16 documents found, page 1 of 2
Synthesis and application of a new carboxylated cellulose derivative. Part I: R...
Ferreira, Gabriel Max Dias; Silva, Luis Henrique Mendes da; Teodoro, Filipe Simões; Ramos, Stela Nhandeyara do Carmo; Elias, Megg Madonyk CotaA new carboxylated cellulose derivative (CTA) was prepared from the esterification of cellulose with 1,2,4-Benzenetricarboxylic anhydride. CTA was characterized by percent weight gain (pwg), amount of carboxylic acid groups (nCOOH), elemental analysis, FTIR, TGA, solid-state 13C NMR, X-ray diffraction (DRX), specific surface area, pore size distribution, SEM and EDX. The best CTA synthesis condition yielded a p...
Aqueous two-phase systems: An efficient, environmentally safe and economically ...
Mageste, Aparecida Barbosa; Lemos, Leandro Rodrigues de; Ferreira, Guilherme Max Dias; Silva, Maria do Carmo Hespanhol daPartition of the natural dye carmine has been studied in aqueous two-phase systems prepared by mixing aqueous solutions of polymer or copolymer with aqueous salt solutions (Na2SO4 and Li2SO4). The carmine dye partition coefficient was investigated as a function of system pH, polymer molar mass, hydrophobicity, system tie-line length and nature of the electrolyte. It has been observed that the carmine partition ...
Thermodynamics and optimization of norbixin transfer processes in aqueous bipha...
Mageste, Aparecida Barbosa; Senra, Tonimar Domiciano Arrighi; Silva, M. Carmo Hespanhol da; Bonomo, Renata Cristina FerreiraPartitioning of the natural dye norbixin has been studied in aqueous two-phase system (ATPS) that are formed by mixing aqueous solutions of a polymer (or copolymer) and an organic salt (sodium tartrate or succinate). In this work, the norbixin partition coefficient (KN) was optimized, taking into account the variables of polymer concentration, salt concentration and pH. It was found that KN is highly dependent ...
Synthesis and application of a new carboxylated cellulose derivative. Part I : ...
Teodoro, Filipe Simões; Ramos, Stela Nhandeyara do Carmo; Elias, Megg Madonyk Cota; Mageste, Aparecida Barbosa; Ferreira, Gabriel Max DiasA new carboxylated cellulose derivative (CTA) was prepared from the esterification of cellulose with 1,2, 4-Benzenetricarboxylic anhydride. CTA was characterized by percent weight gain (pwg), amount of carboxylic acid groups (nCOOH), elemental analysis, FTIR, TGA, solid-state 13C NMR, X-ray diffraction (DRX), specific surface area, pore size distribution, SEM and EDX. The best CTA synthesis condition yielded a ...
Separation of Cd and Ni from Ni–Cd batteries by an environmentally safe methodo...
Lacerda, Vânia Gonçalves; Mageste, Aparecida Barbosa; Santos, Igor José Boggione; Silva, Luis Henrique Mendes da; Silva, Maria do Carmo Hespanhol daThe separation of Cd and Ni from Ni–Cd batteries using an aqueous two-phase system (ATPS) composed of copolymer L35, Li2SO4 and water is investigated. The extraction behavior of these metals from the bottom phase (BP) to the upper phase (UP) of the ATPS is affected by the amount of added extractant (potassium iodide), tie-line length (TLL), mass ratio between the phases of the ATPS, leaching and dilution factor...
Regular article synthesis and application of a new carboxylated cellulose deriv...
Ferreira, Gabriel Max Dias; Teodoro, Filipe Simões; Ramos, Stela Nhandeyara do Carmo; Elias, Megg Madonyk Cota; Mageste, Aparecida BarbosaA new carboxylated cellulose derivative (CTA) was prepared from the esterification of cellulose with 1,2,4- Benzenetricarboxylic anhydride. CTA was characterized by percent weight gain (pwg), amount of carboxylic acid groups (nCOOH), elemental analysis, FTIR, TGA, solid-state ^13C NMR, X-ray diffraction (DRX), specific surface area, pore size distribution, SEM and EDX. The best CTA synthesis condition yielded a...
Phase diagram and thermodynamic modeling of PEO + organic salts + H2O and PPO +...
Patrício, Pamela da Rocha; Mageste, Aparecida Barbosa; Lemos, Leandro Rodrigues de; Carvalho, Raquel Moreira Maduro de; Silva, Luis Henrique Mendes daThe phase diagrams of PEO1500 + sodium tartrate + water, PPO400 + sodium tartrate + water, PEO1500 + sodium succinate + water, PPO400 + sodium succinate + water, PEO1500 + sodium citrate + water, PPO400 + sodium citrate + water and PPO400 + sodium acetate + water aqueous two-phase systems were determined at (283.15, 298.15, and 313.15) K. Both equilibrium phases composition were analyzed by conductimetry and re...
Use of aqueous two-phase PEG-salt systems for the removal of anionic surfactant...
Murari, Gabriella Frade; Penido, Jussara Alves; Silva, Heriveltom Morais da; Baeta, Bruno Eduardo Lobo; Aquino, Sergio Francisco deLinear alkylbenzene sulfonates (LAS) are synthetic anionic surfactants that are extensively used in many industries. As a result, large volumes of effluents containing high levels of these compounds are discharged into water bodies, causing risks to aquatic flora and fauna. Then, there is a need for environmentally safe and economically viable technologies for the removal of LAS from aqueous matrices. The prese...
Green selective recovery of lanthanum from Ni-MH battery leachate using aqueous...
Oliveira, Wbiratan Cesar Macedo de; Rodrigues, Guilherme Dias; Mageste, Aparecida Barbosa; Lemos, Leandro Rodrigues deIn view of the importance of resource recycling and the use of environmentally safe systems to extract the metals contained in wastes, the present study concerns the extraction/separation of lanthanum from spent Ni–MH batteries. Investigation was made of the extraction behavior of lanthanum using aqueous twophase systems (ATPSs), and a new environmentally safe hydrometallurgical method was developed for the sel...
A method for dye extraction using an aqueous two-phase system : effect of co-oc...
Borges, Gabriella Alexandre; Silva, Luciana Pereira; Penido, Jussara Alves; Lemos, Leandro Rodrigues de; Mageste, Aparecida BarbosaThis paper reports a green and efficient procedure for extraction of the dyes Malachite Green (MG), Methylene Blue (MB), and Reactive Red 195 (RR) using an aqueous two-phase system (ATPS). An ATPS consists mainly of water, together with polymer and salt, and does not employ any organic solvent. The extraction efficiency was evaluated by means of the partition coefficients (K) and residual percentages (% R) of t...