—Catalysis With Graphene Oxide “Organic Chemistry: Ultrathin sheets mediate multiple transformations” In another first for the versatile graphene family of materials, graphene oxide has been found to catalyze alcohol and alkene oxidations as well as alkyne hydrations (Angew. Chem. Int. Ed., DOI: 10.1002/anie.201002160). The discovery suggests that graphenes could be useful beyond the realm of displays and electronics. Graphene oxide is an intermediate along traditional routes to graphene, the atom-thick carbon sheets that have taken materials science by storm. But chemists know relatively little about graphene oxide’s inherent reactivity.
by Carmen Drahl | July 19, 2010
But to build foldable displays and solar cells, researchers want to replace this expensive material with cheaper, more flexible graphene. One major hurdle is graphene’s relatively high electrical resistance. To increase its conductance, Barbaros Özyilmaz of the National University of Singapore and colleagues used spin-coating to add a fluorinated copolymer layer to graphene. This fluoropolymer has dipolar charges on its surface that facilitate electron transfer back and forth to graphene, decreasing graphene’s resistance from about 500 ohms to 120 ohms; ITO’s resistance is about 100 ohms. Unlike previous methods to improve graphene’s conductance, this doping method is permanent and doesn’t damage the material, Özyilmaz says. /articles/90/i20/Fluoropolymer-Drops-Graphenes-Resistance.html 20120514 An easily made graphene-polymer film shows promise for transparent, flexible electrodes Concentrates 90 20 /magazine/90/09020.html Fluoropolymer Drops Graphene’s Resistance graphene, ferroelectric polymer, indium tin oxide, polyvinylidene fluoride, transparent electrode con Science & Technology Journal News and Community materials A researcher bends a graphene-fluoropolymer film (inset) deposited on clear plastic. BIG BEND ACS Nano This photo shows a researcher bending a graphene-polyvinylidene-fluoride film deposited on clear plastic. graphene electronics nanotechnology polymers Fluoropolymer Drops Graphene’s Resistance Chemical & Engineering News Fluoropolymer Drops Graphene’s Resistance Fluoropolymer Drops Graphene’s Resistance
by Journal News and Community | May 14, 2012
—Crumpled Graphene Resists Aggregation “Aerosol method wads up graphene flakes into microscopic 'paper balls'” Graphene flakes can be crumpled into balls that resist compression and aggregation, according to work published in ACS Nano by a Northwestern University-led research team (DOI: 10.1021/nn203115u).
by Mitch Jacoby | October 31, 2011
—Nanoreduction Of Graphene Oxide “Materials: Scanning probe method patterns insulator with conducting features” Graphene oxide, an oxidized form of the advanced carbon material graphene, can be controllably reduced by passing a heated atomic force microscope (AFM) tip over the material, according to a report published in Science by an international team of researchers (2010, 328, 1373).
by Mitch Jacoby | June 14, 2010
—Ironing out graphene’s wrinkles “A new growth method produces smooth graphene sheets” With a carefully engineered substrate, researchers can grow high-quality graphene free of troublesome wrinkles that often form during manufacture. The supersmooth graphene has improved electrical properties over material grown by the usual methods (ACS Nano 2017, DOI: 10.1021/acsnano.7b06196). Cu(100)—the crystal facet, or face, of copper that is usually used as a growth substrate—expands at a different rate than graphene at a given temperature. Hailin Peng of Peking University says this mismatch leads to mechanical strain that causes wrinkling as graphene grows on that face during chemical vapor deposition.
by Katherine Bourzac | January 01, 2018
—Plasma gun sprays out high-quality graphene “The fast, low-cost method splits graphite particles into graphene flakes, showing promise for mass production” Graphene has slowly made its way into sports gear, anticorrosion coatings, and even fabric face masks. But widespread use of the strong, conductive material hinges on making high-quality graphene affordably and at large scale.
by Prachi Patel, special to C&EN | February 20, 2021