Structural discrimination of nanosilica particles and mixed-structure silica by multivariate analysis applied to SAXS profiles in combination with FT-IR spectroscopy

摘要: The structural characteristics of silica nanoparticles with functional properties can be investigated using Fourier transform infrared (FT-IR) and small-angle X-ray scattering (SAXS) techniques. Herein, principal component analysis (PCA) hierarchical cluster (HCA) were used to analyze the variance detect similarities between spectroscopic data. To its potentiality, nanosilica mixed-structure samples synthesized by a sol–gel process several reagents, such as SiCl4, octadecylamine, Pluronic®L-31, Tween®80, modify surfaces nanoparticles. Additionally, quantities these reagents in synthesis different particle types studied at distinct levels. A total 168 measurements (IR spectra scatterings) performed 28 samples. FT-IR/SAXS/multivariate results suggest that separated into two major groups associated incorporation organic network organizational structures aggregates low-q region, which surface fractals (3.0 < PL 3.8, class I) from mass (1.7 2.8, classes II III). It was determined only components carried over 96.5 89.7% (FT-IR SAXS, respectively) within sample set. hybrid silicas created more compact denser silicas, increased aggregate radii, decreased DpBJH SBET, shifted halo toward higher 2θ angles due changes densities silicas. We demonstrate FT-IR SAXS techniques combined multivariate simplify interpretation mesoporous materials.