Why Plasma Processing ?
Surface modification of textile/polymeric substrates is important for different industrial applications. Among the available surface modification techniques, plasma processing of textile is gaining area of research interest due its ecological and economical advantages over conventional chemical processing of textile substrates. High-value added product with new functionalities such as water/stain and oil repellency, permanent hydrophillicity, bio-compatibility, flame-retardancy, abrasion resistance, improvement in dyeing/printing and adhesion can be achieved by nano-scale surface engineering of fibre and fabric surface.
What is Plasma ?
Plasma, the fourth state of matter is partially-ionized gas containing a mixture of ions, electrons, neutral and excited molecules and photons. Matter within the universe is most commonly found in the form of plasma rather than solid, liquid or gas. This state of matter was first identified by Sir William Crookes in 1879, and named "plasma" by Irving Langmuir in 1928.
Different types of Plasmas
Plasma can be classified in various ways such as based on temperature, pressure inside the reactor and electric signal. On basis of temperature of the ions and electrons, and degree of ionization plasma can be classified in two ways (i) Hot plasma (ii) Cold plasma. There is (i) Atmospheric pressure plasma and (ii) Low pressure plasma when plasma is classified on basis of pressure. Also, plasma can be classified into A.C. and D.C. based on electric power sources used. Among the various plasmas, cold plasma can only be used for the textile modification. However, cold plasma processing at atmospheric pressure would be more promising compared to cold plasma processing at low pressure from the point of view of ease of operation and industrial application. In this category, atmospheric pressure glow discharge cold plasma is still relatively a new class of plasma and requires more attention to modify the surface of the textile uniformly and safely.
Challenges in Atmospheric Pressure Plasma Reaction
· Generation of glow plasma
o Over a large surface area
o In presence of liquid and gaseous precursors
· Carry out In-situ plasma reaction with textile substrates
· Achievement of durable functional finishes
· Carry out continuous plasma reaction
Current area of Research
The research group is working on textile modification using indigenously developed atmospheric pressure glow discharge cold plasma reactor. The reactor has also been modified for continuous treatment of textile substrates. Current research fields are hydrophobic to superhydrophobic finishing, improvement in hydrophilicity, adhesion, dyeability and printability of the textile materials.