Investigations on fabrics coated with precious metals using the magnetron sputter technique with regard to their anti-microbial properties

Fungal and bacterial infestation can cause material damage to fabrics, damage that becomes visible through discoloration and stains. Some fungi and bacteria are pathogenic. Anti-microbially active coatings might be a possible protection against an infestation of the fabrics. In the investigation here presented, which was conducted on laboratory scale, fabrics consisting of SiO2 fibres were coated with precious metal PVD layers using the magnetron sputtering technique. Layers of silver, copper, platinum, platinum/rhodium and gold were characterized according to their bonding strength and anti-microbial effectiveness. Bonding strengths were measured by peel tests; microbial effectiveness was tested by fouling experiments in line with appropriate standardizations (DIN 53 931 and AATCC 147-1998). It was found that copper was most effective against bacteria and fungi. Silver was also effective against bacteria, but against fungi its effectiveness proved to be limited. The other tested metals did not achieve this effectiveness. The bonding strength between the coatings and the substrates were sufficient due to a plasma treatment.