1. Amy Dale
  2. http://www.igert.org/profiles/4221
  3. Graduate Student
  4. Presenter’s IGERT
  5. Carnegie Mellon University
  1. John Stegemeier
  2. http://www.igert.org/profiles/4772
  3. Graduate Student
  4. Presenter’s IGERT
  5. Carnegie Mellon University

Judges’ Queries and Presenter’s Replies

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Presentation Discussion
  • May 23, 2012 | 12:25 p.m.

    Nice work on an important topic.
    It would seem that the use of silver in textiles has probably the most environmental impact compared with other uses.
    Since silver is quite reactive (unlike other nobel metals) do the nanoparticles dissolve away into silver compounds so that the nanocharacter is not retained?

  • Icon for: Amy Dale

    Amy Dale

    Presenter
    May 23, 2012 | 01:34 p.m.

    Great question!
    It’s hard to know for certain if silver-imbued textiles are the biggest culprit, since we really do not have much data on nanosilver production. The PEN (Project on Emerging Nanotechnologies) database suggests textiles are a major player, but nanosilver is also found in cosmetics and is used for a wide range of antibacterial applications. The PEN database also appears to favor consumer products over other applications of nanomaterials, so the data set may not be entirely representative.
    It’s true that silver is soluble, and that nanosilver is especially so. However, in natural waters and sediments (and especially in sulfur-rich environments like sewage treatment plants), the silver ions released when nanosilver dissolves tend to undergo a precipitation reaction on the surface of the particle, creating a coat of silver sulfide. Silver sulfide is extremely insoluble in water and slows further dissolution of the particle considerably.
    The nanosilver therefore retains its particulate character rather than dissolving away (though over long time scales it will eventually dissolve away). However, the “nano” property of nanosilver that we exploit by shrinking it is its enhanced ability to dissolve (a result of increasing the specific surface area of the particle). In that sense, I would say nanosilver does not retain its nano character in the environment.

  • Icon for: Carol Johnson

    Carol Johnson

    Trainee
    May 24, 2012 | 11:54 a.m.

    Glad to see CEINT represented! :)

  • Further posting is closed as the competition has ended.