Postdoctoral research fellowship

• Postdoctoral Research Associate, Lawrence Berkeley National Laboratory (2005-2007)

Keywords

• Environmental chemistry
• Surface chemistry
• Materials science

Research interests

We are physical/analytical chemistry group with strong emphasis on the development of novel methods that utilize cutting-edge Atomic Force Microscopy (AFM) based techniques to study physical and chemical properties of various chemical systems at the nanoscale. Our work is strongly interdisciplinary and collaborative in nature with researchers from other fields of science and engineering. Two main research themes that we currently pursue are:

1. Nanoscience/materials science with the focus on the size-dependent electrical, mechanical, and (photo)-reactivity studies that encompass organic and inorganic nano- and macro-dimensional solids with unique physical-chemical properties for potential applications in devices, sensing, and energy storage.
2. Atmospheric/environmental chemistry with the focus on the development and application of AFM based methods toward direct measurements of individual submicrometer organic/inorganic environmental particles properties that include humidity-dependent 3D morphology, water uptake, phase state and surface tension.

Recent publications

• Tiba, A; Tivanski, A. V.; MacGillivray, L. R., Size-Dependent Mechanical Properties of a Metal-Organic Framework: Increase in Flexibility of ZIF-8 by Crystal Downsizing. Nano Letters. (Accepted)
• Ray, K. K; Lee, H. D.; Gutierrez, M.; Chang, F.; Tivanski, A. V., Correlating 3D Morphology, Phase State and Viscoelastic Properties of Individual Substrate-Deposited Particles. Analytical Chemistry. 2019, 91, 12, 7621-7630. doi: 10.1021/acs.analchem.9b00333. 
• Kruger, T.; Bell, K.; Lansakara, T.; Tivanski, A. V.; Doorn, J.; Stevens, L. L., Reduced Extracellular Matrix Stiffness Prompts SH-SY5Y Cell Softening and Actin Turnover to Selectively Increase Aβ(1-42) Endocytosis. ACS Chemical Neuroscience, 2019, 10 (3), pp 1284-1293. doi:10.1021/acschemneuro.8b00366.
• Lee, H. D.; Kaluarachchi, C. P.; Hasenecz, E. S.; Zhu, J. Z.; Popa, E.; Stone, E. A.; Tivanski, A. V., Effect of Dry or Wet Substrate Deposition on the Organic Volume Fraction of Core-shell Aerosol Particles. Atmos Meas Tech, 2019, 12, 2033-2042. doi:10.5194/amt-12-2033-2019.
• Kruger, T.; Givens, B. E.; Lansakara, T.; Bell, K.; Mohapatra, H.; Salem, A. K.; Tivanski, A. V.; Stevens, L. L., Mechanosensitive Endocytosis of High-stiffness, Sub-micron Microgels in Macrophage and Hepatocarcinoma Cell Lines. ACS Applied Bio Materials 2018, 1 (5), 1254-1265. doi:10.1021/acsabm.8b00111.
• Hutchins, K. M.; Rupasinghe, T. P.; Oburn, S. M.; Ray, K. K.; Tivanski, A. V.; MacGillivray, L. R., Remarkable Decrease in Stiffness of Aspirin Crystals Upon Reducing Crystal Size to Nanoscale Dimensions via Sonochemistry. CrystEngComm 2018, doi:10.1039/C8CE00764K.
• Or, V. W.; Estillore, A. D.; Tivanski, A. V.; Grassian, V. H., Lab on a Tip: Atomic Force Microscopy - Photothermal Infrared Spectroscopy of Atmospherically Relevant Organic/Inorganic Aerosol Particles in the Nanometer Size Range. Analyst 2018,143, 2765-2774. 
• Lee, H. D.; Ray, K. K.; Tivanski, A. V., Directly Probing the Phase States and Surface Tension of Individual Submicrometer Particles Using Atomic Force Microscopy. ACS eBook Multiphase Environmental Chemistry in the Atmosphere 2018, doi:10.1021/bk-2018-1299.ch012.
• Lee, H. D.; Ray, K. K.; Tivanski, A. V., Solid, Semi-Solid, and Liquid Phases of Individual Submicrometer Particles Directly Probed Using Atomic Force Microscopy. Analytical Chemistry 2017, 89 (23), 12720–12726. 
• Lee, H. D.; Estillore, A. D.; Morris, H. S.; Ray, K. K.; Alejandro, A.; Grassian, V. H.; Tivanski, A. V., Direct Surface Tension Measurements of Individual Sub-Micrometer Particles Using Atomic Force Microscopy. The Journal of Physical Chemistry A 2017, 121 (43), 8296-8305.
• Cochran, R. E.; Laskina, O.; Trueblood, J. V.; Estillore, A. D.; Morris, H. S.; Jayarathne, T.; Sultana, C. M.; Lee, C.; Lin, P.; Laskin, J.; Laskin, A.; Dowling, J. A.; Qin, Z.; Cappa, C. D.; Bertram, T. H.; Tivanski, A. V.; Stone, E. A.; Prather, K. A.; Grassian, V. H., Molecular Diversity of Sea Spray Aerosol Particles: Impact of Ocean Biology on Particle Composition and Hygroscopicity, Chem 2017, 2 (5), 655-667. 
• Estillore, A. D.; Morris, H. S.; Or, V. W.; Lee, H. D.; Alves, M. R.; Marciano, M. A.; Laskina, O.; Qin, Z.; Tivanski, A. V.; Grassian, V. H., Linking hygroscopicity and the surface microstructure of model inorganic salts, simple and complex carbohydrates, and authentic sea spray aerosol particles, Physical Chemistry Chemical Physics 2017, 19 (31), 21101-21111.
• Mohapatra, H.; Kruger, T. M.; Lansakara, T. I.; Tivanski, A. V.; Stevens, L. L. Core and surface microgel mechanics are differentially sensitive to alternative crosslinking concentrations, Soft Matter 2017, 13, 5684-5695.
• Jayarathne, T.; Sultana, C. M.; Lee, C.; Malfatti, F.; Cox, J. L.; Pendergraft, M. A.; Moore, K. A.; Azam, F.; Tivanski, A. V.; Cappa, C. D.; Bertram, T. H.; Grassian, V. H.; Prather, K. A.; Stone, E. A., Enrichment of Saccharides and Divalent Cations in Sea Spray Aerosol During Two Phytoplankton Blooms, Environmental Science & Technology 2016, 50 (21), 11511-11520.
• Morris, H. S.; Estillore, A. D.; Laskina, O.; Grassian, V. H.; Tivanski, A. V. Quantifying the Hygroscopic Growth of Individual Submicrometer Particles with Atomic Force Microscopy, Analytical Chemistry, 2016, 88, 3647.
• Peter, T. K.; Vargo, J. D.; Rupasinghe, T. P.; Jesus, A. D.; Tivanski, A. V.; Edward A. Sander, E. A.; Myung, N. V.; David M. Cwiertny, D.M. Synthesis, optimization, and performance demonstration of electrospun carbon nanofiber−carbon nanotube composite sorbents for point-of-use water treatment, ACS Appl. Mater. Interfaces, 2016, 8, 11431.
• Laskina, O.; Morris, H. S.; Grandquist, J. R.; Estillore, A. D.; Stone,E. A.; Grassian, V. H.; Tivanski, A. V. Substrate-Deposited Sea Spray Aerosol Particles: Influence of Analytical Method, Substrate, and Storage Conditions on Particle Size, Phase, and Morphology, Environmental science and technology. 2015, 49, 13447.
• Ryder, O. S.; Campbell, N. R.; Morris, H. S.; Forestieri, S.; Ruppel, M. J.; Cappa, C.; Tivanski, A.; Prather, A.; Bertram, T. H. Role of Organic Coatings in Regulating N2O5 Reactive Uptake to Sea Spray Aerosol, Journal of Physical Chemistry A. 2015, 119, 11683.
• Rupasinghe, T. P.; Hutchins, K. M.; Bandaranayake, B. S.; Ghorai, S.; Karunatilake, C.; Bucar, D.; Swenson, D. C.; Arnold, M. A.; MacGillivray, L. R.; Tivanski, A. V. Mechanical properties of a series of macro- and nanodimensional organic cocrystals correlate with atomic polarizability, J. Am. Chem. Soc. 2015, 137, 12768. 
• Morris, H.S. Journal Cover titled: Uncover the ties between sea and sky, ACS Central Science. 2015,1, Iss. 3.
• Schill, S. R.; Collins, D. B.; Lee, C.; Morris, H. S.; Novak, G. A.; Prather, K. A.; Patricia K. P.; Sultana, C. M., Tivanski, A. V.; Zimmermann, K.; Cappa, C. D.; Bertram, T. H.; The Impact of Aerosol Particle Mixing State on the Hygroscopicity of Sea Spray Aerosol, ACS Central Science.2015, 1(3), 132. 
• Morris, H.S.; Grassian, V. H.; Tivanski, A. V. Humidity-Dependent Surface Tension Measurements of Individual Inorganic and Organic Submicrometre Liquid Particles, Chemical Science. 2015, 6, 3242.
• Laskina, O.; Morris, H.S.; Grandquist, J.R.; Qin, Z.; Stone, E.A.; Tivanski, A.V.; Grassian, V.H. Size Matters in the Water Uptake and Hygroscopic Growth of Atmospherically Relevant Multicomponent Aerosol Particles, J. Phys. Chem. A. 2015, 119, 4489.
• Morris, H.S.; Tivanski, A.V.; and Kohen, A. Determination of Concentration and Activity of Immobilized Enzymes, Anal. Biochem. 2015, 484, 169172.
• Singh, P., Morris, H.S., Tivanski, A.V., Kohen, A. A Calibration Curve for Immobilized Dihydrofolate Reductase Activity Assay, Data in Brief. 2015, 4, 19.

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