On the other hand, the FTIR spectra of composites CP1 and CP2, Figure 1, clearly shows that the band in 1741 cm−1 is only present in CP2, the composite of equal proportions of cellulose and silica, indicating that the organic matrix is segregating it and it is accepting no more than 43 wt % of NSi to disperse homogeneously into the fibers of the composite CP1. Such behavior is also observed in Figure 2, showing the scale only from 1800–750 cm−1 for zooming the weakest bands, where the spectrum of CP4 shows the same band of 1741 cm−1, meaning that the surface modification of pure cellulose to get AG20 is not affecting the fibers capacity to receive and disperse higher amounts of inorganic particles from 43 to 50 wt %.