- 138 views
- 168 downloads
Online characterization of particle based reactions by laser backscattering
-
- Author / Creator
- Medina, Miguel A
-
A fiber optic dynamic light scattering device was successfully developed for the in-situ characterization of particle size in turbid media. Currently available techniques are only capable of performing characterizations at room temperature and are highly limited by the turbidity of the sample. In-situ particle size characterization was accomplished using the diffuse wave spectroscopy theory and time-dependent autocorrelation analysis. Using this basis for the interpretation, information regarding the particle morphology was obtained from the backscattering signals using two simultaneous lasers, of 532 and 655nm wavelength, at elevated pressures up to 5 MPa, and at temperatures up to 420 °C. Validation of the analytical technique was achieved by studying a stable particulate dispersion of Carbon Lampblack (CB) in water and 1-methylnaphthalene. The 162 nm average particle size of the dispersion was characterized ex-situ with transmission electron microscopy and a commercial laser diffraction apparatus. The average particle size obtained by this technique was 275±39 nm at room temperature and 216±23 nm at 280 °C, showing a good agreement compared with the ex-situ values. Ultimately, the goal of this work is to develop a technique capable to track on-line the size and concentration of nanoscale particles. For this purpose, sulfidation reaction of iron naphthenate was selected to study the in-situ generation of iron based nanoparticles. Particles of 202±33 nm average size were characterized by this technique, finding good agreement with ex-situ characterization of the collected reaction products. Further study of this reaction with the developed technique allowed to determine the temperature on-set for the particle generation at 274.6±0.7 °C. While simultaneous determination of particle size and concentration was not possible in this work, several modifications of the current design are presented in the end of this manuscript aiming to solve the issues encountered during this work.
-
- Graduation date
- Fall 2016
-
- Type of Item
- Thesis
-
- Degree
- Master of Science
-
- License
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.