Playing with the matter at a scale closes to the fundamental building blocks of itself, is at the heart of nanotechnology. Such incredibly complex and often expensive game would however, is often bountiful. Today’s material scientist are equipped to see the nanoscale with microscopes that even can literally count the atoms of a particle. We have developed instruments so powerful that we just have to press a button to move an atom from one place to another. With these tools available to us we have created faster computers, more effective drugs, stronger composites, amazing surfaces and many other wonderful things. However, our generation was not alone on this nanotechnology quest. Hundreds, or sometimes thousands years ago, wonderers, thinkers and master craftsmen from around the world were equally intrigued by the amazing properties of the nanoscale materials. Most of them didn’t have any more than few cups, mortar and a pestle and a wood stove to start with. Yet they have created most amazing of the things with ingenious methods and techniques that still grabs the attention of the general public and material scientists, alike.
Probably most of you may know about this 4th century work of art done by Romans already. That is because if there is “anything” that has been given a special attention due to ingenious ways that ancient craftsmen blended their imagination and technical skill to make work of art, that would be the Lycurgus cup. At the time and many more years to come, Lycurgus cup remained as the most spectacular glass object that man has invented. The amazing feature of the Lycurgus cup is that it shows different colors depending on whether the cup is lit from behind or from front. When the cup is lit from the front side, the cup displays a green color, and when lit from the back, cup shows a brilliant red color.
This strange optical effect in the Lycurgus cup is identified as a result of nanoparticles of gold and silver in the glass matrix. However, the process in which, Romans have produced this glass is still not known. The metallic nanoparticles produce different colors due to absorption of visible light at specific wavelengths. The metal type, particle size and particle shape play an important role in determining the color of the nanoparticle suspension. It’s usually believed that Romans have most likely produced these glasses as a result of a contamination.
Damascus steel is a type of high strength steel that was popular in sword making especially in 400 BC. The Damascus steel was primarily produced from a type of a special steel exported from countries like Sri Lanka and India at the time. The blades that are forged with the Damascus steel show distinctive wave like patterns that resembles the flowing of the water. Damascus steel was the most perfect steel for sword making at the time, providing a tough, shatter resistance blade that is can easily be refined in to a sharp resilient edge.
In year 2006, group of German scientists reported that the Damascus steel contains carbon nanowires and carbon nanotubes and play a major part in the properties of the material. It’s believed that the biomass used in the furnace has left carbon precursor materials trapped in the matrix of the steel during the special smelting process used in production of the steel. During further forging and working of the material, these precursors were converted in to carbon nanotubes producing a type of a steel was the state of the art at the time.
Nanoparticles in Roman hair dyes
Group of researchers at French state museum agency’s center for research and restoration, published an article on Nano Letters, on a rather surprising finding that they have made with hair dye recipes of ancient Greek and Roman times. When they have recreated these recipes and soaked small amount of blond human hair in the solution for three days and observed that the hair becomes progressively black with the treatment. Then they investigated the reason for this black color. Surprisingly, the hair dye formulation has led to formation of 5 nm size lead sulfide crystals that were diffused in to the hair fiber to produce the thick black color. Although this is another great example for roman nanotechnology, many experts agree that the phenomenon was not well understood or controlled by the romans at that time.
Nanoparticles in Ayurveda medicine
Recent investigations on composition of the special type of Ayurveda treatment so called “Bashma” revealed that it actually contain nanoparticles of metals including gold, silver, iron and mercury. The presence of gold nanoparticles in the size range of 50- 60 nm was found in a special Bashma called “Swarna Bashma” where Swarna means gold. The most famous of these findings were made by an Australian chemist, Christopher L Brown, who investigated composition of ancient Indian medicine. Effectiveness of Bashma treatments are scientifically proven and still being used very actively in many parts of south east Asia. For thousands of years, formulations of Ayurvedic agents and their therapeutic effectiveness, has stood the test of time.
Bashma is used in Ayurveda medicine for treatment of number of diseases for past several centuries. The key ingredient of Bashma formulation is metal and during the preparation of the medicine, the metal is converted in to the therapeutically active form. The process of this conversation include, repeated grinding and incineration and reactions with herbal juices.
Cathedral Stained Glass
Artists and glass craftsmen from the medieval era in the Europe discovered that if a metallic salt is incorporated in to the glass forming precursors to prepare molten glass, a characteristic color could be obtained. Stained glass developed in this way prevailed throughout the history and has been used almost exclusively for the decoration of windows of churches, mosques and other places with commercial or political significance.
The most common colors include, green, blue, red, yellow, purple and white which were majorly prepared using chromium, nickel, gold, silver, manganese and tin, respectively. Scientists who have investigated these stained glass objects have found the presence of nanoscale metals or metal oxide particles that produce colors due to localize Plasmon absorption phenomena.