Optical Microscopy: Part 4 Report Outline

5. Viscosity
   1. Procedure
      • Document the samples you prepared and used and how you captured images (camera settings including frame acquisition rate, number of frames, number of particles in the region of interest, choice of sample plane, etc)
   2. Data
   • Include a snapshot of the 0.84 μm fluorescent beads monitored.
   • Plot an example bead trajectory in the X-Y plane.
   • Plot the beads' MSD vs time interval (τ) data on log-log axes.
   3. Analysis and Results
   • Include a table of the viscosities and glycerin/water ratio for each of the samples.
   • Plot the average MSD for all the beads you measured versus τ for each PVP sample.
   • Provide a bullet point outline of all calculations and data processing steps.
   • Explain how you can use the mean squared displacement data to extract D, the diffusion coefficient of a purely viscous fluid. What equation relates D and η, the fluid's viscosity?
   • Estimate diffusion coefficient and viscosity for each water-glycerin mixture sample (A, B, C and D).
   4. Discussion
   • How do your viscosity calculations compare to your expectations? (This chart is a useful reference.)
   • What can you infer about the viscoelastic properties of the PVP gels from your MSD plots?
   • Include a thorough discussion of error sources and the approaches to minimize them.