Rechargeable Infection-Rechargeable Infection-Resistant Materials Resistant Materials

Yuyu SunDepartment of Human Ecology

The University of Texas at Austin

General transmission pathway of General transmission pathway of harmful germsharmful germs

Germ Carriers

Environmental Surfaces

New Victims

Survival of infectious agents on Survival of infectious agents on materialsmaterials

Species Typical Examples Survival Time

Gram-negative bacteria

E. coli Up to 60 days

Gram-positive bacteria

S. aureus Up to 90 days

Fungi C. tropicalis Up to 60 days

Viruses Influenza viruses, SARS

Up to 12 hours

Spores Bacillus subtilis (surrogate of

anthrax)

Months to years

Durable, rechargeable biocidal Durable, rechargeable biocidal surfacessurfaces

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

Biocidal functionsBiocidal functions

MicroorganismsChlorine

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

Biofilm formation was prevented Biofilm formation was prevented in side-by-side comparisonin side-by-side comparison

SEM of (A) pure polypropylene and (B) treated polypropylene after contact with S. epidermidis for 72h

A B

Potential applicationsPotential applications

Hospital equipment Medical and dental device Food storage Water purification and transportation Consumer products Etc.