ISSN:
0934-0866
Keywords:
Chemistry
;
Industrial Chemistry and Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
It is generally recognized that fundamental limitations make data analysis for dynamic light scattering (DLS) not straightforward. In addition to experimental problems such as multiple scattering, number fluctuation and noise, there are intrinsic problems. Data analysis is a so-called reverse problem which, owing to the mathematical equations, becomes “allergic” to noise (an ill-posed inverted problem). In an attempt to overcome at least some of these limitations, a software solution was developed. This mainly aimed to implement a tool that makes it easy to evaluate physically plausible solutions, rather than to determine many (less accurate) parameters related to the size distribution. One of the major goals was to create a “white-box” program. The software is in essence an easy-to-use graphical interface between user and computer. The most important motivation to apply the concept of on-line simulation is the limited information content of DLS autocorrelation functions. In the present approach, the user, rather than the software, has to evaluate the physically plausible solutions and select the most appropriate one. The computer becomes a mirror that calculates but leaves the decision making to the user. Using this software environment, the resolving power of the technique in ideal and noisy conditions was investigated. Results were obtained for monomodal samples where the mean diameter seems to be far more reliable than the polydispersity. For bimodal samples, the convergence of the solution to a monomodal distribution was observed when the noise level increased. The goal is to put into perspective the results as obtained in most “black-box” software without having to use heavy mathematical approaches. One of the major applications is the use of the program as an interactive introductory tool to become acquainted with the power and, above all, with the limitations of DLS.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ppsc.19950120605
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