RESUMO
In this study, the effects of glucose concentration, temperature, and time parameters of the hydrothermal reaction on the growth of prickly-shaped carbonyl iron were studied by using an experimental design to obtain the maximum superhydrophobicity of the magnetic particles. The experimental design was carried out by Response Surface Methodology (RSM) analysis using the Central Composite Design (CCD) method. Field Emission Scanning Electron Microscopy (FESEM) analysis was performed to qualitatively assess the growth of the prickly-shaped carbonyl iron, and Water Contact Angle (WCA) analysis was used to quantify the superhydrophobicity of the resulting particles. The results revealed that the elevation of the concentration and time increased the roughness (prickly shape) of the particle surface and contact angle up to a point, after which it did not affect them. The temperature elevation caused an increase in the prickly shape of the particles and contact angles and then reduced them. The optimum concentration, temperature, and time were 0.75 Mol L-1, 170 °C, and 4 hours, respectively, for the maximum growth of prickly-shaped particles and the maximum contact angle was 169.7°. Fourier-Transform Infrared Spectroscopy (FT-IR) and thermogravimetric analysis (TGA) results confirmed the presence of glucose and stearic acid chemically bonded to the carbonyl iron particles. The X-ray Diffraction (XRD) results showed that the carbonyl iron had been not converted into iron oxide during the synthesis procedures of the superhydrophobic particles. Vibrating Sample Magnetometer (VSM) analysis showed that making the particles superhydrophobic had little effect on the magnetization reduction.