Asymmetric Membrane
Mostrando 1-12 de 166 artigos, teses e dissertações.
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1. AVALIAÇÃO DO PERFIL DE LIBERAÇÃO DO FÁRMACO IBUPROFENO EM MEMBRANAS SIMÉTRICAS E ASSIMÉTRICAS DE ACETATO DE CELULOSE: EFEITO DA MORFOLOGIA
Cellulose derivatives still receive special attention in today biomedical applications due to their biocompatibility, ability to form resistant membranes and compatibility with various bioactive agents. In this work, cellulose acetate (CA) was used to prepare membranes with different morphologies aiming to evaluate the release profile of the drug ibuprofen (
Quím. Nova. Publicado em: 21/10/2019
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2. Production and Characterization of a Silica-Alumina Membrane Using Novel Tubular Freeze-Cast Substrates
Development of new ceramic membranes has recently grown due to its superior thermal and mechanical stability. An interesting approach to manufacture asymmetric membranes is the production of aligned pore structure by the freeze-casting method. The lack of studies involving membrane production with tubular freeze-cast substrates warrants more research. In thi
Mat. Res.. Publicado em: 11/02/2019
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3. A Dual-mode model interpretation of CO2/CH4 permeability in polysulfone membranes at low pressures
ABSTRACT An asymmetric membrane of polysulfone (PSf) was synthesized by phase inversion method. Permeation experiments were carried out between 2 to 5 bar pressure, and at temperatures 20 to 45°C. The dense-selective layer of PSf membrane presents regular thickness (about 5 µm), and was not possible to observe the formation of macrovoids in porous layer. T
An. Acad. Bras. Ciênc.. Publicado em: 2018-04
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4. Water Permeability Increase in Ultrafiltration Cellulose Acetate Membrane Containing Silver Nanoparticles
Inorganic nanoparticles incorporation in polymer membranes for filtration processes has attracted the attention of researchers in order to improve in some ways their performance. In this work, AgNPs were synthesized "in situ" in cellulose acetate (CA) membrane by chemical reduction of a silver salt. The membranes were prepared by the nonsolvent induced phase
Mat. Res.. Publicado em: 22/02/2018
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5. CHARACTERISATION OF ASYMMETRIC ALUMINA HOLLOW FIBRES: APPLICATION FOR HYDROGEN PERMEATION IN COMPOSITE MEMBRANES
Abstract Asymmetric alumina hollow fibres produced by the phase inversion/sintering method present advantages in that high area/volume ratios and low mass transfer resistances are achieved due to the geometric configuration and the pore size distribution, respectively. Here we characterise hollow fibres that were prepared with different internal coagulants a
Braz. J. Chem. Eng.. Publicado em: 2016-09
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6. Ultrafiltration membranes from waste polyethylene terephthalate and additives: synthesis and characterization
The synthesis and characterization of asymmetric ultrafiltration membranes from recycled polyethylene terephthalate (PET) and polyvinylpyrrolidone (PVP) is reported. PET is currently used in many applications, including the manufacture of bottles and tableware. Monomer extraction from waste PET is expensive, and this process has not yet been successfully dem
Quím. Nova. Publicado em: 2014
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7. Effect of non-solvents used in the coagulation bath on morphology of PVDF membranes
The aim of this paper was to prepare a poly (vinylidene fluoride) (PVDF) membrane using different non-solvents in the coagulation bath for the phase inversion method. In order to increase the mechanical strength of membranes, facing the pressure of work, was used a macro-porous polyester support. The morphology and structure of the resulting membranes were e
Mat. Res.. Publicado em: 13/09/2012
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8. Characterization of Polyamide 66 membranes prepared by phase inversion using formic acid and hydrochloric acid such as solvents
The membranes properties prepared from water/formic acid (FA)/ polyamide 66 (PA66) and water/hydrochloric acid (HCl)/polyamide 66 (PA 66) systems has been studied. The different solvents interact distinctly with the polymer, affecting the membrane morphology. The asymmetric structure of the membranes showed a dense top layer and a porous sublayer. The membra
Materials Research. Publicado em: 21/11/2011
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9. Caracterização de membranas de poliamida 66 preparadas pelo método de inversão de fases
In the present study, polyamide 66 (PA 66) membranes were prepared by phase inversion (PI) and characterized in order to verify their potential application in separation processes. PA 66 membranes were prepared using two different solvents, formic acid (FA) and chloridric acid (HCl), and water as a non-solvent. Membranes prepared in film form (not supported)
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/04/2010
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10. Reciclagem química do bagaço de cana-de-açúcar para a produção de membranas assimétricas de diacetato de celulose
In this work, cellulose from sugarcane bagasse was used for producing cellulose acetate aiming the production of asymmetric membranes. The obtained cellulose acetate presented degree of substitution of 2.49, characterized as a cellulose diacetate. Membranes produced from this material were compared to the membrane produced with commercial cellulose acetate (
Publicado em: 2009
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11. Avaliação de assimetrias cerebrais funcionais por SPECT cerebral e termometria timpânica
The objective of this study was to verify the possibility of using tympanic temperature (TT) as an indicator of asymmetric cerebral activity in human patients. To achieve this objective the TT was measured in 32 patients (12 male, 20 female, aged 47.34 + 22.96) with a clinical diagnostic hipothesis of neuropsychiatric disorders who were referred to a Nuclear
Publicado em: 2008
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12. Synthesis and study of photoinduced properties of phenothiazine derivatives on biomimetic systems / Síntese e estudo das propriedades fotoinduzidas de derivados fenotiazínicos em sistemas biomiméticos
The effect of interfaces on photophysical and photochemical properties of methylene blue (MB) and its derivatives was studied in this work, aiming to emploit their potencial as photosensitizers (PS) in photodynamic therapy.The presence of MB in SDS solutions affect the micelle equilibrium decreasing the apparent critical micelle concentration of SDS from 7mm
Publicado em: 2008