CHAPTER 5 DEVELOPMENT OF ANTIMICROBIAL PLAIN WEAVE …shodhganga.inflibnet.ac.in/bitstream/10603/10382/10... · 150 CHAPTER 5 DEVELOPMENT OF ANTIMICROBIAL PLAIN WEAVE COTTON FABRICS

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CHAPTER 5

DEVELOPMENT OF ANTIMICROBIAL PLAIN WEAVE

COTTON FABRICS BY MICROENCAPSULATION AND

NANOENCAPSULATION METHODS

5.1 INTRODUCTION

The nano particles were synthesized, characterized, finished on

cotton fabric and its antibacterial activity was assessed. Since the fabric

finished with the zinc and copper nano particles did not show antibacterial

activity up on washing, the nano particles were now finished by techniques in

such a way to increase the durability. The techniques adopted to increase the

antimicrobial activity were microencapsulation and nanoencapsulation. The

zinc and copper oxide nano particles synthesized by wet chemical method

were used for microencapsulation and nanoencapsulation. The methodology

adopted, results obtained and the relevant figures in support of the results are

presented in this session.

5.2 MICROENCAPSULATION

Functional textiles are being developed in order to provide fabrics

with new properties and added value. They can be obtained either by using

new chemical fibers or by incorporating functional agents to conventional

fabrics. Microencapsulation is an effective method to protect these functional

agents from reactions with moisture, light and oxygen. The synthesized nano

particles were microencapsulated by ionic gelation method using calcium

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alginate as the wall material. The nano particle solution was mixed with

sodium alginate and sprayed into calcium chloride solution. The capsules

were then retained in calcium chloride solution and then washed with iso

propyl alcohol and then dried. The dried microcapsules were then used for

finishing the cotton fabrics.

5.2.1 Microscopic Examination of the Microcapsules

The synthesized microcapsules were viewed under light microscope

at 400 X magnification to determine the structure of the capsules. The

following figure 5.1shows the microscopic view of the microcapsules

synthesized from the nano particles.

Figure 5.1 Microscopic view of microcapsules (400 X magnification)

From the above figure, it was clear the microcapsules were of

uniform size and shape. These microcapsules were then applied on the fabric

by exhaustion method and tested for their properties.

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5.2.2 Finishing of Plain Cotton Fabric with Microcapsules

The dried nano zinc and copper oxide microcapsules were finished

on the fabric by exhaustion method. During the finishing process, 8% citric

acid was used as binder to firmly fix the microcapsules on the fabric. The

microcapsule-finished fabrics were tested for their properties and compared

with that of the nanocapsules finished fabrics.

5.3 NANOENCAPSULATION

The nano particles were nanoencapsulated using bovine serum

albumin as the wall material and inside these capsules; the nano particles are

trapped to exert their properties strongly. The nanocapsules so produced were

applied on the fabric by exhaustion method. The finished fabrics were tested

for their properties using standard methods.

5.3.1 Nanoencapsulation

The nanocapsules were prepared by coacervation process using

protein solution and cross-linked using glutaraldehyde. The organic solvent

was removed under reduced pressure by rotary vacuum evaporator and the

nanocapsules obtained were centrifuged for purification. The nanocapsules

obtained were further dried by lyophilisation and they were applied on the

cotton fabric by exhaustion method using 8% citric acid as binder.

Figure 5.2 Nanocapsules of copper oxide nanoparticles

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5.4 COMPARISON OF MICROCAPSULE FINISHED FABRIC

WITH NANOCAPSULE FINISHED FABRIC

The microcapsules and nanocapsules finished fabrics were dried

and they were subjected to various functional and physical testing in order to

determine the efficiency of the encapsulation methods. The properties of the

finished fabrics such as antibacterial activity, Fourier transform infrared

spectroscopic analysis, scanning electron microscopic analysis were

performed and the results are presented below.

5.4.1 Antibacterial Activity Assessment

The antibacterial activities of the capsule finished fabrics were

assayed by AATCC 147 test method against both Staphylococcus aureus and

Escherichia coli organisms. The results of the antibacterial activities are

presented in Table 5.1 and Figures 5.2 to 5.5.

Table 5.1 Antibacterial activity of capsules finished cotton fabric

S. No. Type of sample

Antibacterial activity

(Zone of Bacteriostasis – mm)

Escherichia

coli

Staphylococcus

aureus

1Copper oxide nano particles

Microencapsulated fabric29 33

2Zinc oxide nano particles

Microencapsulated fabric28 29

3Copper oxide nano particles

nanoencapsulated fabric30 34

4Zinc oxide nano particles

nanoencapsulated fabric27 30

From the above table, it was found that the antibacterial activity

was maximum for copper oxide nano particles nanoencapsulated fabric

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against Staphylococcus aureus followed by microcapsules finished fabric.

Both the nanocapsules and microcapsules finished fabrics showed lesser

reduction against Escherichia coli.

Staphylococcus aureus Escherichia coli

Figure 5.3 Antibacterial activity for plain weave cotton fabric finished

with nano copper oxide microcapsules


Figure 5.4 Antibacterial activity for plain weave cotton fabric finished

with nano zinc oxide microcapsules

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Figure 5.5 Antibacterial activities for plain weave cotton fabric finished

with nano copper oxide nanocapsules


Figure 5.6 Antibacterial activities for plain weave cotton fabric finished

with nano zinc oxide microcapsules

The AATCC 147 test method performed on the plain weave cotton

fabric finished with the copper oxide microcapsules and nanocapsules showed

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excellent results when compared with zinc oxide microcapsules and

nanocapsules finished fabrics.

5.4.2 Fourier Transform Infra Red Spectroscopic Analysis

As the results of the research provided valid evidence favouring

copper oxide microcapsules and nanocapsules finished fabrics, further

research involving FTIR analysis, SEM and other technical specification were

concentrated only for copper oxide microcapsules and nanocapsules coated

fabrics and are shown in figure 5.6 and 5.7.

Figure 5.7 Fourier transform infrared spectrogram of microcapsule

finished plain weave cotton fabric

The fourier transform infrared spectroscopic analysis of the cotton

fabrics shows peaks corresponding to the regions of wavelength 559.77,

615.51, 667.49, 1031.10, 1058.58, 1113.42, 1162.98, 1281.82, 1318.20,

1373.01, 1430.30, 1637.23, 2902.81 and 3399.47 cm-1

. When compared to the

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untreated cotton fabric, the microcapsule finished fabric show many peaks in

the region of 1030 to 1637 cm-1

wavelength.

Figure 5.8 Fourier transform infrared spectrogram of nanocapsules

finished plain weave cotton fabric

The above figure shows the FTIR pattern of nanocapsules finished

cotton fabric. The peaks at regions of wavelength 559.84, 616.24, 667.14,

1059.51, 1113.62, 1163.39, 1235.61, 1281.80, 1318.04, 1337.46, 1372.42,

1430.16, 1637.93, 2901.09 and 3349.47 cm-1

are clearly visible from the

above figure. Similar to the above figure, many peaks were observed between

wavelengths of 1059 to 1430 cm-1

.

5.4.3 Scanning Electron Microscopic Analysis of Capsule Finished

Cotton Fabric

The scanning electron microscopy of the microcapsules and

nanocapsules finished fabrics were determined and the results are presented

below in figures 5.8 and 5.9.

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Figure 5.9 SEM photograph of copper oxide microcapsules finished on

the plain weave cotton fabric

The scanning electron microscopic analysis shows the distribution

of microcapsules over the plain weave cotton fabric. The photograph was

taken at magnification of 5, 500 X and at 3.0 KV.

Figure 5.10 SEM photograph of copper oxide nanocapsules finished on

the plain weave cotton fabric

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The above figure shows the nanocapsules distributed on the plain

weave cotton fabric and the results were taken at the same level of

magnification as that of the above.

5.4.4 Technical Specifications of the Microcapsule and Nanocapsules

Finished Plain Cotton Fabric

The microcapsule and nanocapsules finished fabrics were tested

for their physical properties and the results are presented in the following

table.

Table 5.2 Technical specifications of copper oxide micro and

nanocapsules finished fabrics

S.

No.Physical properties

Microcapsules finished

fabric

Nanocapsules finished

fabric

1.

Construction

Ends/inch

Picks/inch

97

85

100

83

2.

Tensile strength

Warp

Weft

13.2 kgf (145 N)

11.9 kgk (133 N)

13.5 kgf (145 N)

12.1 kgk (133 N)

3.

Tear strength

Warp

Weft

530 g (6.6 N)

512 g (6.2 N)

548 g (6.6 N)

539 g (6.2 N)

4. Resistance to abrasionEnd point reached at

11700 rubs

End point reached at

12000 rubs

5.Resistance to pilling

(No. of cycles)

1253-4 (Moderate to

partially formed pills)

3-4 (Moderate to

partially formed pills)

5003-4 (Moderate to

partially formed pills)3 (Moderate pilling)

1000 3 (Moderate pilling)2-3 (Distinct to

moderate pilling)

20002-3 (Distinct to

moderate pilling)

2-3 (Distinct to

moderate pilling)

6.

Dimension stability

Single wash (-) Shrinkage

Warp

Weft

(-) 0.7 %

(-) 0.3 %

(-) 0.8 %

(-) 0.4 %

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The above table showed the physical properties of the copper

microcapsule and nanocapsules finished fabric. The results showed that

compared to the microcapsule finished fabric, the nanocapsules finished

fabric showed better resistance to the physical factors.

5.5 WASH DURABILITY ANALYSIS

The microcapsules and nanocapsules finished plain cotton fabrics

were subjected to wash durability test and the antibacterial activity of the

washed fabrics were analyzed and the results are presented in the following

table.

Table 5.3 Antibacterial assessments of nano copper oxide microcapsules

and nanocapsules finished plain cotton fabrics after washing

S.

No.Fabric sample

Antibacterial activity

(Zone of Bacteriostasis –

mm)

Escherichia

coli

Staphylococcus

aureus

1.After 10

washes

Microcapsules finished fabric 28 31

Nanocapsules finished fabric 29 31

2.After 20

washes



3.After 30

washes

Microcapsules finished fabric 0* 26


4.After 40

washes



0* - No bacterial growth beneath the test fabric

The results of the above table showed that the microencapsulated

copper oxide nano particle finished fabric was able to withstand the

antibacterial activity for about 30 washes, whereas the nanoencapsulated

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copper oxide nano particle finished fabric showed antibacterial activity even

after 40 washes.

5.6 CONCLUSION

The synthesized nano particles were microencapsulated by ionic

gelation method and nanoencapsulated using glutaraldehyde and protein

solution. The capsules finished plain cotton fabrics were tested for their

physical and antibacterial properties and the results showed that the

nanoencapsulated fabric was able to retain the antibacterial activity even after

40 washes compared to the microencapsulated fabric. Hence the

nanoencapsulation process was utilised further for the composite analysis.

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CHAPTER 5 DEVELOPMENT OF ANTIMICROBIAL PLAIN WEAVE …shodhganga.inflibnet.ac.in/bitstream/10603/10382/10... · 150 CHAPTER 5 DEVELOPMENT OF ANTIMICROBIAL PLAIN WEAVE COTTON FABRICS