Indian Journal of Fibre & Texti le Research Vol. 30, December 2005, pp. 477-479

Seminar Report

Nanotechnology : Opportunities in Textiles Mangla Joshi

Department of Textile Technology, Indian Institute of Technology, New Delh i 1 1 0 0 1 6, India

One day seminar on 'Nanotechnology: Opportuni­ties in Textiles' was organized by the Department of Textile Technology, Indian Insti tute of Technology, New Delhi, on 1 0th September 2005. Prof Surendra Prasad, Director-in-Charge, lIT-Delhi , inaugurated the seminar. In the inaugural address, he emphasized the growing importance of nanoscience and nanotechnology as the promising new area with wide ranging implications in all fields of science and tech­nology. He further informed that the nanoscience and nanotechnology have been identified by lIT -Delhi as one of the thrust areas of research. The Department of Science and Technology (DST), Govt. of India, has recognized I IT-Delhi as one of the core groups under national nanoscience and nanotechnology ini tiative. Recently, a step further has been taken to harness the vast potential of nanoscience and nanotechnology in biomedical research for theoretical and diagnostic purpose between lIlT-Delhi and All India Institute of Medical Sciences (AIIMS). The lIT-Delhi, one of the premier academic institutes of science and technol­ogy, is the only lIT in the country which has a De­partment of Textile Technology and occupies a spe­cial place in Textile R & D of the country.

Prof V K Kothari, Head of the Department of Tex­tile Technology, l IT-Delhi, in his welcome address said that 'Nano' is the latest buzz word to excite uni­versal interest because of the enomorous potential it offers in all fields including textiles and clothing. In­corporation of nanomaterials in fibres and coatings provides a range of possibilities of imparting specific functionality to textiles, such as antimicrobial, flame retardant, water and stain repellent, etc. Over the next decade, the imaginative use of nanotechnology could create a considerable market in textiles with major enhancement in their properties and performance. He informed that a group of faculty members of the de­partment has been engaged in the research in the area of nanoscience and nanotechnology applications in

textiles for the last couple of years. The objective of this seminar was to interact with experts from indus­try, and research and educational institutions to dis­cuss the critical issues in this area and to decide on further direction for R & D activities which would benefit both industry and academia.

Dr Mangala Joshi of lIT-Delhi informed that a very enthusiastic response for participation in this seminar was received from industry, R & D institutes, and faculty and students from academic insti tutes. The programme comprised eight invited lectures by ex­perts from industry, R & D organization and IIT­Delhi, which were presented in two technical ses­sions.

The first session on 'Nanofinishing' was chaired by Dr Anjan Ray, Head of Business and Performance Chemicals, Mis Jubilant Organosys Ltd, Noida. Prof M L Gulrajani of the Department of Textile Technol­ogy, l IT-Delhi , gave the opening presentation on 'Overview of nanotechnology applications in tex­tiles ' . He presented the latest R & D efforts being made world wide on the emerging nanotechnology towards the development of new texti le materials and processes. The concept of nanotechnology is believed to have been originated from the famous lecture on 'There is plenty of room at the bottom' by Richard P Feymann on 29th December 1 959, where he described for the first time the immense possibility existing at the molecular level through manipulation of atoms and molecules. The words 'Nanotechnology and Na­noscience' were in fact coined by K Eric Drexler, an undergraduate at MIT in 1 977, who in a book 'En­gines of creation' gave the concept of 'Bottom up ap­proach' and described i ts importance through minis­cule robots, molecular assemblers and tiny machines. Nanotechnology, often refen'ed to as 'Bottom up' which means producing materials through assembling molecule by molecule and atom by atom, while con­ventional technology is considered 'Top down' .

478 INDIAN J . FIBRE TEXT. RES. , DECEMBER 2005

He described the pioneering work of Dr David So­ane, who for the first time devised ways to use nanotechnology to add unusual properties to natural and synthetic textiles, without changing look or feel of fabric . Later his efforts combined with initiative from Dr George Henderson and Burlington Industries, USA, led to the l aunching of a company 'Nanotex' in 1 998, which is the first company in the world to bring nanotechnology to the textile i ndustry. Prof Gulrajani gave a comprehensive view of other products and processes based on nanotechnology being developed by leading companies worldwide, e.g. Nanosphere@ from Schoeller, Switzerland for stain protection, oil and water repellent and washing performance at high­est level; self cleaning clothes with nano Ti02 (tita­nium dioxide) coatings developed by Institute of Textiles and Clothing, Hong Kong; self c leaning tex­tiles based on silver nanoparticle coating by Dr Philip J Brown from Clemson University; antimicrobial fi­bres based on silver nanoparticles by Japanese Nis­shimba under trade name ' Agfresh and Gaiacoat' ; flame-retardants for textiles based on colloidal anti­mony pentoxide by Nyacol Nanotechnologies Inc . ; cleanest underwear based on negative ions generation by Green Shield (a Taiwanese Nanotech Company); and 'Chito Sante' a new chitosan deposition on fibre by Shanghai Dragon Bioscience Co. Ltd.

Dr Anjani Prasad, Vice President (Textile Chemi­cals), Clariant India Ltd, gave his talk on 'Specialty finishes' , launched by his company and described the various finishes and their potential to create stunning new effects and value addition to textiles. The promi­nent nano evolution finishes developed by Clariant are Sandoperm and Ceraperm, which have distinct advantages of stretchabi lity, elasticity and wash per­formance over conventional cationic softeners. Other developments included are: sanitized nano flash tech­nology which is based on nanosilver for imparting antimicrobial protection to polymers; Sandotex IR, an insect repellent finish for textiles; Nuva HPC- a water/oil repellent finish which gives soil repellent and stain release properties; and others, such as chemical blast, sand blast and corrosion look, and de­stroyed look for denim effects.

Mr Nitin Jain , Managing Director (South Asia), Nanotex Inc., USA, presented a talk on 'Comerciali­zation of nanotechnology in textiles' . He described Nanotex as one of the fabric innovation companies with real products, real customers and real revenues. Nanotex has developed specialized enhancements for

fabrics based on nanotechnology, available under the TM TM TM trade names Nano-Care , Nano-Pel , Nano-Dry and Nano-Touch™. Their molecular enhancement of fabrics is a three step process : ( i) design molecules that have 'performance characteristics' , (ii) engineer molecules to assemble i n a precise order on the fibres, and (ii i) permanently attach the molecules to the fab­rics. Mr Jain i nformed that Nanotex products are be­ing sold under 1 00 brands globally and these en­hanced clothing can be sourced from over 50 licensed mills world wide. I n India also, some leading textile mills have l icensed this technology and are in the pro­cess of launching commercial products.

Mr Arvind Patel, Head of Manufacturing unit, Arvind Mills Ltd, India, presented a case study on nanofinishing being carried out at A,rvind Mil ls ' Shirting Division . The nanofinishes were procured from Nanotex and applied on 1 00% cotton (product mix) by pad-dry-cure and pad-flash-cure methods. The water/oil repellent fin ished fabrics based on 'Nano-Care' displayed good spray rating and drop test results. They were also more durable to l aundry and had better handle as compared to conventional fin ishing. Arvind Mi l ls has already commercialized these products and launched them in the export mar­ket with good consistent results.

The post lunch technical session on 'Nanomaterials, Nanocoatings, Nanocomposites and Nano fibres' was chaired by Mr M Venkatraman, Vice President, SRF Ltd, Chennai . The first presentation on 'Nanomaterials: synthesis, characterization and properties' was given by Dr Tata N Rao, Scientist 'E' of International Advanced Research Center for Powder Metallurgy and New Materials (ARCl), Hyderabad. Dr Rao enumerated several applications of metal and metal oxide nanoparticles such as nano-Ti02, nano­silver, nano-ZnO, nano-MgO, nano-Ah03, nano-Sb20s and nano-ZrC for imparting properties, such as antimicrobial, self-cleaning, UV absorbing, flame retardant, etc. on textiles. He also informed that ARCI, Hyderabad, has infrastructure and faci lities for bulk production of metal and metal oxide nano-particles and nanopowders by different techniques, such as electrical explosion of wire method, chemical vapour synthesis, microwave plasma synthesis and spray pyrolys:s . CVD method and arc discharge method for production of carbon nanomaterials are also available at ARCI, Hyderabad.

Prof B L Deopura of lIT-Delhi presented a talk on 'Carbon nanomaterial based polymer composites' .

S EM INAR REPORT 479

Polymer nanocomposites have polymers as matrix and nanomaterials as reinforcement. Carbon nanomateri­als, such as nanotubes and nanofibres, having excel­lent mechanical properties and very high thermal and electrical conductivity are promising new reinforce­ment options for making polymer nanocomposites. A very large surface area and i ncreased interfacial i nter­action of matrixlreinforcement interface lead to sig­nificantly enhanced properties of the nanocomposites at very low loading of the fil lers ( 1 - 5 wt %). He enumerated this with several examples of PP, Nylon, PYA and PBO fibres contai ning Single Wal led Car­bon Nanotubes (SWNT).

A talk on 'Polymer nanocomposites and nanocoatings : Appl ication perspective in textiles' was given by Dr Mangala Joshi of l IT-Delhi . She covered the work being done on polymer nanocomposite based on nanoc\ays and hybrid nanofi l ler l ike POSS (polyhedral oligomeric s i lsesquioxanes) in the department over the last five years. The hybrid nanocomposites based on layered si licate (MMT clays and nanostructured POSS chemicals ) have superior thermal stabi l ity, improved mechanical and thermo mechanical properties and higher dimensional stabi l ity. Some of the highlights of research on high performance fil amens based on these nanocomposites, i .e . PP/c\ay and HDPE/POSS, were also presented. Dr Joshi further informed that a joint R&D project with ADRDE, Ministry of Defence, Govt. of I ndia, on 'Development of polymer nanocomposite coatings for inflatables' i s under progress a t l IT-Delhi . She l ater briefed on various techn iques being prevalent for nanocoatings on textiles, such as plasma and layer by layer coating through self-assembly , for imparting functionali ty on

texti les without affecting the feel and texture of fabric.

The last presentation by Dr Ashwini K Agrawal of l IT-Delhi was on ' Nanofibres' . He informed that a facility for production of nanofibres through electro spinning has been developed at l IT-Delhi . Nanofibres (diam. - I OOmm) are exciting new class of materials and possess extraordinary high surface area per unit mass, coupled with high porosity, excel lent structural and mechanical properties, high axial strength com­bined with extreme flexibi l ity. These make them suit­able for applications, such as filtration, barriers, wipes and several medical products. While most nanofibres are produced as nonwoven, attempts are being made to develop uniaxial polymer fibre bundles via electro spinning by the research group working at l IT-Delhi . Dr Agrawal also informed that work has been initiated to develop i n-house facility for plasma modification and coating of texti les substrates using atmospheric low temperature plasma technique.

The technical sessions were fol lowed by an inter­active open house discussion where all the partici­pants and speakers discussed various possibi l i ties of nanotechnology in creating unique properties and new applications of various texti le forms. There was a general concern about giving due attention to toxicity issues in handling nanoparticles and nanopowders. Prof Y K Kothari summed up the proceedings of the seminar and expressed a hope that this event which was probably the first attempt made in the country to focus on opportunities in texti les in the l ight of the emerging new nanoscience and nanotechnology has been useful to all the participants and would act as a catalyst for increased activity in the exciting area of nanotechnology app lications i n textiles.