Tuesday, September 23, 2014

Old wisdom new tools

Some of the shapes depicted in ancient artefacts that were invisible to the human eye came into view with the advent of 20th century tools. Some being nano and microstructures. These tools also help chemists to see the formation of chemical bonds in real time.

The rapid development of modern nano-technological tools such as the Atomic Force Microscope (AFM), Scanning Tunnelling Microscope (STM) and Laser Scanning Confocal Microscope (LSCM) allow scientists to invent, explore and validate old scientific discoveries. From the perspective of scientists involved with chemistry, it helps to manipulate atoms and molecules precisely for the fabrication of macro scale products as well as to look at the real time covalent bond formation in a single molecule. Observing chemical reactions by force microscopy at sub molecular resolution has been reported by de Oteyza et al.  They reported  the atomically resolved imaging of a complex molecule as it undergoes a chemical reaction on a metal surface.

In addition to the normal covalent bond formation, very recently Wilson Ho et.al., revealed the image of hydrogen bonding in porphyrin molecules using chemically modified STM tip, enlightening  us with the rapid advance in this field. These developments will have a huge impact in nanoscience especially in the field of single molecular electronics and bottom up fabrications. This new evolution of molecular nanotechnology will bring chemists, physicists, engineers and biologists together.

How practical is it to prove old theoroes with morden, technologically advanced tools? Is it really possible? However, if it is indeed possible, would it be a landmark achievement that would push chemistry into a new era, in the coming years? Let me exemplify. Mayan blue is a bright blue pigment that had been used by Mayans about 2000 years ago to paint murals. The distinct feature about these murals is that the mayan-blue has withstood the wrath of weather over centuries, and refuse to fade even to this day. Whereas, on the other hand, even the most advanced of paints of today, tend to wear off after a couple of years of harsh weather and negligent maintenance. This is a phenomenon that has baffled the scientists for several years. They were able to gain some insight into this in the recent past with the help of modern nano technological tools. The Mayan dye is based on Indigo dye, which is trapped in a porous fame work of clay called palygorskite.  The silicate hull forms a protective layer around the dye molecules. This prevents the dye pigments from directly interacting with the forces of nature, and other interferences such as organic solvents, acid and alkali treatment etc.

             It is the mayan’s ingenuity at developing the pigments for mayan blue that has set them eons beyond out reach. Reverse engineering this could help us understand its structure and shed some light into the properties of advanced hybrid materials. May be, the day is not far off, when we are able to decode this chemical phenomenon and come up with commercial paints that will last forever.