Neutron Science and Engineering at Virginia Tech

1
Neutron Science and Engineering at Virginia Tech

• Mark Pitt (pitt_at_vt.edu)
• Assistant Professor
• Physics Department

2
Departments Currently Involved

• Chemical Engineering
• Chemistry
• Mechanical Engineering
• Materials Science and Engineering
• Physics

3
Chemical Engineering
Chemical Engineering

• 16 full time faculty members
• 50 full-time graduate students
• 200 undergraduate chemical engineering majors
• Faculty Participation in 6 different research
  centers and consortia

4
ChE Faculty Involved in Materials-Related
Research Projects
Chemical Engineering

• Donald G. Baird, polymer rheology
• David F. Cox, ultrahigh vacuum (UHV) surface
  science
• Richey M. Davis, colloid and surface chemistry,
  polymer science
• Aaron S. Goldstein, biomedical engineering
• Erdogan Kiran, supercritical fluids, polymer
  processing (work includes prior collaboration in
  neutron scattering with Drs. Yuri Melnichenko and
  George Wignall of ORNL)
• Eva Marand, polymer materials, membrane science
• S. Ted Oyama, heterogeneous catalysis, inorganic
  materials synthesis
• Ravi F. Saraf, polymer thin films,
  photonic/electronic nanodevices
• Kevin E. Vann Cott, biomedical engineering
• Garth L. Wilkes, polymer structure/property
  relationships

5
Ongoing Research Program in CE
Chemical Engineering

• Characterization and Reactivity of model
  metal-oxide and transition-metal carbide surfaces
  structure/ property relationships in
  heterogeneous catalysis
• Synthesis and catalytic chemistry of
  transition-metal oxide, carbide, nitride and
  phosphides catalysts
• Polymer adsorption and inorganic nanoparticle
  stabilization
• Polymer thin films for nanodevices and
  nanocomposites
• Synthesis and characterization of
  organic/inorganic hybrid materials
• Polymers synthesis and characterization
• High pressure miscibility and phase separation in
  polymers
• Microstructured materials formation in or with
  supercritical fluids
• Interfaces in biological systems, protein
  adsorption, cell/surface interactions

6
Neutron-Based Tools of Interest
Chemical Engineering

• Wide-angle neutron scattering
• Small-angle neutron scattering
• Neutron reflectivity
• Inelastic Neutron Scattering
• Real-time and in-situ studies

7
Chemistry
Chemistry

• 33 full time faculty members, 40 support staff
• 30 post docs, 15 research scientists
• 110 graduate students (M.S. and Ph.D.)
• 250 undergraduate chemistry majors
• 3 research centers
• Faculty Involved in Neutron Related Projects
• Alan R. Esker, Polymer Physical Chemistry
• Timothy E. Long, Polymer Organic Chemistry
• Harry C. Dorn, Materials Chemistry

8
Ongoing Environment Projects
Chemistry

• Membrane mediated polymer interdiffusion by
  neutron reflectivity (NR).
• Coil Polymer Chain Conformations in
  Langmuir-Blodgett (LB) Films by Small Angle
  Neutorn Scattering (SANS).
• Diffusion and structure in ultrathin LB-networks
  (SANS and NR).
• Structural studies of biomimetic membranes on
  polyelectrolyte networks.
• Rod-Coil Polymer Miscibility (SANS and NR).
• Osmotically driven transport in filled
  polymer/membrane systems (NR and
  Grazing-Incidence Prompt Gamma Emissions).

9
Mechanical Engineering Department
Mechanical Engineering

• Interdisciplinary Project on Microwave Processing
  of Materials
• J. R. Thomas and C. H. Stern (M.E.) W. A. Davis
  (E.E.)
• 5 graduate students
• Cooperation with and support from Los Alamos and
  DuPont
• Several Research Areas
• Continuous processing of thermal runaway
  materials
• Microwave-enhanced chemical catalysis
• Microwave freeze-drying of pharmaceuticals
• Emphasis on coupled modeling verified by
  experiments

10
Microwave-enhanced Chemical Catalysis
Mechanical Engineering

• Many reports of enhanced catalytic activity under
  microwave irradiation
• why ?
• Can microwaves preferentially heat nm-size
  metallic catalyst sites ?
• Modeling suggests it might be possible, but there
  are too many unknown parameters
• Proposed experiment at Los Alamos Neutron Science
  Center (LANSCE)
• Will use neutron resonance spectroscopy to
  perform resolved temperature measurements of
  supported-metal catalysts
• Will be first known resolved temperature
  measurements of objects in nanometer-size range
• Experiment has been postponed for nearly 2 years
  because of equipment malfunctions at LANSCE

11
Materials Science and Engineering
Materials Science and Engineering

• Sean G. Corcoran (sgc_at_vt.edu) is studying the
  surface chemical and electrochemical effects on
  the mechanical properties of small scale
  contacts dealloying as a method to produce
  nanoporous metals for biomedical sensor
  applications controlled corrosion mechanical
  properties of nanoscale designed hard overcoats
• Small angle neutron scattering is one of his
  analytical techniques using NIST facilities

12
Physics
Physics

• Particle and Nuclear
• Interested faculty
• Luke Mo (lmo_at_vt.edu)
• Leo Piilonen (piilonen_at_vt.edu)
• Mark Pitt (pitt_at_vt.edu)
• Bruce Vogelaar (vogelaar_at_vt.edu)
• SNS-related research
• Current
• Neutron beta asymmetry at LANL (Vogelaar, Pitt)
• Solar neutrinos Borexino at Gran Sasso
  (Vogelaar)
• Neutrino properties ORLAND (Mo)
• Past
• Precision beta decay measurements (Piilonen,
  Pitt)
• Nuclear astrophysics (Vogelaar)
• Future
• Neutron activation analysis of materials for
  solar neutrino detectors (Vogelaar)

13
Borexino
Physics

• ? e- ? ? e-
• directly measure the 7Be
• neutrino flux in real time
• 100 ton liquid scintillator
• fiducial volume
• event rate 50/d (SSM) 10/d (SMA)
• extreme purity requirements 10-16 g/g U,Th or
  better

14
Physics
Physics

• Condensed Matter
• Interested faculty
• Willi Graupner (graupner_at_vt.edu)
• Randy Heflin (rheflin_at_vt.edu)
• Richey Davis (rmdavis_at_vt.edu), Dept. of Chemical
  Engineering
• Neutron-related research interests concerning
  organic semiconductors
• Activation analysis of electronically active
  defects in thin organic layers
• Neutron reflectivity studies of modulated
  heterostructures
• Neutron scattering study of interactions in a
  colloid-nonadsorbing polymer mixture
• Quantum molecular motions in polymer systems
• Interfacial instability of thin polymer films on
  substrates