Title page for ETD etd-11082011-133800


Type of Document Master's Thesis
Author Kent, Ronald Douglas
URN etd-11082011-133800
Title Controlled Evaluation of Silver Nanoparticle Dissolution Using Atomic Force Microscopy
Degree Master of Science
Department Civil Engineering
Advisory Committee
Advisor Name Title
Vikesland, Peter J. Committee Chair
Dietrich, Andrea M. Committee Member
Marr, Linsey C. Committee Member
Keywords
  • chloride
  • atomic force microscopy
  • Nanomaterials
  • silver nanoparticles
  • oxidation
  • dissolution
  • nanosphere lithography
  • convective self-assembly
Date of Defense 2011-11-08
Availability unrestricted
Abstract
Incorporation of silver nanoparticles (AgNPs) into an increasing number of consumer products has led to concern over the potential ecological impacts of their unintended release to the environment. Dissolution is an important environmental transformation that affects the form and concentration of AgNPs in natural waters; however, studies on AgNP dissolution kinetics are complicated by nanoparticle aggregation. Herein, nanosphere lithography (NSL) was used to fabricate uniform arrays of AgNPs immobilized on glass substrates. Nanoparticle immobilization enabled controlled evaluation of AgNP dissolution in an air-saturated phosphate buffer (pH 7, 25 °C) under variable NaCl concentrations in the absence of aggregation. Atomic force microscopy (AFM) was used to monitor changes in particle morphology and dissolution. Over the first day of exposure to ≥10 mM NaCl, the in-plane AgNP shape changed from triangular to circular, the sidewalls steepened, and the height increased by 6-12 nm. Subsequently, particle height and in-plane radius decreased at a constant rate over a 2-week period. Dissolution rates varied linearly from 0.4 to 2.2 nm/d over the 10-550 mM NaCl concentration range tested. NaCl-catalyzed dissolution of AgNPs may play an important role in AgNP fate in saline waters and biological media. This study demonstrates the utility of NSL and AFM for the direct investigation of un-aggregated AgNP dissolution.
Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Kent_RD_T_2011.pdf 1.06 Mb 00:04:53 00:02:31 00:02:12 00:01:06 00:00:05

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.