Bourns College of Engineering

A345 Bourns Hall
Riverside, Ca 92521
Phone: 951-827-5487
FAX: 951-827-5696

Anders Wistrom

Assistant Professor,
Chemical and Environmental
Engineering

Professor Anders Wistrom is a graduate Civil Engineer from the Royal Institute of Technology, (KTH), Stockholm, Sweden. He received his M.S. degree in Engineering (Civil Engineering) in 1982 and his Ph.D. degree in Engineering (Civil and Environmental Engineering) in 1993, both from the University of California, Davis. He came to the University of California, Riverside from Los Alamos National Laboratory in January 1994.

Research Topics

(1) Pair- and many-body interaction forces, (2) Colloid stability and facilitated transport - waste migration in the natural environment, and (3) Analysis of particulate systems for pollution control, flocculation, sedimentation and filtration processes.

Fundamentals : A long-standing area of research in colloid science concerns the determination of electrostatic forces in dispersions comprised of densely packed inclusions. Despite methodological advances there are virtually no accurate large-scale numerical simulations of random media at high volume fraction in a three-dimensional setting.

A framework for solving many-body interface problems is being developed. The goal is to construct a numerical tool for point-wise evaluation of transport properties of very concentrated dispersions. A different problem is the exact calibration of electrostatic force and electrostatic torque.

Applications: Knowledge of many-body interaction forces is essential for developing predictive models for many-particle phenomena of different size scales ranging from atomic to macroscopic. For example, stability, reactivity and chirality of chemical compounds, nucleation, condensation and growth, and colloidal and interfacial interactions are many-body phenomena of great technological importance.

Ongoing projects are: (1) Formulation of mathematical algorithms for development and application of point-wise analysis for many-body systems, (2) Development of predictive models for particle aggregation and condensation phenomena, and (3) Investigation of fouling mechanisms for microfiltration and RO membranes.

Latest Results

Electrostatic spin is observed in experiments that comprise three conducting spheres held at constant potential. Theory predicts that electrostatic spin is the direct consequence of the Coulomb force acting on an asymmetric distribution of surface charges and where spin direction follows directly from the equation for electrostatic torque.

The most important aspect of the discovery is that electrostatic spin is general and would apply to systems of all size scales where the electrostatic force is the dominant operative force. This result invites the investigation of new molecular models, novel fabrication techniques for nano materials, devices, and motors.

Lab Facilities

The Environmental Engineering Research Laboratory (5000 ft2) in Bourns Hall is fully equipped for bench and pilot scale testing of physical, chemical, and biological treatment systems. In addition, a Class 100 Clean Room equipped with particle characterization instrumentation (Brookhaven Instruments Dynamic/Static Light Scattering with 3W Ar Laser, Coulter Counter Multisizer II) is available for investigating natural and engineered particulate systems. The Environmental Engineering Modeling Laboratory outfitted with Sun and SGI Unix workstations support the experimental research.

Selected Publications

Wistrom, A. O. and A.V. Khachatourian. 1999. Calibration of the electrostatic force. Measurement Science and Technology 12, 10: 1296-1299.

Khachatourian, A.V.M. and A.O. Wistrom. 2000. Evaluation of the Coulomb force via the Fredholm Integral Equation. Journal of Physics A: Mathematical and General 33:307-317.

Aurell, C.A. and A.O. Wistrom. 2000. Coagulation of kaolinite colloids in high carbonate strength water. Colloids and Surfaces A: Physiochemical and Engineering Aspects 168: 277-285.

Khachatourian, A.V.M. and A.O. Wistrom. 2001. Size effects in aerosol interactions, Journal of Colloid and Interface Science, 242, 52-58.

A.O. Wistrom and A.V.M. Khachatourian. 2002. A Coulomb motor by rotation of spherical conductors via the electrostatic force, Applied Physics Letters, 80 (15) 2800-2801. (Correction: Applied Physics Letters, 81 (25) 4871.)

Khachatourian, A.V.M. and A.O. Wistrom. 2002. Electrostatic rotation of spherical conductors, Europhysics Letters, 59 (4), 521-525. (Correction: Europhysics Letters, 60 (2) 330.)

Khachatourian, A.V.M. and A.O. Wistrom. 2003. A sum rule for Associated Legendre polynomials with spherical triangles. Journal of Mathematical Physics. 44(2), 849-852.