Suck It Up - Wicking

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Author Contact Information

Peter M. Amati, Jr.
Holliston High School
Holliston, Ma. 01746
School Phone 508-429-0677
amati@tea.rice.edu

Overview
In this activity students will investigate the "wicking capacity " of fabric; that is how well various fabrics draw water ["perspiration"] away from the body and let it vent to the outside. To do so, student research teams , under the leadership of their PIs (See Is Your Underwear Cool ? for methods of establishing research teams), will brainstorm possible protocols to measure, tabulate and analyze the wicking capacities of the of various fabrics.

The students will:

• brainstorm to establish what is met by wicking and why it must be looked at in designing insulated underwear.
• design possible experiments to measure the wicking capacity of various material types.
• carry out experiments to test the wicking capacity of various materials.
• create a lab report for sharing with the class.
• arrive a consensus as to which material has the best wicking capacity and why?

Grade Level/Discipline
Grades 9-12, but may be adapted to middle school Physical science and general science classes.

National Standards

1. Benchmarks 1A, 2A, 3A, 1B, 1C, 3C, 4D, 4E, 6E, 11A, 11C

1. Strand 1 Inquiry #'s 1 -34
2. Strand 2 Domains of Science
3. Physical Science #'s 3, 64, 69
4. Life Science #'s 46, 47,
5. Earth and Space Science #'s 46, ,63, 65
6. Strand 3 Technology #'s 2, 6, 10, 15, 16, 18, 19, 27, 32, 37, 38, 40, 53, 54, 56, 60, 61, 62, 63, 78,
7. Strand 4 Science Technology and Human Affairs #'s 2, 3, 10, 11, 15, 16

Pre-activity set-up

• obtain samples of 16 different types of material … obtain test tubes
• balance

Materials

• obtain samples of 16 different types of material
• incubator at 37° C
• balance
• elastic bands
• ruler
• eye dropper

Time Frame
Two class periods (approximately 55 minutes per period)

Engagement and Exploration (Student Inquiry Activity)
Have kids read Internet sites. One dealing with a cold weather quiz HTTP://www.gorefabrics.com/wintersports/coldfaqs.htm#coldfact

Have the PIs take charge of the research teams, there has to be leader. PIs now list on the board definitions and protocols that the research teams come up to address the problem being looked at. What is it that is being looked at? How can it be investigated? How can this information be reported?

A definition of wicking capacity is crucial. A definition that is frequently used is how rapidly does a piece of fabric draw up a liquid. This seems to fit the bill. Question as to whether this is really absorption. This frequently develops into a great discussion. See the following web site for good description of wicking http://www.beprepared.com/Arcticles/weather.html

">http://www.beprepared.com/Arcticles/weather.html">http://www.beprepared.com/Arcticles/weather.html

Have PIs , using a consensus of groups, lay out one protocol that is to be followed by all groups in the testing of materials . Make sure discussion centers on what is being measured and how this is to take place. Agreement as to what and how data sets are to be reported must be established.

There is no real right answer. Two possible protocols that work well are as follows:

One possible protocol is to

• cover wide mouth jar (150 ml beaker works well) with cloth sample held very taught by elastic band
• add one drop of water to center of cloth
• measure the ever increasing diameter of "wetness" at specific time intervals (your call -10, 60, 300 seconds. A great place for intense discussions about the significance of fixed times, control, and things like if we wait too long won't it be evaporating and not wicking.?!)
• rate at which circle, diameter, grows could represent wicking.

• put a fixed mass of water in a test tube. The wider the mouth the better.
• cover with cloth sample held in place by an elastic band.
• place in an incubator set at 37° C. A box with a light bulb my be used to get a fixed temperature that at least approaches normal body temperature of 37° C.
• leave in box over night and remass.
• find surface area of cloth (area of a circle=3.14 times radius squared)
• find loss in mass of water in tube that occurred over night. This should represent the mass of water lost/area/time.

Discussion of the significance of mouth size; the rational for having temperature fixed, preferably at 37° C and the concept of loss in mass/ area / time should be stressed.

Allow class to run the protocol that was agreed upon. Data should be reported graphically. A line graph of diameter of drop as a function of time (separate curve for each cloth type) works well for the first protocol and a and a bar graph the of change in mass (mass of water evaporated "wicked" during the course of the night) as a function of cloth type works well for the second protocol.

Explanation (Discussing)
Discuss with students, based on THEIR observations, how each of the "wicking capacities" of the various cloths compare. This will vary greatly with material type; but, there will be significant (obvious) differences among some. N.B. Which is the "best" depends on what is being compared and how it (wicking) is being looked at. This will become obvious and somewhat frustrating for kids when, as usually is the case , they get back to exactly how THEY are defining wicking. (That's OK, let them defend their positions.)

Elaboration (Polar Applications)
Set the scene by explaining that students will be role-playing the parts of clothing designers developing long underwear for a sea ice research team taking ice cores from the Weddell Sea.

Ask students to read about Peter Amati's research in the Weddell Sea on the Teachers Experiencing Antarctica and the Arctic web site ../../tea_amatifrontpage.html

In parcticular, note the journal entry from June 6, 1992 ../../amati/6.5.1992.html In this entry, Peter describes the extreme cold and dryness of Antarctica.

Another interesting reference can be found on the GLACIER web site at ../../expedition/2_trainingcamp.html

Exchange (Students Draw Conclusions)
Student PIs present graphed data acquired from all research teams and lead discussion that will lead to a consensus as to which material was most effective at wicking moisture away from the body. Transparencies of pooled data sets showing graphs of diameter of drop as a function of time (separate curve for each cloth type) if first protocol is used or a bar graph the of change in mass (mass of water evaporated "wicked" during the course of the night) as a function of cloth type works well is the second protocol was used . N.B. Graphic presentation is what is important here. Class's decision as to what protocol will be followed will determine data sets, Graphic and/or tabulated data; and its interpretation are what MUST be presented.

Evaluation (Assessing Student Performance)
Rubric dealing with formal lab report and graphed data sets.

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