Was Ben Franklin an Early Nanoscientist ?

Excerpt from Letter of Benjamin Franklin to William Brownrigg (Nov. 7, 1773)...At length being at Clapham, where there is, on the Common, a large Pond... I fetched out a Cruet of Oil, and dropt a little of it on the Water. I saw it spread itself with surprising Swiftness upon the Surface... the Oil tho' not more than a Tea Spoonful... which spread amazingly, and extended itself gradually till it reached the Lee Side, making all that Quarter of the Pond, perhaps half an Acre, as smooth as a Looking Glass....

... the Oil tho' not more than a Tea Spoonful perhaps half an Acre CHALLENGE: How thick was the film of Ben Franklins oil? Volume = (Area)(Thickness) V = A T V = 1 teaspoonful A = 0.5 acre ~ 2 cm 3 ~ 2,000 m 2 T = V/A 20,000,000 cm 2 = 2 cm 3 20,000,000 cm 2 = cm = 1 x cm = 1 x m T = 1 nanometer (nm)

The Campus Pond

A plastic tray will be your model of a pond A plastic tray will be your model of a pond.

You will form a thin film using one of the ingredients in olive oil.

That ingredient is called oleic acid.

One end of the oleic acid molecule is attracted to water molecules.

If you oleic acid on water, the ends of oleic acid molecules that contain oxygen atoms are attracted to the surface of the water

So, even in a small drop of oleic acid, billions of small oleic acid molecules will stand up like blades of grass on the surface of water So, even in a small drop of oleic acid, billions of small oleic acid molecules will stand up like blades of grass on the surface of water.

Now its your turn to create a thin layer on the surface of water. The directions for making a thin film of oleic acid are at each end of a table.The directions for making a thin film of oleic acid are at each end of a table. Water has been poured into the plastic tray.Water has been poured into the plastic tray. Your group needs to make a very dilute solution of oleic acid.Your group needs to make a very dilute solution of oleic acid. One drop of the solution will spread out across the surface of the water.One drop of the solution will spread out across the surface of the water. The alcohol dissolves in the water leaving a thin film of oleic acid on the surface of the water.The alcohol dissolves in the water leaving a thin film of oleic acid on the surface of the water. Then you can measure the average diameter of the somewhat circular thin layer of oleic acid.Then you can measure the average diameter of the somewhat circular thin layer of oleic acid.

Nanoscale Calculations Worksheets have been provided for the activity.Worksheets have been provided for the activity. One side of the worksheet includes hints for calculations.One side of the worksheet includes hints for calculations. Calculators have also been provided but need to be shared by the groupsCalculators have also been provided but need to be shared by the groups.

Form lab groups There are 7 tables in the room.There are 7 tables in the room. Two groups of 3 people will work at each table.Two groups of 3 people will work at each table.

You Have Created a Langmuir Film water hydrophobic end hydrophilic end

Lets Compare the Results of the Two Activities. How are the two activities similar?How are the two activities similar? How are the two activities different?How are the two activities different?