One of the issues with adding silver nanoparticles to textiles is that they wash off and eventually enter our water supply. According to a Dec. 14. 2015 news item on Nanotechnology Now, Iranian scientists has devised a technique for affixing silver nanoparticles,

Iranian researchers produced laboratorial samples of antibacterial woolen fabrics by using nanoparticles which are able to preserve their properties even after five times of washing.

A Dec. 12, 2015 Iran Nanotechnology Initiative Council (INIC) press release, which originated the news item, provides more detail,

Nanoparticles used in the production of fabrics have been produced through a cost-effective method and by using environmentally-friendly materials.

The aim of the research was to obtain an eco-friendly method for the production and application of silver nanoparticles in carpet weaving industry to create antibacterial properties in the final product. The interesting point in this research is the application of pomegranate skin as the reducer in the process to produce nanoparticles.

Results showed that pigment extracted from pomegranate skin is able to be used in the production of silver nanoparticles. Therefore, this method decreases the application of chemical reducers in the synthesis of these nanoparticles, and it also decreases the environmental pollution. In addition, the synthesized nanoparticles preserve their antibacterial properties after being loaded on woolen fiber samples. Therefore, carpets woven by these fibers have antibacterial properties and no bacteria will grow on them.

After carrying out complementary tests and producing the fabrics and fibers at a large scale, the products can be used in carpet weaving industries and also in production of medical devices.

Based on the results, fabrics completed with silver nanoparticles synthesized at low ratio of pigment have antibacterial properties and they do not affect the color of samples. Fabric samples also conserve their antibacterial properties even after five times of washing. The decrease in pH value and increase in temperature improves exhaustion of silver nanoparticles on the wool.

Here’s a link to and a citation for the paper,

Novel method for synthesis of silver nanoparticles and their application on wool by Majid Nasiri Boroumand, Majid Montazer, Frank Simon, Jolanta Liesiene, Zoran Šaponjic, Victoria Dutschk. Applied Surface Science Volume 346, 15 August 2015, Pages 477–483 doi:10.1016/j.apsusc.2015.04.047

This paper is behind a paywall.