Vol. 122, No. 1 • Janvier-Février 2005
Nanotechnologies
Smal Wonders in Textiles
By Dominic Tessier
Nanomaterials present a real commercial potential for the textile industry. Differently from microscopic
materials such as microfibers, microfilaments, microcapsules, and micrometric powders, nanomaterials are
represented, for example, by nanofibers, nanofilaments, nanocapsules, and nanoparticles. They generally
possess dimensions varying from several tens of nanometers up to hundreds of nanometers. This article
describe then useful information relating to nanotechnologies, nanomaterials, canadian-based nanotech
companies, and textile applications. Nanomaterials of interest for the textile industry include nanofibers by
electrospinning (including carbon nanofibers), carbon nanotubes, colloidal solutions, nanomaterials by solgel,
controlled-delivery encapsulated nanosystems (nanocapsules with insect-repellents, perfumes, drugs, etc.),
broad range of nanoparticles, metallic nanoparticles, sputtered metal coatings, cold plasma surface coatings,
and monolayer coatings. To mention, the Canadian NanoBusiness Alliance and NanoQuebec are the main
organizations involved in nanotechnologies in Canada and Quebec, respectively.
NANOTUBES
Carbon nanotubes are found in two types, single-walled carbon nanotubes SWNT and multi-walled carbon
nanotubes MWNT, the latter being more common. The properties of nanotubes are high mechanical strength,
light weight, high electrical conductivity, thermal and chemical resistance. Recent developments mention
microfiber composites 4 times stronger than spider silk. Among possible technical textile applications, there is
the bullet-proof vest, safety harness, explosion-proof blanket, composite additives, filtration materials, medical
and structural materials.
NANOFIBERS BY ELECTROSPINNING
Polymeric nanofibers are applied as a thin, light weight, invisible, flexible, coating layer over fabrics.
Numerous applications to provide new capabilities for non-wovens, foam materials, and membranes.
Commercial products may be manufactured such as protective clothing (military, etc.), multifunctional filters
(ultrafine particles, bacteria, viruses), and medical textiles and devices. Otherwise, carbon nanofibers
possessing high mechanical strength, light weight, high electrical conductivity, thermal and chemical
resistance, may be used in textile composites and coatings to confer an added value.
SPUTTERED METAL COATINGS AND COLD PLASMA SURFACE COATINGS
Relating to nanotechnologies allowing surface treatment and coating deposition on textiles, medical or biotech
applications are particularly considered for their growing importance and acceptance. Application products are
various, such as : bio-filtration materials, medical garments, medical fabrics, textile implants, textile substrates
for cell growth, and other textile products for medical systems.
COLD PLASMA TECHNOLOGY
Plasma technology is an alternative to conventional wet chemical processes and provide efficient surface
treatment opportunities. In addition, this technology uses no water and less chemicals. Among different
applications, in particular for medical textiles, surface activation may confer hydrophilic properties to wovens
and non-wovens used in blood filtration devices or in body fluid filtration membranes. Other applications
include plasma grafting for growth test fabrics, fermentation membranes, implants, catheter fabrics,
enzymeimmobilization substrates, textile grafts, and other reinforcement synthetic materials comprising
textiles for tissues, human organs, and members repair. Plasma coatings are particularly considered for
textile-made biomaterials to improve their biocompatibility or improve (or reduce) the biological activity to the
surface. Medical applications may result in sterile fabrics for bandages, implants, and blood bags. Already
involved in this growing market, Dow Corning Plasma Solutions (Ireland) mentions that their liquid deposition
atmospheric plasma technology allows fast deposition of thin polymeric coatings for the improvement of
biocompatibility, filtration efficiency, or even barrier properties for surgery garments. Different properties are
expected, such as water and oil repellency, antimicrobial activity, flame resistance, UV protection, odor
control, delivery of biologically active agents.
METAL SPUTTERING TECHNOLOGY AND METALLIC NANOPARTICLES
Different plasma technologies may be used to apply metals onto textiles. Plasma sputtering is a vacuum
process which allows the direct application of metal coatings onto fabrics. Other high energy physical
processes (plasma torch) are used to manufacture metallic nanopowders which can be used as prepared or
dispersed in solutions to form colloidal solutions or either dispersed in polymer emulsions and applied by
padding. Metal- and metal oxyde nanoparticles may depict antimicrobial activity, auto-decontamination and
UVprotection properties.Among the main canadian manufacturers of metallic nanopowders, there are retrouve
Tekna Plasma Systems Inc., Nucryst Pharmaceuticals, Quantiam Technologies Inc., Integran Technologies
Inc., Lightyear Technologies Inc., Cycle Nanoscience and Technology Inc., Nanox Inc. (pilot scale, R&D),
Canano Technologies, and Groupe Minutia. Fabrics, yarns and filaments that have been metal-sputtered by
plasma, for example with silver or silver oxide, are part of efficient antimicrobial products in medical bandages
and wound dressings for treatment of burns, ulcers, scars, etc.
COLLOIDAL SOLUTIONS
Colloidal solutions consist of nao-sized particles dispersed into solutions. These particles, once applied to
fabrics, confer different surface properties such as improved water and oil resistance. In respect to those
advantages and the growing popularity of the “Nano-world” to the public, Nano-Tex LLC (USA) and Schoeller
Textil (Germany) marketed the used of such colloidal solutions of nanoparticles to textile and clothing
manufacturers / designers. In Canada, the CTT Group is particularly active to develop high added value
colloidal solutions of nanoparticles. Presently, ther is a high demand for colloidal solution confering to fabrics
various properties such as antimicrobial properties. A broad diversity of technical textiles and niche markets
can benefit from the application of colloidal solutions.