Described in the present application are methods of producing silane-crosslinked polymer membranes at moderate temperatures using acid catalysts that, in certain embodiments, result in membranes with unexpectedly high permeabilities and selectivities. In certain embodiments, grafting and crosslinking of the silanes occur by immersing a preformed membrane in a solution comprising a silane and an acid catalyst. Alternatively, in certain embodiments, grafting of silanes to a polymer occurs in the presence of acid catalyst in solution and subsequent casting and drying produces crosslinked membranes. In certain embodiments, an acid catalyst is a weak acid catalyst. Also described in the present application are asymmetric crosslinked polymer membranes with porous layers. In certain embodiments, crosslinked cellulose acetate membranes have permeability up to an order of magnitude greater than the permeability of unmodified cellulose acetate membranes. The membranes have porous layers with a high porosity due to their processing in moderate conditions.

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.

A composite membrane comprising: a) a porous support; b) a gutter layer; and c) a discriminating layer;
wherein at least 10% of the discriminating layer is intermixed with the gutter layer.

A filter molded article using a graphene with water passage holes having a desired size is produced in a simple step. A method for producing a filter molded article having a graphene layer as a filtering material is characterized by including a step of forming a support 3 layer on a surface of a graphene 1 layer formed on initial substrates for a graphene 2 and 9, a step of forming water passage holes in the support 3 layer, a step of removing the initial substrates for a graphene 2 and 9, and a step of forming water passage holes by heating and holding the graphene 1 layer at a low temperature in the air containing oxygen of 160 to 250? C. for a predetermined time.

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.

A semiconductor device and method of manufacturing using carbon nanotubes are provided. In embodiments a stack of nanotubes are formed and then a non-destructive removal process is utilized to reduce the thickness of the stack of nanotubes. A device such as a transistor may then be formed from the reduced stack of nanotubes.

A method for fabricating a nanopore at a particular location in a membrane includes controlling a dielectric strength of the membrane at a particular location on the membrane while applying one of an electric potential or an electric current to the membrane, monitoring an electrical property across the membrane while one of the electric potential or the electric current is being applied across the membrane, detecting an abrupt change in the electrical property across the membrane while one of the electric potential or the electric current is being applied across the membrane; and removing the electric potential or the electric current from the membrane in response to detecting the abrupt change in the electrical property.

A membrane, in which the membrane is an ultrapure water membrane; a food and/or beverage processing membrane; a municipal water membrane; a peel oil recovery membrane; a (bio) refinery dewatering membrane; an oily wastewater (pre-)treatment membrane; a metal extraction membrane; a desalination membrane; and/or a protein fraction membrane. The membrane includes a porous substrate layer and an active layer arranged over at least a part of the substrate layer. The active layer is at least partially crosslinked and comprises a superhydrophilic agent. Also described is a method of producing the separation membrane.

A fluid deionizer includes at least one graphene sheet perforated with apertures dimensioned to allow a flow of fluid and to disallow at least one particular type of ion contained in the flow of fluid. A purge valve is placed in an open position so as to collect the at least one particular type of ion disallowed by the graphene sheet so as to clean off the at least one graphene sheet. Another embodiment provides a deionizer with graphene sheets in cylindrical form. A separation apparatus is also provided in a cross-flow arrangement where a pressurized source directs a medium along a path substantially parallel to at least one sheet of graphene from an inlet to an outlet. The medium flows through the plural perforated apertures while a remaining portion of the medium and the disallowed components in the medium flow out the outlet.

A composite membrane comprising: a) a porous support; b) a gutter layer; and c) a discriminating layer;
wherein at least 10% of the discriminating layer is intermixed with the gutter layer.