My work

Some of you asked me to write about my research. Let me begin with a famous quote from Einstein..

You do not really understand something unless you can explain it to your grandmother.

So, I need to do a lot more of explanation or I better dont write anything at all.

I worked for my Ph.D. on a hot area called 'conducting polymers' (CP). We know that polymers (platics, as we generally know) are bad conductors of electricity; but the CPs belong to 'speciality polymers'. This field is younger than me (the inventors won the Nobel Prize in 2000); one important invention in 1990 was that some of the CPs can be used to generate light when a voltage is applied (just like LEDs). That was one major breakthrough in terms of a huge potential for applications. What are they rivals to? Pretty much anything to do with lighting and colors..

Display technology is one area where they have already been brought in the market. Flat-panelled displays based on liquid crystals (LCDs as we call) can be potentially be replaced by these light-emitting polymers. Advantages? Plenty - light weight, flexibility and processability - to name a few. Imagine how it would be to have a roll of plastics which, when you plug in, will light an entire room.. or laptops with flexible display monitors. Also, unlike LCDs where you have to watch the screen straight (due to 'polarized' light), the displays from polymers would emit light in all directions.. so thats a huge plus too.

One important criterion was to be able to access all the colors required for making a complete display. Visible light has VIBGYOR of colors of which B, G and R are called 'primary colors' bcos you can get all the colors (from black to white) by suitably mixing the three of them. Initial work all over the world in this 'color control' showed that you can access them by using different polymers, each of which has a unique 'band gap', which can be explained as

Color --> A certain energy --> Energy gap --> Chemical structure.

Leaves are green bcos they have certain chemicals with the suitable energy gap (such chemicals are called 'chromophores') whereas carrot is red bcos it has a different chromophore which absorb the sunlight differently. All the things I have said so far form the introduction to my work.My work was to get all these different chromophores in different ratios in the same polymer chains so that it would be possible to fine-tune the color of light emitted. One rule of thumb is that as you increase the length of the chromophore, it tends to absorb/emit light towards the right side of the 'VIBGYOR' spectrum.

So, I prepared a series of polymers with different populations of the 'differently long' chromophores. How different? Statistics helped me in that. My chemistry was such that, according to purely random statistical probability, when I populate my polymer with more and more chromophores, their length also tend to increase. And all the polymers could be made to dissolve in a lot of solvents and cast into films. I used to be proud that time that 'We were the first in the world to prepare soluble conducting polymers with different populations of chromophores'. Those polymes emitted blue, green, yellow, orange and red colors, as we expected.

As a chemist, I improved my own method of making the polymers and studied various properties of all of them. We published it in a reputed journal and a lot of research groups in the world were interested in studying our polymers by different physical techniques. That helped in some collaborations by which my polymers flew from one continent to other and gave some interesting results and publications to me.

PS: I wrote this post in the 'first person' mode bcos you people know only me; but my research supervisor was the brain behind all of my work, so, convert I, my etc. to we, our, etc.