In this edition of the Preservation Technology Podcast, we join NCPTT’s Jason Church as he speaks with Derek Patton, Assistant Professor in the School of Polymers and High Performance Materials at The University of Southern Mississippi. NCPTT is partnering with USM and Hybrid Plastics on a National Science Foundation grant to advance the science of stone preservation.
Church: Derek, tell us a little bit more about your background as a polymer chemist.
Patton: I got my Ph.D. from the University of Houston and I spent two years in Gaithersburg, Maryland, as a post doc in the polymer’s division and that’s where I really learned to apply my background as a Polymer Synthetic Chemist and apply those skills in a way that you can look at the interaction of surfaces with polymers and vice-versa and so I developed a fundamental interest of studying the interaction of the interface of polymers and their underlying substrates. So most of what my group does is polymer synthesis at interfaces. We’re interested in developing synthetic methods to fundamentally change the way the surface interacts with its environment. Whether that’s in a protective coating or to change the way the chemistry reacts. This is the largest part of my background and the focus of my research.
Church: I hear you are a principal investigator of a newly awarded science foundation grant. What makes this NSF grant different than others?
Patton: Yeah absolutely. So we were recently awarded a grant under the Chemistry and Materials Research between science and art. For short they call it the SCIART program. So, with the SCIART award, the National Science Foundation really sought to enhance collaborative opportunities between conservation scientist and chemist or material scientist to address grand challenges in the field of science of conservation of cultural heritage. So that’s the unique feature of this particular grant. It’s one of the first instances where we’re taking a skill set of a physical or a material scientist and combining that with the skill of a conservationist.
Church: You said that this grant was a collaborative effort. Who are the partners on this grant and why were they chosen?
Patton: My co-principal investigators are Mary Striegel, at the National Center for Preservation Technology and Training in Natchitoches, La., and Joe Lichtenhan at Hybrid Plastics and they’re located in Hattiesburg Mississippi. At the fundamental level we want to look at the interaction of new polymers with stone surfaces. So we’re interested in developing polymers that are modified by POSS, which are inorganic silica cages. And we’re interested in incorporating those silica cages into polymeric material that interact and enhance the interaction with stone surfaces as consolidants or as stone strengtheners.
Church: What part will each of these partners play in the research and final outcome of this grant?
Patton: NCPTT, as the only national preservation research and technology centers in the National Park Service, Mary and her staff will bring years of experience in conservation and preservation of cultural heritage items, specifically of stone and masonry on which is the focus of this NSF project. Being at the forefront of the preservation field, they have opportunities of interfacing with experts from industry government and academia. They will be instrumental in helping to identify and address grand challenges in preservation of America’s cultural heritage. Their role essentially, is to help facilitate the transfer of the technology development as a result of this grant to the end user and on the more experimental side they will be involved in analyzing the long-term effects of the stone treatments weathering, stability, of the treatments on the stone surfaces.
Hybrid on the other hand is more on the materials supply side. Hybrid is one of the world leaders in the commercial production of POSS materials. Hybrid has over the years demonstrated very innovative uses of POSS containing materials for a broad range of technologies. For example one related to the conservation of stone. They’ve used POSS materials to modify dental restoration so that you mimic the surfaces of the tooth by incorporating the silica into the formulation. So that’s one of the properties that we can use in terms of modifying stone surfaces or consolidation stone surfaces and taking advantage of the inherent properties of the POSS material in many ways mimics the properties of a stone surface being an inorganic material so many times you can match the refractive index and the modules properties by incorporating the various amounts of POSS into these polymer formulations.
Their role in the project is to synthesize and supply those POSS materials with specific functional groups that can be incorporated into a polymeric material. It also enhances the interaction with the stone surface and supply them to us in multi-gram quantities that really give us a large enough scale that we can actually do realistic size conservation efforts of stone surfaces.
From the university side, one of our fundamental goals is to produce students that are capable of entering the work place with a specific skill set and so one specific thing that this grant does because it is collaboration between academia and a conservation government laboratory and an industrial company like Hybrid Plastics. It gives us an opportunity to train students with a new skills set so that they come out thinking in a different way about using material science and how to apply that specific skill set with problems that are observed in the conservation of cultural heritage. That’s one of our fundamental goals as a professor to train those students so that they’re capable of going out into a newly developing field where they’re having to address different problems. So if we can take the skill set that we as material scientists or as chemists know and apply those to the challenges conservationists face I think that we produce something that lasts far reaching into the future as a product from the academia side.
Church: Now, once the testing is established and you have an end result. What sort of cultural materials do you think you might be looking at treating with these POSS consolidants?
Patton: I guess we can take some examples from Natchitoches. During a recent visit to Natchitoches at NCPTT we actually went out into the field and learned how some of the traditional methods, traditional products that are on the market today, are being used to treat stone surfaces that are used to make gravestone markers. The U.S. is full of buildings of historical significance so treating those stone surfaces that were used to build those historic buildings is another example. And then stone and sculpture would be another example, where new products with specific properties of consolidating the stone surfaces while one of the ultimate goals is to do no harm to the surface–those are areas where new products are needed and where we might in a collaborative effort develop those types of materials.
Church: I’ve toured your labs there at the University of Southern Mississippi and met some of your research group. How many of your students are working on this grant project and what types of facilities and what types of things are going to be used from your labs?
Patton: It’s funded through the NSF, National Science Foundation. Through that support we’re able to support two full-time graduate students and two part-time undergraduate students to work on the project. So those four students will be actively involved in the development of both the fundamental interactions of the polymers with stone surfaces all the way through going to Hybrid Plastics to develop the actual POSS materials and then on to NCPTT to do the testing on stone surfaces and actually doing field tests with some of the new materials once we get to that point. At the university in my lab we’re actually going to focus more on the interaction with the materials of stone surface so we’re looking at things like microscopy and spectroscopy, things that are surface sensitive so that in a very detailed fashion we can probe the interface between the polymeric material and the stone surface so that we can do things like raising angle transform IR for instance to probe that interface and see how it’s actually interacting with the stone surface other things are quartz crystal microbalance. We can measure the absorption of POSS materials in a very sensitive manner and learn how these materials interact with stone mimic surfaces like calcium carbonate for instance or silicone oxide. So those are two examples of things we’ll be doing in my lab, along with developing the chemistry that will incorporate POSS into polymeric materials.
Church: Well Derek, thank you for coming out today and we look forward to talking to you again.