In the context of assessing the potential risks of nanomaterials, a lifecycle approach (covering production, use and disposal of the nanomaterial or nano-product) represents a holistic view of their potential impacts. Considering nanomaterial life cycles are determined by application within a product, relevant exposure scenarios and particle aging/transformations are strongly dependent on the life-cycle of nano-enhanced products themselves. For example, nanomaterials embedded in textiles would transform after exposure to oxidants and detergents during washing. Building on previous results which demonstrated the quantity and general size fractions of various silver additives released from textiles, we further characterized specific nanoparticle properties in the laundry wash cycle. Using a number of different liquid and powdered commercial detergents, simulated washing studies were preformed on nanoparticles suspended in wash solution and released from laboratory prepared textiles with known nanoparticulate additives to better understand particle release, (change to) particle size distribution, dissolution, re-precipitation (i.e. « new » particle formation) and complexation of manufactured nanomaterials to particulate matter in the washing solutions, such as zeolite. Ag NPs were studied for their relevance to the textile industry alongside Ag+ (added as AgNO3) which served as a baseline for any particle re-precipitation or Ag+ adhering to the particulate matter in the wash solution. Au NPs were used as a « tracer » through the system, since it is less reactive or prone to dissolution, to ensure analytical characterization techniques did not distort particle size or number concentrations throughout the tests. TEM and EDX analysis were performed to observe morphological and chemical changes to the particles after washing. Single particle ICP-MS (spICP-MS), capable of analyzing the size of individual particles in the ng/L concentration range, was used to build a size distribution of particles in solution and detect complexation with larger floc material in the washing solution. These studies help to further the understanding of nanomaterials through the product life cycle and give a better indication of how nanomaterials will be aged and transformed over time during regular nano-enhanced product use.

Tracking nanomaterials through the laundry wash cycle: Release, dissolution, and complexation

249th National Meeting (2015)

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