TEACHING MATERIALS for staff trainess

Nanotechnology (NT) repersents a growing interdisciplinary technology often seen as a new industrial revolution. NT deals with materials 1 to 100 nm in length. The fundamentals of nanotechnology lie in the fact that the properties of materials drastically change when their dimensions are reduced to nanometer scale. 

Nowadays, the textile industry has discovered the possibilities of nanotechnology through understanding, manipulation, and control of matter at the above-stated length, such that the physical, chemical, and biological properties of the materials (individual atoms, molecules, and bulk matter) can be engineered, synthesized, and altered to develop the next generation of improved materials, devices, structures, and systems. 

It is used to develop desired textile characteristics, such as high tensile strength, unique surface structure, soft hand, durability, water repellency, fire retardancy, antimicrobial properties, and the like. 

Nanotechnology offering huge potential in a wide range of end uses and new properties of nano materials have attracted not only scientists and researchers but also businesses, due to their huge economical potential.

Nanotechnology also has real commercial potential for the textile industry; it can provide high durability for fabrics, because nano-particles have a large surface area-to-volume ratio and high surface energy, thus presenting better affinity for fabrics and leading to an increase in durability of the function. It well known that conventional methods used to impart different properties to fabrics often do not lead to permanent effects, and will lose their functions after laundering or wearing. In addition, a coating of nano-particles on fabrics will not affect their breath ability or hand feel.

Examples of use of nano whiskers:

Nano whiskers keep the fabric breathable, 

Material (fabric) posses: Water and oil repellency, Superior durability, Fabric remains soft, natural Wrinkle resistance.

Three Dimensional Molecular Nano Net completely cover the core fiber.

Alters the property of synthetic fibers - Polyester to give a feel of cotton & linen, much better wicking properties, quickly drying gives the cooling effect.

Nano sheet wraps the fiber completely to cover it & alter its property.

                                                                                                                      

Incresed Strength and Durability, Improvement in colorfastness and Crease Retention as well as Static Resist.

                                                                        Application of nanotechnology:

1.  incorporation in fibres and yarns (fabrics),
   
2.  textile finishing by coating, 
   
3.  e-textiles.
   

Nanoparticles can be introduced in the textile production process at two levels :

• during the melt extrusion of yarns nanoparticles based on clay, metal oxides or carbon nanotubes (CNTs) can be mixed in the polymer before the extrusion process,

      - Antibacterial and Deodorant finishes

      - Self cleaning clothes

      - Water Repellent and Self Cleaning by Nano-Sphere 

• during the coating - using padding process and after drying and curing the water compound evaporates; polymer was melted and spread over the surface resulting in uniform coating of fibre due to the nano size of the finishing agent. 

The surface properties of a fabric can be manipulated and enhanced, by implementing appropriate surface finishing, coating, and/ or altering techniques, using nanotechnology. A few representative applications of fabric finishing using NT are schematically displayed in Figure.
Fabric finishing for enhanced properties and performanc

Concepts of surface-engineered modifications through NT to develop certain high-performance fabrics, through trademarks:
- superior durability, softness, tear strength, abrasion resistance, and durable-press/ wrinkle-resistance


Nano-Pel technology for stain-resistance and oil-repellency treatments based on the concept of surface engineering and develops hydrophobic fabric surfaces that are capable of repelling liquids and resisting stains, while complementing the other desirable fabric attributes, such as breathability, softness, and comfort. Nano-whiskers, which are nano-structures, to provide roughness to the fabric surface so that fluid-surface interaction and consequently fluid penetration can be avoided - the treated fabric has permanent water- and stain-resistant properties.
Nano Touch is a trademark for one of their nanotechnologies for treating a “core-wrap” type of fabrics. Core is usually synthetic fibers wrapped with natural fibers, such as cotton. The (nano)-treated core component of a core-wrap bicomponent fabric provides high strength, permanent anti-static behavior, and durability, while the traditionally-treated wrap component of the fabric provides desirable softness, comfort, and aesthetic characteristics.
Nano Care technology is offered to produce wrinklefree/resistant and shrink-proof fabrics made of cellulosic fibers, such as cotton.
Nano Dry technology, provides hydrophilic finishing to synthetic fabrics. This nano-based finish allows the fabric to whisk away the contact body’s moisture/sweat, which quickly evaporates to provide comfort to the wearer. 
Nanobeads are used into the textile substrate for carrying bioactive or anti-biological agents, drugs, pharmaceuticals, sun blocks, and textile dyes, which subsequently can provide desired high performance attributes and functionalities to the treated fabrics.

By combining the nano-particles of hydroxylapatite, TiO₂, ZnO and Fe₂O₃ with other organic and inorganic substances, the surfaces of the textile fabrics can be appreciably modified to achieve considerably greater abrasion resistance, water repellency, ultraviolet (UV) resistance, and electromagnetic- and infrared-protection properties.
Titanium-dioxide nano-particles have been utilized for UV protection. Similarly, by using nanosized silicon dioxide as an additive in coating materials, significant improvements in the strength and flame-resistance of textile fabrics can be achieved.
Wrinkle resistance can be developed for cotton fabrics by using the nano-engineered cross-linking agents during the fabric finishing process, but also for eliminating toxic agents, while maintaining the desired comfort properties of cotton.

Source:
Nanofinishing, Adv. Text. Tech., 11, 4 (2002).
Beringer, J., and Hofer, D., Melliand Int., 10, 295 (2004).
De Meyere, T., Meyvis, T., Laperre, J., Poorteman, M., and Libert, D., Unitex, 4, 4 2004).
De Meyere, T. , Meyvis, T., Laperre, J., Poorteman, M., and Libert, D., Tinctoria, 101, 39 (2004).
A.P.S. Sawhney: Modern Applications of Nanotechnology in Textiles, Textile Research Journal Vol 78 (8): 731–739 

• e-textiles

Warning Signaling - wearable txtiles 

The sensors can monitor heart rate, respiration, and temperature. If vital signals were below critical values, a FLED would automatically display, for example, a flashing red light, and a wireless communication system could send a distress signal to a remote location.

Source:
(PDF) Nanotechnology Applications in Textiles. available from: https://www.researchgate.net/publication/322466138_Nanotechnology_Applications_in_Textiles [accessed Jan 21 2022].