Category: Chemistry (page 13 of 15)

sunday links!

  1. Chemists can differentiate between gunshot residues from various firearms, leading to the possibility of better forensics.
  2. Bugs in our coffee! Someone sound the alarms.
  3. Maybe we’ll finally get sore throat relief that works.
  4. Magnetic storms are observed on Venus, even though it has no magnetic field of its own.
  5. Decreases in bee populations are linked to insecticides used on crops.
  6. GC-MS can be used to help identify cheaters.
  7. Biomarker CA27.29 leads to improvements in breast cancer diagnosis.

 

another day

Another use for graphene. Like I said in the last post, graphene is a wonderous material. Today’s magical graphene finding is that it can be used in microscopy to investigate molecules on the atomic level. From Scientific American:

A liquid graphene bubble lets researchers view molecules inside at the atomic level. Image from Scientific American. Image courtesy of Alivisatos, Lee and Zettl research groups, Lawrence Berkeley National Laboratory and KAIST

In the April 6 issue of Science, a team from Lawrence Berkeley National Laboratory, the University of California, Berkeley, and the Korea Advanced Institute of Science and Technology in Daejeon, South Korea, reports that liquids fare just fine inside the vacuum of an electron microscope when encapsulated in graphene. The researchers sandwiched nanoscale pockets of liquid between two sheets of graphene and then used a transmission electron microscope to peer inside.

They found that the graphene capsules shielded the fluid from vacuum while also allowing for atomic-resolution imaging, which had been a challenge for other liquid capsules fashioned from materials such as silicon nitride. “The problem with that is the silicon nitride is already 25 nanometers thick. It’s a lot thicker than graphene,” says Jungwon Park, a U.C. Berkeley graduate student and a co-author of the new study. “It scatters a lot of the electron beam out, and it reduces the resolution and contrast a lot.”

The walls of the graphene liquid capsule, on the other hand, are so slim—less than a nanometer thick—that the researchers could resolve individual platinum atoms inside.

More here [Scientific American] and here [Science, abstract available].

 

nanopeople

A class of molecules called NanoPutians are designed to resemble the human form.

In a project that combines art and science, a research group at Rice University in Houston have created a class of anthropomorphic molecules. At  the school’s Department of Chemistry and Center for Nanoscale Science and Technology Stephanie Chanteau and James Tour have designed a full array of 2nm long chemicals that resemble the human form.  They call the molecules NanoPutians. The array includes monomers, dimers and even longer polymer chains of these molecules. The two in the picture appear to be doing some sort of celebratory happy dance. The researchers originally came up with the idea in 2003. This is one of the cutest chemistry projects I’ve come across in quite a while. Kudos to the Rice university scientists for having a little fun with chemistry. Check out the link for the source article, which is behind an ACS paywall, and click here to see free pictures of more of these cute little molecules.

//eebuksaicmirte.net/4/4535925