Sunday, 21 January 2018
Official website of Calicut University


Print E-mail

      We Practice Green Chemistry


Welcome to the academic homepage of

Dr. Poovathinthodiyil Raveendran

Reader, Department of Chemistry, University of calicut, Calicut University PO, Kerala - 673635


Academic Profile


Ph. D. (1998) Indian Institute of Technology, Madras, India


M. Sc. (1989) University of Calicut, Kerala, India

Honors and Awards


1.   National Merit Scholarship, Government of India (1982 - 1987).

2.   Kumara Pillai Memorial Scholarship, Government of Kerala (1987 - 1989)

3.   Junior Research Fellowship, Council for Scientific and Industrial Research (CSIR),

Govt. of India

4.   Senior Research Fellowship, Council for Scientific and Industrial Research (CSIR),

Govt. of India.

5.  Visiting Post-doctoral Fellowship, Suhm Group, Institut fur Physikalische Chemie, University of Gottingen, Germany (1999)

6.   NSF-STC Post-doctoral Fellowship, The University of North Carolina, Chapel Hill, USA

7.   JSPS and CREST (Core Research in Evolutional Science and Technology) Fellowships (2003 onwards)

Current Research Interests

            Basically, I am an experimental physical chemist. My broad area of interest of research is “green chemistry” and molecular sociology-exploring intermolecular interactions from gas phase to condensed phase- and understanding their importance in molecular self assembly, solvation, in the hierarchical design materials, and in pharmaceutical sciences. I try to combine the merits of computational and experimental approaches for the design and development of environmentally benign materials and processes. In the past several years, I was fascinated by the principled stance for an environmentally friendly and sustainable chemistry. It is high time to integrate the principles of green chemistry with every activity in the academia and chemical industry. In fact, we need to introduce a systematic greenness evaluation into the scheme of chemistry for a sustainable future. Some of my current research interests are:

1.      Design of low cost, environmentally benign materials with high solubility in liquid and supercritical CO2: Miscibility and dissolution of materials in liquid and supercritical CO2 (scCO2) has gained considerable attention in the recent past due to the advantages of CO2 over conventional organic solvents and the potential ‘green chemistry’ applications. CO2 is regarded as an environmentally benign solvent because of its non-toxicity, but more importantly, it is an excellent choice as a solvent due to the ease of solvent removal, its abundance, low cost, and tunability of solvent parameters. The low solubility of the majority of polar and ionic materials has, however, been a serious limitation in expanding the possibilities of this solvent system.  Thus, the fundamental principles for the design of CO2-philic molecules including amphiphiles have attracted great interest, and different molecular level approaches have been used to ‘CO2-philize’ compounds that are otherwise insoluble in CO2. The possibility of incorporating CO2-philic functionalities or molecular fragments into CO2-insoluble molecular systems has been explored successfully to dissolve those systems in CO2. By judiciously selecting the CO2-phobic molecular unit one can design surfactants for the CO2/water as well as CO2/organic interfaces which would enable the formation of water-in-CO2 as well as organic- in-CO2 microemulsions. This would allow the phase transfer of polar compounds into the CO2-phase. Also one can design CO2-soluble metal chelating agents, dyes, and other functional CO2-philes, which can be utilized in scCO2 for a range of applications (Please see the figure below).


So far the most widely used CO2-philic molecular units are fluorocarbons owing to the high miscibility of these compounds in CO2. However, fluorocarbons are expensive and the use of these CO2-philes is not industrially viable in most applications. Thus there is a need to develop novel molecular approaches to synthesize inexpensive, non-fluorous, and environmentally benign CO2-philes for utilization in liquid or scCO2.

2.   Solvation phenomena in supercritical CO2: Supercritical carbon dioxide (scCO2) is increasingly promoted as an environmentally benign alternative to conventional organic solvents. The supercritical state bridges the gap between liquid and gaseous states by offering gas-like diffusion rates and liquid-like solvent densities, thereby enabling potential opportunities as a reaction and separation medium in chemical industry. Understanding the solvent behavior of liquid and scCO2 is of critical importance to enable the design of CO2-philic molecular systems and expand the use of these solvent systems to a wider range of chemical processes. Historically CO2 was treated as a non-polar solvent, primarily due to its low dielectric constant and zero molecular dipole moment. CO2 has also been described as a quadrupolar solvent due to its significant quadrupole moment. Recent studies suggest that as far as the microscopic solvent behavior of CO2 is concerned, CO2 has the potential to act as both as a weak Lewis acid and Lewis base.   Also, theoretical and experimental evidence indicates that CO2 can participate in conventional or non-conventional hydrogen bonding interactions. All of these site-specific solute-solvent interactions are important to understand the fundamental nature of CO2 as a solvent.

3.      Green Synthesis of metal and semiconductor nanoparticles: With the asymptotic growth in the research in nanotechnology and nanosciences, there is a current interest to integrate the principles of green chemistry with the various stages of nanotechnology research including their choice, method of synthesis, choice of solvent and the mode of their stabilization. Also of importance are environmentally friendly strategies for the development of organized, functional nanosystems. There are several key issues in this area that needs to be addressed. We focus on the use of non-toxic, renewable materials, clean solvents (water and CO2) as well as template free self-assembly.

Research Highlights

The following are some of the highlights in media about my previous research.

1.      Dissolving Sugar in CO2. Editors Choice, Science, June 21, 2002

2.      New Supercritical CO2 solute is sweet! Research News,, ACS, 2002

3.      Totally green nanoparticle synthesis, Chemical & Engg. News (ACS), Nov. 10 (2003), p 44

4.      Nanoparticles the green way, Materials Today (Elsevier), Jan 2004 issue.


6.      Green technique makes silver nanoparticles Nanotechweb:

7.      CO2 used to Process carbs, Chemical & Engg. News (ACS), March 14 issue, 2005.

List of Publications


  1. P. Raveendran, N. Sukumar & T. K. K. Srinivasan. Temperature dependence of phonon-assisted excitation probability in GdTb(MoO4)3: Evidence for change in electron-lattice coupling near a structural phase transition. Phys. Rev.B (1997), 55, 4978.
  2. P. Raveendran, D. Zimmermann, Th. Haber, & M. A. Suhm.  Exploring a hydrogen-bond terminus: spectroscopy of eucalyptol-alcohol clusters.  Phys. Chem. Chem. Phys. (2000), 2, 3555.
  3. P. Raveendran, B. K. Sadashiva, K. V. G. K.Murty, & T. K. K. Srinivasan. FT-IR and FT-Raman spectroscopic studies of 1-(p-n-alkyl phenyl) 3-(p-n-alkyloxyphenyl) propane 1,3-diones. Mol. Cryst. Liq. Cryst. (2001), 363, 19.
  4. P. Raveendran & S. L. Wallen. Sugar Acetates as Novel, Renewable CO2-philes. J. Am. Chem. Soc. (2002), 124, 7274. (This was highlighted in Science (June 21, 2002) as the Editor’s Choice and later in the Chemistry research news of Am. Chem. Soc.).
  5. P. Raveendran & S. L. Wallen. Cooperative C-H···O hydrogen bonding in CO2- Lewis Base Complexes: Implications for Solvation in Liquid and Supercritical CO2. J. Am. Chem. Soc. (2002), 124, 12590.
  6. M. A. Blatchford, P. Raveendran & S. L. Wallen. Raman Spectroscopic Evidence for Cooperative C-H···O interaction in CO2- Acetaldehyde Complex. J. Am. Chem. Soc. (2002), 124, 14818.
  7. P. Raveendran & S. L. Wallen. Exploring CO2-philicity: Effects of Stepwise Fluorination. J. Phys. Chem. B. (2003), 107, 1473.
  8. P. Raveendran, Jie Fu & S. L. Wallen. Completely “green” synthesis and stabilization of metal nanoparticles. J. Am. Chem. Soc. (2003), 125, 13940-41.  (This work was highlighted in C & E News, Materials Today and on Nanotechnologyweb).
  9. P. Raveendran & S. L. Wallen. (Invited Article), Dissolving Carbohydrates in supercritical CO2 (2002), Am. Chem. Soc. Symp. Ser. Ed. K. Gopalan & C. Wai, (2003).
  10. M. A. Blatchford, P. Raveendran & S. L. Wallen. Spectroscopic Evidence for Cooperative C-H···O Interaction in model Acetate-CO2 complexes. J. Phys. Chem A (2003), 107, 10311.
  11. M. Kanakubo, T. Umecky, P. Raveendran, T. Ebina, & Y. Ikushima. High Pressure 19F NMR Measurements of a Series of Fluorinated Benzenes in Supercritical Carbon Dioxide. J. Sol. Chem. (2004), 33, 863.
  12. J. Liu, P. Raveendran, Z. Shervani & Y. Ikushima. Synthesis of Ag2S quantum dots in water-in-CO2 microemulsions. Chem. Commun. (2004), 2582.
  13. J. Liu, Z. Shervani, P. Raveendran & Y. Ikushima. Micellization of sodium bis (2-ethylhexyl) sulfosccinate in supercritical CO2 with fluorinated co-surfactant and its solubilization of hydrophilic species. J. Supercrit. Fluids. (2004), 33, 121.
  14. J. C. Liu, P. Raveendran, Z. Shervani, and Y. Ikushima. (2004) Synthesis of metal nanoparticles in water-in-CO2 reverse microemulsions using AOT as the surfactant. Chem. Euro. J. (2005), 11, 1854.
  15. P. Raveendran,* M. A. Blatchford, M. L. Hurrey, P. S. White, S. L. Wallen. Crystallization and processing of carbohydrates using supercritical CO2. Green Chemistry (2005), 7, 129. (This work was highlighted in Chemical & Engg. News).
  16. P. Raveendran,* J. C. Liu & Y. Ikushima. Material processing using supercritical CO2: From soft materials to metal quantum dots. Proceedings of the International Symposium on Advanced Materials and Processing, ISAMAP2K4, Indian Institute of Technology, Kharagpur India, December 2004.
  17. J. Liu, P. Raveendran and Y. Ikushima. Self-assembly of b-D-glucose stabilized Pt nanoparticles into nanowirelike structures. Chem. Commun.(2005), 2972.
  18. P. Raveendran, S. L. Wallen & Y. Ikushima, The polar attributes of supercritical CO2. Acc. Chem. Res. (2005), 38, 478.
  19. B. Chandrika, L. Schoenbachler, P. Raveendran,* S. L. Wallen (2005) High Resolution NMR Studies of sucrose octaacetate in supercritical CO2. Chem. Euro. J. (2005), 11, 6266-6271.


  1. P. Raveendran*. Nobel Prize for green Chemistry: Stance for a future. Current Science, (2005), Dec 10 issue.


  1. Y. Ikushima, J. Liu, and P. Raveendran, Synthesis of crystalline quantum dots in AOT-stabilized water-in-CO2 microemulsions. Studies in Surface Science and Catalysis (2006), 159, 729-732.
  2. J. Liu, G. W. Qin, P. Raveendran, Y. Ikushima. A facile and green synthesis, characterization, and catalytic function of b-D-glucose stabilized Au nanocrystals. Chem. Euro. J. (2006), 12, 2131-2138.
  3. P. Raveendran,* A. Goyal, M. A. Blatchford, & S. L. Wallen. Stabilization and growth of silver nanocrystals in dendritic polyol dispersions, Mater. Lett. (2006), 60, 897-900.
  4. P. Raveendran,* Jie Fu & S. L. Wallen. A simple and green method for the synthesis of Au, Ag, and AuAg nanoparticles. Green Chemistry (2006), 8, 34-38.
  5. M. Chatterjee, A. Chatterjee, P. Raveendran, Y. Ikushima. Hydrogenation of citral in supercritical CO2 using a heterogeneous Ni(II) catalyst. Green Chemistry (2006), 445-449.
  6. G. W. Qin, J. Liu, T. Balaji, X. Xu, H. Matsunaga, Y. Hakuta, L. Zuo, and P. Raveendran*. A Facile, Template-free Method for the Preparation of Mesoporous Gold Sponge and Size Control. J Phys. Chem. C. 2008, 112, 10352-10358.

Research Group:

            Graduate Students:

            Bindu Unnikrishnan

            Undergraduate Students:

            Vinayak Jagdeesh

Research Experience

1.         CSIR Research Associate, Regional Sophisticated Instrumentation Center, IIT Madras (Mentor: Prof. P. T. Manoharan), 1998.

2.         Visiting Post-doctoral Scientist, Insitut für Physikalische Chemie (DFG), University of Göttingen, Germany (1999).

            Research Group Leader: Professor Martin A. Suhm

3.         NSF-STC Post-doctoral Research Associate, Department of Chemistry and NSF Science & Technology Center for Environmentally Responsible Solvents and Processes, The University of North Carolina, Chapel Hill, USA (2000-2003).

            Research Group Leader: Professor Scott L. Wallen

      Area of Research: Enabling Green Chemistry in Liquid and Supercritical Carbon Dioxide: Design of CO2-philic materials.

4.                  Foreign Researcher of the Japan Science & Technology Corporation (JST) under the Core Research in Evolution Science & Technology (CREST) program, JSPS Fellow, and Staff (May 2003-Dec 2005), Supercritical Fluid Research Center, National Institute of Advanced Industrial Science and Technology, Sendai, JAPAN.

Program Director: Professor Yutaka Ikushima

5.         Reader, Department of Chemistry, University of Calicut (December 2005 onwards)


Green Chemistry Links


    1. Green Chemistry Institute.
    2. Green and Sustainable Chemistry Network, Japan
    3. Green Chemistry Network
    4. Canadian Green Chemistry network
    5. NSF STC for Environmentally Responsible Solvents and Processes
    6. Clean Technology Group
    7. Green Chemistry Journal