Study of the interactions between carboxymethylcellulose and ethylenediamine for synthesis of nanoparticles

In Brazil, there are areas where drinking water is scarce, mainly in the semi-arid region, where the mean annual precipitation is low (<500 mm/year). One alternative for obtaining drinking water is through the groundwater, however, contaminations or high salt content prevent its use for human consumption and farming activities. An alternative for the removal of these solutes is through nanoparticles and ionic interaction. Thus, this work reports the preparation of a new nanoparticle system, from carboxymethylcellulose (CMC) and ethylenediamine (EDA), aiming the interaction and removing of soluble ions. The synthesis was performed from 50.0 cm3 of CMC (5.0 mg cm-3) with 3.5 cm3 of EDA in acid and neutral media. The ionic interaction was accompanied by turbidity variation (UV-Visible spectroscopy), during ethanol addition. The precipitated was characterized by FTIR spectroscopy. Effective interaction between CMC and EDA was observed. In neutral medium, the CMC-EDA interaction occurred upon addition of 0.5 cm3 of ethanol with high turbidity and precipitated at 1.0 cm3 of ethanol. For pure CMC (control), the turbidity did not vary, forming only a clear gel that become denser at 6.0 cm3 of ethanol (Figure 1a). In acid media, the precipitation was faster, forming a high turbidity suspension (Figure 1b). The characterization by FTIR showed that interaction between CMC and EDA occurred, mainly in the acid medium, where it was possible to identify in the precipitate, NH bands due stretching (3200 cm-1) and angular deformation (1601 cm-1), characteristics of EDA.