Dear Reader,

An impressive number of people viewed the messages posted in this forum over the past year as indicated by the viewer count that is displayed for each discussion thread. In fact, the counter for this thread incremented by one when you opened it. Now that you’re here in the Particle Characterization & Analysis forum, why not post a message? I’m sure that you can think of something you want to share with the other readers—a question you may have or an observation that may help others. Start a new subject thread, or join an on-going discussion. Together, we can make this forum a valuable resource for information about particle characterization.

Best wishes for a successful 2003,

Paul Webb, Moderator


Which is the most efficient method of degassing a sample prior to BET surface area determination-- heat + vacuum or heat + flowing inert gas? Share your opinion by joining the 'Surface characterization by gas sorption' discussion thread.

Bulk density, tap density, envelope density, apparent density, skeletal density, true density, absolute density, theoretical density-- open the 'Density (volume) determinations' discussion thread and tell us what you think are the best analytical techniques for determining these?

Do you think the unique capabilities of mercury porosimetry outweigh the risks associated with the handling of mercury and the environmental impact of its disposal? If so or if not, let’s get your opinion.

Particle sizing by laser light scattering, sedimentation, electrozone sensing, sieving, microscopy, and various other methods each have applications in which they perform better than the other choices. How does one know which is best for their application?

Why do so many labs still depend on BET surface area determinations when the shortcomings of this model are well known?

What is the minimum pore size for which the Kelvin equation should be applied? Why?

What is the maximum pore size that should be analyzed by gas adsorption? Why?

What are some of the effects that limit the pore size range of mercury porosimetry?

What are the limitations of using Mie theory (in low angle light scattering technique) for particle sizing?

What does ‘particle diameter’ mean if the particles are of irregular geometry?

Is the application of density functional theory (DFT) to surface characterization just another way of getting the same results, or does it really provide new insights to surface features?

What are the 5 most important features or characteristics of an analytical instrument?