Quantifying the structure of very small (<25 nm) natural aquatic colloids
Lead Research Organisation:
University of Birmingham
Department Name: Sch of Geography, Earth & Env Sciences
Abstract
Natural aquatic colloids are defined as solid phase material between the sizes of 1 nm and 1 um (10^-9 / 10^-6 m) in size and are thus extremely small and finely divided with very large surface areas. They are ubiquitous in the aquatic (and terrestrial) environment and composed of different types of material such as organic (humic substances and polysaccharides), inorganic (metal oxides) and biological (viruses and bacteria) and these phases are mixed together in complex ways. We know that colloids chemically and physically bind trace pollutants such as metals and that these metals such as mercury, cadmium, nickel etc., may be toxic. In addition, we know that these colloids affect trace metal fate and behaviour and control metal transport and bioavailability. Further, it is known that the very small fraction (less than approximately 25 nm) is very important in metal binding under many environmental conditions and plays a defining role in bioavailability. Despite this knowledge which is primarily qualitative rather quantitative, there is a great deal that remains unknown in this area. In particular, our knowledge of 'nano-colloidal' (< ca 25 nm) structure is poor and improving our knowledge base here is essential to further understanding trace element chemistry, transport and bioavailability. This project aims to address some of these uncertainties by validating a methodology coupling flow field-flow fractionation (FlFFF) and atomic force microscopy (AFM) to quantify the shape of nanocolloids and their permeability (to solute and solvent molecules). Information about these structural measures can be contained within a simple ratio, usable in further modelling studies on speciation and bioavailability are essential to better fundamental understanding of the environmental 'function' of nanocolloids in trace element behaviour. The area of investigation is analogous to research over the last century into the structure-function relationships of biological macromolecules such as proteins and genetic material.
Organisations
People |
ORCID iD |
Jamie Lead (Principal Investigator) |
Publications
Lowry GV
(2012)
Transformations of nanomaterials in the environment.
in Environmental science & technology
Baalousha M
(2012)
Rationalizing nanomaterial sizes measured by atomic force microscopy, flow field-flow fractionation, and dynamic light scattering: sample preparation, polydispersity, and particle structure.
in Environmental science & technology
Tejamaya M
(2012)
Stability of citrate, PVP, and PEG coated silver nanoparticles in ecotoxicology media.
in Environmental science & technology
Baalousha M
(2014)
Quantitative measurement of the nanoparticle size and number concentration from liquid suspensions by atomic force microscopy.
in Environmental science. Processes & impacts
Baalousha M
(2012)
Characterization of cerium oxide nanoparticles-part 1: size measurements.
in Environmental toxicology and chemistry
Baalousha M
(2012)
Characterization of cerium oxide nanoparticles-part 2: nonsize measurements.
in Environmental toxicology and chemistry
Hartland A
(2014)
Preservation of NOM-metal complexes in a modern hyperalkaline stalagmite: Implications for speleothem trace element geochemistry
in Geochimica et Cosmochimica Acta
Baalousha M
(2011)
Flow field-flow fractionation for the analysis and characterization of natural colloids and manufactured nanoparticles in environmental systems: A critical review
in Journal of Chromatography A
Nur Y
(2015)
Evaluation of charge and agglomeration behavior of TiO2 nanoparticles in ecotoxicological media.
in The Science of the total environment
Baalousha M
(2013)
Effect of monovalent and divalent cations, anions and fulvic acid on aggregation of citrate-coated silver nanoparticles.
in The Science of the total environment
Baalousha M
(2015)
Transformations of citrate and Tween coated silver nanoparticles reacted with Na2S.
in The Science of the total environment