The Network Structure and Fractal Behavior of SiO₂-PEG Sols

PEG was added into TEOS-water-etahanol-ammounia sol system, which could change the particle growth and then tailor the fractal network of the SiO₂ sol. By means of SAXS, TEM and SDP, the effects of PEG on sol particie was discussed and the mechanism on sol particle growing was suggested in terms of sol-gel chemistry, and the fractal behaviors of SiO₂-PEG sol were proved to be present and the change of the fractal dimension was studied emphatically, the results showed that PEG additive limited particle growth but also accelerated particle agglomeration. It was found that the acton of PEG was similar to that of organic structure-directing agent and made the sol cluster cross-linked ring-like network in short order, and the model of the PEG behavior in the SiO₂ sol-gel process was described. The SiO₂-PEG sol-gel process was recognized quantitatively at a more essential level.