# In Situ and Partial In Situ Synthesis of Cellulose Magnetic/Maghemite Composites
## 3 Results
### Structural Characterization
#### 3.1.2 X-Ray Diffraction Analysis  
X-ray diffraction (XRD) analysis was used to accomplish a deeper structural characterization of the studied cellulose and ferromagnetic composites. Diffractograms for native cellulose and sonicated composites are depicted in Figure 2.  
The quantitative and qualitative data: lattice parameters (a, b, c [A], \(\alpha\), \(\beta\), \(\gamma\) [\({}^{\circ}\)]), lattice volume (V), WPPF weight fraction [\(\%\)], interplanar distance d [A], Miller planes hkl, and crystallinity index CrI are provided in Tables 3-6. The microcrystalline cellulose diffractogram presents a typical cellulosic pattern for cellulose I with five crystalline planes at about 14.8\({}^{\circ}\), 16.2\({}^{\circ}\), 20.3\({}^{\circ}\), 22.4\({}^{\circ}\), and 34.3\({}^{\circ}\) corresponding to (1-10), (110), (102), (200), and (004) crystallographic planes [8]. The peaks from 20 of 14.8, 22.4, and 34.3 degrees are prominent and can be easily observed in the cellulose spectrum. During the ultrasonication, the cellulose undergoes small changes in terms of the interplanar distances. Thus, for the crystallographic plane (1-10), d decreases from 5.96 A to 5.89 A (CM\({}_{0}\)) and 5.87 A (CM\({}_{15}\)), respectively; for (110), from 5.45 A to 5.39 A and 5.34 A; for (102), we see a very small increase from 4.35 A to 4.36 A and 4.37 A; for (200), a \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Phase** & **WPPF [\%]** & **a [Å]** & **b [Å]** & **c [Å]** & \(\alpha\) [\({}^{\circ}\)] & \(\beta\) [\({}^{\circ}\)] & \(\gamma\) [\({}^{\circ}\)] & **V [Å \({}^{\circ}\)]** \\ \hline Cellulose & 74.6 & 7.8 & 8 & 10.5 & 90 & 90 & 95.4 & 662.6 \\ Magnetite & 12.5 & 5.9 & 5.9 & 16.7 & 90 & 90.2 & 90 & 587.8 \\ Magnemite & 12.9 & 8.4 & 8.4 & 24.9 & 90 & 90 & 90 & 1791.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Lattice parameters for CM\({}_{15}\) composite. Figure 2: XRD patterns for pristine cellulose (C) and ferromagnetic composites (CM\({}_{0}\) and CM\({}_{15}\)). small decrease from 3.96 A to 3.94 A and 3.92 A; and for plane (004), from 2.6 A to 2.62 A and 2.19 A. All these movements are attributed to the ultrasonication process and do not fundamentally change the structure of the cellulose. It is evident from the WPPF weight fraction study that magnetite and maghemite are components of both cellulosic composites. With the exception of temperature, the coprecipitation synthesis of magnetite and maghemite is the same. For magnetite, temperatures above 90 degrees are required for the complete conversion of the iron salt. Maghemite can be synthesized at temperatures below 80 degrees. It also contains iron oxyhydroxides such as goethite, lepidocrocite, or akaganeite but at room temperature (20-25 \({}^{\circ}\)C) [5,8]. In contrast to partial in situ synthesis (CM\({}_{15}\)), where the temperature ultimately reaches 87 \({}^{\circ}\)C, in total, during situ synthesis (CM\({}_{0}\)), part of the energy of the ultrasonic waves is also absorbed by the cellulose, resulting in a maximum reaction medium temperature of 71 \({}^{\circ}\)C. Maghemite and magnetite are present in approximately equal amounts (12.5% and 12.9%) in the CM\({}_{15}\) composite. Another direct effect of this ultrasonic synthesis method is found \begin{table}
\begin{tabular}{c c} \hline
**Sample** & **Cr.I. \%** \\ \hline C & 73.22 \\ CM\({}_{0}\) & 36.47 \\ CM\({}_{15}\) & 38.32 \\ \hline \end{tabular}
\end{table} 
Table 6: Crystallinity index (CrI) for cellulose fibers in C, CM\({}_{0}\), and CM\({}_{15}\). \begin{table}
\begin{tabular}{c c c c} \hline \multirow{2}{*}{C} & 20 [Deg] & d [Å] & (hkl) \\ \cline{2-4}  & 14.8 & 5.96 & (1–10) \\  & 16.2 & 5.45 & (11  
in the degradation of the crystalline structure of the cellulose. The crystallinity index CrI dropped from 73% to 36% and 38%, respectively, for the two composites. This phenomenon was in agreement with other studies [9]. In accordance with the data obtained by X-ray diffraction, we propose the following reaction schemes for the two syntheses.