1. Improving the Hydrophobicity of Fabrics with the Use of Phosphonic Acids Craig Barretto, Jonathan P. Chen, Ishaan Desai, Samuel Finegold, Aamod George, Madeleine Hu, Karen Nan, Rei Otake, Amrita Rao, Carli Smolen, Lu Yin, David Zhao Supervisor: Dr. Michael AvaltroniAssistant: Darius Rackus

2. Teflon® Teflon (PTFE) widely known and used hydrophobic substance Resistant to many extreme conditions, low µ value Tends to flake off, potentially carcinogenic

3. Rain-X® Polydimethylsiloxane (PDMS) Sprayed on Disadvantage: Not permanent, weakens under external pressures n Si(CH 3 ) 2 Cl 2 + n H 2 O → [Si(CH 3 ) 2 O] n + 2n HCl http://en.wikipedia.org/wiki/File:Water_beads_on_glass_surface.jpg http://en.wikipedia.org/wiki/File:Silicone-3D-vdW.png http://en.wikipedia.org/wiki/File:Pdms.png

4. Scotchgard™ Treated fabrics become water- and stain-resistant Original formula shown to the right Was shown to be carcinogenic Main ingredient was changed to PFBS

5. Phosphonic Acids Self-Assembled Monolayers (SAM) Structure & Function Chain Lengths HPA (C6) OPA (C8) DPA (C10)DDPA (C12)TDPA (C14)HDPA (C16)ODPA (C18)

6. Hydrophobicity Hydrophobic molecules usually non-polar Water beads from cohesion and hydrogen bonds Surface and water share least amount of area θ Hydrophobic Hydrophilic θ

7. Surface Energy Lower surface energy indicates greater hydrophobicity Relationship between contact angle and surface energy described by Young's Equation θcθc

8. Nylon-Spandex Blend (NSB) Nylon is a polyamide of amide linkages Spandex is an elastic, synthetic fiber 85% nylon, 15% spandex www.chemistryexplained.com/Ny-Pi/Nylon.html

9. Purpose and Hypothesis Optimal phosphonic acid and procedure to coat fabric Increase hydrophobicity Speed up binding process Develop more hydrophobic swimwear http://1.bp.blogspot.com/_ouC92wvILSw/SIFspwmW_BI/AAAAAAAACcY/mYej0D2fYMg/s400/Natural+water+drop+in+the+leaf.jpg

10. Preliminary Tests on NSB Qualitative hydrophobicity test Heat resistance tests: Conventional oven, iron, microwave, heat gun Tests to see how NSB handled the solution NSB being ironed www.asia.ru/images/target/photo/51646912/Steam_Iron.jpg

11. toluene ethanol upload.wikimedia.org/wikipedia/commons/e/e8/Ethanol-structure.svg upload.wikimedia.org/wikipedia/commons/c/c3/Beaker.svg Preliminary Tests on NSB Qualitative hydrophobicity test Heat resistance tests: Conventional oven, iron, microwave, heat gun Tests to see how NSB handled the solution

12. Chain Length Tests on Glass Slides Solution dropped on and spread 3 heating methods for dehydration Contact angles measured

13. NSB Hydrophobicity Dipped in solution then air dried 3 heating methods for dehydration Contact angles measured

14. Cotton Testing Procedure Dipped in ODPA and air dried Heated using iron and microwave Six coatings applied Contact angles measured

15. Exposure Tests Tests Washing Machine Chlorinated Water Deionized Water Control C18 3 heating methods www.toondoo.com/cartoon/557143

16. Glass Results

17. NSB Results

18. Comparison of Effectiveness of Drying Methods Contact Angle (Degrees)

19. Exposure Tests on NSB- Results Contrasted with expectation Hydrophobicity higher after tests Control showed most decrease in hydrophobicity Theories Residue from detergent Reaction with surface Surface cleaning

21. Future Work More samples to confirm findings More chain lengths used for exposure tests, eg. C-12 and C-14 (worked best on glass) Multiple coatings to one surface to determine its effects Different surfaces

22. Conclusion Based on the results obtained from this project, it can be concluded that the physical properties of a surface can be permanently altered to increase the hydrophobicity of the surface.

23. Acknowledgements Thanks to: Dr. Michael Avaltroni Darius Rackus Dr. David Miyamoto Ramé-Hart Instrument Company John and Laura Overdeck Sponsors of NJGSS 2010 Program Bayer HealthCare Bristol-Myers Squibb Novartis

24. Questions?