We use nanofibers every day without realising it. What makes them special?
Nanofibers are polymeric fibrous formations with a diameter of tens to hundreds of nanometres. They have specific dimensions and properties, with one dimension (typically length) significantly exceeding the fibre diameter.
Nanofibers are of interest to researchers and manufacturers for their unique properties:
- high surface-to-volume ratio
- large porosity
- many times greater surface area compared to, e.g., microfibres
- chemical and thermal stability
- controllable morphology
What polymers are nanofibers made from?
Nanofibers are made from various types of polymers. Currently, more than 50 synthetic and natural polymers can be used. Synthetic polymer nanofibers are made from, e.g., polyamide, polyvinylidene fluoride, polyurethane and polyvinyl alcohol. Biological polymer nanofibers are made of materials such as polycaprolactone, polylactic acid, chitosan and gelatine.
Nanofiber production technology – electrospinning
A nanofiber material is a product with a fibre diameter of less than 1 micron (µm) = 1,000 nanometres (nm). Such a fine textile fibre can be produced using various sophisticated methods, among which so-called electrospinning stands out. The technology based on electrostatic propulsion enables the continuous production of high-purity, high-quality nanofibers.
Electrospinning enables the production of nanofibers from a wide variety of natural, synthetic and hybrid polymers with different physical, chemical and mechanical properties. Considering the robustness of the electrospinning process, various electrospinning techniques are offered for the production of nanofibers involving different input parameters and strategies.
The most common type used, especially on a laboratory scale, is needle electrospinning such as melt electrospinning, gas jet electrospinning, coaxial electrospinning and emulsion electrospinning.
A new technique for the production of nanofibers and microfibres is the so-called needleless electrospinning, which brings additional advantages:
- the production of homogeneous 2D nanomaterials on an industrial scale
- the possibility of spinning a wide range of polymers
Unlike needle spinning, this type requires a much higher voltage between the electrodes.
Spinning using the NanospiderTM method – a breakthrough in the industrial production of nanofibers
NanospiderTM is a unique needleless spinning technology from the free surface of a polymer solution in a strong electrostatic field that enables the production of nanofibers on an industrial scale. In 2003, Prof. Oldřich Jirsák developed this method together with his team at the Technical University of Liberec (TUL). Already a year later, Elmarco signed a license agreement with TUL and over the years has become a global leader in the field of providing technology for the production of nanofibers for a wide range of applications on an industrial scale.
What is the NanospiderTM method?
The technology not only makes it possible to spin from a drop of polymer passing through the nozzle into the electric field, but from the entire thin layer of the polymer solution.
Nanospider™ technology uses a spinning electrode in the shape of a thin string and a head to apply a polymer solution along the entire length of the string. Under the influence of a strong electric field, nanofibers are then formed from a thin layer of polymer on the electrode. One of the advantages of this method is that a small amount of always fresh solution is used for spinning, which is a prerequisite for maintaining constant parameters of the output material during long-term production.
Advantages of spinning with the Nanospider method:
- Production of nanofibers on an industrial scale.
- High uniformity of input and output material.
- Possibility of using a wide range of polymers and substrates.
- Easy maintenance.
Where do the nanofibres help?
Nanofibers are among the most attractive materials of the modern scientific world due to their flexible use in various fields. The application potential starts in the field of energy production, addressing environmental problems and continues through medicine, the automotive industry and other fields such as:
- Air filtration,
- Liquid filtration,
- Protective textiles in healthcare,
- Wound dressing to support the healing process,
- Tissue engineering,
- Distribution of drugs,
- Battery separators,
- Fuel cells,
- Functional sportswear and shoes