Microwave Chemistry

Green chemistry is designed to carry out chemical reactions in an environmentally friendly fashion that consume less chemicals and generate less waste. In some cases more toxic chemicals are replaced by relatively benign ones. In its simplest form, by reducing the use of chemicals we generate fewer pollutants, and by reducing energy requirements we generate less green house emissions.  The overall benefits besides environmental protection can also be saving in money.

Let us take the example of energy, typically heating in chemistry laboratory experiments are carried out using a heating mantle or a burner. To heat the desired chemical/reagents, the heat has to pass through a solid and a liquid medium. As result, besides slow transmission of heat, much of the energy is wasted. During microwave heating such as in the ones carried out in our kitchens, the heating is carried out in-situ almost at molecular levels. Under microwave radiation, some of the molecules are set to rotate and vibrate preferentially and friction generates the heat. Consequently, a cup of tea that may 15+ minute in a regular stove can now be made within 30 sec to a minute. The bulk of the cup is not heated either.

Chemistry under microwave radiation is known to be somewhat different, faster and more efficient than under conventional chemical processing conditions.  Microwave processing also reduces the need for solvents, thus it is eco-friendly. It can be exploited in a variety of organic and inorganic reactions. Some of the advantages are rapid reactions and high purity products. Both energy saving and pollution prevention in terms of savings in chemicals can be significant. Almost analogous to making the fast cup of tea. Our group has been working on microwave based nanotechnology for the last five years. For example, in some of his research shows that reactions that take as long as 2 days can be completed in 10-20 min; leading to significant savings in energy. Some publications from our group are listed below. 

A major objective of this project is to identify microwave-based alternatives to laboratory experiments that can be used in teaching laboratories in colleges and in high schools. The specific goal will be to point out the energy savings as well as the prevention of the pollutants. This will allow us to demonstrate to the students early in their career that the energy and material savings from green chemistry has great environmental value.  We expect that such ideas learned early will become part of the chemistry knowledge base for the students and will be useful no matter what career they eventually practice.

1.            We plan to set up microwave based chemistry experiments in the NJIT freshman chemistry program. We will also encourage and promote high schools to do the same. We propose to carry out microwave-based experiments in side by side with classical chemical approaches so students can quantify the differences in energy and material consumption “Rapid, low temperature microwave synthesis of novel carbon nanotube- ceramic composite”. Yubing Wang, Zafar Iqbal and Somenath Mitra. 44, 2804-2808, Carbon, (2006).

Publications On Microwave Processes from Our group:

1. Sample Preparation Techniques in Analytical Chemistry: Edited by Somenath Mitra. John Wiley and Sons, New York; (2003). Chapter 2 and 5.

2.      “Microwave Induced Rapid Nanocomposite Synthesis Using Dispersed Single Wall Carbon Nanotubes as the Building Blocks”. Subhendu Ray Chowdhury, Yuhong Chen, Yubing Wang and Somenath Mitra. In Press, J. Mater. Chem., 2008.

3.      “Fast microwave-assisted purification, functionalization and dispersion of multi-walled carbon nanotubes”. Yuhong Chen and Somenath Mitra. In Press, Nano. Sci. Tech.  (2008).

4.      “Microwave assisted purification of Single-walled carbon nanotubes without sidewall functionalization”. Yuhong Chen, Zafar Iqbal and Somenath Mitra,  Adv. Func. Matl. In Press (2008).

5.      “Rapidly functionalized and highly water-soluble carbon nanotubes”. Yubing Wang, Zafar Iqbal and Somenath Mitra.  Journal of Am. Chem. Soc.  43 1015-1020, (2006)

6.      “Microwave-induced rapid chemical functionalization of single-walled carbon nanotubes.” Yubing Wang, Zafar Iqbal and Somenath Mitra. Carbon, 43 1015-1020, (2005).