IRG 1

Stability in Glasses: New Materials and New Insights

IRG 1 Leaders:

paul voyles

Paul Voyles
223 MSE Building
1509 University Avenue
Madison, WI 53706
608-265-6740
voyles@engr.wisc.edu

Mark Ediger

Mark Ediger
7303A Chemistry Building
1101 University Avenue
Madison, WI 53706
608-262-7273
ediger@chem.wisc.edu

More group members

 

 

Glasses are ubiquitous across materials types and technological applications but their structure – property – processing relationships and underlying fundamental physics remain poorly understood. IRG 1 uses cross-fertilization of ideas and techniques from organic and inorganic glasses to address fundamental problems in glass science through the lens of stability. Glasses of the same composition can be created in states of widely varying thermodynamic and kinetic stability. The IRG seeks to use these materials to develop fundamental stability-structure-property relationships for glasses. Efforts include establishing control over stability in organic and inorganic glasses; understanding the structures associated with varying states of stability ; discovering the molecular nature of polyamorphism – the existence of two stable liquid states of the same substance; and determining the relationship between the structure and dynamics of liquids as they cool into the glassy state. The IRG integrates theory, simulations, and experiments to expand the range of ultrastable glassy materials and to enable new applications in areas as diverse as hard coatings and quantum information.

IRG 1 Highlights

  • (2020) Order From Disorder: Molecular Packing in Glasses

    Using physical vapor deposition, researchers produced glassy films that are smooth and uniform, but which also have the molecules aligned with one another and organized in layers. This added structure could make the glass more efficient for conductors and expand the range of materials that can be used in future organic electronics.  The colorful images in the figure show measurements using synchrotron x-rays that contrast the disordered starting material and the ordered glass.

  • (2020) Why Sound Waves Travel So Far Unimpeded in Glasses at Low Temperatures

    IRG 1 showed how the atoms around the defects can restrict their ability to jump between configurations and how defects can talk to each other via sound waves. Both phenomena keep the defects from interfering with sound waves allowing the waves to travel long distances.

  • Poster Showing Control and Tuning of Molecular Organization in Vapor-Deposited Glasses Presented at Gordon Conference by MRSEC Graduate Student

    Camille Bishop, a 5th-year graduate student working in Mark Ediger’s group as part of the MRSEC IRG 1, presented her work on liquid crystal-like order in vapor-deposited glasses at the Gordon Conference on Liquid Crystals in New London, NH that took place from July 7th-12th, 2019. The conference brings together researchers in a diverse range of disciplines involving liquid crystal science and technology.

  • (2019) Predicting Surface Diffusion from Molecular Structures

    Many kinds of materials, including thin films, are created by adding atoms or molecules to a surface. As a result, understanding how molecules move along a surface is an important part of making new materials. In general, diffusion and crystal growth are much faster on the surface of glasses than in the interior. How much faster depends on how big the molecules are, and how many hydrogen bonds the surface molecule has to the bulk, as MRSEC researchers have recently discovered. This model works for many different molecules, giving a quick and easy way to predict surface motion and guide the synthesis of new materials.

  • (2019) Mechanical Properties of Structure-TunableVapor-Deposited TPD Glass

    Creating glassy thin films of organic molecules at different temperatures changes both their stability in the glassy state – their density, and how hard they are to melt – and it changes how the molecules in the films are arranged – whether they tend to lie down flat on the surface or stand straight up. Wisconsin MRSEC researchers have shown that these changes in stability and average molecular orientation also change the mechanical properties of the film, including how stiff it is and how hard it is.

  • More IRG 1 posts