Characterization of pSi particles

pSiO₂ particles were suspended in EtOH. One drop of the suspension was poured on a glass microscope slide and the solvent was allowed to evaporate. The particles were imaged on a bright field microscope mounted with an ×5 lens. Four randomly chosen independent fields of view (a total of at least 200 particles) were imaged for each sample and the images were then processed using ImageJ (Schneider et al., 2012). Each individual particle was manually delimited and the size of each zone was calculated against a reference given by a standard stage micrometer (100 × 0.01 = 1 mm) imaged under the same conditions. All data from each sample were then imported to Excel and a statistical evaluation of the average size and standard deviation were automatically calculated. Scanning electron microscope (SEM) images were obtained by using Phillips XL30 field emission electron microscope to reveal the pore structure on the surface of the particle. Nitrogen adsorption/desorption experiments were run on a Micromeritics Asap 2020. The specific surface area, pore size diameter, and total pore volume parameters were calculated from nitrogen adsorption/desorption isotherms of particles with the application of the Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods.