Nanotextiles …..An Opportunity

Nanotextiles …..An Opportunity

Written By : Dr Khalid Mughal
Nanotextiles …..An Opportunity New technologies are revolutionalizing the human civilization dramatically. Stone, bronze and iron have impacted the mankind during the identified periods of history. The coming up technology is Nanotechnology. A lot of research work has been or being done in the developed world and newly Industrialized Economies (NIEs). USA and China are going neck -to –neck in this field. The other nations are taking the road. Pakistan has lost much of its comparative advantage to competitive advantage to other countries as in sports goods, garments, electrical, electronics and various other manufactures. The only reason is that world is enhancing its technological base through Research and Development (R&D). Unfortunately the Industrial Sector in Pakistan has not sensed the current loss as yet what to say about the future. If they do not respond to the potential threats, we might be exporting the raw hides and skins or cotton in bales. Let’s consider the major component of Pakistan’s exports which is the Textiles. The research work so far cited reveals that intelligent and sensible clothing have been developed which are stain, wrinkle and liquid resistant. It is not a miracle but simply the use of Nanotechnology. It is a science of studying material smaller than one hundredth the width of a human hair or one billionth of a meter. Water and Oil Resistance Nano-Tex fabric protection is a chemical enhancement, attached at the molecular level, to fundamentally transform the fibers. The nano-tec achieve unsurpassed durability without loosing the natural hand and breathability of the fiber. It’s application of water-and-oil repellent character is effective for use in natural fiber, polyester, nylon and acryl. Nano-Pel cotton withstands 50 home launderings, with functionality levels well-maintained for water and oil repellency (80 and 4) even after 20 washes. It can endure 20 dry cleanings when applied to wool or linen, a distinctive feature in contrast to conventional methods that display hardly any durability. Heat treatment, such as through ironing or tumble drying, is required for the onset of water-and-oil repellency. Anti-bectarial sensing NanoHorizons, a commercial concern, based in States College, Pa is selling a line of silver, gold and other nanoparticals which are compatible with standard polymer manufacturing process that kill bacteria and other odores. If applied to shoes, athletic equipment,plastic and nylon products, such clothing is capable of absorbing the bosy odoures. Another process of micro-encapsulation has enabled fragrenced fabrics which automatically remove unwanted hair while being worn against the skin of the user eliminating chances of irritation. Nano-carpet developed by University of Pittsburg unlike other nano-tubes can sense their environment, change color and can be trained to kill bacteria. Nanolayering to natural fibers customized for different chemicals and poisons can block warfare agents like mustard or nerve gas, or chemicals leaving the clothes breathable and allowing air and moisture to pass. Gloves coated with arthritis drugs, military uniforms coated with anti-bacterial layers to prevent infection. ________________________________________ If gloves coated with arthritis drugs; military uniforms coated with antibacterial layers to prevent infection in case of wound; antibacterial sheets for submarine bunks to prevent illness spread as these bunks are shared by enlisted personnel; and comfortable protective clothing against several chemical and biological warfare agents as explained by Hinestroza. Although high quality diapers are available for childern but if these are coated with anti-itchingpolyelectrolytes or tissues coated with anti-allergy medicine it will help the working women and the baby-sittersfor safty and health of the childern. Carbon Nano- Tubes---------- Discovery The discovery of Carbon Nano Tubes (CNT) by Iijima [1991], has led to the exploration of high strength and superior performance fibers. Such yarns exhibit extraordinary mechanical properties, elastic strain up to 5 %, and breaking strain about 20 %. Such synthetic nano fibers that are being produced by electro spinning process can significantly enhance the strength and conductivity of the fabric after suitable heat treatment. Hence, these nano fibers and yarns can also be efficiently used as super capacitors in electronic textile components [Dalton et al., 2002, Schreuder et al., 2002, Dersch, et. al. 2003, Zarkoob, et. al., 2004, and Subbiah, et. al., 2005]. It is also shown that by simultaneous reduction of fiber diameter and increase in twist (1000 times), nano yarns can be spun comprising Multi-Walled Carbon Nano Tube (MWCNT) that consist several (7 to 20 usually) concentric cylinders of Single Walled CNT. Such yarns provide specific mechanical properties (such as strength, toughness, energy damping capability, etc.), which then can be deployed to produce electronic textiles for supporting multi-functionalities, such as capability for actuation, energy storage capacity, radio or microwave absorption, electrostatic discharge protection, textile heating, or wiring for electronic devices [Zhang et. al., 2004]. Nano-Tex is one of the leading companies to implement the nano-technology have developed several fabric treatments such as (a) permanent anti-static treatment; (b) wrinkle free treatment using moisture-wicking technology; (c) stain resistance and oil repellent treatments; and (d) “nanobeads” to carry bioactive or anti-biological agents, drugs, pharmaceuticals, sun blocks, and even textile dyes by developing the novel nano-technologies. Such treatments onto textile substrates permanently alter properties of the textiles and are said to have superior durability, softness, tear strength, abrasion resistance and capable of providing softness to durable press garments. Another leading is Chemical Oxidative disposition technology for finishing purposes, which deals with the deposition of Conducting Electro - active Polymers (CEP) onto different kinds of fibers and textiles, resulting Composite materials with high tensile strength and good thermal stability. Furthermore, Surface polymerization of polymer fibers has a potential to increase the conductivity almost 10 times by decreasing the electrical resistivity Such coated polymeric composite materials can be used in microwave attenuation, EMI shielding, and dissipation of static electric charge. Hence, they can be useful for military applications, e.g., camouflage, stealth technology. By combining the nano-particles with the organic and inorganic compounds, the surfaces of the fabrics treated with abrasion resistant, water repellent, ultraviolet (UV), electro-magnetic and infrared protection finishes can be appreciably modified. Recently, the titanium-dioxide nano-particles have been utilized for the UV protection. Also by using nano-sized silicon dioxide, improvements in the strength and flame-resistance of textile fabrics can be achieved. The usage of nano-engineered cross-link agents during finishing process enhances the wrinkle resistance of cotton fabrics .The newly developed micro encapsulation technique is being used in textile industry for flame or fire retardant (FR) agents. Microcapsules containing silver nano-particles (Silver Cap) are also being investigated for providing anti-microbial effects. Applications in Textiles A widespread scope has been found while application of Nano-technology in the manufacturing of fibers/yarns as well as in the development of fabric finishes. Otsuka Kagaku has developed new electro conductive fibers to be used for the protection from radiation emitted by electronics. For the purpose of de-odorizing, Traptek is developed odor-free clothing using activated carbon; J R Nanotech has developed socks containing nano-particles of silver; Fuji Spinning's have developed "V-Up" functionalized fibers for de-odorizing the undergarments; and Mitsubishi and Solutia have developed an antimicrobial and deodorant fiber made from seashells. Asahi Kasei has developed a stretchable raschel knitted fabric with elastomeric yarns to avoid yellowing in foundation and under garments. Nano-filtration membranes are also being used successfully for the treatment of dye effluents. These grafted membranes are capable of removing dyes so that the processed water can be recycled and reused. Strong graphite nano-fibers have been developed, which can support large loads and high pressure at room temperature. A research group in Belgium is exploring the possibility of developing novel yarns by melt extruding a range of nano-additives. Investigators at USDA have developed a technology by which the nano-composites can be developed by using variety of types and sources of cellulose, such as grass, kenaf, cotton fiber, cotton plant material, etc with clays, which is used as the nano-filler material. Such composites improve the thermal stability of the cellulose and it could lead to the development of flame retardant end-products such as nonevents, papers, filament fibers, coatings, etc. Future Applications The researches indicate that there will be lots of profitable applications of Nano-technology in cotton and other textiles. Several possibilities can be extended to attain the performance enhancement of textile manufacturing machines & processes. In future, interdisciplinary research collaborations are needed which will lead to significant advancements in the desirable attributes of cotton and cotton blend textile applications. The textile industry has the biggest customer base in the world. Therefore, advances in the customer-oriented products should be the focus for the future nanotechnology applications. The research should be targeted on developing improved dirt, crease and shrink resistance properties in fabrics, temperature adaptable clothing and odor-less undergarments. We envisage that by combining the optical fibers, micro mirrors, functional coatings and electronic textiles customized fabrics can be developed which can change its color as per the desire of consumer’s taste. Several advances can also be made towards the development of strong fibers and fabrics for biomedical and military applications. Some of the examples may elicit the significance of Nano- Textiles. Swimming Gold Meddle in Olympics has been won due to use of costume made of nano- fibers which was water resistant and water repellent. Latest detergents, stain removers are partially using this technology. Opportunities Pakistan’s major foreign exchange earning comes from export of textiles. Pakistan has a great potential in textiles sector in the home market as well as the world around. An early initiative at industrial and government level should be taken if we have to survive in the textiles field domestically or internationally. The senses of private sector are always quicker than the public sector because of self interest. They must be on the way in thinking and planning to take a step in this direction. Capacity Building Preston University has taken the first step by launching an Institute of Nano Technology for capacity building of suitable human resource and manpower to enable our industrial sector to cope with the future needs. It will also undertake industrial research to help enhance the material technology and improve product quality, durability, performance and compatibility at home and abroad. It is time for the concerned to take home this massage to take some serious initiative to grab the opportunity to achieve competitive advantage.