Showing posts with label nanotechnology. Show all posts
Showing posts with label nanotechnology. Show all posts

Tuesday, September 23, 2014

Old wisdom new tools

Some of the shapes depicted in ancient artifacts 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 macroscale 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 theories with modern, 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. on the 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 scientists for several years. They were able to gain some insight into this in the recent past with the help of modern nanotechnological 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 outreach. Reverse engineering could help us understand its structure and shed some light into the properties of advanced hybrid materials. Maybe, 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.

Monday, May 28, 2012

Picture of Olympicene

AFM image of Olympicene molecule
Back in 2009, at the IBM Research lab scientists imaged, for the first time, the chemical structure of an individual molecule (pentacene) with unprecedented resolution, using technique they developed called noncontact atomic force microscopy. The same IBM team, has once again come up with an interesting image. This time they have imaged a new organic molecule, Olympicene.

Olympicene, gets its name because its five linked rings resemble the Olympic symbol. The compound is a powder, that is very sensitive to light. In fact, even with brief exposure it changes color. It is only 1.2 nanometers wide, or 100,000 times thinner than a human hair. This AFM technique could become a real structure-determination tool for organic chemist.