Sunday, 10 October 2010

Green Engineering: Self-Cleaning NanoTechnology

Green Engineering: Self-Cleaning NanoTechnology


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Sunday, 10 October 2010
 
Dedicated to David Suzuki, and THRC's Green Technical Textile Knowledge Network Initiative.
 
Nature has nurtured our environment with abundance of resources and green energy. Can we harvest, harness and sustain these free energy to foster innovative solutions to clean our environment?  Yes, we can. How? Imagine a green engineering solution to clean air-pollution to foster a sustainable clean environment. Imagine a truly textile substrate, integrated with green nanomaterial, keeps cleaning air and environment to provide us comfort and quality lifestyle that we envision.
Plant's chlorophyll, a typical natural photocatalyst, captures sunlight to turn water (H2O) and carbon dioxide (CO2) into oxygen (O2) and glucose. On the contrary in the presence of light and water, photocatalyst nTiO2, creates strong oxidation agent and electronic holes to breakdown the organic matter to CO2 and H2O as shown in figure..
Image  
Chemical Reactions:
  • Reduction Reaction: O2+e- → O2- Superoxide anion
  • Oxidation Reaction: H2O+h+ → -OH Hydroxyl radical
Disinfections by nTiO2 is x3 stronger than Cl2 & x1.5 stronger than O3
 
Wavelength of light required for Photo-excitation ʎ  =Planck’s Constant, h:1240/Band Gap Energy: 3.2eV = 388nm
 
 
Research reveals that bacteria, molds and mites inside carpets and air conditioners can be airborne - dust particles, paints, varnishes and pressed wood products used in interior decoration, form formaldehyde, benzene and other hazardous and carcinogenic chemicals as well as matters produced in human metabolism and ammonia inside toilets have made the indoor air severely polluted than the outdoor air. 
Usually people spend about 80-90% of their time indoors. They are exposed to polluted indoor air that may cause headaches, dizziness, irritation, fatigue and even lung cancer and other malignancies. Scientists have been modifying materials and offering creative solutions to these challenging problems.
TiO2 Crystal Structures:
  1. Rutile: Tetragonal crystal system, Band gap: 3.0eV. Less reduction power. More stable at high temperature. Density: 4.2743. UV resistance. Blocks  sunlight
  2. Anatase: Tetragonal crystal system, Band gap: 3.2eV. More reduction power. More stable at low temperature. Density: 3.895. Photocatalyst
  3. Brookite: Density: 4.123
Features:
  • Self-cleaning
  • Air purification
  • Anti-bacterial, Anti-fungi, and Anti-mold
  • Super hydrophilicity
  • Antistatic surface
  • UV resistance
  • Easy-cleaning
Benefits
  • Keeps the surface clean
  • Purifies air pollutants e.g. VOCs, NOx, Formaldehyde, Benzene
  • Decomposes bacteria and virus on the surface and in the air
  • Restrains growing mildew, mold, fungi, or algae
  • Decomposes the organic pollutants on the surface
  • Protects the surface from dust, dirt and air pollutant damage
  • Absorbs UV rays from sun and protects the surface from UV damage 
Self-Cleaning Mechanism:
Toxic VOC + Light + H2O + TiO2 = Non-Toxic Inorganic Gas + TiO2
  • Micro-organisms carry '–ve' charge.
  • nTiO2 surfaces carry '+ve' charge.
  • •Photo-excitation
  • •ElectroMagnetic Attraction
  • •Oxidation
  • •Decomposition

Click on the links below for in-depth information. Explore and enjoy!


Green Engineering: Self-Cleaning NanoTechnology


Interesting Links:
Featured Insights:
2010 Self-Cleaning Coatings, P A Carpentier, K D Burgess, WO/210/078649, PCT/CA2010/000009, Jul 15
2010 Extreme Engineered Materials Design, S Islam, Textile, biggani.org, Jul10
2010 Super Strong NanoCrystalline Cellulose Synthesis: Challenges and Opportunities, S Islam, Nanotechnology, biggani.org, Jul 04
2010 Progress and Perspectives in the Carbon Nanotube World, M Endo, AZoNano.com, Jun 23
2009 Nanoparticles Used in Common Household Items Cause Genetic Damage in Mice, Science Daily, Nov 17
2007 Boiactive Silk Proteins as Geotextile Substrates, M Tsukada, S Islam, Y Ishiguro, Textiles & Clothing, Jan-Mar 5-6
2006 Methods and apparatus for spinning spider silk protein, S Islam et al., USP 7,057,023 Jun 6
2005 TiO2 Photocatalysis: A Historical Overview and Future Prospects, K Hashimoto, H Irie, A Fujishima, Japanese Journal of Applied Physics, Vol. 44, No. 12, 8269-8285
2005 Value-added Textile Technology, S Islam, Textile Excellence J., Anniversary Issue, Jul. 3(1) 55-56
2005 Photocatalyst technology adds value to fabric, K Tagawa, Fabric Architechture, May
2005 Titanium dioxide photocatalysis: present situation and future approaches, A Fujishima, X Zhang, Elsevier, Feb 2, 750-760
2004 Enhancing Sorption Properties of Natural Fibrous Protein Substrates.   Part I: Absorption of malodorous gases, M Tsukada, H Katoh, S Islam, N Kasai, Text. J., 121(6) 48-50
2004 Antibiotic Silk Substrates for Healthcare, M Tsukada, G Shen, S Islam, Text. J. 121(5) 47-49
2003 Process of producing a titanium oxide-forming solution and a dispersion with crystalline titanium oxide particles, I Hiromichi, USP 6,602,918, Aug 5
2002 Photocatalytic body and method for making same, I Hiromichi, USP 6,429,169, Aug 6
1999 Suppression of Surface Recombination on TiO2 Anatase Photocatalysts in Aqueous Solutions Containing Alcohol, O A Semenikhin, V E Kazarinov, L Jiang, K Hashimoto, A Fujishima, American Chemical Society, May 06, 3731-3737
 
Picture Credit: courtesy of medilamp.com
 
Stay tuned. More to come....
 
Acknowledgements: TexTek Solutions :: MW Canada Material Innovations.  

সৌজন্যে: TexTek Solutions ::  Vision Creates Value
 

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ইমেইল:   shafiul_i@yahoo.com :: ওয়েবঃ textek.weebly.com :: Canada :: www.linkedin.com/in/shafiul2009     
সর্বশেষ আপডেট ( Wednesday, 08 February 2012 )

Green Engineering: Self-Cleaning NanoTechnology: http://biggani.com/content/view/1431/178/
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