GREGORY  HOLLAND

AST PROF RESEARCH
Ph.D., University of Wyoming, 2003

  Office: ISTB1 477  
  Phone: (480) 965-7915  Lab Phone: (480) 965-3613
  Fax: (480) 965-2747
  Email: greg.holland@asu.edu

Structure of V2O5 xerogel lithium intercalation host for rechargeable battery applications.

Research and Teaching Interests

My primary research interest involves the development and application of Solid-State NMR spectroscopy towards understanding structure and dynamics in complex systems of technological and biological relevance. The materials of interest are typically amorphous or disordered and therefore, are not easily characterized with conventional structural probes like X-ray diffraction. Four projects currently being pursued are listed below:

• Metal Oxide Cathode Materials for Li-ion Rechargeable Batteries – ⁶Li and ⁷Li MAS NMR spectroscopy are implemented to understand Li intercalation processes in amorphous battery materials such as xerogels, aerogels and nanoparticle assemblies. These experiments yield important information on local structure and dynamics regarding defect sites, polaron hopping, and charge pinning.
  
  
• Proton Conduction in Polymer Electrolyte Membranes (PEM) – ¹H high-speed MAS NMR is currently being pursued to understand the proton conduction mechanism in PEM materials containing ionic liquids for fuel cell applications.
  
  
• Spider Silk Fibers – The combined strength and elasticity of spider silk rivals almost all synthetically produced materials. Multi-dimensional solid-state NMR methods are utilized to unravel the molecular structure responsible for the silk fiber’s remarkable mechanical properties.
  
  
• Lipid Raft Formation - The viewpoint that cell membranes are comprised of a continuous phospholipid liquid crystalline phase is changing. Recent evidence strongly supports the existence of phase-separated domains rich in cholesterol and sphingomyelin in biological membranes. These rafts have been linked to numerous cellular processes and diseases. ¹H, ¹³C, and ³¹P MAS NMR are applied to understand how these raft phases form and self-assemble on the molecular scale.

Nephila clavipes spider dragline silk

Representative Publications

"Solid-State NMR Investigation of Major and Minor Ampullate Spider Silks in the Native and Hydrated States," G.P. Holland, J.E. Jenkins, M.S. Creager, R.V. Lewis, J.L. Yarger, Biomacromolecules 9, 651-657 (2008).

"Determining Secondary Structure in Spider Dragline Silk by Carbon-Carbon Solid-State NMR Spectroscopy," G.P. Holland, M.S. Creager, J.E. Jenkins, R.V. Lewis, J.L. Yarger, J. Am. Chem. Soc. ASAP, (2008).

"Unique Backbone-Water Interaction Detected in Sphingomyelin Bilayers with ¹H/³¹P and ¹H/¹³C HETCOR MAS NMR Spectroscopy," G.P. Holland and T.M. Alam, Biophys. J. BioFast, (2008).

"NMR Characterization of Phosphonic Acid Capped SnO₂ Nanoparticles," G. P. Holland, R. Sharma, J. O. Agola, S. Amin, V. C. Solomon, P. Singh, D. A. Buttry, J. L. Yarger, Chem. Mater. 19, 2519-2526 (2007).

"Distinguishing Individual Lipid Headgroup Mobility and Phase Transitions in Raft-Forming Lipid Mixtures with ³¹P MAS NMR," G. P. Holland, S. K. McIntyre, and T. M. Alam, Biophys. J. 90, 4248-4260 (2006).

"Multi-dimensional ¹H-¹³C HETCOR and FSLG-HETCOR NMR Study of Sphingomyelin Bilayers Containing Cholesterol in the Gel and Liquid Crystalline States," G. P. Holland and T. M. Alam, J. Magn. Reson. 181, 316-326 (2006).

"Location and Orientation of Adsorbed Molecules in Zeolites from Solid-State REAPDOR NMR," G. P. Holland and T. M. Alam, Phys. Chem. Chem. Phys. 7, 1739-1742 (2005).

"WISE NMR Characterization of Nanoscale Heterogeneity and Mobility in Supercontracted Nephila clavipes Spider Dragline Silk," G. P. Holland, R. V. Lewis, and J. L. Yarger, J. Amer. Chem. Soc. 126, 5867-5872 (2004).

"⁷Li NMR Studies of Electrochemically Lithiated V₂O₅Xerogels," G. P. Holland, D. A. Buttry, and J. L. Yarger, Chem. Mater 14, 3875-3881 (2002).