Masters Theses


Mehrdad Alfi

Keywords and Phrases

Hydrodynamic interaction; Lift-hyperlayer mode; Particle shape separation; Rodlike particles; Slender body theory


"Size separation of spherical and rod-like particles in Flow Field-flow Fractionation was investigated theoretically. The effect of cross flow migration and rod orientation was also investigated as a new mode of study. It has been shown that the rod local orientation makes different diffusivity values in comparison with spherical particles and helps particle separation. Additionally, a new mechanism of lift-hypelayer mode was used for rod-like particles which can be compared with steric mode of spherical particles. This mechanism is said to be due to hydrodynamic interaction of rod-like particle with wall and with other rods.

As a measure of axial and cross flow velocity, Peclet number was defined in each case with respect to spherical particle or rod-like particle. Based on different Peclet numbers, operations were divided into four different regions each with a dominant mode. Additionally, retention ratio of each particle category was calculated using concentration profile and velocity profile. Summing up all the effects, the conclusion was drawn that according to what size of particle to separate, one should choose proper axial and cross-flow velocity together with proper mode of operation.

Finally, based on theoretical studies, it was concluded that shape separation of rod-like particles is feasible for particles in micro size. However, for smaller particles experimental investigation may be needed."--Abstract, page iv.


Park, Joontaek

Committee Member(s)

Zahedi, Gholamreza
Nath, Manashi
Liang, Xinhua


Chemical and Biochemical Engineering

Degree Name

M.S. in Chemical Engineering


Missouri University of Science and Technology. Department of Chemical and Biochemical Engineering


Missouri University of Science and Technology

Publication Date

Spring 2014

Journal article titles appearing in thesis/dissertation

  • Theoretical analysis of the local orientation effect and the lift-hyperlayer mode of rod-like particles in field-flow fractionation


viii, 35 pages

Note about bibliography

Includes bibliographical references.


© 2014 Mehrdad Alfi, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Field-flow fractionation
Nanotubes -- Testing

Thesis Number

T 10434

Electronic OCLC #