The present invention relates to a device for producing electrical energy, including two vessels A and B intended for each receiving a concentrated electrolyte solution C.sub.A and C.sub.B in the same solute and each including an electrode arranged so as to come into contact with the electrolyte solution, a membrane separating the two vessels, said membrane including at least one nanochannel arranged to allow the diffusion of the electrolytes from one vessel to the other through said one or more nanochannels, and a device making it possible to supply the electrical energy spontaneously generated by the differential in potential that exists between the two electrodes, characterised in that at least one portion of the inner surface of the one or more nanochannels is essentially made up of at least one titanium oxide. The present invention likewise relates to a method for producing electrical energy using said device.

Provided in one embodiment is a filtering article, comprising: powders comprising bundles of nanotubes, each bundle comprising hollow titania nanotubes. Embodiments of the methods of making and using the filtering articles are also provided.

Microdialysis sampling is an essential tool for in vivo neuro-chemical monitoring. Conventional dialysis probes are over 220 ?m in diameter and have limited flexibility in design because they are made by assembly using preformed membranes. The probe size constrains spatial resolution and governs the amount of tissue damaged caused by probe insertion. To overcome these limitations, we have developed a method to microfabricate probes in Si that are 45 ?m thick 180 ?m wide. The probes contain a buried, U-shaped channel that is 30 ?m deep 60 ?m wide and terminates in ports for external connection. A 4 mm length of the probe is covered with a 5 ?m thick nanoporous membrane. The membrane was microfabricated by deep reactive ion etching through a porous aluminum oxide layer. The microfabricated probe has cross-sectional area that is 79% less than that of the smallest conventional microdialysis probes. The probes yield 2-7% relative recovery at 100 nL/min perfusion rate for a variety of small molecules. The probe was successfully tested in vivo by sampling from the striatum of live rats. Fractions were collected at 20 min intervals (2 ?L) before and after an injection of 5 mg/kg, i.p amphetamine. Analysis of fractions by liquid chromatography-mass spectrometry revealed reliable detection of 13 neurochemicals, including dopamine and acetylcholine, at basal conditions. Amphetamine evoked a 43-fold rise in dopamine, a result nearly identical to a conventional dialysis probe in the same animal. The microfabricated probes have potential for sampling with higher spatial resolution and less tissue disruption than conventional probes. It may also be possible to add functionality to the probes by integrating other components, such as electrodes, optics, and additional channels.

The invention relates to a method for producing a membrane and such membrane. The method comprises the steps of: providing a container with electrolyte; placing a structure in the container; and providing at least two electrodes with a potential difference to achieve a plasma electrolytic oxidation on the structure. Preferably, the structure comprises a metallic structure, with the metallic structure chosen from the group of Titanium, Aluminum, Magnesium, Zirconium, Zinc and Niobium, and/or an alloy.

The invention relates to membrane gas separation, in particular to a method of fractionating mixtures of low molecular weight hydrocarbons based on the capillary condensation of the mixture components in the pores of microporous membranes having uniform porosity and a pore diameter of 5 to 250 nm, wherein, for capillary condensation, the temperature of the membrane and the pressure on the permeate side are kept below the temperature and the pressure of the feed mixture. The method provides significantly increasing membrane permeability with respect to condensable components, and also component separation factors, while also allowing to avoid deep cooling of the gas stream fed to a membrane module, and to carry out gas separation under insignificant cooling of the membrane on the permeate side (down to -50? C.). The invention provides for energy-efficient fractionation of hydrocarbon mixtures, including separation and drying of natural and associated petroleum gases.

The invention relates to the field of membrane gas separation and can be used for the energy-efficient fractionation of hydrocarbon mixtures, including separation and drying of natural and associated petroleum gases. Proposed is a method of fractionating mixtures of low molecular weight hydrocarbons which is based on the capillary condensation of the components of a mixture in the pores of microporous membranes with uniform porosity and a pore diameter in a range of 5 to 250 nm, wherein, for capillary condensation, the temperature of the membrane and the pressure on the permeate side are kept below the temperature and the pressure of the feed mixture such that the equilibrium pressure of the saturated vapors of the separated components on the permeate side is lower than the partial pressure of the components in the feed stream. This method makes it possible to significantly increase membrane permeability with respect to condensable components (over 500 m.sup.3/(m.sup.2.Math.atm.Math.h) for n-butane), and also component separation factors (the n-C.sub.4H.sub.10/CH.sub.4 separation factor is greater than 60 for a mixture having an associated petroleum gas composition), while also making it possible to dispense with deep cooling of the gas stream fed to a membrane module, and to carry out gas separation under insignificant cooling of the membrane on the permeate side (down to ?50? C.) For more effective gas separation, permeate is collected in a liquid state. A technical effect of the invention resides in providing a method that makes it possible to efficiently remove high-boiling hydrocarbons (C.sub.3-C.sub.6) from natural gas and associated petroleum gases, as well as to obtain gas mixtures with a constant composition.

Disclosed is an alumina membrane, its preparation method and application. The preparation method comprises the following steps: carrying out constant voltage anodizing treatment on a surface on one side of an aluminum sheet to obtain an alumina membrane with a porous structure on the surface on one side; removing pure aluminum on an other side of the alumina membrane by a physical processing method, and carrying out pore-enlarging treatment to obtain a membrane with interconnected pores on both sides; and depositing a silicon coating on the surface of the membrane on the side that has been physically processed to obtain the alumina membrane. According to the disclosure, the pure aluminum on the other side is etched by physical processing method after the aluminum on one side is oxidized, so as to avoid an absorbability of an alumina crystal form formed by chemical reagent corrosion on a platelet membrane protein.

In a method for forming nanopores, two opposing surfaces of a membrane are exposed to an electrically conducting liquid environment. A nanopore nucleation voltage pulse, having a first nucleation pulse amplitude and duration, is applied between the two membrane surfaces, through the liquid environment. After applying the nanopore nucleation voltage pulse, the electrical conductance of the membrane is measured and compared to a first prespecified electrical conductance. Then at least one additional nanopore nucleation voltage pulse is applied between the two membrane surfaces, through the liquid environment, if the measured electrical conductance is no greater than the first prespecified electrical conductance.

A fluid permeable anodic oxide film includes a plurality of regularly-disposed pores formed by anodizing metal and a plurality of permeation holes having an inner width larger than an inner width of the pores and extending through the fluid permeable anodic oxide film. Also provided is a fluid permeable body which makes use of the fluid permeable anodic oxide film.

In a method for forming nanopores, two opposing surfaces of a membrane are exposed to an electrically conducting liquid environment. A nanopore nucleation voltage pulse, having a first nucleation pulse amplitude and duration, is applied between the two membrane surfaces, through the liquid environment. After applying the nanopore nucleation voltage pulse, the electrical conductance of the membrane is measured and compared to a first prespecified electrical conductance. Then at least one additional nanopore nucleation voltage pulse is applied between the two membrane surfaces, through the liquid environment, if the measured electrical conductance is no greater than the first prespecified electrical conductance. At least one nanopore diameter tuning voltage pulse, having a tuning pulse voltage amplitude and duration, is applied between the two membrane surfaces, through the liquid environment, if the measured electrical conductance is greater than the first prespecified electrical conductance and no greater than a second prespecified electrical conductance.