Claims:
1. An apparel exhibiting microbicidal property comprising ZnO/PVA nanoparticles applied on to cotton fabrics, wherein the ZnO/PVA nanoparticles impart the microbicidal property to the fabrics that were used for developing healthcare apparel.

2. The cotton fabrics (typically used for healthcare apparel) treated with ZnO/PVA as in Claim 1 were further treated with fluid repellent finish.

3. The apparel as claimed in Claim 1, wherein the apparel is an apparel worn by medical practitioner or healthcare personnel.

4. The apparel as claimed in Claim 1, wherein the microbicidal property lasts even after 50 washes.

5. A process for applying ZnO nanoparticles along with PVA as binder where the nanoparticles are prepared by wet chemical method, whereby process comprises:
a. dissolving 0.1M Zinc acetate was in deionised water;
b. adding NaOH solution was dropwise into zinc acetate solution to adjust the pH of solution to 7 under constant stirring;
c. allowing the solution was then to settle and supernatant solution was discarded carefully;
d. rinsing the nanoparticles obtained in Step (c) with ethanol, deionised water;
e. dehydrating the nanoparticles of Step (d) at 100°C for 2 hours in ambient conditions, and
f. grounding the particles were then with mortar to powder.

6. The process as claimed in Claim 5, wherein the process further comprises:
a. dissolving PVA in water and adding ZnO-nanoparticles in the solution;
b. homogenizing the prepared solution of step (a) in high pressure sheer homogenizer at 9000 RPM, and
c. applying the solution of Step (b) on fabrics using pad dry cure method.

7. The process as claimed in Claim 5, wherein, the process further comprises of application of fluid repellent finish on the ZnO/PVA treated fabric.
, Description:Field of Invention
The present invention is in field of reusable healthcare apparel with speciality finishes on cotton woven fabrics. More particularly, the present invention relates to nanofinished apparel demonstrating antimicrobial and fluid repellent properties.

Background of Invention
In clinical settings or hospitals, textiles like doctor’s coat, scrub suits etc. can be source of nosocomial infections, contributing to the transmission of pathogens. Contaminated textiles are the one of the most probable causes of hospital infections.

Sterilisation and other measures are adopted but they do not completely remove the microbes. To address this issue hospitals have resorted to using one-time-use and disposable healthcare apparel made of synthetic materials which is a serious concern in waste accumulation. Treating woven cotton fabrics with specialty finishes such as antimicrobial and fluid repellent finishes are ways of adding special properties without hampering the inherent nature of the fabrics thereby, providing an alternative of using natural cotton woven fabrics as a substrate for reusable healthcare apparel. It is a well-known fact that most of the cross infections in hospitals are due to bacteria such as Staphylococcus aureus, coagulase-negative staphylococci (CoNS), Streptococcus pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Haemophilus influenzae, Klebsiella pneumoniae, Acinetobacter spp., Enterococci spp. etc.

One option which has been utilised to effectively reduce the microbial load has been to incorporate metal nanoparticles in the fabric. For instance, beginning in the mid-2000s, many clothing companies started incorporating silver nanoparticles into their products. Silver nanoparticles are antimicrobial, which means they kill the bacteria that cause bad odours.

However, Silver being costly, the overall cost for manufacturing the fabric with Silver nanoparticles is a costly affair. As a consequence, of inflated manufacturing cost, the overall cost of the product also increases, thereby making the apparel less economic for daily usage.

Recently, it has been observed that the partial dissolution of zinc oxide (ZnO) particles releases Zn2+ ions in aqueous suspension that contributes to the antimicrobial activity of ZnO as has been discussed in Pasquet, Julia, et al. (2014). The same activity was also confirmed by Farzana R, et al (2017).

Therefore, it may be envisaged that a akin to silver, even healthcare apparel made of cotton woven fabrics coated with ZnO-nanoparticles would also exhibit microbicidal activity and effectively reduce microbial load present on the fabric. This in addition with fluid repellent finish makes such products with commercial potential.

Hence, in view of the above, it is an object of invention to provide ZnO-nano-finished and fluorocarbon based fluid repellent treated cotton woven for healthcare apparel that exhibits microbicidal activity properties. It is, also, an object of the present invention to provide the apparel which also exhibits fluid repellent properties.

Summary of the Invention
In view of above objects, the present invention provides an apparel which is treated with ZnO nanoparticles.

Further, ZnO nanoparticles are applied together with polyvinyl alcohol binder (PVA binder).

Furthermore, the ZnO/PVA treated fabric is further treated with fluid repellent finish to prevent any accidental absorption of liquids.

In another aspect, the invention provides a process for manufacturing said microbicidal apparel.

Brief Description of Drawings
Fig. 1 illustrates the XRD Pattern of the ZnO-nanoparticles.

Fig. 2 illustrates the FTIR analysis of ZnO/PVA treated fabric.

Fig. 3 illustrates the Scanning electron micrograph of the treated fabric of the invention.

Detailed Description of Drawings
As can be seen from Figs. 1, 2 and 3, the process of the invention leads to an effective application of the ZnO/PVA nanoparticles (31). Said ZnO-nanoparticles function as microbicidal agents.

Detailed Description of Invention
Described herein is an antimicrobial apparel, wherein the microbicidal property is imparted by application of ZnO-nanoparticles onto the cotton fabric that is typically used to make healthcare apparel.

Further, the apparel is made fluid repellent by application of fluid repellent finish.

The applied ZnO-nanoparticles provide the fabric with microbicidal properties and the fluid repellent finish acts as additional protection to the wearer.
In an embodiment, the ZnO-nanoparticles were prepared by wet chemical method. Zinc acetate and sodium hydroxide were used as precursors for the synthesis of Zinc Oxide nanoparticles. 2M NaOH was dissolved in deionized water and 0.1M Zinc acetate was dissolved in deionised water. NaOH solution was added dropwise into zinc acetate solution to adjust the pH of solution to 7 under constant stirring. The reaction was continued for after the addition of NaOH. The solution was then allowed to settle and supernatant solution was discarded carefully. The obtained nanoparticles were rinsed several times with ethanol, deionised water and finally dehydrated at 100°C for 2 hours in ambient conditions. The particles were then ground with mortar to powder.

ZnO-nanoparticles were applied on the substrate to impart desired antimicrobial property along with 2% PVA (W/V) used as a binder on 100% cotton fabric. The PVA was dissolved in water after which ZnO-nanoparticles were added in the solution and the prepared solution was homogenized in high pressure sheer homogenizer at 9000 RPM and applied on fabrics using pad dry cure method. The fabric sample was immersed in prepared solution for sufficient time to allow penetration of ZnO-nanoparticles into the fabric structure.

In further embodiment, the ZnO/PVA nanoparticle treated fabric was further treated with fluorocarbon-based fluid repellent finish. The fluorocarbon-based fluid repellent finish was applied on the ZnO/PVA treated antibacterial fabric using pad dry cure process.

The appeals were tested for the retention of antibacterial properties after 30 and 50 launderings using standard test methods. ZnO/PVA fabric of the invention after further treatment with standardized fluid repellent finish (FRF) indicated that the treated fabric of the invention retained its microbicidal property after 50 washes. The fabric of the invention thus has potential to be used in the field of medical textiles for healthcare apparel as it has antibacterial and fluid repellent properties. The finishes applied on fabric for antibacterial action and fluid repellency can provide protection to the wearer in addition to being comfortable.

Example 1: XRD Pattern of ZnO-nanoparticles:
The particles were prepared in batches using zinc acetate and NaOH by wet chemical method. The yield of nanoparticles per batch was approx.0.9 gm from 4.39 gm of Zinc Acetate and 1.5 gm of NaOH. The ZnO-nanoparticles prepared for the research work were characterized for their structure, shape and size using XRD, TEM and PSD tests.

XRD Pattern:
The XRD pattern shows evident peaks at 2? =31, 34, 36, 47, 62, 67 and 69 typical of hexagonal ZnO wurtzite structure according to JCPDS card number 040831 indicating crystallinity in nanoparticles corresponding to diffraction planes (100), (002), (101), (102),(110), (103), (112), and (201) respectively. This indicates the presence of nanoparticles in crystalline form with the wurtzite structure. The XRD pattern is presented in Fig. 1

TEM Analysis:
The particles were subjected to TEM analysis and the test revealed the dumbbell shaped ZnO particles.

ZnO nanoparticles were characterized for size determination using particles size analysis test. PSD based on number: The obtained particles were in the form of mixture of particles with varying sizes of approximately 37.7 nm (10 % by number), 45.3 nm (50% by number) and 67.8 nm (90% by number). The average size of the nanoparticles is 90.5 nm. PSD based on volume: The smaller particles are invisible in the volume plot which indicated that the powder sample dispersion consisted of few larger agglomerates of small nanoparticles. PSD based on intensity: The intensity distribution plots of the synthesized ZnO nanoparticles sample shows two broad peaks centred at 168.4 nm and 5452.9 nm therefore the nanoparticles were polydisperse. The intensity plot suggests presence of aggregated particles above 2000 nm.

Example 2: Antibacterial Activity:
The control (untreated) sample did not exhibit any antibacterial activity. The treated ZnO/PVA fabric exhibited 99.98% bacteria reduction against S. aureus 99.96% bacteria reduction against K. pneumoniae. The wash durability of the treated fabric was carried out after 30 and 50 washes.

Nano ZnO/PVA treated fabric showed minimal loss in activity after washing and it can be inferred that adhesion and formation of polymer nanoparticle network was better on the surface of the fabrics and thus retained antibacterial activity after 30 and 50 wash cycles. The results are presented in Table 1

Table 1 – Results of Antibacterial activity of ZnO/PVA fabric
Fabric No. of Laundering Cycles Antibacterial Activity
(Bacterial Reduction %)
S. aureus K. pneumoniae
ZnO/PVA fabric 0 99.98 99.96
5 99.97 99.93
30 99.23 99.10
50 98.92 98.03
Example 3: Antiviral Activity:
The fabric of Example 2 was further tested for antiviral activity. The results are tabulated in Table 2. The fabric treated with ZnO/PVA was evaluated as per AATCC 100-2012 that was modified for viruses as preliminary screening against MS2 Bacteriophage. MS2 Bacteriophage (MS2) is an RNA virus of the family Leviviridae. Escherichia coli 15597 are the hosts for MS2 bacteriophages. Due to its environmental resistance, MS2 bacteriophages are used as a surrogate virus (particularly in place of Picornaviruses such as Poliovirus, human Norovirus) in water quality and antimicrobial studies.

Table 2: Antiviral Activity:
Fabric samples (ZnO/PVA) Test Organism:
MS2 Bacteriophage Log
Reduction
of Virus
at
2 hours Percentage
Reduction
of Virus
at
2 hours MS2
Bacteriophage Log
Reduction
of Virus
at
24 hours Percentage
Reduction
of Virus
at
24 hours
Average
PFU/Carrier
at 0 hours (B) Average
PFU/Carrier
at 2 hours (A) Average
PFU/Carrier
at 24 hours (A)
PFU log PFU log PFU log
Treated Fabric ZnO/PVA 9.10x104 4.95 3.40x102 2.53 2.42 99.62 40 1.60 3.35 99.95
Lab Control -
Untreated 1.00x105 5.00 0.00 0.00 1.50x104 5.17 0.00 0.00

The treated fabric with nano ZnO/PVA showed 99.62% and 99.95% reduction in 2 hours and 24 hours respectively when analysed as per AATCC 100 -2012 test Method using MS2 Bacteriophage as surrogate virus.

Example 4: SEM and FTIR:
The treated samples with ZnO/PVA were taken for characterization using SEM and FTIR tests to investigate the deposition and presence of ZnO nanoparticles.

FTIR Analysis:
FTIR analysis technique was used to recognize the chemical bonding of the materials and was used to identify the elemental constituents of the material. Typically, cellulosic materials show two main absorbance regions in IR spectrum. The first one at low wavenumbers in the range 700 – 1800 cm-1 and the second one at higher wavenumbers in range 2700-3500 cm-1.The characteristic peaks exhibited by FTIR spectrum of zinc oxide nanoparticles treated fabric was investigated in Fig 2.

Peaks were observed at wavelength 3277.66, 2887.14, 2361.99, 1704.19, 1240.24, 1014.21, 714.14, 660.89, 513.21, 484.28, 469.82, 464.68, 447.37 and 440.01 for the treated fabric. The absorbance bands of zinc oxide lie between 400-700 indicating the presence of Zn-O vibrational modes confirmed by characteristic peaks at 469 and 484.

SEM Analysis:
The surface observation of zinc oxide nano-?nished fabric was carried out with a scanning electron microscope represented in Fig. 3.

SEM of the treated fabric shows the presence of ZnO-nanoparticles on the fabric surface. The untreated cotton fabric seems to have smooth and plain surface of ribbon like fibers without any particles while the cotton fabric treated with ZnO/PVA showed uniform deposition of nanoparticles on the surface.

Example 5: Cytotoxicity Test:
The invitro toxic nature of treated fabric was then tested for toxicity as per in vitro cytotoxicity test method In vitro cytotoxicity ISO 10993-5:2009. The cytotoxicity study results indicated that the tested sample is non-toxic to the L929 fibroblast cells at the incubated period and concentrations, proving the material non-cytotoxic. The results are presented in Table 3.
Table 3

Example 6: Antibacterial Activity of ZnO/PVA+FRF treated fabric:
The samples were then tested for antibacterial properties as per AATCC 100. The treated samples were tested for the retention of antibacterial properties after 30 and 50 launderings using standard test methods. The observations are tabulated in Table 4
Table 4

ZnO/PVA fabric after further treatment with standardized fluid repellent finish indicated that the fabric treated with ZnO/PVA +FRF retained its antibacterial property after 50 washes. The treated fabric ZnO/PVA+FRF has thus potential to be used in the field of medical textiles for healthcare apparel as it has antibacterial and fluid repellent properties. The finishes applied on fabric samples for antibacterial action and fluid repellency can provide protection to medical personnel in addition to being comfortable.