Espectroscopia no infravermelho associada à quimioterapia para análise da formação de agregados no sistema argila polifosfato

Abstract

Clay is a natural, fine-grained, earthy material consisting essentially of clay minerals and may contain other ores. In the presence of water they develop a number of properties such as: plasticities, mechanical strength, linear drying shrinkage, thixotropic compaction and aqueous suspended viscosity that explain the large number of technological applications. Among the clays, the class highlighted by industrial applications are bentonites, which belong to the group of smectites, silicates belonging to the class of phyllosilicates, with a predominance of montmorillonite. These are chemically inert, inexpensive, abundant and have high cation exchange capacity and interact with polyphosphate systems, forming clusters, which are evaluated by high cost techniques. In this sense, the objective of this work was the development of an analytical evaluation method to evaluate bentonite interaction with polyphosphate using near infrared spectroscopy associated with unsupervised pattern recognition technique. In the present study, different systems were analyzed with association between bentonite, polyphosphate and sodium chloride, in different concentrations. Some preprocessions were used and the databases were treated with PCA and HCA to evaluate cluster formation. The working range was from 750 to 1350 nm and it is observed that the presence of salt highlights the spectra in some concentrations. At 0.4 and 0.6 mol / L concentrations of polyphosphate the system behaves equally, noting that the system can saturate at 0.4 mol / L and in the system with low concentrations are well separated. Thus, when applying the treatments to the original and pretreated NIR spectral data, the samples were separated into clusters, also observing an overlap between them in the score graph, for higher concentrations of polyphosphate. In this sense, NIR spectroscopy is a promising analytical technique associated with chemometrics to identify different polyphosphate clay systems.