Particle Characterization

Though most ThFFF samples are polymers, the ability of ThFFF to retain and separate both submicron and micron size particles (latex and silica) suspended in various organic carrier liquids has also been demonstrated by Shiundu, Lee and Giddings. In their article, the dependence of particle retention on various factors (solvent properties, amount of added electrolyte, particle size and composition, and cold-wall temperature) is evaluated and discussed.

Thermophoretic mobilities of several latexsolvent combinations have been obtained from the ThFFF retention data. The studies were carried out in polar organic solvents, cyclohexane and aqueous carriers. As a rule, the thermophoretic mobilities of particles range from 10 ~8 to 10 ~ 7 cm2/s• K, while the particle size ranges from about 0.04 to about 1 micron.

The retention of colloidal particles in ThFFF demonstrates a strong dependence on the chemical composition of the particles or their surfaces. These results are observed among both similar particles (such as latex particles) and different particles (including latex particles, and inorganic and metallic colloids). These compositional effects are observed for particles suspended in both aqueous and non-aqueous carrier liquids. Also, metal particles (e.g. palladium) are less retained than silica particles, with latex particles most retained. The resolution of particles of equal size in ThFFF experiments is also demonstrated. Surface compositional effects were also demonstrated in this study. These effects confirm the possibility of colloid particle surface analysis by thermal FFF.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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