| Abstract
| - Pristine fumed silica and powders with dried residuals of centrifuged aqueous suspensions of fumedsilica, silica/PVP, or silica/protein were studied using nitrogen adsorption and IR spectroscopy methods.The aqueous suspensions of silica with added polymers, surfactant, or ethanol were investigated by meansof photon correlation spectroscopy, 1H NMR, and adsorption methods. The impact of polymers on thesuspension and dried powder characteristics depends on the adsorption mechanism and the conformationof polymer molecules (globular or unfolded) due to strong or weak intramolecular interactions. Globularproteins interacting with silica through the flocculation mechanism affect the textural characteristics ofdried powders more weakly than do unfolded proteins but strongly impact the aqueous suspension, thusshifting the swarm size distribution toward larger sizes compared to the size distribution of poly(vinylpyrrolidone), PVP. PVP is adsorbed in the unfolded state and gives a nearly monomodal particle sizedistribution (PSD). The ionogenic surfactant 1,2-ethylene-bis(N-dimethyl carbodecyloxymethyl)ammoniumdichloride at CAet< 0.01 wt % and ethanol at CEtOH = 10−50 wt % impacts the silica's PSD-dependentnonlinearly on the concentrations and pH.
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