Fractal Studies on Titanium‐Silica Aerogels using SMARTer

Power‐law scattering approximation has been employed to reveal the fractal structures of solid‐state titanium‐silica aerogel samples. All small‐angle neutron scattering (SANS) measurements were performed using 36 meters SANS BATAN spectrometer (SMARTer) at the neutron scattering laboratory (NSL) in Serpong, Indonesia. The mass fractal dimension of titanium‐silica aerogels at low scattering vector q range increases from $−1.4$ to $−1.92$ with the decrease of acid concentrations during sol‐gel process. These results are attributed to the titanium‐silica aerogels that are growing to more polymeric and branched structures. At high scattering vector q range the Porod slope of $−3.9$ significantly down to $−2.24$ as the roughness of particle surfaces becomes higher. The cross over between these two regimes decreases from 0.4 to $0.16 nm−1$ with the increase of acid concentrations indicating also that the titanium‐silica aerogels are growing.