This is a repository copy of A review of current techniques for the evaluation of powder mixing.

Graphical abstract2 ABSTRACT A novel one-pot method was developed in this work to synthesize and disperse nanoparticles in a binary base fluid. As an example, stable magnetite iron oxide (Fe3O4) dispersions, i.e., nanofluids, were produced in a high ionic media of binary lithium bromide-water using a microemulsion-mediated method. The effects of temperature and precursor concentration on morphology and size distribution of produced nanoparticles were evaluated. An effective steric repulsion force was provided by the surface functionalization of nanoparticles during the phase transfer, supported by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The formed nanoparticles exhibited a superior stability against agglomeration in the presence of high concentrations of lithium bromide, i.e., from 20 to 50 wt.%, which make them good candidates for a range of novel applications.

Conducting a numerical simulation for cohesive granular mixtures that is well comparable with experiments has always been a challenge. In this study, a systematic methodology is proposed for increasing the fidelity of Discrete Element Method (DEM) simulations of cohesive powder mixtures. Segregation of granules during heap formation of a ternary powder mixture is simulated as a proof of concept. The mixture contains three model particles, one of which is an enzyme placebo granule (EP), in order to simulate the segregation of the actual enzyme granules used in detergent formulations. These granules are at a low content level (wt) and are highly prone to segregation. In this study the segregation tendency of the EP granules is mitigated by coating them with Polyethylene Glycol 400 (PEG 400). The resulting adhesion is expressed in terms of equivalent interfacial energy for the DEM numerical simulations, and is tuned by careful calibration using the concept of the angle of repose. The Cohesion number is used to scale material stiffness or changing the particle size for faster simulation. The particles shapes in DEM are modelled as clumped spheres based on the X-ray tomograms of the real particles. The rest of the DEM input parameters are also selected and tuned based on the particles physical and mechanical properties. Considerable reduction in segregation tendency of the low level ingredient granules is observed as a result of coating its surfaces by PEG400. Following the proposed calibration strategy, the DEM simulations have predicted the experimental trends closely and a reasonable agreement is achieved. It is observed that using the Cohesion number for scaling the interfacial energy can significantly reduce the number of calibration trials.

This is a repository copy of Synthesis of stable nanoparticles at harsh environment using the synergistic effect of surfactants blend.

Segregation in particulate systems may be caused by particle size, density and shape distributions leading to negative effects on product quality as well as the production costs. Quantifying powder segregation using a reliable and robust method is challenging, particularly for low content level ingredients. In this paper, we evaluate the application of NIR spectral analysis for detecting the extent of segregation of components in a multi-component mixture. As a model system, a typical laundry detergent formulation, comprising spray-dried powder, known as Blown Powder (BP), Tetraacetylethylenediamine (TAED) and enzyme placebo granules, is used. The effect of using different pre-processing methods on the measured component fractions is analysed. These are scatter correction using Standard Normal Variate (SNV) as well as derivative correction using first, second, Norris-Williams and Savitzky-Golay derivatives. The results from the NIR technique are compared to those obtained by image analysis. Concepts of Mean Absolute Error (MAE) and Mean Absolute Percentage Error (MAPE) are used to evaluate the accuracy of different preprocessing methods. The second derivative of Norris-Williams method shows the best pre-processing method for the quantification of low content level enzyme placebo granules in the ternary mixture of detergent powder. Using the proposed NIR technique and the optimum pre-processing method, the segregation index of a low content level ingredient, such as enzyme placebo granules, is estimated to be 0.71 for a ternary heap of washing powders.

This is a repository copy of Experimental evaluation of the effect of particle properties on the segregation of ternary powder mixtures.

ReuseThis article is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) licence. This licence only allows you to download this work and share it with others as long as you credit the authors, but you can't change the article in any way or use it commercially. More information and the full terms of the licence here: https://creativecommons.org/licenses/ TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. AbstractThe Stablity and photo-thermal conversion characteristics of a novel binary iron oxide nanofluid (including 50 wt% lithium bromide and 50wt% water) were investigated in this work. The stability of the binary nanofluid against agglomeration and sedimentation was analyzed by a centrifuge analyzer and transmission and electron microscopy (TEM), and the effects of iron oxide nanoparticle concentration and morphology on photo thermal conversion efficiency of nanofluid using a solar simulator were studied. Highly stable nanofluids were formulated.Experimental results indicated that the use of binary nanofluid could significantly increase light trapping efficiency to increase the bulk temperature, and in the same time, increase the evaporation rate due to surface localized heat generation. Possessing both high stability and excellent photothermal conversion rate, iron oxide nanoparitlce is is suggested as a good candidate for using in solar absorption refrigeration systems.

Self-assembly of individual units into multicomponent complexes is a powerful approach for the generation of functional superstructures. We present the coordinative interaction of oligohistidine-tags (His-tags) with metalorganic framework nanoparticles (MOF NPs). By this novel concept, different molecular units can be anchored on the outer surface of MOF NPs in a self-assembly process generating multifunctional nanosystems. The article focuses on two main objectives: first, the detailed investigation of the assembly process and fundamental establishment of the novel functionalization concept; and second, its subsequent use for the development of biomacromolecule (e.g. peptides and proteins) delivery vehicles. Three exemplary MOF structures, MIL-88A, HKUST-1 and Zr-fum, based on different metal components, were selected for the external binding of various His-tagged synthetic peptides and recombinant or chemically H 6-modified proteins. Evidence for simultaneous assembly of different functional units with Zr-fum MOF NPs as well as their successful transport into living cells illustrate the promising potential of the self-assembly approach for the generation of multifunctional NPs and future biological applications. Taking the high number of possible MOF NPs and different functional units into account, the reported functionalization approach opens great flexibility for the targeted synthesis of multifunctional NPs for specific purposes. ASSOCIATED CONTENT Supporting Information. Additional Materials and Methods, synthesis and analysis of peptides and His-tagged functional units, characterization of MOF NPs, Supplementary Figures. This material is available free of charge via the Internet at http://pubs.acs.org.