Why Silver?

Since ancient times silver has been used as a maedicine as well as to accelerate the healing of wounds. Hippocrates, the "father of medicine", wrote that silver had beneficial healing and anti- disease properties. Ancient Phoenicians are supposed to have made the first use of silver. They used to store water, wine and vinegar in silver bottles to prevent spoiling. In the early 1900s people would put silver coins in milk bottles to prolong the freshness of milk. Silver was earlier used in the form of Silver Nitrate but it was later discontinued due to risk involved in causing blindness.

Now why silver imparts antibacterial properties?

Well, silver ions and silver compounds show a toxic effect on some bacetria, viruse, algae, fungi typicla of heavy metals like mercury or lead, but without the high toxicity to humans that are normally associated with these other materials. The germicidal effects of silver can kill many bacteria in vitro. The exact process of silver's germicidal effects is still not entirely understood, although theories exist. Oligodynamic effect is one of which explains the effect on micro-organisms but does not explain the antiviral effects.

The wide antibacterial properties of silver stem up from the chemical properties of its ionised form, Ag+. This ion forms strong molecular bonds with other substances used by bacteria to respire, such as molecules containing sulphur, nitrogen and oxygen. When the Ag+ ions form a complex with these molecules, they are rendered unusable by the bacteria, depriving them of necessary compounds and eventually leading to the bacteria's death.

Silver nitrate solution use continued, then was largely replaced by silver sulfadiazine cream (SSD cream), which had become the 'standard of care' for the antibacterial and antibiotic treatment of several burns until the late 1990s. Now, other options like silver coated dressings are used in addition to SSDs. Silver in the form of SSDs was used on a huge scale during the World War 1 before the advent of antibiotics.

Lately there have been many efforts to use silver as a broad spectrum antibacterial agent, some of them include using silver along with alginate or applying an electric field to enhance its antibacterial properties and many more.

People are now diving into the fields of nanotechnology since the last decade in order to increase the effectiveness, reactivity of silver and to enhance its properties as an antibacterial, antiviral, germicide and pesticide without causing any harmful effect on the Human race.

-Chinmaya Joshi.

Why Nano?

     Nanotechnology, which is sometimes shortened to "Nanotech", is defined as the research and technology involving the dimensions within 100 nanometres the aim of which is to created materials with new properties and functions associated with the small size as well as to enhance and improve the behaviour of materials in current devices. Researches in the fields of electronics, instrumentation, modern devices and apparatus finally boils down to the field of material sciences. The characteristics of nanomaterials can be surprisingly different from the same materials in their bulk form. This is because in nano dimensions, the laws of quantum physics and not of classical physics are valid. Insulating materials may become electrically conductive and insoluble materials soluble. In addition, features such as hardness, strength, toughness, durability may increase dramatically. Many of these characteristics are highly desirable for various products.

     One feature of the materials is that the smaller the particle gets, the higher the surface area is to the volume ratio. This means that the material in nano dimensions gets more reactive with other reagents as compared with the same material in bulk.

    Another important property of nanoparticles is the 'Quantum Confinement effects' shown by them. It is basically due to this effect that the electronic and the optical properties of the nanoparticles of same elements deviate substantially from their bulk form. It involves a lot of solid state physics relating to band-gap and blue-shift. We shall study them keeping silver and copper nanoparticles as our subject in some of the posts to come.

    The official definition of the US National Nanotechnology Initiative is that nanotechnology involves 'research and technology development at the atomic, molecular, or macromolecular levels, in the length scale of approximately 1 to 100 nm range, to provide a fundamental understanding of phenomena and materials at the nanoscale and to create and use structures, devices, and systems that have novel properties and functions because of their small and/or intermediate size' .

Hello World !

Hello World !

This is a blog dedicated to knowledge & applied knowledge in the vast field of Silver Nano Particles as well as Copper Nano Particles ! Our work, papers, research and related ongoing research can be found here.

by Chinmaya Joshi & Hemchandra Inamdar.