Background. Laboratory technique of analytical photocentrifugation (AC) is based on continuous in-situ measurement of spatial resolved light transmission through sample cell from top to bottom during centrifugation (STEP-Technology®). Different procedures were proposed for characterization of different properties of various sample types (usually, diluted or concentrated suspensions or emulsions).
AC was initially introduced for accelerated evaluation of colloidal stability, particle interaction, and particle size distribution based on particle or separation velocity [Lerche and Sobisch, J. Disp. Sci. Technol., 2011]. Later, different methods were proposed for characterizing concentrated dispersions, including determination of compressibility and permeability (pressure dependencies of particle volume fraction and specific cake resistance) from the measurements of centrifugal settling-consolidation rate and sediment height [Lerche and Sobisch, Powder Technol., 2007; Loginov et al., Sep. Purif. Technol., 2012; Lerche, Filtration, 2014], which may be optionally completed by with X-ray analysis of local sediment structure [Loginov et al., Sep. Purif. Technol., 2017]. It was further demonstrated that AC with special centrifugal filtration modules can be used for characterizing filter cakes obtained from small samples of concentrated aggregated suspensions [Loginov et al., Chem. Eng. Sci., 2014]. This presentation focusses on development on in situ characterization of membrane filtration via the AC (fouled membrane resistance, filtration mechanism, filter cake specific resistance and compressibility) [Loginov et al., FILTECH 2015]. New methods were proposed for the quantitative analysis of dead-end ultrafiltration of polymer solutions and nanoparticle suspensions [Loginov et al., J. Membr. Sci., 2017; J. Taiwan Inst. Chem. Eng., 2018]. Common features of these methods are the small sample volume, simultaneous analysis of many samples in one experiment, automated data measurement and analysis. This suggests that AC is a useful tool for high throughput characterization of colloids, their filtration properties and optimization of their physicochemical treatment.
Aim. The current contribution aims at latest developments of analytical photocentrifugation for high throughput characterization of ultrafiltration of colloidal samples. It summarizes two modes of centrifugal ultrafiltration (experimental protocol, model and method for data treatment) and demonstrates their application for characterization of colloids filterability and membranes fouling (on an example of protein solutions and polymer ultrafiltration membranes). The perspectives of centrifugal filtration method development for the case of centrifugal microfiltration will be discussed too.
Session: L10 - Short Oral + Poster Presentations
Day: 14 March 2018
Time: 14:45 - 16:45 h