The University of Iowa

Sarah C. Larsen

Sarah C. Larsen
Professor
Phone: 
319-335-1346
Office: 
W176 CB
Office Hours: 
Tues 3-4:30 and Wed 9-10:30 in W176CB
Biosketch: 
  • B.A., Bowdoin College (1986)
  • Ph.D., Harvard University (1992)
  • DOE Distinguished Postdoctoral Fellow, Lawrence Berkeley Laboratory (1993-1995)
Keywords: 

Applications of nanoscience and nanotechnology in environmental catalysis, remediation, CWA decontamination, drug delivery; EPR and solid state NMR; synthesis and characterization of nanocrystalline zeolites and zeolite structures.

Research Interests: 

Research Interests: 

In the Larsen group, we are interested in the synthesis, characterization and environmental and health applications and implications of porous nanomaterials, such as zeolites and mesoporous silica. Zeolites are crystalline, microporous materials which have large surface areas and are widely used in applications such as separations, ion exchange and catalysis. Zeolites can be synthesized with a wide range of pore sizes and topologies. The zeolite chemical composition, framework topology and pore size can be varied to control selectivity and reactivity. Similarly, mesoporous silica materials have high surface areas, tunable pore sizes with narrow distributions, well-defined surface properties, and low toxicity which are advantageous for environmental and biomedical applications.  The main differences between zeolites and mesoporous silica are the pore sizes which are typically less than 1 nm in diameter for microporous zeolites and greater than 1 nm in diameter for mesoporous silica and the crystallinity in that the walls of mesoporous silica materials are amorphous while zeolites are crystalline.  Our approach is to systematically and strategically vary the properties of the zeolites and mesoporous silica such as particle size and surface functionalization in order to optimize their performance in various applications.

Synthesis and Characterization of Zeolite and Mesoporous Silica Nanomaterials

We are interested in the synthesis of new zeolite and mesoporous silica materials with improved properties, such as those shown in the electron microscope images below.

By controlling particle size and porosity, the properties of the zeolite or mesoporous silica host can be varied to increase diffusion, mass transfer and potentially, reactive surface area.  The zeolite and mesoporous silica nanomaterials characterization of zeolite and mesoporous silica nanomaterials using magnetic resonance methods (solid state and liquid NMR and EPR) as well as other physicochemical techniques.   Solution state NMR methods can be exploited to study the structure and dynamics of the surface functionalized zeolite and mesoporous silica nanoparticles.

Environmental and Health Applications and Implications

Environmental and health applications for zeolite and mesoporous silica nanoparticles are being explored.  For example, magnetic mesoporous silica nanoparticles are being explored as adsorbents for heavy metals from water followed by the magnetic recovery of the contaminated particles.  Mesoporous silica and zeolites generally exhibit low toxicity and good biocompatibility and are being investigated for use in drug delivery and imaging.  The loading and release of small drug molecules, such as aspirin, doxorubicin, and fluorouracil, are being examined as a function of zeolite/mesoporous silica pore size and surface functionality.  Density functional theory (DFT) methods are being used to model to better understand the loading and release properties.  In addition, the environmental and health implications of porous nanomaterials are being investigated specifically with in vitro studies of the cytotoxicity of zeolite and mesoporous silica nanomaterials as a function of size and surface modification.  These results are closely correlated with careful characterization of nanomaterial properties.

 

Recent Publications: 
  • Incorporation of Germanium into the Framework of Nanocrystalline Faujasite, Paul S. Mueller and Sarah C. Larsen, Microporous and Mesoporous Materials, 2013, 180, 229-334.
  • Development of Porous Nanomaterials for Applications in Drug Delivery and Imaging, Ashish Datt, Nicholas Ndiege and Sarah C. Larsen, Nanomaterials for Biomedicine, American Chemical Society, 2013.
  • Loading and Release of 5-Fluorouracil from HY Zeolites with Varying SiO2/Al2O3 Ratios, Ashish Datt, Eric Burns, Nikhil Dhuna, Sarah C. Larsen, Microporous and Mesoporous Materials, 2013, 167, 182-187.
  • An Experimental and Computational Study of the Loading and Release of Aspirin from Zeolite HY, Ashish Datt, Daryl Fields, Sarah C. Larsen, Journal of Physical Chemistry C, 2012, 116 (40), 21382–21390.
  • Aspirin Loading and Release from MCM-41 Functionalized with Aminopropyl Groups Via Co-Condensation or Post-Synthesis Modification Methods, Ashish Datt, Izz El-Maazawi, Sarah C. Larsen, Journal of Physical Chemistry C, 2012, 116 (34), 18358–18366.
  • Photochemical CO2 Reduction on a Molecular Rhenium Catalyst Adsorbed in a Hierarchical Mesoporous ZSM-5, Kevin D. Dubois, Anton Petushkov,Elizabeth Garcia Cardona, Sarah C. Larsen and Gonghu Li, Journal of Physical Chemistry Letters, 2012, 3, pp 486–492
  • Surface Selective Solution NMR Studies of Functionalized Zeolite Nanoparticles, Yulia Tataurova, Michael J. Sealy, Russell G. Larsen, Sarah C. Larsen, Journal of Physical Chemistry Letters, 2012, 3, 425–429
  • Synthesis of Nanocrystalline Nab Zeolite with Hierarchical Porosity, Anton Petushkov, Giorvanni Merilis, Sarah C. Larsen, Microporous and Mesoporous Materials, 2011, 143, 97-103.
  • Preparation of a Versatile Bifunctional Zeolite for Targeted Imaging Applications, Nicholas Ndiege, Renugan Raidoo, Michael K. Schultz, Sarah Larsen, Langmuir, 2011, 27 (6), pp 2904–2909
  • Synthesis of Hierarchical Nanocrystalline ZSM-5 with Controlled Particle Size and Mesoporosity, Anton Petushkov, Suhyoung Yoon, Sarah C. Larsen, Microporous and Mesoporous Materials, 2011, 137, 92-100.
  • Toxicity of Silica Nanomaterials: Zeolites, Mesoporous Silica, and Amorphous Silica Nanoparticles (Chapter 7), Anton Petushkov, Nicholas Ndiege, Aliasger K. Salem, Sarah C. Larsen, Adv. Mol. Tox., 2010, Volume 4, 223-266.
  • Framework Stability of Nanocrystalline NaY in Aqueous Solution at Varying pH.  Anton Petushkov, Jasmine Freeman, Sarah C. Larsen, Langmuir, 2010, 26(9), 6695–6701.
  • Chromate Adsorption on Bifunctional, Magnetic Zeolite Composites, Karna Barquist, Sarah C. Larsen, Microporous and Mesoporous Materials, 2010, 130, 197-202
  • DFT Calculations of EPR Parameters for Copper(II)-Exchanged Zeolites Using Cluster Models, William M. Ames and Sarah C. Larsen, Journal of Physical Chemistry A, 2010, 114 (1), pp 589–594.
  • Effect of Crystal Size and Surface Functionalization on the Cytotoxicity of Silicalite-1 Nanoparticles, Anton Petushkov, Janjira Intra, Jessica B. Graham, Sarah C. Larsen, Aliasger K. Salem, Chemical Research in Toxicology, 2009, 22, 1359-1368.
  • DFT Calculations of the EPR Parameters for Cu(II) DETA Imidazole Complexes, William M. Ames and Sarah C. Larsen, Physical Chemistry Chemical Physics, 2009, 11, 8266 – 8274 ( DOI: 10.1039/b905750a).
  • A Density Functional Theory Investigation of EPR Parameters for Tetragonal Cu(II) Model Complexes with Oxygen Ligands, William M. Ames and Sarah C. Larsen, Journal of Physical Chemistry A, 2009, 113 (16), pp 4305–4312
  • Carbon Dioxide Adsorption in Zeolite Y Materials: A Transmission FTIR Spectroscopy and Quantum Chemical Calculations Study, Pragati Galhotra, Juan Navea, Sarah C. Larsen, Vicki H. Grassian, Energy and Environmental Science, 2009, 2, 401 - 409
  • Insight into Copper Coordination Environment in the Prion Protein through DFT Calculations of EPR Parameters, William M. Ames and Sarah C. Larsen, Journal of Biological Inorganic Chemistry, 2009, 14, 547-557
  • Adsorption of Chromate on Amino-Functionalized Nanocrystalline Silicalite-1, Karna Barquist, Sarah C. Larsen, Microporous and Mesoporous Materials, 2008, 116, 365-369.
  • Transition Metal and Organic Functionalization of Hollow Zeolite Structures, Ramasubramanian Kanthasamy, Karna Barquist and Sarah C. Larsen, Microporous and Mesoporous Materials, 2008, 113, 554-561.
  • Silicalite Nanoparticles that Promote Transgene Expression, Megan E. Pearce, Benjamin Mai, Namhoon Lee, Sarah C. Larsen and Aliasger K. Salem, Nanotechnology, 2008, 19 175103-175109.
  • Nanocrystalline Zeolites and Zeolite Structures: Synthesis, Characterization and Applications, Sarah C. Larsen, Journal of Physical Chemistry, 2007, 111, 18464-18474.