The preparation of protein doped silica particles is impeded by the difficulty of incorporating proteins within the silica mesostructure under conditions that do not lead to denaturation. Herein, the synthesis of spherical silica particles (diameter 150 nm-550 nm) under protein friendly conditions in a one step process is described. Diglyceroxysilane (DGS) was reacted in ethanol and methanol-free conditions in pure water or in buffer solutions with or without the presence of additional glycerol. Stabilization of the particles, consistent with steric stabilization, was obtained using poly(ethylene glycol) (PEG) of various molecular weights and with various end groups, including allyl and (CH 2 ) 3 Si(OEt) 3 groups, as a co-reagent. The particles can be prepared at ambient temperature and are reasonably monodisperse in size. At large molecular weights, all PEG led to stable, spherical particles. At lower molecular weights, hydrophobic end groups were necessary to prepare particles. The influence of different molecular weights of PEG, additives and reaction conditions on the size and porosity of particles are analyzed with SEM, TGA and nitrogen adsorption measurements. To demonstrate the biocompatibility of the processing conditions, horse radish peroxidase (HRP) was incorporated into the particles and was observed to remain active for more than 3 months.
Particle size distributions of polydisperse oil aerosols are determined by using single jet impactors together with a light scattering meter. The aerosol is drawn from a sampling probe through the jet impactor and then into the light scattering meter.The jet impactor removes particles larger than a certain size range, identified by the characteristic diameter of the impactor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.