In this study, magnetic nanoparticles of MnFe۲O۴@SiO۲ activated with N-phosphonomethyl amino di-acetic acid were synthesized with a core-shell structure. Moreover, the characteristics of surface functional groups, crystal structure, magnetic properties, size and surface morphology of these nanoparticles were investigated by using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), microscope Scanning electrons (FESEM, Thermal Weight Analysis (TGA) and vibrating sample magnetometer(VSM). In this study, the antiscalant effect of precipitation for magnetic nanoparticles MnFe۲O۴@SiO۲ were examined according to the reference test (NACE TM۰۳۷۴) by using ۵ ppm MnFe۲O۴@SiO۲. In this experiment, the precipitation effect of calcium sulfate and calcium carbonate on the surface of carbon steel was investigated. For this purpose, in one test a piece of carbon steel is placed in the presence of the precipitative compound and absence of antiscalant (control test) and in the other test of carbon steel is placed in precipitative compound with the antiscalant (main test) for a certain period of time. Afterwards, the amount of precipitation of the control and main experiment for carbon steel in the similar environment of the cooling tower of thermal power plants containing ۱۰۰۰ ppm sulfate and ۵۰۰ ppm chloride were investigated.  The tafel polarization test and impedance spectroscopy were used to measure the amount of fouling on the surface of the control and main carbon steel samples. The results indicate that the rate of precipitation formation is greatly reduced in the presence of antiscalant.

Nanoparticles, MnFe۲O۴@SiO۲, Antiscalant, Thermal Powerplant, Tafel Polarization, Impedance spectroscopy, نانوذرات MnFe۲O۴@SiO۲؛ بازدارنده رسوب گذاری؛ نیروگاه حرارتی؛ آزمون تافل؛ آزمون امپدانس.