Friday, December 29, 2006

Nanotechnology For Coating

In coating industry, nanotechnology are increasingly being viewed as next generation effective method. Whether it is abrasion or problems due to uv light- nanomodified paints have shown great potential in overcoming this problems. Nanotechnology, deals with subatomic structures having dimensions in nanometer scale (0.1-100nm). In other words, nanotechnology is a scientific tool for developing materials by controlling atoms and molecules.

Some of the unique properties of nanoparticles are:
- Sizes of nanoparticles are smaller than wavelength of visible light.
- Vander wall force, electron resistance force and magnetic force are more dominant than gravitational force.
- The surface-to-volume ratio of nanoparticles makes modification in nanoparticles possible.
- It is Chemical and heat resistant.

NANOTECHNOLOGY IN THE COATING INDUSTRY
The coating industry is showing signs of growth globally. Today, Coating not only serve the purpose of beautification but are also a mean of protecting valuable metals from corrosion. Hence, nowadays more money is invested in research and development sector.

In coating industry ,Nanocoating can be applied in many ways by procedures such as chemical vapour phase deposition, physical vapour phase deposition, electrochemical deposition, sol-gel methods, electro-spark deposition, and laser beam surface treatment. The appearance and usefulness of nanoparticles have brought about several advantages and oppurtuinities to the paints and coating industry.

Some of the advantages of nanotechnology include
- Better surface appearance.
- Good chemical resistance.
- Anti-reflective in nature.
- Good adherence on different type of materials.
- Optical clarity.
USE OF NANOCOATING
Nanotechnology has been used to for coating of automotive engines, aircraft engines, cutting and machine tools, and equipment for manufacturing ceramic parts.

Self Cleaning Window Glass Products
Two major glass manufactures, Pilkington and PPG, have come out with self-cleaning window glass products with a surface layer of nanoscale titanium dioxide particles. The self cleaning window glass product is uses the property of UV rays in sunlight When the particles interact with ultraviolet rays in sunlight it starts loosing dirt and with water, UV rays distributes dirt evenly across the surface. As a result, most dirt gets washed off easily without streaking whenever it rains.

Making use of hydrophobic and oil repellent property of nanoparticles
When nanoparticles is coated on surface of water or other solvents, the surface area of water increases, and hence, decreases the surface tensions of a surface. E.g. DELETUM 3000TM, a unique paint, which has oil and water repellency, impressive scratch and UV resistance could be used on stone, brick, mortar, glass, plastics and other materials, as well as the potential application in clean rooms, surgery facilities and a number of forensic needs.

Use of Nanoparticles for high performance coating
When Nanoparticles are produced by standard synthesis methods such as sol-gel route. They leave number of either unreacted or still- active chemical groups on their surfaces that can be used for various chemical reactions. In other words, nanotechnology is used to create and arrange nanopigments by altering electric field due to which paints change its colour as a function of voltage. Using this method, research group at Universidad Nacional Autónoma de México has produced nanobiomaterials. Nanobiomaterial are nanoparticles for metal ion removal in polluted water. It is also used for coating purpose, which provides protection ranging from anti-corrosion, anti-staining of pure silver objects, caries-resistance for human teeth, etc.

Nanopowders
Nanopowders that are made by using nanotechnology are currently used to manufacture a wide variety of products such as engine components, electronic devices, cosmetics, machining tools, medical/surgical instruments, nutraceuticals, paints, coatings, optics, magnetic devices, semiconductors, and graphitic parts. The manufacture of these involves grinding common, safe inorganic compounds such as zinc oxide (used in sunscreens) into a powder of ultra fine nanoparticles.

Future of nanotechnology
Nanotechnology is going to bring the current technology to a new height. . Computers will compute faster, materials will become stronger, and medicine will cure more diseases. Nanotechnology, which works on the nanometer scale of molecules and atoms, will be a large part of this future, enabling great improvements in all these fields. Advanced nanotechnology will work with molecular precision, making a wide range of products that are impossible to make today. For example nanoparticles can be used to produce hybrid coating that will provide coating systems, which can withstand various environment impacts.

Conclusion
Nanotechnology is going to uplift coating industry to new level. Its useful properties like corrosion resistance, UV stability, gloss retention, chemical and mechanical can be used for modification of product in required pattern. However, nanocoatings also have some limitations, like agglomeration of nanoparticles, hardening of ultra fine particles, etc. but the benefits of nanocoating definitely out-weigh its drawbacks.