Desenvolvimento de um nanossensor de prata para detecção e quantificação de íons incrustantes na indústria do petróleo

Abstract

In this work, a simple silver nanosensor (AgNPs-PYRO) was developed by the reduction method with sodium citrate and sodium borohydride at low temperatures. The nanosensor showed satisfactory performance in the detection of barium ions (Ba+2), strontium (Sr+2), magnesium (Mg+2), calcium (Ca+2), and iron (Fe+3), scales from the oil industry. The analysis carried out through UV-Vis spectroscopy allowed identifying the species at concentrations between 0.5 and 10 ppm. In addition, the obtained colors also made it possible to distinguish the bivalent species (Ba+2, Sr+2, Mg+2, and Ca+2) and iron III, trivalent. The decrease in the plasmon band at 400 nm after the addition of the metallic sample, directly related to the stability of the nanosensor, indicated the destabilization and aggregation of AgNPs. The morphology was analyzed by FE-SEM, where silver showed a size of approximately 20 nm and uniform distribution. After adding barium, it was possible to observe relatively empty spaces and the aggregation of nanoparticles, which is the detection mechanism of the proposed nanosensor. The Zeta potential values obtained for the samples AgNPs, AgNPs-PYRO and AgNPs-PYRO-Metal were -25.0, -52.2, and -43.2, confirming that the sensor is based on the aggregation process since the decrease in charge is a sign of less stability. The nanosensor proved to be sensitive to metals, where the inserted samples resulted in colors of different intensities, proportional to the concentrations. The obtained results prove that the nanosensor is efficient for qualitative and quantitative analysis of these species involved in the scaling process, in an easy and simple analysis, and can be used as an alternative method for this application.