This document discusses the application of nano TiO2 as an antimicrobial agent. Nano TiO2 has photocatalytic and antimicrobial properties and can be used as a food-grade pigment, in effluent treatment, and to coat photovoltaic cells. It acts against both gram-positive and gram-negative bacteria as well as fungi by inhibiting bacterial growth, degrading cell walls, and damaging DNA. Potential applications include use in food packaging to extend shelf-life, coating on polymers and paints for antimicrobial surfaces, and in self-cleaning coatings by breaking down dirt and organic materials photcatalytically. Upon absorbing light, nano TiO2 generates reactive oxygen species that act as powerful oxid

1. Application of Nano TiO2 as
Antimicrobial Agents
Megha R
ESBE Self Study

2. Nano TiO2
• Photocatalytic properties, high photoreactivity
• Food grade
• Antimicrobial properties
• Strong oxidising power in UV light
• Applications
– White pigment in paint and food colouring
– Effluent treatment
– Coating on PV cells

3. Antimicrobial properties
• Act against Gram positive and gram negative
strains of bacteria as well as fungi
• Non-toxic, environment friendly and possess
non contact biocidal properties
• Inhibits reproduction ability of bacteria by
arresting growth in lag phase
• Can also decompose phospholipid part of cell
walls and completely degrade microbial cells

4. Antimicrobial properties
• Also decreases the expression of co-enzyme
related activities
• Lowers the ability to transport iron and
phosphorous
• Damages DNA with hydroxyl ions

5. Applications
Food Packaging Material
• TiO2 nanoparticles coated on plastics can be used as
packaging material for foods and other sterile coverings
• Due to antimicrobial and non contact properties
• Successful in extending shelf, quality and safety assurance
• Can be coated or adsorbed onto polymer films or used as
sachets

6. Applications
Coatings and Paints
• Coated onto polymer films and tested for microbial activity
• Tested for action against Escherichia coli (E. coli),
Staphylococcus aureus, and Pseudomonas putida

7. Applications
Coatings and Paints
• Can be coated onto high and low density polyethylene (LDPE
and HDPE)
• Forms stable nanocomposite without altering properties of
either polymer or nanomaterial
• Can also be doped with metals such Ag and Cu to increase
bacteriocidal properties and wavelength range
• New antimicrobial interior paints developed – coated on walls
and absorb light from fluorescent bulbs and undermines
bacterial growth

8. Applications
Photoinduced hydrophilic coatings and
self-cleaning devices
• High hydrophilcity - self cleaning effect
• Photo-catalysis helps in breaking down accumulated dirt and
organic matter removing colouration and odour
• Biocidal properties prevent build-up algae, fungus and mould
• Gens Nano TiO2 coating - special coating developed for wall
exteriors
• Used in self cleaning textiles

9. Photocatalytic Action

10. Photocatalytic Action
• Anatase TiO2 used which has a bandgap of
3.2eV
• On absorption of photons of that bandgap
electron and hole pairs are generated
• Can either recombine or move to the surface
• At the surface, react with adsorbed electron
acceptor and donor

11. Photocatalytic Action
• Water and oxygen act as electron donor and
acceptor to produce hydroxyl ions and
superoxide ions
• The products, combined with holes, are
powerful oxidising agents

12. References
• Understanding the antimicrobial mechanism
of TiO2-based nanocomposite films in a
pathogenic bacterium
• http://www.mchnanosolutions.com/
• http://www.sciencedirect.com/
• Antimicrobial Activity of TiO2 Nanoparticle-
Coated Film for Potential Food Packaging
Applications