Magnetic iron oxide nanoparticles have been widely studied for technological and biomedical applications due to its small size and the possibility of functionalizing the surface with intended molecules. Magnetite is the most used phase because of superparamagnetic characteristic, and it is synthesized by co-precipitation, starting from ferrous and ferric ions in alkaline media. However, depending on parameters of chemical reactions, such as molar ratio between iron and hydroxyl groups, stirring rate, and temperature, different iron oxide structures are formed through distinct pathways. Since several variables can affect the size, chemical composition, and crystalline structure of iron oxide nanoparticles during the synthesis, it is very important to apply experimental routines with a well-defined protocol and planning practical steps can significantly improve the quality of products. Plackett-Burman methodology from design of experiments is a filtration analysis, used in the initial stages of a process to investigate the main effects of factors over a characteristic of the final material. In this work, Plackett-Burman technique was employed in order to optimize bare iron oxide nanoparticle production by co-precipitation method, relating the different crystalline phases produced to the experimental routine. Dynamic light scattering, Fourier transform infrared spectroscopy, and X-ray diffractometry were used to characterize the samples.
Este artigo tem como objetivo apresentar o índice de qualidade da água (IQA) feito na lagoa da estação de tratamento da UNIVAP. O índice de qualidade da água (IQA) é um parâmetro de classificação que pode ser obtido por meio da Companhia de Saneamento do Estado de São Paulo (CETESB), no qual apresenta a classificação de ótima, boa, regular e péssima para cada curso de água, lago, lagoa ou rio analisado. Os parâmetros físicos, químicos e biológicos foram comparados aos estipulados pela Resolução CONAMA 357/2005.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.