WATER-PROOFING A PIECE OF FILTER PAPER*
Chang-Ning Wu (NSF-POLYED Scholar), Jean Opsteen and J. Droske*
POLYED National Information Center for Polymer Education
University of Wisconsin-Stevens Point
Stevens Point, WI 54481
Materials:
- filter paper (9 cm diameter paper is a convenient size for a standard petri dish)
- petri dish
- dichlorodimethylsilane
- pentane
- tongs
- wash bottle containing water
WORK IN A GOOD FUME HOOD! WEAR GOGGLES!
Procedure:
- Place 10 mL of pentane in a petri dish in a fume hood. Add 5 mL of
dichlorodimethylsilane and swirl to mix.
- Using tongs, place a piece of filter paper into the dichlorodimethylsilane/pentane
solution for about thirty seconds. Fully immerse the filter paper in the solution.
- Keeping the filter paper in the hood, remove it from the solution and allow the smoke
to clear (about thirty seconds).
- Spray water on the treated paper and note that the water just beads up and rolls off
due to the silicone polymer coating on the paper. Try this with an untreated filter
paper and note that the water completely soaks the paper.
This was developed as part of the NSF-POLYED Scholars Project, a program of the POLYED National Information Center for Polymer Education at the University of Wisconsin-Stevens Point. Chang-Ning Wu is Professor of Chemistry at the University of Massachusetts-Dartmouth.