This document summarizes research on using atmospheric pressure plasma treatment to remove impurities from gray cotton fabric. The plasma treatment physically modifies the cotton surface, etching away impurities like wax and making the surface more hydrophilic. Fourier transform infrared spectroscopy analysis showed the plasma treatment successfully removed alkyl groups from the surface and increased polar groups. Scanning electron microscopy images also showed the plasma-treated cotton had a smoother surface. The plasma treatment provides an environmentally friendly alternative to conventional wet scouring processes for cotton fabric pretreatment.

1. Ethiopian Institute of Textile and Fashion Technology (EiTEX)
Prepared By
Yekoye Tadele
Seminar on :Removal of impurities from gray cotton fabric by
atmospheric pressure plasma treatment and characterization using
ATR-FTIR spectroscopy.

2. Contents
 Introduction
 Plasma Treatment
 ATR-FTIR Characterization
 Exposed samples to the HCl vapor
 Wettability improvement
 SEM analysis
 Benefits of plasma treatment

3. INTRODUCTION
Cotton fiber is the most abundant, renewable, and biocompatible
polymer
Natural cotton fibers contain cellulose and non-cellulosic
constituents such as.
is the ‘king of textile’ fibers

4. These non-cellulosic components are mainly found at
the surface
This leads to some problems in quality of dyeing and
finishing in subsequent wet processing
Alkaline scouring is commonly used the removal of
impurities from cotton fabric by treating it with hot
sodium hydroxide solution.
hydrophobic characteristics Hydrophilic characteristics

5.  Conventional wet pre-treatment processes of textiles
are generally energy consuming process. It is not an
eco-friendly process
 Plasma modification of textiles saves large quantity of
water, chemicals, and electrical.
 Large savings are possible since the plasma process
does not produce large volumes of waste or toxic by
products.

6. Plasma Treatment
Plasma is known as the 4th state of matter b/c of the
unique physical properties.
Plasma is highly energetic partially ionized gases
consisting of ions, electrons and neutral particles.
These gases are produced by electrical discharges.
Plasma treatment of textiles is a surface treatment.
It is physico-chemical method of modifying the
surface of the polymer without changing the nature of
the bulk of the substrate.

8.  Gray cotton fabric is treated with air dielectric barrier discharge
at different time interval
 The surface of the component is etched with a reactive process
gas.
 Material from the surface is etched away, converted to the gas
phase and removed by the vacuum system.
 The surface area is greatly increased, raising the surface energy
and making the material easily wettable
Cont…

9. ATR-FTIR Characterization
Four samples are used Gray fabric , desized fabric ,scoured
fabric and plasma treated fabric
ATR-FTIR spectroscopy is a surface sensitive technique, since
the waxes and other impurities are located in outer most layers
of cotton fibers.
In spectrum of gray fabric, two distinguished peaks
corresponding to the symmetric and asymmetric stretching
mode of meth-ylene groups in long alkyl chain are clearly
visible at 2852.24 and 2917.81 cm-1

10. ATR-FTIR spectra of gray and chemically treated cotton
-CH2-groups from cellulose never give separate peaks
corresponding to the symmetric and asymmetric stretching
mode in ATR spectra of pure cellulose. Intensity of this peaks
indicates the amount of wax present on the fabric

11. ATR-FTIR spectra of gray and plasma treated cotton.

12. Untreated Acid desized Scoured Plasma treated Peak characterization
2956-3463 2956-3463 2956-3463 2956-3463 H-bonded OH stretch
2817-2979 2817-2979 2817-2979 2817-2979
C-H stretching
2917.81 2917.81 - - Asymmetric CH2 stretch
2852.24 2852.24 - - Symmetric CH2 stretch
1749.14 1749.14 - - C=O stretch in -COOH
Table 1 IR absorption bands of gray and treated fabrics.
Experimental peak obtained (cm-1)

13. At 1641 Wavenumber cm-1 (adsorbed H2O )
 In case of gray cotton: the band is completely disappeared
 In the case of Desized cotton : completely disappeared.
 In case of scoured cotton : clear peak is developed
 In case of plasma treated clear peak is developed (from 2-5 min)
At 1749Wavenumber cm-1
 Gray cotton : new peaks in FTIR spectrum is induced (ionized
carboxylate present in wax and pectin)
 Desized cotton : same as gray cotton
 Scour cotton : no peak induced
 Plasma treated cotton : strong peak is developed (This indicates
that plasma treatment is creating carbonyl functional groups
(COOH, COO- )
Exposed samples to the HCl vapor

14. ATR-FTIR spectra of gray and treated fabrics showing
new induced bands after exposure to HCl vapor

15. Samples Experimental peak obtained
after HCl vapor exposure
1641cm-1 1749 cm-1
Untreated gray cotton - Strong peak
Acid desized cotton - Strong peak
Scoured cotton Clear peak -
1 min plasma treated cotton - Relatively weak
2 min plasma treated cotton Clear peak Very weak
5 min plasma treated cotton Clear peak Strong peak
Table 2. Experimental peak obtained in ATR-FTIR spectra of HCl
vapor exposed fabrics

16. Improvement in wettability after plasma treatment,
(a) untreated fabric and (b) plasma treated fabric (treatment
time: 5 min).
Wettability increase after plasma treatment due to
Removal of no-cellulosic material
Formation of polar groups
Wettability improvement

17. SEM analysis
Non-uniform with ridges
and groves.
 Relatively smooth (present
of cuticular wax)
Parallel cellulose micro fibrils
Similar to secondary wall of cellulose fibers

18. Benefits of plasma treatment
Better performance
Cost effective (saves water, chemical and energy)
Environmentally and workplace safe
Conventional wet treatment processes:
 Energy consuming
 Effluent load

19. References
1. Plasma Technologies for Textiles 1st Edition (wood head
publishing)
2. Chemical Technology In The Pretreatment Process Of Textile
by s.KARMAKAR
3. The removal of impurities from gray cotton fabric by
atmospheric pressure plasma treatment and its characterization
using ATR-FTIR spectroscopy.
4. Abidi N. and Hequet E., Cotton Graft Copolymerization Using
Microwave Plasma. I. Universal ATR-FTIR Study, J. Appl
Polym Sci., 93, 145-154, (2004).