Award-winning poster from COST young researchers forum 2013 in Barcelona

1. ANTIBACTERIAL FIBRES
FOR A SUSTAINABLE FUTURE
Josefin Illergård · Lars Wågberg · Monica Ek
An eco-friendly antibacterial fibre-material has been developed. The
material does not release toxic compounds and the method of fabrication is
water-based, adding to the sustainability.
This material is a potential
competitor to conventional antibacterial fibre-based products, which
commonly are leaching harmful compound such as silver or triclosan.
By having an irreversible attached antibacterial substance on the
material, an antibacterial surface is obtained where the bacteria are inactivated upon contact. The approach prevents the spreading of toxic
compounds and do not promote antibiotic resistance.
Comparing the antibacterial efficiency with the total charge of the substrate
fibres and the subsequent polymer adsorption, the initial charge corresponded well with the resulting end-properties. The charge does thereby
seem to be an important factor for the antibacterial properties. A further
indication of this was that the efficiency was affected by the surrounding
ionic strength.
Fluff
CTMP
TEMPO
Kraft
Dissolving
Comparision of nitrogen content in the samples, sorted after the initial total charge of the fibres.
The polymers are attached to the surface of the treated material in a water-based process.
Bacteria are drawn to the surface by the positive charges and are inactivated upon the contact.
A problem with the contact-active materials have been the fabrication, as
the existing protocols usually involves organic solvents and harsh
conditions. We have developed an alternative method based on adsorption
of cationic polyvinylamine (PVAm) in multilayers with polyacrylic acid, giving
the material a positive charge. The process is water-based and carried out
at room temperature, which gives both a sustainable use and fabrication
process of the material. It is applicable of several types of materials, including wood-fibres, but the type of substrate may influence the properties.
When studying the bacteria on the material, the numbers were strikingly
increased on the treated material and the bacteria were deformed. The
positive charges do not only seem to attract and immobilise the bacteria, but also cause irreparable damage to the cells.
NO FIBRES
DISSOLVING
The developed eco-friendly antibacterial fibres show great potential for
future fiber-based products, especially within health-care and in the
hygienic sector. We now want to expand our research to study the macroscale effects of having an eco-friendly antibacterial product.
FLUFF
KRAFT
CTMP
TEMPO
0.00
0.05
0.10
0.15
The bacterial growth is inhibited by the use of fibres, as measured by optical density (turbidity)
measurements after 24 hours. For TEMPO, no growth was detected even several days.
Several types of cellulosic fibres have been modified, including fluff
fibres, TEMPO-oxidized fluff fibres, CTMP, dissolving-grade pulp and unbleached kraft pulp. The treated fibres were shown to reduce bacteria
with more than 99.9 % and suppress the bacterial growth in the
presence of nutrients.
Potential product applications includes material for the health-care sector as well as in the
hygienic sector and for water purification.
For more information, contact Josefin Illergård, PhD, at josefika@kth.se
KTH Royal Institute of Technology
Wood Chemistry and Pulp Technonogy
Stockholm, Sweden
A project financed by