Ionic Strength Effect
Mostrando 1-12 de 227 artigos, teses e dissertações.
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1. A New Approach for Histamine Functionalized Nanoparticles as Sorbent Phase for Bar Adsorptive Microextraction (BAµE) and Determination of Parabens in Water by HPLC-DAD
In this study, for the first time, histamine-functionalized magnetic nanoparticles (HIS-MNP) were used as sorbent phase combined with bar adsorptive microextraction (BAµE) for the determination of methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP) in water samples by high performance liquid chromatography coupled with diode arr
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Water-uptake properties of a fish protein-based superabsorbent hydrogel chemically modified with ethanol
Abstract Hydrophilic polymers can form hydrogels, which are able to absorb and retain as much water as one hundred times their weight. Polymers based on natural products have been drawing attention since they are biocompatible, biodegradable and nontoxic. The aims of this study were to produce and to characterize a biopolymer with superabsorbent properties
Polímeros. Publicado em: 06/07/2018
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3. NANOPARTÍCULAS DE PROTEÍNA ISOLADA DE SOJA EM ÁGUA: EFEITO DA FORÇA IÔNICA E DAS CONCENTRAÇÕES DE PROTEÍNA E SURFACTANTE
Soft nanoparticles of size 200-400 nm were obtained from soybean protein isolate (SPI). The particles were formed and suspended in water by the coacervation of aqueous suspensions of SPI in hostile buffered aqueous solutions in the presence of surfactants. We investigate the effect of storage, ionic strength, and concentrations of SPI and surfactant on nanop
Quím. Nova. Publicado em: 2015-01
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4. Ligandless cloud point extraction of trace amounts of palladium and rhodium in road dust samples using Span 80 prior to their determination by flame atomic absorption spectrometry
In this study, a procedure is developed for cloud point extraction of Pd(II) and Rh(III) ions in aqueous solution using Span 80 (non-ionic surfactant) prior to their determination by flame atomic absorption spectroscopy. This method is based on the extraction of Pd(II) and Rh(III) ions at a pH of 10 using Span 80 with no chelating agent. We investigated the
Quím. Nova. Publicado em: 2014
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5. Specific ion effects on the interfacial tension of water/hydrocarbon systems
Specific ion effects - also known as Hofmeister effects - are ubiquitous in several areas of chemistry, chemical engineering and biology. The interfacial tension corresponds to the energy per unit of area at the interface. Thus, the presence of different salts in different concentrations changes the interfacial tension of a system containing an aqueous phase
Braz. J. Chem. Eng.. Publicado em: 2013-03
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6. Visual demonstration of the ionic strength effect in the classroom: the Debye-Hückel limiting law
The effects of ionic strength on ions in aqueous solutions are quite relevant, especially for biochemical systems, in which proteins and amino acids are involved. The teaching of this topic and more specifically, the Debye-Hückel limiting law, is central in chemistry undergraduate courses. In this work, we present a description of an experimental procedure
Quím. Nova. Publicado em: 2013
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7. Efeito da carga dos lipídios na interação do BP100 em modelos de membrana / Charge effect of lipids in interaction of BP100 and model membranes
Antimicrobial peptides (AMPs) have been a promising alternative therapy to antibiotics. These molecules, consisting of less than 80 amino acids, with different structures and amino acids composition, have amphipathic character which gives them the ability to act on lipid bilayers. They act, by different mechanisms, over bacteria to mammal cells. The AMPs are
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/02/2012
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8. Synthesis of a biocopolymer carrageenan-g-poly(AAm-co-IA)/ montmorilonite superabsorbent hydrogel composite
A novel superabsorbent hydrogel composite based on kappa-carrageenan (κC) has been prepared via graft copolymerization of acrylamide (AAm) and itaconic acid (IA) monomers in the presence of montmorolonite clay powder, methylenebisacrylamide (MBA) as the crosslinking agent and ammonium persulfate (APS) as initiator. Evidence of grafting and montmorolonite in
Brazilian Journal of Chemical Engineering. Publicado em: 2012-06
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9. Nickel adsorption by variable charge soils: effect of pH and ionic strength
The effects of pH and ionic strength (I) on Ni adsorption in variable charge soils were evaluated by laboratory batch experiments. Experimental results fitted the Langmuir model. Maximum adsorption (Ads max) ranged from 260-2818 mg kg-1 (topsoil) to 532-1541 mg kg-1 (subsoil). Nickel affinity (K L) was higher in the subsoil samples (0.022-0.236 L kg-1) than
Brazilian Archives of Biology and Technology. Publicado em: 2011-02
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10. Influence of physical and chemical caracteristics of plasticizers in the manufacturing and on the structural behavior and hygroscopic of films of calcium alginate / Influencia de caracteristicas fisicas e quimicas de plastificantes na confecção e no comportamento estrutural e higroscopico de filmes de alginato de calcio
Responsible consumers are looking for processed food with higher nutritional value and extended shelf live, without disregarding the damaging cumulative effects of sub products discharge on the environment. Biodegradable films are part of this concept. They are produced from natural polymers, mainly saccharides and proteins, with potential applications in th
Publicado em: 2010
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11. A novel indicator reaction for the catalytic determination of V(V) at ppb levels by the kinetic spectrophotometric method
A novel sensitive and relatively selective kinetic method is presented for the determination of V(V), based on its catalytic effect on the oxidation reaction of Ponceau Xylydine by potassium bromate in presence of 5-sulfosalicylic acid (SSA) as activator. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of Ponceau Xyl
Eclética Química. Publicado em: 2009-12
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12. Lixiviado de aterros sanitários brasileiros: estudo de remoção do nitrogênio amoniacal por processo de arraste com ar ("stripping") / Sanitary landfill leachate in Brazil: evaluation of ammonia nitrogen removal by air stripping process
Sanitary landfills are considered as the most appropriate way for final disposal of municipal solid wastes in Brazil, in the technical and economical point of view. Open dumps have been progressively substituted by well engineered and operated landfills. However, landfills still present environmental risks due to the gas emission and leachate production. Gas
Publicado em: 2009