On-line sizing of colloidal

On-line Sizing of Colloidal Nanoparticles via Electrospray and Aerosol Techniques... 

In conclusion, although there is plenty of room for improvements in the measurement technique proposed, it does clearly offer promise for on-line sizing of colloidal nanoparticles. 

DE JUAN DE LA MORA On-line Sizing of Colloidal Nanopartides... 

Aerosol techniques on-line sizing of colloidal nanoparticles, 20-40 ultrafine powder synthesis, 64 Ag particles, synthesis method, 128 Aluminum nitride powder prepared via chemical synthesis, characterization using Fourier-transform IR spectroscopy, 312-332... 

Hassellov, M., Lyven, V., Haraldsson, C., and Sirinawin, W. (1999) determination of continuous size and trace element distribution of colloidal material in natural water by on-line coupling of flow field fractionation with ICPMS. Anal. Chem.. 71, 3497-3502. 

Contado et al. [4] coupled sedimentation FFF indirectly to GF-AAS as well as directly to ICP-MS to produce element composition data across the size distribution. The high levels of Cu, Pb, Cr, and Cd found were associated with colloidal particles taken from a river situated in a highly industrialized site. The two methods give comparable results, with on-line coupling of ICP-MS having a higher resolution, but ICP-AES yields data for some elements (such as potassium and calcium) where ICP-MS produces interferences. 

Nguyen, S. H. and Berek, D., Adsorption and desorption of macromolecules on solid surfaces studied by on-line size exclusion chromatography 2. Preferential adsorption and exchange processes. Colloid Polym. Sci., TITl, 1179,... 

R. Brill has carried out a series of experiments which indicate very clearly the influence of particle size on the sharpness of the Debye-Scherrer lines for iron powder. There is quite a powerful effect, the evaluation of which would be very profitable. Scherrer has already established in the work previously mentioned that the particle sizes of colloidal gold calculated by the use of his formula agree very satisfactorily with those obtained by the Zsigmondy method of direct counting. Later, Brill compared the different relations available for the computation with one another and obtained the data contained in Table 72. This includes a comparison of the relation originally given by Scherrer with the Laue formula modified by Brill and Pelzer. Various preparations of very fine-grained iron, which are of importance in the technique of catalysis in the ammonia process, served as material. 

Model simulations of particle volume concentrations in the summer as functions of the particle production flux in the epilimnion of Lake Zurich, adapted from Weilenmann, O Melia and Stumm (1989). Predictions are made for the epilimnion (A) and the hypolimnion (B). Simulations are made for input particle size distributions ranging from 0.3 to 30 pm described by a power law with an exponent of p. For p = 3, the particle size distribution of inputs peaks at the largest size, i.e., 30 pm. For p = 4, an equal mass or volume input of particles is in every logaritmic size interval. Two particle or aggregate densities (pp) are considered, and a colloidal stability factor (a) of 0.1 us used. The broken line in (A) denotes predicted particle concentrations in the epilimnion when particles are removed from the lake only in the river outflow. Shaded areas show input fluxes based on the collections of total suspendet solids in sediment traps and the composition of the collected solids. 

Our water-column sampling techniques include in-line filtration using an all-Teflon sampling device with quartz fiber filters (0.7- xm nominal size cutoff) to differentiate between dissolved and particulate phases (21). Particulate concentrations (nanograms per gram) and subsequent calculations of partitioning between particle and aqueous phases (log KD) are based on this particle size division. This fractionation scheme precludes direct estimates of colloidal influences on Hg transport. 

Beckett described inductively coupled plasma mass spectrometry (ICP-MS) as an off-line detector for FFF which could be applied to collected fractions [ 149]. This detector is so sensitive that even trace elements can be detected making it very useful for the analysis of environmental samples where the particle size distribution can be determined together with the amount of different ele-ments/pollutants, etc. in the various fractions. In case of copolymers, ICP-MS detection coupled to Th-FFF was suggested to yield the ratio of the different monomers as a function of the molar mass. In several works, the ICP-MS detector was coupled on-line to FFF [150,151]. This on-line coupling proved very useful for detecting changes in the chemical composition of mixtures, in the described case of the clay minerals kaolinite and illite as natural suspended colloidal matter. 

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