These benefits are derived from the enhanced reactivity, surface area, and subsurface transport characteristics of nanomaterials.
The use of nanotechnology in effluent, water, and soil clean-up applications largely makes use of the enhanced reactivity, surface area, and/or enhanced mobility of nanoparticles.
For example, evidence suggests that the ultrafine fraction of these particles shows more toxicity at equal mass concentrations compared to larger particles, because of their increased reactivity, surface area, and particle number on a mass basis.
Reactivity heterogeneity is expressed in terms of distributions of flux over cumulative time of exposure of the solution to reactive surface area, termed here 'cumulative reactivity'.
The intrinsic chemical reactivity of the char surface is assessed by the reactive surface area (RSA).
Industrial scale methods have been developed to produce silica particles of specific size, reactivity and surface area.
The lesser reactivity and surface area of goethite compared to 2-line ferrihydrite is the most likely reason for the observed disparity in sorption maximum.
Our data demonstrate that among various carbonaceous UFPs of different chemical composition and surface reactivity, BET surface area is most valid in characterizing the efficient particle exposure dose for the lungs.
Because ENMs behave as particles, their size, shape, agglomeration state, surface chemistry, reactivity, and surface area, along with the number of particles, are all important parameters of ENM dose and are therefore factors in determining the ENM dose response relationship.
The unique properties stemming from their small dimensions, such as high reactivity, large surface area, and the tunable nature of their optical, electrical, and magnetic properties, differentiate them from other materials in fundamental ways.
Finally, ENMs can behave both as particles or waves and as chemicals; therefore, exposure assessment poses unique challenges, with measures of dose for ENMs including size, shape, number of particles, agglomeration state, surface chemistry, reactivity, and surface area, in addition to traditional particle exposure metrics such as mass and concentration.
