1. Rechargeable Infection-Resistant Materials Yuyu Sun Department of Human Ecology The University of Texas at Austin

2. General transmission pathway of harmful germs Germ Carriers Environmental Surfaces New Victims

3. Survival of infectious agents on materials SpeciesTypical ExamplesSurvival Time Gram-negative bacteria E. coliUp to 60 days Gram-positive bacteria S. aureusUp to 90 days FungiC. tropicalisUp to 60 days VirusesInfluenza viruses, SARSUp to 12 hours SporesBacillus subtilis (surrogate of anthrax) Months to years

4. Durable, rechargeable biocidal surfaces Dead bacteria Live bacteria 1. Surface treated with our technology 2.Bacteria come into contact with surface 3.Bacteria are killed 4.Chlorine is consumed 5.Chlorine bleach rinse recharges surface

5. Biocidal functions Microorganisms Chlorine content (%) Minimum contact time for a total kill E. coli*0.5%3 min S. aureus*0.5%3 min C. tropicalis*0.5%3 min MS2 virus**1.0%5 min Bacillus subtilis spores 1.0%4 hr

6. Biofilm formation was prevented in side-by-side comparison  SEM of (A) pure polypropylene and (B) treated polypropylene after contact with S. epidermidis for 72h AB

7. Potential applications  Hospital equipment  Medical and dental device  Food storage  Water purification and transportation  Consumer products  Etc.