Síntese e aplicação de nanopartículas de prata para quantificação de inibidores de incrustação e de cátions incrustantes na indústria do petróleo

Abstract

The search for alternative analytical methods for determining scale inhibitors and scale cations has aroused interest in the petroleum industry. In this sense, silver nanoparticles (AgNPs), more specifically the optical properties of Localized Surface Plasmon Resonance (LSPR), become a promising material for the development of nanoplatforms for spectral optimization and nanosensors. optics. Thus, the objective of this work was to combine AgNPs with Raman spectroscopy (SERS), UV-Vis spectroscopy and digital images (using a smartphone and free software, ImageJ) to determine the concentration of scale inhibitors (ATMP and DTPMP) and fouling cations (Mg+2, Ca+2, Sr+2 and Ba+2). These methodologies were based, respectively, on the properties of AgNPs for Raman signal amplification, variation in the absorbance intensity of the plasmonic band (400 nm) and changes in the color of the silver nanoparticle solution in the presence of the analyte. The development of SERS substrate suitable allowed the detection of ATMP in concentrations in the order of 10-4 M. Furthermore, digital imaging and UV-Vis spectroscopy analyzes quantified fouling cations and the inhibitor DTPMP in concentrations in the order of 10-6 M, with excellent linear regression. The colorimetric sensor based on UV-Vis spectroscopy achieved a limit of detection (LOD) of 50.9 µM for DTPMP and less than 30 µM for cátions. Characterizations by UV-vis spectroscopy and Dynamic Light Scattering (DLS) proved that the sensor is based on the mechanism of aggregation or stabilization of AgNPs, depending on the analyte with which they interact. Thus, the results obtained demonstrated that the methodologies developed are efficient, reliable, low-cost and less laborious, when compared to traditionally used methodologies (ion chromatography and ICP-OES).