As there is an increasing global demand from fashion as well as sportswear consumers for long-lasting and sustainable practical clothing, nanomaterials have eventually become all-time favorites in the textile industry.
Nanoparticles such as silver, zinc oxide, titanium dioxide, and silicon dioxide have been used to impart functional attributes to fabrics so as to meet current market demands. Silver nanoparticles, for example, are applied to fabrics to inhibit the growth of bacteria. Ultraviolet protection, stain release, and antifungal activity, are also achieved using titanium dioxide (TiO2) nanoparticles.
In this article, I will introduce to you a nanoparticle known as zinc oxide, and how this chemical structure adds paramount value to the clothing market players. Nevertheless, before we jump right into the functional aspects of this particular type of nanomaterial, it is imperative that we have a general understanding of what such innovation pertains to.
What is Nanotechnology?
Nanotechnology refers to using nano-sized chemical structures in the creation of materials, devices, or infrastructures to improve or add functional values to their original properties (Tania & Ali, 2021). In other words, any consumer goods or professional services made with the application of nanomaterials can be said as using nanotech.
What is ZnO Nanoparticle and What are Its Functions?
Zinc Oxide (aka. ZnO) nanoparticles are white powders in sizes smaller than 100 nanometers used to absorb UV from natural sunlight as well as lamplights, and to reduce bacterial irritations on human skin.
They have also been found to be safe and inexpensive; thus, people across industries, especially the biomedical profession, have used them to develop products meeting the desired functions. Even under extremely high temperatures, ZnO nanoparticles still remain to be harmless and chemically stable.
However, some limitations have been found regarding the use of ZnO nanoparticles. For instance, using them on cotton fabrics to reduce bacterial activity may at the same time undermine the tensile strength, tearing strength, and abrasion resistance of woven fabrics.
A research by Arputharaj et al. (2017) reports that “ZnO nano-treated cotton fabric showed a 5.43% reduction in tensile strength for [fabrics knitted in] the warp direction” (Tania & Ali, 2021, p.2). This then raises the issue of how durable and time-lasting such ZnO nano-treated fabrics are when consumers put them to normal laundry.
Fortunately, to tackle with the impediment caused by ZnO on cotton materials, chemical researchers have discovered that by applying a polyethylene (PE) lubricant wax made by JIXTEX, Taiwan, to the cotton fabric, the level of abrasion resistance as well as tensile strength may be improved greatly.
Furthermore, the emulsion has also been used to soften the originally rough touch of the repeatedly-washed and therefore torn fabric, while increasing its smoothness as well as flexibility in the long run (Tania & Ali, 2021).
How Are ZnO Nanoparticles Coated on Fabrics?
According to the experimentation of Tania & Ali (2021), nanoparticles of zinc oxide are varnished to cotton or other textile materials in a similar fashion as that of dyeing fabrics, that is, thermo-fixation. Thermo-fixation is a quick temperature heating process where the material is treated between 90-101 degrees Celsius (i.e., 196 – 213° F) to prevent it from distortion in future washes.
Likewise, to effectively cover cotton fabrics with ZnO nanoparticles, manufacturers need to go through three successive coating stages (Tania & Ali, 2021).
Firstly, 1% of a ZnO nanoparticle is adhered to the processing fabric using the thermo-fixation technique.
Then, a second layer of ZnO nano-coating is implemented by mixing the zinc oxide structure with some soluble binder for 10 minutes; all the while, heat setting is employed.
Finally comes the last part of the coating process. The worker is to apply another 1% of ZnO nanoparticles, 1% of binders, and 10 grams of the JIXTEX-made polyethylene (PE) lubricant wax to the material for another 15 minutes.
Once the fabric has gone through the above-mentioned processes, it should now have the ultraviolet (UV) protection and antibacterial attributes.
Nanoparticles of zinc oxide are varnished to cotton or other textile materials in a similar fashion as that of dyeing fabrics, that is, thermo-fixation.
Now that you’ve learned the general properties and applications of ZnO nanoparticles for textile materials, why not look again on the functional clothings around you. Not only will you be amazed by how much minute details and hard works are put into place just for the high functionality and durability of a single piece of cloth, you’ll also be awed by the creation of the Universe.
- Arputharaj, A., Nadanathangam, V., Shukla, S. R. (2017). A simple and efficient protocol to develop durable multifunctional property to cellulosic materials using in situ generated nano-ZnO. Cellulose, 24, 3399-3410. https://doi.org/10.1007/s10570-017-1335-5
- Tania, I. S., & Ali, M. (2021). Coating of ZnO nanoparticle on cotton fabric to create a functional textile with enhanced mechanical properties. Polymers, 13, 1-16. https://doi.org/10.3390/polym13162701