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Self-diffusion of Colloidal Particles at Soft
(Liquid/Liquid) Interfaces
by
PENG Yuan
A thesis Submitted to
The Hong Kong University of Science and Technology
in Partial Fulfillment of the Requirements for
the Degree of Master of Philosophy
in Department of Physics
August 2007, Hong Kong

Acknowledgements
I would like to express my most sincere gratitude to my thesis supervisor, Prof.
Penger Tong for his guidance, encouragement, and patience throughout the past two
years.
I would like to thank Prof. Jiannong Wang and Prof. Zikang Tang for serving
the examination committee and providing valuable comments on my thesis.
I would like to thank Dr. Wei Chen for teaching me how to operate the
microscope and his particle tracking program, and also for his helpful guidance,
discussion and patient support. In addition, I want to thank Patrick Luk for his
technical support.
I would like to thank Dr. Xiaomin Xiong, Dr. Yongjian Wang, Xiaozhou He,
Song Hao and Zuli Xu for their kind help.
At last I would like to thank my family and my friends for their continuous
encouragement in my university life.

TABLE OF CONTENTS
Title Page i
Authorization Page ii
Signature Page iii
Acknowledgements iv
Table of Contents v
List of Figures viii
List of Tables xii
List of Symbols xiii
Abstract xiv
Chapter 1 Introduction 1
1.1 Motivations 1
1.2 Outline of this Thesis 3
Chapter 2 Background on colloidal suspension 4
2.1 Inter-particle forces 4
2.1.1 Van der Waals attraction 4
2.1.2 Charge stabilization 6
2.1.3 Steric stabilization and specific coating interactions 8
2.2 Model systems www.51lunwen.org 9
2.2.1 Polystyrene latex particles 9
2.2.2 Silica spheres 11
2.2.3 Polymethylmethacrylate (PMMA) spheres 12
2.2.4 Other systems 13
2.3 Dynamics in unperturbed 3D suspensions 14
2.3.1 Justification of configuration-space picture 15
2.3.2 Inclusion of hydrodynamic interactions 18
2.3.3 Short-time self-diffusion 20
2.3.4 Long-time self diffusion 22
2.4 Particles at the interfaces 24
2.4.1 Energetic adsorption 24
2.4.2 Hydrodynamic drag at the interfaces 25
Chapter 3 Experimental Setup and Methods 28
3.1 Water-air interface 28
3.2 Liquid-liquid interface 29
3.3 Cleaning procedures 31
3.4 Dispersion of particles onto the interface 31
3.5 Optical microscopy 33
3.6 Particle tracking 35
3.7 Determination of bulk diffusion coefficient by dynamic light scattering
38
Chapter 4 Measurement of short-time self-diffusion at the decalin-water interface 42
4.1 pair correlation function and inter-particle potentials 42
4.2 Measurement of for the PMMA particles with radius 600 nm and
350nm 47
4.3 Discussion of the experimental results 52
Chapter 5 Long-time self diffusion of charged Polystyrene particles 57
5.1 Interactions between polystyrene latex spheres at the water-air
interface 57
5.2 Excess entropy in colloidal suspension 60
5.3 Relationship between excess entropy and 2 S L
s D 65
Chapter 6 Summary of this Thesis 69
References 72
Appendix A 75
Appendix B 78

List of Figures
Figure 2.1 Illustration of three typical position of a tracer particle at the interface.
The value of h indicates the distance of the center of the sphere to the interface (z = 0)
of two fluids. . 26
Figure 3.1 Schematic diagram of the experimental setup (side view) 2本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。