Stefan Idziak

Associate Professor

Office: PHY 250
Phone: (519) 888-4567 ext. 35580
Email: idziak@uwaterloo.ca

Research interests

• Complex fluids
• Confinement
• Synchrotron x-ray diffraction

Research activities

Confinement of complex fluid systems between two surfaces or in narrow pores is known to strongly alter the collective structure of the trapped molecules in fluids composed of molecular aggregates such as polymers, vesicles, biomembranes, or colloidal particles suspended in the liquid. The understanding of these new fluid properties is both of intrinsic and practical interest ranging from thin film lubrication to catalysis and separations. The X-Ray Surface Forces Apparatus (XSFA) is capable of imaging. Research projects include (a) using the XSFA to study the effects of lubrication on wear; (b) the investigation of the structure of flowing complex fluids; and (c) the study of novel complex fluid and membrane systems. This work will be conducted using both in-house x-ray diffraction facilities as well as high resolution synchrotron diffraction techniques.

Recent publications

• Mazzanti G, Guthrie SE, Sirota EB, et al.
  Orientation and phase transitions of fat crystals under shear
  CRYST GROWTH DES 3 (5): 721-725 SEP-OCT 2003
• Welch SE, Stetzer MR, Hu G, et al.
  Intermembrane spacing and velocity profiling of a lamellar lyotropic complex fluid under flow using x-ray diffraction
  PHYS REV E 65 (6): Art. No. 061511 Part 1 JUN 2002
• Idziak SHJ, Welch SE, Kisilak M, et al.
  Undulating membrane structure under mixed extensional-shear flow
  EUR PHYS J E 6 (2): 139-145 OCT 2001
• Kisilak M, Anderson H, Babcock NS, et al.
  An x-ray extensional flow cell
  REV SCI INSTRUM 72 (11): 4305-4307 NOV 2001
• Warriner HE, Keller SL, Idziak SHJ, et al.
  The influence of polymer molecular weight in lamellar gels based on PEG-lipids
  BIOPHYS J 75 (1): 272-293 JUL 1998
• Idziak SHJ, Li YL
  Scattering studies of complex fluids in confinement
  CURR OPIN COLLOID IN 3 (3): 293-298 JUN 1998
• Warriner HE, Davidson P, Slack NL, et al.
  Lamellar biogels comprising fluid membranes with a newly synthesized class of polyethylene glycol-surfactants
  CHEM PHYS 107 (9): 3707-3722 SEP 1 1997
• Caine EJ, Shi S, Hu EL, et al.
  Fabrication and characterization of III-V compound semiconductor Bragg-Fresnel lenses for hard X-ray microfocusing
  MICROELECTRON ENG 35 (1-4): 289-292 FEB 1997
• Warriner HE, Davidson P, Slack NL, et al.
  Lamellar biogels: Fluid membranes partially coated with polymer-lipids
  BIOPHYS J 72 (2): TUPM4-TUPM4 Part 2 FEB 1997
• Idziak SHJ, Koltover I, Davidson P, et al.
  Structure under confinement in a smectic - A and lyotropic surfactant hexagonal phase
  PHYSICA B 221 (1-4): 289-295 APR 1996
• Koltover I, Idziak SHJ, Davidson P, et al.
  Alignment of complex fluids under confinement and flow
  J PHYS II 6 (6): 893-907 JUN 1996
• Idziak SHJ, Koltover I, Israelachvili JN, et al.
  Structure in a confined smectic liquid crystal with competing surface and sample elasticities
  PHYS REV LETT 76 (9): 1477-1480 FEB 26 1996
• Warriner HE, Idziak SHJ, Slack NL, et al.
  Lamellar biogels: Fluid-membrane-based hydrogels containing polymer lipids
  SCIENCE 271 (5251): 969-973 FEB 16 1996