My Account: Log In | Join | Renew
Search
Author
Title
Vol.
Issue
Year
1st Page

Abstract

 

This article in SSSAJ

  1. Vol. 75 No. 2, p. 533-541
     
    Received: Feb 25, 2010
    Published: Mar, 2011


    * Corresponding author(s): mkwang@ntu.edu.tw
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2136/sssaj2010.0098

Structural Transformation and Physicochemical Properties of Environmental Nanoparticles by Comparison of Various Particle-Size Fractions

  1. Tsung Ming Tsaoa,
  2. Yue Ming Chena,
  3. Ming Kuang Wang *a and
  4. Pan Ming Huangb
  1. a Dep. of Agricultural Chemistry National Taiwan Univ. Taipei, 10617, Taiwan
    b Dep. of Soil Science Univ. of Saskatchewan SK S7N 5A8, Canada

Abstract

Information on the nature, physicochemical properties, and environmental fate of nanoparticles is severely lacking. Zeolite A was used to demonstrate its structural transformation from well crystalline to short-range-ordered (SRO) particles, including nanoparticles with size fractions in the range of 450 to 2000, 100 to 450, 25 to 100, and 1 to 25 nm. The chemical properties of a zeolite are dependent on its framework structure, which is formed by connecting truncated octahedra (sodalite) through the simple double four rings (D4-R) with external linkage in each sodalite. With decreasing particle size, the T(Si, Al)-O asymmetric and symmetric stretching vibrations shifted toward higher frequencies and the Si to Al molar ratio increased consistently from 1.8 to 5.2. The chemical shift of 27Al and 29Si magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectra was related to its structural transformation from well crystalline to SRO particles, which was attributed to the loss of external linkage D4-R units in the structure. Comparing the various particle-size fractions (PSFs) showed significant differences in surface area, Si/Al molar ratio, morphology, crystallinity, framework structure, and surface atomic structure of nanoparticles from those of the bulk sample (i.e.,<2000 nm) before particle-size fractionations. Formation of these most reactive nanoparticles were caused by physicochemical weathering merits increasing attention with reference to their nature and properties, and their importance in ecosystem integrity.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2011. Soil Science SocietySoil Science Society of America