Size fractionation and characterization of naturalaquatic colloids and nanoparticles

Research output: Contribution to journalArticle

Abstract

Atomic force microscopy (AFM) was used to image and quantify natural nanoparticles (prefiltered <25 nm) from three different freshwater sites (Vale Lake, Bailey Brook and Tern Rivers). Four fractions were analysed by AFM; the prefiltered fraction (<25 nm) and three fractions collected after separation of this prefiltered sample by flow field-flow fractionation (FIFFF) which corresponds to material which has size ranges of <4.2 nm, 4.2-15.8 nm and 15.8-32.4 nm, as determined by FIFFF theory. The large majority of materials in all samples appeared as <3 nm nanoparticles, nearly spherical and rich in chromophores active at 254 rim, UV, which thus correspond to natural organic matter. However, nanoparticles were also imaged up to slightly more than 25 inn in size, indicating a slight disagreement in sizing between filtration and FIFFF. In addition, some particles in certain fractions were found to be covered with a thin film of less than 0.5-1.0 nm. Substantial differences between sites were observed. (c) 2007 Elsevier B.V. All rights reserved.

Details

Original languageEnglish
Pages (from-to)93-102
Number of pages10
JournalScience of the Total Environment
Volume386
Early online date17 Jul 2007
Publication statusPublished - 1 Nov 2007

Keywords

  • colloids, aquatic chemistry, atomic force microscopy, nanoparticles, field flow fractionation