nano-chemistry-2017-keynote

7 / 21

Page 17
Notes:
Mater Sci Nanotechnol 2017 | Volume 1 Issue 2
allied
academies
Nanomaterials and Nanochemistry
November 29-30, 2017 | Atlanta, USA
International Conference on
We report synthesis of Au and Ag nanocolliods and
structured Au nanofluids that have been synthesized
by simple, green and one step methods. Both the methods#
one using a natural fibre like Jute, and other using an
excimer laser give rise to stable colloids with nanoparticles
diameters less than few tens of nanometers. In both the
methods no reducing agent and stabilizing agentor any
hazardous chemicals need be added or used and water is
the dispersing medium. The stability of the nanocolloids
and structured nanofluids has been tested for over a year
using absorbance by the metal plasmonic bands in the
dispersing medium as a monitoring tool. In case of the
Jute based synthesis of Ag nanocolliods, the surface of the
natural fibre jute that has nanosized pores, acts as a reaction
“vessel” on which the Ag nanoparticles are produced in-situ.
It utilizes α–cellulose present in the jute fibre as a reducing
agent of Ag salt and no extra chemicals need be added.
The resulting Ag nanoparticles have size dispersion within
the range 12-15nm. In case of laser based synthesis of Au
nanofluids, laser ablation of a gold coin by an excimer laser
(248 nm) created Au nanoparticles dispersed directly into
the liquid medium. No reducing agent/chemical is needed
for making the nanoparticles of average diameter ≈ 8-10 nm.
Interestingly, the resulting nanofluid can be made structured
(like a connected network of Au nanoparticles that make a
Au necklace) using ethylene glycol as the dispersing medium
instead of water. The method can also be used for making Ag
nanocolliods where an Ag target is used in place of Au target.
For application, we tested both the Ag and Au nanocolloids as
heat transport medium where they were used as nanofluids.
Both the nanofluids show enhanced thermal conduction
over that of the dispersing medium. This was tested using a
dynamic technique where the frequency dependence of the
thermal effusively can be tested and the enhancement of the
thermal conduction can be evaluated.
Speaker Biography
Prof. Raychaudhuri obtained his from IIT, Kanpur (1975) and Ph.D from Cornell
University (1980). He had post-doctoral experience at the Max Planck Institute (FKF),
Stuttgart as an Alexander von Humboldt Fellow (1980-1982). He served as the Director
and Distinguished Professor of S.N.Bose National Centre for Basic Sciences fromMarch
2006 to September 2014. Prior to joining the Centre in 2004 as a Senior Professor , he
worked as a Professor of Physics in Indian Institute Science (IISc), Bangalore from 1982
and as Director, National Physical Laboratory (NPL), New Delhi from 1997-2000.
e:
Arup Kumar Raychaudhuri
S N Bose National Centre for Basic Sciences, India
Novel green synthesis of gold and silver nanocolloids, and structured nanofluid
and enhanced thermal transport in them