RESUMEN
In this study, the ionic liquid (IL) trioctylmethylammonium salicylate (TOMAS) was prepared and incorporated into a polymer inclusion membrane (PIM) based on cellulose triacetate (CTA) as the polymer for the removal of Cr(VI). Various parameters including the effect of membrane composition (plasticizer and carrier concentration) as well as variables affecting both the feed phase and receiving solution have been investigated. Optimal results were achieved with a PIM made of 50% CTA and 50% TOMAS (% in mass) without the addition of any plasticizer. Using this PIM, Cr(VI) was effectively transported from a feed solution consisting of 10 mg L-1 Cr(VI) in 0.01 mol L-1 NaNO3 at pH = 2, to a receiving solution containing 0.1 mol L-1 NaOH. The transport of Cr(VI) was not affected by the presence of other metals, such as Cr(III), Cd(II), Zn(II), Cu(II), and Ni(II), and a selective recovery rate of 93.61% for both single-ion and mixed-ion solutions after 24 h of processing was obtained. Finally, the stability of the membrane was also investigated, with a slight decrease in efficiency observed after 5 days of reuse.
Asunto(s)
Cromo , Polímeros , Cromo/química , Polímeros/química , Compuestos de Amonio Cuaternario/química , Contaminantes Químicos del Agua/química , Membranas Artificiales , Celulosa/química , Celulosa/análogos & derivadosRESUMEN
A novel and simple device that includes a polymer inclusion membrane (PIM) has been prepared and tested for the first time to detect low concentration levels of cadmium in seawater. The ionic liquid trihexyl (tetradecyl) phosphonium chloride (THTDPCl) has been shown to be an effective extractant when incorporated in a PIM that uses cellulose triacetate (CTA) as a polymer. However, it has been reported that the use of a plasticizer is mandatory to ensure an effective transport, which uses both ultrapure water and a nitric acid solution as a stripping phase. A special device incorporating a PIM made of 50% CTA, 40% nitrophenyl octyl ether (as a plasticizer), and 10% THTDPCl, effectively allows the quantitative transport and preconcentration of 10 µg L-1 Cd from seawater samples to a stripping phase consisting of 0.5 M HNO3 solution. This study shows that the efficiency of the PIM system is not affected by high salinity nor the presence of large amounts of other ions, and can thus facilitate Cd monitoring in seawater samples.
RESUMEN
The synthesis of silicalites and Mesoporous Silica Nanoparticles (MSN), which covalently incorporate original water-soluble photosensitizers for PDT applications is described. PDT was performed on MDA-MB-231 breast cancer cells. All the nanoparticles showed significant cell death after irradiation, which was not correlated with (1)O(2) quantum yield of the nanoparticles. Other parameters are involved and in particular the surface and shape of the nanoparticles which influence the pathway of endocytosis. Functionalization with mannose was necessary to obtain the best results with PDT due to an active endocytosis of mannose-functionalized nanoparticles. The quantity of mannose on the surface should be carefully adjusted as a too high amount of mannose impairs the phototoxicity of the nanoparticles. Fluorescein was also encapsulated in MCM-41 type MSN in order to localize the nanoparticles in the organelles of the cells by confocal microscopy. The MSN were localized in lysosomes after active endocytosis by mannose receptors.
Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Fotoquimioterapia/métodos , Silicatos/química , Dióxido de Silicio/química , Neoplasias de la Mama/patología , Línea Celular Tumoral , Sistemas de Liberación de Medicamentos , Endocitosis , Femenino , Fluoresceína/administración & dosificación , Colorantes Fluorescentes/administración & dosificación , Humanos , Lectinas Tipo C/metabolismo , Lisosomas/metabolismo , Manosa/química , Receptor de Manosa , Lectinas de Unión a Manosa/metabolismo , Microscopía Confocal , Nanopartículas , Receptores de Superficie Celular/metabolismo , Oxígeno Singlete/químicaRESUMEN
The solvent extraction of chromium(VI) in chloroform, dichloromethane, dichloroethane and its transport through a chloroformic bulk liquid membrane from sulphuric acid solutions with the neutral extractant triphenylphosphine (TPP) were studied. It was highlighted that the TPP extractant is an interesting complexing and efficient carrier for transport of chromium(VI) as [(HTPP)HCr2O7] complex from a 2M sulphuric acid solutions. It has a high ability to concentrate the chromium(VI) in the receiving phase according to the Donnan equilibrium. The co-extraction and the co-transport of sulphuric acid is very low and has no effect on the transport efficiency. The transport rate depends mainly on the initial concentration of the extractant.