{"id":23786,"date":"2020-03-03T18:15:17","date_gmt":"2020-03-03T18:15:17","guid":{"rendered":"http:\/\/blogs.oregonstate.edu\/scarc\/?p=23786"},"modified":"2020-03-03T18:16:05","modified_gmt":"2020-03-03T18:16:05","slug":"linus-lost-marbles-the-issues-in-preserving-space-filling-balloon-models","status":"publish","type":"post","link":"https:\/\/blogs.oregonstate.edu\/scarc\/2020\/03\/03\/linus-lost-marbles-the-issues-in-preserving-space-filling-balloon-models\/","title":{"rendered":"Linus\u2019 Lost Marbles – The Issues in Preserving Space-Filling Balloon Models"},"content":{"rendered":"\n


Among the wide variety of items in the Ava Helen and Linus Pauling Papers is the collection of
molecular models, which sit serenely on display in the back shelves of the archives. These
models were created by Pauling throughout his career; the earliest dates to the 1920s, and the
later ones to the 1980s. Each piece is testament to how incredibly useful the visualization of
molecular bonding and 3D space can be for scientific comprehension, particularly before
computer modeling was commonly available. Pauling himself was an early and vital proponent
of using these models in a classroom setting, and would often use them during his own lectures at Oregon State University and Cal Tech.  From paper to aluminum, wood, plastic, and wire, the collection of Linus Pauling\u2019s molecular models is diverse, and shows the progression of Pauling\u2019s various interests in molecular chemistry, as well as advancements in the understanding of these concepts. Understanding the materials comprising an artifact and how those materials degrade is extremely important for a conservation team, as no two materials will deteriorate in the exact same way in similar environments. One of the more problematic pieces within this collection of models is the close- packing hard sphere models, which are comprised of latex balloons and marbles. After filling balloons with water, Pauling would insert the appropriate number of marbles and then drain the water and tie off the balloons. The final product is a small, globular object which was meant to demonstrate how atoms arrange themselves in solid crystalline patterns. While in its time this was a unique and useful tactic to show these chemical structures, the materials of these models have posed many issues with regards to archival use and display. Today, the balloons that once were elastic and held together the shape of the molecular model, have all but completely degraded. Some of the balloons have become brittle, flaking away with the slightest touch or movement. This rendered two of the balloon and marble models unstable- as soon as the balloon encapsulating the marbles breaks away, the marbles lose their structure and tumble down, spilling across the display stand. Many of the marbles themselves have degraded significantly, shattering into a dust-like consistency. The models, once practical and pristine, have been reduced to  a pile of fractured rubber and glass, and it is almost impossible to understand what molecular form they once took.<\/p>\n\n\n\n