The Energy Safety Research Institute or ESRI at Swansea University collaborated with Rice University laboratory to develop and share a low-cost method to handle the transfer of bulk carbon nanotubes and other nanomaterials safely. It does not take much more than 10 minutes, a big bucket to keep the nanomaterials in their place and a couple of bags.
Andrew R. Barron, the Director of the Energy Safety Research Institute at Swansea University, works with bulk carbon nanotubes on a variety of projects. Years ago, members of his team at Rice University in Houston, Texas, became concerned that nanotubes could escape into the air, so they developed a clean and cheap method to keep them contained as they were transferred from large containers into small jars for experimental use.
Recently, Professor Barron himself became concerned that unlike the BREEAM Outstanding laboratories of ESRI, too few labs around the world were employing best practices to handle nanomaterials, so he decided to share what his team had learned so far.
Professor Barron said: "There were a series of studies that said if you're going to handle nanotubes, you really need to use safety protocols. Then I saw a study that said many labs didn't use any form of hood or containment system. In the U.S., it was bad, and in Asia, it was worse even though there were a significant number of labs scaling up to use these materials at the kilogram scale without taking the proper precautions."
Carbon nanotubes are fluffy in bulk form and disperse easily if they are disturbed. The Barron research labs typically store the tubes in 5-gallon plastic buckets, and simply opening the lid is enough to send them flying to their low density.
A research scientist in Barron's lab, Varun Shenoy Gangoli, and Pavan Raja, a scientist with Rice's Nanotechnology-Enabled Water Treatment center, developed their own method that involves protecting the worker and sequestering loose tubes when removing smaller amounts of the material for use in experiments.
The precautions include making sure that the workers are properly attired and wearing lab coats, full goggles and face masks, along with two pairs of gloves duct-taped to the lab coat sleeves. The improvised glove bag involves a 25-gallon rubbish bin with a plastic bag taped to the rim. The unopened storage container is placed inside and the bin is covered with another transparent trash bag, with small holes cut in the top for access.
After transferring the nanotubes, acetone wipes are used to clean the gloves and acetone is sprayed inside the barrel so settling nanotubes would stick to the surface. These can be recovered and returned to the storage container.
Professor Barron said: "It took lab members time to learn to use the protocol efficiently, but now they can get their samples in 5 to 10 minutes. I'm sure other labs can and will enhance the technique for their own circumstances."