538
M. Singh et al.
2.5.3 Grafting
In the grafting process, argon is used as the plasma-forming gas, and active plasma
species are created. These active species interact with the substrate surface and produce free radicals. When a monomer capable of forming covalent bonds with the
free radicals is introduced into the chamber, it reacts with the active plasma species
and gets grafted. Some classic examples of monomers used for grafting are acrylic
acid or allyl alcohol or allylamine.
2.5.4 Deposition or Plasma Polymerization
The deposition of polymer in the form of a thin film on a plasma-activated surface via
polymerisation of an organic monomer like CH 4 and CCl 4 is referred to as plasma
polymerisation. A complex monomer gas is introduced in the chamber to initiate the
process which is ionised by colliding plasma species. The monomer molecule thus
undergoes fragmentation in smaller species like ions, free radicals, metastable and
ultimately react with each other to combine or gets condensed and polymerised on
the substrate. The advantage of plasma polymerisation is that it creates cross-linked
polymers on the top layer with no repeat units (Nema and Jhala 2015; Sparavigna
2008).
3 Nanotechnology
The revolutionary lecture titled ‘There is Plenty of Room at the Bottom’, given by
Nobel laureate, physicist Richard Feynman on December 29, 1959, opened a new
door of experimentation to then-existing scientific methods and technologies. In that
lecture, he advocated that atoms can be manipulated at the nanoscale level, but it
was in 1980 that his visions were materialised into a new branch of science called
nanotechnology supported by years of substantiated research efforts. Nanotechnology is a branch of science that deals with particles within the dimensions of 100 nm
which can include nanoparticles, nanorods and nanotubes, nanowires, nanocages,
nanocrystals, nanofiber, thin films and all the other particles which fall under the
specified range (Vigneshwaran 2009). Broadly, a material can be considered as a
nanomaterial if it possesses properties different from the bulk form of the same
chemical constituent. The characteristics of nanoparticles which make them such a
sought after materials are as follows:
• They have small size but an extensive surface area and most of the interacting
atoms reside in the surface layer; thus the interparticle distance is minimal.
• They have a smaller energy band gap compared to bulk particles.
• They can have an amorphous or crystalline nature.
• Their surface is used as a carrier for liquid or gaseous agents.
M. Singh et al.
2.5.3 Grafting
In the grafting process, argon is used as the plasma-forming gas, and active plasma
species are created. These active species interact with the substrate surface and produce free radicals. When a monomer capable of forming covalent bonds with the
free radicals is introduced into the chamber, it reacts with the active plasma species
and gets grafted. Some classic examples of monomers used for grafting are acrylic
acid or allyl alcohol or allylamine.
2.5.4 Deposition or Plasma Polymerization
The deposition of polymer in the form of a thin film on a plasma-activated surface via
polymerisation of an organic monomer like CH 4 and CCl 4 is referred to as plasma
polymerisation. A complex monomer gas is introduced in the chamber to initiate the
process which is ionised by colliding plasma species. The monomer molecule thus
undergoes fragmentation in smaller species like ions, free radicals, metastable and
ultimately react with each other to combine or gets condensed and polymerised on
the substrate. The advantage of plasma polymerisation is that it creates cross-linked
polymers on the top layer with no repeat units (Nema and Jhala 2015; Sparavigna
2008).
3 Nanotechnology
The revolutionary lecture titled ‘There is Plenty of Room at the Bottom’, given by
Nobel laureate, physicist Richard Feynman on December 29, 1959, opened a new
door of experimentation to then-existing scientific methods and technologies. In that
lecture, he advocated that atoms can be manipulated at the nanoscale level, but it
was in 1980 that his visions were materialised into a new branch of science called
nanotechnology supported by years of substantiated research efforts. Nanotechnology is a branch of science that deals with particles within the dimensions of 100 nm
which can include nanoparticles, nanorods and nanotubes, nanowires, nanocages,
nanocrystals, nanofiber, thin films and all the other particles which fall under the
specified range (Vigneshwaran 2009). Broadly, a material can be considered as a
nanomaterial if it possesses properties different from the bulk form of the same
chemical constituent. The characteristics of nanoparticles which make them such a
sought after materials are as follows:
• They have small size but an extensive surface area and most of the interacting
atoms reside in the surface layer; thus the interparticle distance is minimal.
• They have a smaller energy band gap compared to bulk particles.
• They can have an amorphous or crystalline nature.
• Their surface is used as a carrier for liquid or gaseous agents.