Wen-Yi Shih

Polymer and Separations (PolySep) Research Laboratory

Last update:

12/27/2005

Wen Yi (Winnie) Shih

B.S. University of Washington, 2000

Research Interests

Mineral Salt Crystallization

Scale Formation Kinetics and Mechanisms

Membrane Fouling

Surface nanostructuring/Topology Characterization

Current Project

My current research focuses on calcium sulfate (gypsum) scaling on polymer surfaces. Calcium, sulfate, and bicarbonate ions are found in the surface and ground waters. By desalinating these waters at high recovery ratios, a concentration polarization layer forms which leads to calcium sulfate and calcium carbonate precipitation. The build-up of these crystals reduces permeate flux.

Numerous research groups have focused their studies on bulk homogeneous crystallization, but surface nucleation and its role in the overall crystallization process has not been clearly established. Processes on the membrane surfaces are crucial to understanding scale formation and will eventually lead to formulating preventive measures against membrane fouling. In my work, a a quartz crystal microbalance (QCM) flow crystallization flow cell will be one of the tools used in my research to determine the scaling rate. Other characterization tools will include optical microscopy, SEM and AFM. Surface topology and chemistry will be investigated and enhance our understanding of how surface properties contribute to the scaling process.

Publications:

Wen-Yi Shih, K. Albrecht, J. Glater and Y. Cohen, "A Dual Probe Approach for Evaluation of Gypsum Crystallization in Response to Antiscalant Treatment," Desalination, in press.

Wen-Yi Shih and Y. Cohen, Structural Gypsum Scale Development on Low Pressure RO Membranes, J. Membrane Sci., in preparation.

Presentations:

W-Shih, R-W, Lee, J Gao, J. Glater and Y. Cohen, "Surface Characterization of CaSO4 Crystals on RO Membranes", Annual AIChE Meeting, November 16-21, 2003, San Francisco, CA.

Ron-Wai Lee, Wen-Yi Shih, Y. Cohen, and Mark D. Williams, "Flux Decline due to Gypsum Scale Formation in RO Desalting," May 17-21, 2003, Snow King Resort Hotel, Jackson Hole, Wyoming

Wen-Yi Shih and Y. Cohen, "Axial Development of CaSO4 crystals on Reverse Osmosis Membranes,", 2003 North American Membrane Society, May 17-21, 2003, Snow King Resort Hotel, Jackson Hole, Wyoming.

Contact Information

5531 Boelter Hall

Chemical Engineering Department

UCLA, Los Angeles

CA-90095, USA

PH: (310) 2061297

Fax: (310)206 4107

E-mail: wenyi@seas.ucla.edu

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