Self-Cleaning Property of Textiles

What if our clothes can wash themselves without any machine?

What if our clothes act as a barrier to harmful pathogens?

What if we can wear clothes in rain without it getting wet?

Wondering how is it possible? Well, the answer lies in the lap of nature. Our nature is the solution to all kinds of problems. Barthlott and his team were the first to observe and identify the cause of this effect, termed the ‘Lotus Effect’. The lotus leaves have a very unique feature that enables them to get rid of the dirt that falls on them. Barthlott investigated this feature and attempted to incorporate it into the textile material. This was called the self-cleaning property.

self-cleaning smart fabric
Image source: https://navork.com/


What is the self-cleaning property in textiles? 

The self-cleaning qualities of any textile material provide protection against infections such as bacteria or spores. This feature mimics our nature to generate a textile that does not need to be washed frequently. This phenomenon is known as the 'Lotus Effect,' and it is based on the function of lotus plant leaves. The micro-and nanostructured superhydrophobic surfaces of the leaves help it to get cleaned by rainfall. In simple words, the Lotus flower has a micro and nanostructured super hydrophobic surface that completely wards off dirt and completely gets washed by rainwater. The double layer of the lotus minimizes the contact area of the surface with the dirt particles. The hydrophobic nature of the surface keeps the material away from dirt and dust. This is known as the lotus effect and can even repel very viscous fluid from its surface.

The principle is to minimize the contact area of hydrophobic surfaces by an overlapping double structure approximately 100 nm to approximately 100 ┬Ám in size. The interfacial tensions arising at the intersection point of water, air, and the material surface govern the wettability of the surface. The relation of the tensions determines the contact angle between the surface and the tangent at the water drop lying on it. The superhydrophobic surface tends to have lower surface energy that allows the droplets to assume a spherical shape with a higher contact angle. Hence the wettability of the surface reduces thus making it possible for dirt and dust to be carried away by the droplets without clinging to the surface.

It can be done by two methods:

  1. Fluorocarbons – It helps to form a thin film layer on the fiber surface reducing the surface tension of the surface to as low as 10dyne/cm.
  2. Nanotechnology – It is a more advanced technology and is under process.


Related post: Nano finishing in textiles

Although the self-cleaning by fluorocarbons process is simple it does come with a few limitations. These are as follows:-
  1. Fluorocarbon is not durable with cotton products
  2. It produces skin rashes
  3. The fluorocarbon film comes off after a few washes.

Application of self-cleaning properties

There are numerous applications of this property of textile materials. 
  1. Architectural applications for weather protection, decorative or other technical functions.
  2. Algae-resistant fabric with fewer requirements for maintenance.
  3. Outdoor applications, such as textile roofs for airports and sports stadiums, sunscreen textiles, outdoor clothing etc.
  4. Indoor applications such as shower curtains.
  5. It has wide applications in sports function and safety wear.

The goal of this study is to give insight into the world of smart textiles and their wide potential for the development of new materials based on self-cleaning properties. These next-generation textiles have immense architectural applications for weather protection, decorative or other technical functions along with interesting applications in the apparel sector that include sports functions and safety wear. The superhydrophobic and self-cleaning effect of textiles could be made into used to manufacture apparel without deteriorating the aesthetic value of the material. Further studies of nano-scaled structures for the self-cleaning effect are needed to understand the prospect for growth.

References:

About the Author: Adita Banerjee is pursuing her graduate degree in Textile Technology from the Government College of Engineering and Textile Technology, Serampore. She loves writing content and reading books.