Comparative Test of Methods to Determine Particle Size and Particle Size Distribution in the Submicron Range

Abstract

Among the most important characteristic properties of disperse systems such as latices, pigments, ceramic materials or drug formulations are the particle size and the particle size distribution. To measure these quantities, several methods and measuring instruments based on different physical principles are available. These include turbidimetry, dynamic and static light scattering, electron microscopy with image analysis, ultra‐ and disc centrifugation, light diffraction and the electrical sensing zone method. All these measuring techniques are doubtless necessary because of the large product variety and the broad particle size range. However, some problems arise if different techniques are used and the results are compared uncritically without considering to the application range and the resolution of the methods. An extensive comparative test was therefore carried out using seven latices in the submicron range with defined monomodal, bimodal and hexamodal particle size distributions. The most important methods of determining average particle size values and particle size distributions were tested and compared. Of the methods to determine only average particle sizes, turbidimetry is the most efficient, followed by dynamic light scattering with cumulants evaluation. Static light scattering only yields accurate results for small particles with narrow particle size distributions. Of the methods to determine particle size distributions, ultracentrifugation and, somewhat less, disc centrifugation and electron microscopy with image analysis are the most efficient. Dynamic light scattering only yields reliable results in the case of small particles with narrow distribution curves. Light diffraction and the electrical sensing zone method are less suitable for the submicron range.

Porous HA/Alumina composites intended for bone-tissue engineering

“…Large-sized particles started to agglomerate and the sediment corresponded with lower turbidity values, whereas the yield of the reaction was unchanged. 8,24 The high level of agglomeration was confirmed with a morphology analysis and laser-diffraction measurements (Figure 2). The phase purity and crystallinity of the prepared powders are given in Figure 3.…”

Particle Characterization Using Multiple Scattering Decorrelation Methods. Part 1: Standard Latex Particles

“…In what follows we shall review known sources of deviation from thè`t rue'' particle radius for the methods utilized in this contribution. Let us start by noting that the absolute calibration of a transmission electron microscope is uncertain to within 5% [5]. This is also the error given in Table 1 for this method.…”

“…This decorrelation of multiple scattering is applicable not only to colloidal suspensions of high concentration, but also to turbid media in general, for example liquid mixtures approaching a critical point. Recently, a survey of different methods to determine the particle size in dilute suspensions has been published [5]. In addition, a sophisticated single particle tracking experiment has been applied to yield particle size distributions [6].…”

Weighing nanoparticles in solution at the attogram scale

“…In all these cases, function is strongly correlated to particle size and concentration. Established methods for characterizing these particles such as electron microscopy, dynamic light scattering (DLS), and disk centrifugation can determine the size of particles down to the nanometer scale, but generally have limitations when it comes to heterogeneous samples, throughput, measuring concentration, or ease of use (6)(7)(8). Miniaturized resistive pulse sensors (9,10) can quantify size, heterogeneity, and concentration of particles bigger than about 50 nm, but require high salinity, which is an important consideration when characterizing biological nanoparticles, such as protein aggregates.…”