David Vaknin

Senior Scientist, Condensed Matter Physics, Ames Laboratory Adjunct Professor, Department of Physics and Astronomy A500 Physics Iowa State University Ames, IA 50011 Phone: 1-515-294-6023 vaknin@ameslab.gov Surface X-ray and Neutron Scattering Neutron and X-ray Scattering

PERSONAL HISTORY

HONORS, AWARDS, AND PROFESSIONAL ACTIVITIES

• 2003- American Chemical Society

• 1998- Spallation Neutron Source and High Flux Isotope Reactor Users' Group (SHUG).

• 1996-1998 Material Research Society

• 1992- APS-users' Group and Midwest Universities Collaborative Access Team (MU-CAT) ID-6

• 1992- Neutron Scattering Society of America

• 1988- American Physical Society

• Mentoring graduate, post-graduate, and under graduates.

• SHUG Executive Committee (2000-2003).

• Structural Biology Task Force.

• Referee for scientific journals, and proposals.

• Construct, commission and maintain the Liquid-Surfaces Diffractometer at the 6ID-B beamline at the Advanced Photon Source at Argonne National Laboratory.
  　

RESEARCH INTERESTS

Systems: Magnetism, superconductivity, biomimetic-membranes, thin organic films (polymers, proteins, lipids), nanostructures, interfacial properties of organic, polymeric, and biological materials at surfaces and interfaces, magnetism in low dimensional systems, graphite intercalation compounds. Experimental: Neutron scattering techniques, X-ray scattering techniques, ESR, transport properties, low temperature physics. Materials: lipids, membrane proteins, polymers, water solutions, fullerenes, high Tc superconducting cuprates, magnetic molecules, Li-orthophosphates, spin-glasses, graphite intercalation compounds.
　

INVITED TALKS

• “Neutron Reflectivity from Biomimetic Membranes” - Using Neutrons to Probe Structure and Dynamics in Biological Systems” Oak Ridge Tennessee, April 8-10, 2002.
  　
• “X-ray Synchrotron Studies of Biomimetic Membranes”. Solid State Seminar, Racah Institute of Physics, Hebrew University, Israel, July 15, 2002.
  　
• “Biomimetic Membranes” D. Vaknin, Advanced Photon Source, Argonne August 9, 2002.
  　
• “Commensurate-Incommensurate Magnetic Phase Transition in Magnetoelectric Single Crystal LiNiPO4.” D. Vaknin et al., Magnetoelectric Interactions Phenomena in Crystals MEIPIC – NATO Advanced Research Workshop, Sudak, Ukraine 21-24 September 2003.

PROJECTS

SELECTED PUBLICATIONS

[92]      Fatty-Acid Reversed-Bilayer Formation Induced by Ca²⁺ at the Air/Water Interface. 
D. Vaknin and A. Travesset
(to be submitted, draft available).

[91]      Interfacial Micellar Structures from Novel Amphiphilic Star Polymers.   
K. L. Genson, J. Hoffman, J. Teng, E. R. Zubarev, D. Vaknin, V. V. Tsukruk
Langmuir  20, 9044-9052 (2004). 
 

[90]      Induced Crystallization of Polyelectrolyte-Surfactant Complexes at Water surfaces.
D. Vaknin, S. Dahlke, A. Travesset, G. Nizri, and S. Magdassi
Phys. Rev. Lett. (accepted). 

[89]      Commensurate-Incommensurate Magnetic Phase Transition in Magnetoelectric Single Crystal LiNiPO₄.
D. Vaknin, J. L. ,Zarestky, J.-P. Rivera, and H. Schmid
Phys. Rev. Lett. 92, 20720 (2004). 

[88]     Antiferromagnetism in Magnetoelectric Single Crystals LiCoPO₄ and LiNiPO₄.
D. Vaknin, J. L. Zarestky, J.-P. Rivera, and H. Schmid
Ferroelectrics (accepted).

[87]      In situ characterization of functional purple membrane monolayers at the air-water interface.
M. Méthot, P. Desmeules, D. Vaknin, C. Salesse ,and F. Boucher
Langmuir 20, 934-940 (2004).

[86]      Structure-function Relations in Self-assembled C18- and C20-Sphingosines Monolayers at Gas/Water Interfaces.
D. Vaknin
J. Am. Chem. Soc.  125, 1313-1318 (2003).    

[85]      Amphiphilic Hyperbranched Polyesters with Alkyl-Terminated Branches.

X. Zhai, S. Peleshanko, N. S. Klimenko, K. L. Janson, M. Ya. Vortman, V. V. Shevchenko, D. Vaknin, V. V. Tsukruk
Macromolecules 36,  3101-3110, (2003). 

[84]      Anomalous X-ray Reflectivity Characterization of Ions at Biomimetic Membranes.
D. Vaknin, P. Krüger and M. Lösche.
Phys. Rev. Lett. 90, 178102/1-4 (2003).

[83]      Structure-function Relations in Self-assembled Sphingolipids at Gas/Water Interfaces.
D. Vaknin
Nanotech 2003 3, 408-411 (2003)

[82]      Molecular Packing of Amphiphiles with Crown Polar Heads at the Air-Water Interface.
K. Larson, D. Vaknin, O. Villavicencio, D. McGrath and V. V. Tsukruk
J. Phys. Chem. B 106, 7246-7251 (2002).     

[81]      Amphiphilic Hairy Disks with Branched Hydrophilic Tails and Hexa-perihexabenzocoronene Core.  

M.  Lee, J.-W. Kim, S. Peleshanko, K. Larson, Y. S. Yoo, D. Vaknin, S. Markutsya and V. V. Tsukruk
J. Am. Chem. Soc. 124, 9121-9128 (2002).    

[80]      Weakly Coupled Antiferromagnetic Planes in Single-Crystal LiCoPO₄.
D. Vaknin, J.L. Zaretsky, L.L. Miller, J.-P. Rivera and H. Schmid
Phys. Rev. B, 65, 224414 (2002).  

[79]      Microstructure of Amphiphilic Monodendrons at the Air-Water Interface.
K. L. Genson, D. Vaknin, O. Villacencio, D. V. McGrath, V. V. Tsukruk
J. Phys. Chem. B 106,  11277-11284 (2002). 

[78]      Spectroscopic and Structural Properties of Valine-Gramicidin A in Monolayers at the Air-Water Interface.
H. Lavoie, D. Blaudez, D. Vaknin, B. Desbat, B. M. Ocko and C. Salesse
Biophys. J. 83, 3558-3569 (2002). 

                                                                                                                                            
[77]      Structure of Rhodopsin in Monolayers at the Air-Water Interface: A PM-IRRAS and X-ray Reflectivity Study.
H. Lavoie, B. Desbat, D. Vaknin, and C. Salesse.
Biochemistry  41(45),  13424-13434 (2002).

　

 [76]     Magnetic Molecules at the Air/Water Interface.
D. Vaknin, L. L. Miller, M. Eshel and A. Bino
J. Phys. Chem. B 105, 8014-8017 (2001).

[75]      X-ray Diffraction Techniques to Characterize Liquid Surfaces and Monomolecular Layers at Gas-Liquid Interfaces.
D. Vaknin.
Methods in Materials Research (E.N. Kaufmann, et al. eds.) pp. 10d.2.1-10.d.2.21. John Wiley & Sons, New York (2001).  

[74]      Sphingomyelin at the air-water interface.
David Vaknin, Michael S. Kelley and Benjamin M. Ocko
J. Chem. Phys. 115, 7697-7704 (2001).

[73]      Synchrotron Studies of Amphiphiles with Crown Polar Heads at Air-Water Interfaces.
K. Larson, D. Vaknin, O. Villacicencio, D. McGrath, N. Stephenson, and V. V. Tsukruk.
Polymer Materials: Science & Engineering 85, 229- (2001).

[72]      Antiferromagnetism in a-Li₃Fe₂(PO₄)₃.
J. L. Zarestky, D. Vaknin, B. C. Chakoumakos, T. Rojo, A. Goñi, and G. E. Barberis
J. Mag. Mag. Matt. 234, 401-408 (2001).   

[71]      On the possibility of antiferromagnetic vortex cores in superconducting YBa₂Cu₃O_7-d.
D. Vaknin, J. L. Zarestky and L. L. Miller
Physica C 329, 109-113 (2000). ]

[70]      The Structure of D-Erythro-C18 Ceramide at the Air-Water Interface.
D. Vaknin and M. S. Kelley
Biophys. J. 79, 2616-2623 (2000).