Presentation on theme: "Contact Angles Coyotes Ashley Steffe, Michele King, Matt Tillma, Dustin Little."— Presentation transcript:
Contact Angles Coyotes Ashley Steffe, Michele King, Matt Tillma, Dustin Little
Introduction Ionic liquid An ionic liquid is defined as a liquid that is constituted only of ions, as opposed to many familiar liquids which are composed purely of molecules. They contain large cations and anions concentrations. These liquids have similar properties as molten salts like NaCl, when they are at temperatures greater than 800 degrees Celsius. However they have relatively low melting points and are liquid around room temperature. Contact angle The contact angle is the angle at which a liquid meets the solid surface. The contact angle is specific for any given substance on a particular surface. When measuring contact angle the amount of drops placed on the surface does not change the contact angle. You could place anywhere from 1-10 drops and the measurement would be the same.
Objective: The objective of our experiment is to measure and compare the contact angles of two ionic liquids on different surfaces, to water on those same surfaces. The ionic liquids that we used were trioctylmethylammonium methylcarbonate and trihexylmethylammonium methylcarbonate. We used these two liquids since they are liquid at room temperature. Surfaces Cu atoms Borosilicate(glass) Polystyrate Zn oxide Al oxide
Procedure: 1.First place one drop of water on all five of the surfaces. 2.Take a digital photograph of the drops. Make sure that the camera is level with the surface the drop is on. 3.Place one drop of trioctylmethylammonium methylcarbonate on each of the surfaces. 4.Take a digital photograph of the drops. Again make sure that your camera is level with the surface the drop is on. 5.Place one drop of trihexylmethylammonium methylcarbonate on each of the surfaces. 6.Take a digital photograph of the drops. Make sure that your camera is level with the surface the drop is on. 7.Take and enlarge all of the photographs and measure the contact angles. 8.Then record and compare the results.
Results: Water Trioctylmethyl ammonium Trihexylmethyl ammonium Zn (oxide)554724 Borosilicate 5948 Cu (atoms)534950 Al (oxide)564450 Polystyrate543646
Discussion: We chose to use water on glass as our standard reading. We found that the contact angle was 14˚. This was inaccurate with our measurement due to the different type of glass used in the experiments. We were unable to find a measurement for water on borosilicate. We found that water has greater contact angles than ionic liquids, due to the lack of wetting (spreading) on a surface. Based on our data we found that the surfaces containing oxides tend to produce greater contact angles, which makes the liquid bead up more intensely on the surface. We had an inaccurate reading for the sample of Trihexylmethylammonium on the Zn surface. Our data was not consistent so we were unable to include this reading in our conclusions. Our data also shows that polystyrate causes the liquids to spread out more producing a smaller contact angle. Trioctylmethylammonium was the most reactive with the plolystyrate producing a contact angle of 36˚. We were unable to be certain on our conclusions because we did not find significant results.
Summary For future experimentation with contact angles of ionic liquids We would use a device that determined if we were exactly level with the surface that drop was on. We would also make sure that each surface is 100% flat. We would use a device to place the same size drop every time. We also would use a higher quality camera to clearly view the angles. Overall we would use better equipment and more accurate techniques.