Textiles with chitosan core-shell particles

The present invention describes a novel antibacterial therapy on textile materials employing polymeric core-shell particles dispersing in water. These particles are prepared from a surfactant-free emulsion polymerization based on the method of U.S. Pat. No. 6,573,313 and have average particle sizes in the range of 100 to 1000 nm in diameter. When applied to a textile article, the particles form a uniform coating, which prevents the growth of bacteria and microbes. The therapy does not change the fabric mechanical properties, hand sense and appearance. Antibacterial action on cotton is maintained even after 50 days of residence laundering.


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In comparison with artificial fibers, natural fabrics, such as the ones manufactured from cellulose and protein fibers, are a lot more vulnerable to microbe assault because of their hydrophilic porous structure and moisture transportation characteristics. The use ofantibacterial agents to stop or retard the growth of bacteria on textile content was becoming a standard finishing method for textile goods, especially for those used in hospitals, hotels, sports and healthcare industries. But, there isan increasing public concerns for possible effects of antibacterial completing on environmental and biological methods. An perfect cloth antibacterial finishing should not only kill undesirable germs and stop the spread of diseases, but also besafe and environmentally benign. Furthermore, the antibacterial purpose should be maintained for as many cycles via a house laundering process as you can.

Obtained from the shells of crabs, shrimps and other crustaceans, chitosan (CTS) is a non-toxic, biodegradable and biocompatible natural polymer, and has long been used as a biopolymer and organic substance in pharmaceutical, health, papermakingand food processing industries. Because of its polycationic nature, chitosan possesses good antibacterial property against various fungi and bacteria. But, direct coating of chitosan onto fabric content has suffered from four big downsides: 1)Chitosan doesn’t dissolve in water but instead only dissolve in acidic aqueous solution. Therefore, a significant amount of acid is used during the chitosan completing procedure. This may cause many environmental issues as a result of strong odor and corrosiveproperty of acids. 2) The aqueous solution containing dissolved chitosan usually is rather viscous, thus the completing procedure is hard to deal with. 3) Chitosan is a stiff substance. It impacts the fabric hand following coating. 4) Chitosan has strongwater-absorption capability due to the presence of many polar groups. Hence the water-repellency of all chitosan-treated textile goods is significantly decreased.

Chitosan-containing particles with core-parts and shell-parts are reported by Kuwahara et al in two U.S. patents (U.S. Pat Nos. 6,359,032 and 6,252,003) used for other uses like coloring and deodorizing agents. However, the chitosanmolecules on the particle surface are not permanent due to the physical absorption land, thus can be easily released with environmental changes like pH.

Thus today, textiles with chitosan particles have not been able to satisfactorily provide an antibacterial action of any permanence without significant drawbacks.

IP reviewed by Plant-Grow agriculture technology news