Wooley said that they don't know where the guest molecules are residing in the host material, and her group is now inserting stable isotopes into the host and guest molecules and with the help of her colleague Jacob Schaefer, Ph.D., Washington University Charles Allen Thomas Professor of Chemistry, will measure the difference between those stable isotopes to help find where the guests are located relative to the host..
"We want to know where they reside because that should tell us why this material is providing a favorable environment at room temperature but at elevated temperature for some reason everything is being expelled rapidly,," she said. "We don't know if there is some reorganization of the morphology of the material or whether the guests partition to different domains at different temperatures."
Wooley says that the results of her research with the polymers ?the promoted release, the anti-fouling application ?are "strange, if not weird, but there is so much going on here, we want to explore it all.."
That weirdness suggests equally weird mechanical properties. Wooley and her post doctoral researcher Jinqi Xu, Ph.D., are exploring those properties and one essential irony ?the material, similar to a hydrogel because it takes in water, oddly becomes stronger when water absorbs into it. Think of a soggy diaper as a hydrogel. If you liken Wooley' s materials to a diaper, that wet one becomes nearly petrified. That's known as an increased modulus value ?a measure of stress versus strain.
"When you pull on a sponge, the water comes back out," she said. "But in our case, because our sponge and the channels within it are essentially nanosco
Source:Washington University in St. Louis