26-03-2012, 02:36 PM
NANO POLYMERS
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INTRODUCTION
The important development due to advancements in Polymer technologies are the production of Nano polymers.
Particles having sizes less than 100nm are generally called Nanoparticles. These have strikingly different properties due to their small sizes and thus are found useful in many applications.
Nanopolymers in simple words are nanostructured polymers. The nanostructure determines important modifications in the intrinsic properties
Polymers are produced by the process of polymerisation.
PROPERTIES OF NANO POLYMERS
The flow induced alignment of nanotubes in a polymer matrix can lead to preferential orientation of the tubes, into either ribbion fibres. Raman spectroscopy is able to determine the degree of shear orientation and the polarization direction of the nanotubes.
The nanofilms show considerable reinforcement when subjected to small deformations, where as at high elongations, the rheology approaches that of the pure nanolatex form.
Vapour condensation process
This process is used to make the metal oxide ceramic nanopolymers.
It involves Vapouration of solid metal followed by rapid condensation to form nano-sized clusters.
Various approaches to Vapourize the metal can be used and variation of the medium in which the Vapour is released affects the size of the particles.
Inert gases are used to avoid oxygen while creating nanopolymers, where as the reactive oxygen is used to produce metal oxide ceramic products.
Electro-spinning method
PRINCIPLE: In the electro-spinning process, the fibres are spun under a high voltage electrical field. A polymer solution is contained in a syringe, which is equipped with a piston and a stainless steel capillary serving as an electrode. A grounded counter electrode (round metal plate at the bottom) is placed down the capillary and a high voltage is applied between the capillary and the counter electrode.