A Golden Learning Opportunity
Associate Professor Dean Campbell, left, holds a glass plate in a spectrophotometer while students Abby Brennan and Jacob Grant read the results from the instrument.
October 2, 2012
By Frank Radosevich II
When Lydia Moss Bradley set forth to teach students at her newly created institute the “means of living independent, industrious and useful lives” she probably didn’t imagine her tableware would play a part in that mission.
But recently in a laboratory on the second floor of Olin Hall, a plate from her cranberry glass luncheon set became part of an experiment in a chemistry class.
Dr. Dean Campbell, associate professor of chemistry and biochemistry, employed the 100-plus-year-old plate to show the presence of gold nanoparticles in the ruby-colored glass to students in his materials chemistry class.
Using a technique known as visible light spectroscopy on the plate, Dr. Campbell's students were able to identify the signal associated with the green-colored light that is absorbed by gold nanoparticles in the glass.
The very small concentrations of the gold nanoparticles give the glass its so-called cranberry color, and its richness depends on the size and dispersion of the particles. Dr. Campbell said nowadays manufacturers use selenium compounds to achieve the same reddish hue.
“People are using them as dyes,” he explained about the tiny flecks of gold in the glass. “This shows that nanotechnology has been around for a long time.”
The spectrophotometer shines white light through the glass, and a sensor detects and measures the amount of light at different wavelengths that pass through an object. Those measurements allow students to determine what materials are present in the glass as well as their concentration.
The instrument, Dr. Campbell said, also lets students examine the delicate plate in a safe manner without breaking off a small piece to sample.
“Do you want to check for gold in this by doing a destructive technique?” Dr. Campbell asked. “No, you don’t.”
Students in the materials chemistry class took a crack of their own at dyeing objects with nanoparticles. Dr. Campbell’s students made plastic casts dyed with gold and silver nanoparticles, which gave the flexible polymer molds reddish and yellowish colors respectively.
Abby Brennan, a senior in chemistry, said learning about both chemistry and history through the plate from the University’s founder was a new experience.
“It was surprising to learn there were gold particles in something that old,” she said. “And when you think of gold, you’d think it would give off a yellowish color, but instead that comes from silver.”
Items from Mrs. Bradley's 75-piece cranberry glass luncheon set are currently on display in the Cullom-Davis Library and the Hayden-Clark Alumni Center. The entire collection was appraised at more than $15,000.