Clean aqueous colloidal dispersions

Ingredients

2 Large pickle jars.
- Eagle-Picher Environmental clear straight sided jars (with solid PP caps and Teflon liners), 1L, clean, Fisher Scientific 12-100-160.
1 bottle of colloids
- Nanobead NIST Traceable Particle Size Standard, 600 nm 1.0% Polystyrene Microspheres in water, Polysciences, Inc. Lot # 525612 cat.64021.
- Microbead NIST Traceable Particle Size Standard, 1 micron 1.0% Polystyrene Microspheres in water, Polysciences, Inc. Lot # 549367 cat.64030.
- Microbead NIST Traceable Particle Size Standard, 1.5 micron 1.0% Polystyrene Microspheres in water, Polysciences, Inc. Lot # 526826 cat.64040.
1 Dialysis membrane tubing
- See How To Choose Dialysis Membranes
- Spectra/Por CE Membrane MWCO: 100,000, Diameter: 15 mm, Spectrum Laboratories Reorder No. 131417.
- Spectra/Por RE Membrane MWCO: 6-8,000, Diameter: 14.6 mm, Spectrum medical industries Reorder No. 132650.
1 pack Dialysis membrane closures
- Universal Closures for CE membranes, sealing width 50 mm, Fisher Scientific Reorder No. 142155.

Clean pickle jars by filling them with deionized water, then putting them in a Pyrex jar filled with deionized water and boiling the whole constellation. Warning: make sure that the jars are placed on glass beads to minimize the direct heat transfer from the hot plate. Jars have been known to crack otherwise. Let cool off slowly
Clean the membrane. Fisrt cut off two 14 cm long pieces from the membrane tubing. Place them for half an hour in deionized water with a stir bar and stir. Then change water and let stand for another half hour.
Seal one end of a membrane with two clamps. Make sure the membrane is completely flat (we don't want colloids to run away).
Vortex the colloids to be used for about 2 min.
Fill the "pickle" you are making half way with the colloids.
Make sure thereare no air bubles in the pickle by flatening the empty part of the pickle and then use two more clamps to close it.
Put two pickles in a jar and fill with deionized water. Adding water sould be done on the side of the jar to minimize the air dissolving in the water.
Change water every hour in the first day or until the pickle starts to swell, then do it about twice a day.