Flow correction to weak flow in particle tracking microrheology

다국어 초록 (Multilingual Abstract)

Particle tracking microrheology(PTM) is one of passive measurements of thermally excited probes, in which no external force is applied. PTM has been developed to directly image the position of a colloidal particle as a function of time, and allowed analysis of individual particle trajectories. Because of its advantages, PTM is a valuable tool capable of measuring the local dynamics in heterogeneous systems.
However, viscoelastic properties of solutions under flow are also of great interest in various processes. Especially in drying process, because of the effect of internal flows in a drying solution, measurement of local dynamics was often limited to a qualitative description of the particle flow, or to the visualization of the velocity field. To overcome this difficulty and to measure the rheological properties, the flow must be corrected. Hence, flow correction is important in the application of PTM to drying process of polymer solutions.
In this study, we tracked the motion of probing particles in one dimensional flow. In case of weak two dimensional flow, to eliminate the effect of motion due to the external flow by using noise reduction, ensemble averaged mean square displacement was investigated. We proved that the modulus after flow correction is the same with the one without flow.

목차 (Table of Contents)

• Chapter 1 Introduction 1
• 1.1. Microrheology 1
• 1.2. Drying process 2
• Chapter 2 Materials and methods 3
• 2.1. Materials 3
• 2.2. Micro device 3
• 2.3. Flow rate control 4
• 2.4. Particle tracking microrheology 4
• 2.5. Data processing 6
• Chapter 3 Results and Discussion 8
• 3.1. Comparing PTM results with conventional rheometry 8
• 3.2. Flow correction 12
• 3.2.1. One dimensional flow 12
• 3.2.2. Two dimensional flow 20
• Chapter 4 Conclusion 24
• Reference 25
• 국문요약 27