Home bleaching products contain less peroxide (6–12%), but they usually require weeks of treatment and don’t work as well. When a bleaching gel is applied to teeth, hydrogen peroxide and peroxide-derived reactive oxygen species (mainly the hydroxyl radical) degrade pigments in stains. The hydroxyl radical is much better at doing this than hydrogen peroxide itself, so researchers have tried to improve the bleaching capacity of low-concentration hydrogen peroxide by boosting the generation of powerful hydroxyl radicals. Because previous approaches have had limitations, Xingyu Hu, Li Xie, Weidong Tian and colleagues wanted to develop a safe, effective whitening gel containing a catalyst that, when exposed to NIR light, would convert low levels of hydrogen peroxide into abundant hydroxyl radicals. The researchers made oxygen-deficient titania nanoparticles that catalyzed hydroxyl rad-
A new bleaching gel whitened tooth samples by six shades, using a low level of hydrogen peroxide (12%).
Credit: Adapted from ACS Applied Materials & Interfaces 2021, DOI: 10.1021/acsami.1c06774
ical production from hydrogen peroxide. Exposing the nanoparticles to NIR light increased their catalytic activity, allowing them to completely bleach tooth samples stained with orange dye, tea or red dye within 2 hours. Then, the researchers made a gel containing the nanoparticles, a carbomer gel and 12% hydrogen peroxide. They applied it to naturally stained tooth samples and treated them with NIR light for an hour. The gel bleached teeth just as well as a popular tooth whitening gel containing 40% hydrogen peroxide, with less damage to enamel. The nanoparticle system is highly promising for tooth bleaching and could also be extended to
