Chemical Engineering Science, Vol.203, 113-121, 2019
Design of nanoscale structured composite particles through mechanical process for fabricating a powder layer with rapid drying properties
Nanoscale structured composite particles consisting of spherical porous SiO2 particles with nanoscaled surface roughness as the core particles and SiO2 nanoparticles as the depositing particles were designed using a high-shear mechanical composing process to develop a powder material that can form a layer with apparent rapid drying properties. The spherical porous SiO2 core particles and depositing nanoparticles were selected to enhance the water extension on the core particle surface and amongst the composite particles in the powder layer, respectively. The effects of the composite particle nanoparticle content on the morphology of the composite particles and their relationships with the water droplet extending and drying properties in the powder layer of the designed composite particles were systematically investigated based on FE-SEM observations, characterization of N-2 adsorption/desorption isotherms, and H-1 spin-spin relaxation rate measurements of composite particles. The FE-SEM observations show that the pulverized nanoparticles could be successfully attached to porous core particles without the core particles collapsing. The reduction of the specific surface area and increase of the particle specific external surface area after the compositing process strongly supported the fact of nanoparticle attachment. While a small amount of nanoparticle attachment decreased the water droplet extended area, wet area circularity, and apparent drying rate, 15 wt% loading of the pulverized nanoparticles resulted in a drastic increase of the water extended area, wet area circularity, and apparent drying rate. Keywords: Composite particle H-1 pulsed NMR Drying Microstructure Mechanical process (C) 2019 Elsevier Ltd. All rights reserved.