Guilherme B. C. Martins

COLORIMETRIC KIT FOR DETECTION OF METHANOL IN ETHANOL FUEL FOR MONITORING THE QUALITY OF FUELS

A colorimetric kit for methanol detection in ethanol-containing fuels and ease of use in the field was developed and tested. The analysis can detect the presence of methanol in fuels when exceeding specification (0.5% v/v) in about 20 min and its simple instrumentation does not require a specialist. The kit method was successfully validated at gas stations located in Sao Paulo State and the Federal District.

Extraction and Characterization of Passion Fruit and Guava Oils from Industrial Residual Seeds and Their Application as Biofuels

A great diversity of fruits is used in the food industry to obtain different products such as juices, sauces and foods. However, the food industry produces high amounts of residues. Passion fruit and guava are worldwide known fruits and very used by the food industry and generate tons of seed as residue. This work aims to study the extraction of oils from passion fruit and guava juice industries residues, their characterization and potential application as raw materials to obtain biodiesel and bio-oil. The passion fruit and guava seed oils content were 25 and 9%, respectively. In both oils, polyunsaturated fatty acids are predominant. Biodiesel obtained by esterification/ transesterification of both seed oils match most of the parameters specified for biodiesel in Brazil. Bio-oils obtained by thermal cracking of the seed oils were mainly composed by hydrocarbons similar to those observed in petroleum diesel.

Papel indicador colorimétrico para detecção de formol em produtos lácteos e produtos de higiene pessoal

Due to its low cost, formaldehyde was commonly used as conservative in hygienic and cosmetic products. However, formaldehyde is strongly reactive and toxic, so its use has been forbidden in several products. Recently, it was reported by different media that formaldehyde has been added illegally in milk, causing innumerous health problems. In this work we developed a colorimetric indicator paper based on Schiff s reagent, which can be associated with a smartphone application. It was observed that the paper stabilizes the Schiff s reagent, avoiding its decomposition during short periods. It was also possible to successfully detect the presence of formaldehyde in commercial products, such as: detergents, shampoos and conditioners. Regarding milk based products, the indicator paper is very sensitive to detect formaldehyde, having a sensibility of 0.01% (v/v). The developed indicator paper has low cost and can help the supervision of milk products, as a trial test. Also it is possible to commercialize this product to common consumer, due to its simplicity.

Cellulose Oxidation and the Use of Carboxyl Cellulose Metal Complexes in Heterogeneous Catalytic Systems to Promote Suzuki-Miyaura Coupling and C-O Bond Formation Reaction

This work shows the modification of microcrystalline cellulose by the selective oxidation of primary hydroxyl groups to carboxylate groups by a 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated system and its application as a heterogeneous ligand by ionic exchange with catalytic metals ions such as palladium, nickel and copper. Afterwards is described the application of the synthesized material as catalyst in coupling reactions such as Suzuki-Miyaura coupling and C−O bond formation reaction in different conditions, which are of great importance for the synthesis of drugs, natural products and new materials such as dendrimers, liquid crystals and polymers with magnetic and optical properties. The carboxyl cellulose matrix shows to have superior catalytic results as a ligand for all coupling reactions. Can be also highlighted the affinity of the carboxyl cellulose ligand in polar solvents such as water and alcohols and its application in mild conditions.