Speciality Chemicals Magazine NOV / DEC 2022 | Page 33

BIOCIDES development of new AGXX particles according to customer specifications . The company can configure the parameters of particle size and particle brightness , as well as the carrier material .

Product types & applications

AGXX is ideally suited for incorporation into multiple materials and coatings due to its particle form , including dry powder and suspension . The initial particles consist of cellulose as the carrier material for the two precious metals , thereby enabling perfect integration into lyocell fibres and exhibiting excellent antimicrobial efficacy according to DIN EN ISO 20743 ( antimicrobial tests on textile products ). In order to optimise the applicability of AGXX particles to a broader range of materials and products , they have been further developed by , for example ., designing smaller particles using a variety of carrier types , including aluminates , titanates and activated carbon ( Figure 3 ). These smaller AGXX particles are particularly well suited for incorporation into polymeric materials , coatings or fine textile fibres . Tests in accordance with ISO 22196 ( Figure 4 ) on AGXX-modified polyamide plates showed very good antimicrobial efficacy against S . aureus . In the area of textile coatings , AGXX particles were incorporated into polyurethane ( PUR ) -based systems , washed several times and then tested for antimicrobial efficacy ( in accordance with ISO 22196 ). All AGXX-containing samples have shown a very good antimicrobial efficacy against S . aureus ( germ reduction > 99.9 %) ( Figure 5 ). Moreover , the incorporation of AGXX had no detrimental impact on the PUR-based system . To make AGXX technology suitable for filtration applications , AGXX particles based on activated carbon as carrier material have been developed . These can be easily incorporated into active carbon filters , for instance for use in air filtration such as car filters or indoor filters as well as in water filtration . AGXX in filter systems keeps the system free of pathogens and also makes a valuable contribution to consumer health , such as in carsharing vehicles , public buildings or drinking water filtration . The use of the particles is conceivable in all applications that have problems caused by microorganisms .

Conclusion

AGXX is a new long-lasting antimicrobial technology with a broad effect against bacteria ,

Figure 5 - Antimicrobial efficacy of AGXX in PUR

viruses , algae and fungi . It is based on a circular redox reaction initiated by the interaction of two precious metals generating ROS from water and oxygen further supported by a metal-induced microelectric field . It is not based on the release of metal ions or any harmful substances . Its antimicrobial efficacy has been shown in multiple microbiological tests including pathogens resistant to antibiotics , silver-based antimicrobials , or those prone to biofilm formation . Various AGXX product types have been developed for optimal application in polymers , textile , activated carbon and other materials . It can therefore be easily incorporated into various systems to protect them from microbial contamination . This extends the product lifetime , prevents corrosion and , most importantly , protects people by limiting the spread of harmful microorganisms . • * Also contributing to this article was Martin Danz

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