Initiated by a discussion about 2-D or eventually better 3-D image analysis for particle description I decided to post a copy of a course I gave on that theme to show the complexity of this question. Please have a look at the detailed presentation.
By its cross correlation method (PCCS) NANOPHOX is able to eliminate scattering information that is not due to Brownian motion as e.g. multiple scatter, cuvette surface inhomogeneity etc.. This results in the best possible raw data for evaluation.
In NANOPHOX the user has the choice between 2nd Cumulant, auto-NNLS
(an operator independent evaluation mode for validation tasks) and the expert-NNLS mode (with guided manual fit range seting).
This is a translated excert of a chapter from famous Prof. Leschonski’s “Clausthaler Kurs” describing the necessity of large numbers of particles to count for accurate sizing.
The fear of new unknown technologies is as old as progress itself and often leads to irrational suggestions for coping with it as shown in this image of protection against railway accidents from 1847. read more about it in detail: Reasonal risk evaluation needs deeper insight.
An impressive and coherent course about risk evaluation. (Also applicable to nano particle risk evaluation!)
Just recently Toni Harrison on LinkedIn pointed to a very helpfull video regarding risk evaluation done by Peter Sandman.
This explains in a coherent way why nano danger pubications gain so much publicity, but also how they gain influence and what they mean whith respect to real danger.
This clip is a brief excerpt (9:37) from a two-day seminar I gave in 2010 for the Rio Tinto mining company. The excerpt explains my signature formula, “Risk = Hazard + Outrage” — which aims to capture the crucial truth that people focus more on how upsetting a risk is than on how dangerous it is.
A much longer clip explaining the ramifications of this formula is available on Vimeo at http://vimeo.com/18611416. I’m posting this excerpt on YouTube almost as an advertisement. I’d really rather people watched the longer version.
Links to all my clips from this Rio Tinto training (as well as other audio and video resources) can be found on my website at http://www.psandman.com/media.htm. The Rio Tinto clips add up to a free online course on my approach to risk communication and especially to low-hazard high-outrage risk communication, which I call “outrage management.” –Peter Sandman
This is a list of the actually links regarding NANO in the web,
state of oct. 2011 .
Open the list view
An attempt to screen the actual available particle sizing methods and instruments.
The most complete compendium for nano behavior I could find is:
“Intermolecular and surface forces“ by Jacob N. Israelachvili
issued by Academic Press
This forms a reasonable scientific basis for all discussions on nano particles, their properties, interactions and enables deep insight into fundaments.
Just for some days there is an interesting discussion going on to: Nano particle counting
You only get what you pay for! Are low budget instruments worth what you pay for it?
“Nano” is one of the most attractive and modern terms in research, industry and marketing.
Due to the excellent definition work of the ISO committee TC229 since August 2008 there is a precise determination what “Nano” really means (ISO/TS27687). Also development in this field, as well as increasing knowledge is growing daily at an accelerating speed. Continue reading
According to the valid definitions in ISO/TS 27687: August 2008 and the standardl particle definitions in accordance with ISO TC 24/SC 4, TC 146 and TC 209 there is a clear definition of nano particles respectively nano objects. Only for these nano objects, where one, two or three external dimensions are in the nanometer range below 100nm, the term nano particles should be used.
All coarser particles are submicron particles and should not be called nano particles anymore. The same is valid for so called nano structured material, which is aggregated from nano objects. Continue reading
In relation with production and stabilization of Nano-objects there is very often the talk about observing/ setting the right Zeta-potential. Also a lot of actual analytical instruments promote Zeta-potential determination together with e.g. size determination.
NANO is an in many cases even in technical literature incorrectly used term. The Technical Committee 229 of ISO is deserving thanks for an exact definition with respect to particle size measurement in August 2008. (ISO/TS27687).
According to this definition only NANO-objects should be called NANO-particles if its three coordinate dimensions are all within the NANO-range of about 1 nm to 100 nm.
Regrettably even today many scientific publications still use the NANO-term in very imprecise manners. One reason for this might be the difficulty to measure NANO-Particles sufficiently precise. Imprecise knowledge of dimensions often leads to inaccurate classification. Continue reading