Babak Sanii
Associate Professor of Chemistry
Email: bsanii@kecksci.claremont.edu
Office: Keck Science Center131D
Phone: 909-607-9851
Web Site: https://faculty.kecksci.claremont.edu/bsanii/
Selected Publications
- Katherine Snell, Isabelle Lopez, Brandon Louie, Roxanna Kiessling, Babak Sanii. (2019). Drawing and Hydrophobicity-patterning Long Polydimethylsiloxane Silicone Filaments. Journal of Visualized Experiments.
Abstract – Polydimethylsiloxane (PDMS) silicone is a versatile polymer that cannot readily be formed into long filaments. Traditional spinning methods fail because PDMS does not exhibit long-range fluidity at melting. We introduce an improved method to produce filaments of PDMS by a stepped temperature profile of the polymer as it cross-links from a fluid to an elastomer. By monitoring its warm-temperature viscosity, we estimate a window of time when its material properties are amendable to drawing into long filaments. The filaments pass through a high-temperature tube oven, curing them sufficiently to be harvested. These filaments are on the order of hundreds of micrometers in diameter and tens of centimeters in length, and even longer and thinner filaments are possible. These filaments retain many of the material properties of bulk PDMS, including switchable hydrophobicity. We demonstrate this capability with an automated corona-discharge patterning method. These patternable PDMS silicone filaments have applications in silicone weavings, gas-permeable sensor components, and model microscale foldamers.
Article – URL not found - Roxanna Kiessling, Samuel J.S. Rubin, Jacquelyn Zehner, Collin Barraugh, Katherine Snell, Corinna Fukushima, Matthew Mulligan, Melissa Keckley, Anthony Bosshardt, Walter Cook, and Babak Sanii. (2017). Gravity-Drawn Silicone Filaments: Production, Characterization, and Wormlike Chain Dynamics. ACS Applied Materials & Interfaces 9: 39916–39920.
Abstract – We introduce a method to produce continuous polydimethylsiloxane (PDMS) silicone filaments on the order of 0.5m long and 100 1¼m in diameter. The approach overcomes traditional limitations in silicone drawing by partially precuring the polymer and drawing through a tube furnace. We characterize the filaments ‘mechanical properties, and their ability to switch hydrophobicity by UV-ozone and corona discharge patterning. The flexible filaments’ dynamic properties were evaluated by way of athermal acoustic excitation at the air’s water interface, revealing conformational reconfigurability consistent with a wormlike chain model. We envision applications in rapid prototyping and as a platform for model foldamer studies.
Article – URL not found - Victoria Nguyen, John Rizzo, Babak Sanii . (2016). An Assemblable, Multi-Angle Fluorescence and Ellipsometric Microscope. PLOS ONE.
Abstract – We introduce a multi-functional microscope for research laboratories that have significant cost and space limitations. The microscope pivots around the sample, operating in upright, inverted, side-on and oblique geometries. At these geometries it is able to perform bright-field, fluorescence and qualitative ellipsometric imaging. It is the first single instrument in the literature to be able to perform all of these functionalities. The system can be assembled by two undergraduate students from a provided manual in less than a day, from off-the-shelf and 3D printed components, which together cost approximately $16k at 2016 market prices. We include a highly specified assembly manual, a summary of design methodologies, and all associated 3D-printing files in hopes that the utility of the design outlives the current component market. This open design approach prepares readers to customize the instrument to specific needs and applications. We also discuss how to select household LEDs as low-cost light sources for fluorescence microscopy. We demonstrate the utility of the microscope in varied geometries and functionalities, with particular emphasis on studying hydrated, solid-supported lipid films and wet biological samples.
Article – https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0166735 - Katherine N. Liu, Chen-min S. Hung, Michael A. Swift, Kristen A. Muñoz, Jose L. Cortez and Babak Sanii*. (2015). Configurable lipid membrane gradients quantify diffusion, phase separations and binding densities. Soft Matter Royal Society of Chemistry 11: 8217-8220.
Abstract – Single-experiment analysis of phospholipid compositional gradients reveals diffusion coefficients, phase separation parameters, and binding densities as a function of localized lipid mixture. Compositional gradients are formed by directed self assembly where rapid-prototyping techniques (i.e., additive manufacturing or laser-cutting) prescribe lipid geometries that self-spread, heal and mix by diffusion.
Article – URL not found - B. Sanii, T. Haxton, G.K. Olivier, A. Cho, B. Barton, C. Proulx, S. Whitelam, and R.N. Zuckermann. (2014). Structure-determining intermediates in the assembly path of supramolecular peptoid nanosheets. ACS Nano.
- B. Sanii, O. Martinez-Avila, C. Simpliciano, R.N. Zuckermann, S. Habelitz. (2014). Amelogenin Nanoribbons Are Comprised of Beta-Sheets and Match X-ray Diffraction Pattern of Enamel Matrix. Journal of Dental Research (cover).
- D.J. Gargas, E.M. Chan, A.D. Ostrowski, S. Aloni, V. Altoe, E.S. Barnard, B. Sanii, J.J. Urban, D.M. Milliron, B.E. Cohen, P.J. Schuck. (2014). Engineering bright sub-10-nm upconverting nanocrystals for single-molecule imaging. Nature Nanotechnology.