The present invention provides a porous carbon fiber which has an excellent permeation amount and excellent pressure resistance, which is prevented from the occurrence of detachment or cracking at an interface, and which can exhibit excellent properties needed for use as a support for a fluid separation membrane. The present invention is a porous carbon fiber having a bicontinuous porous structure, wherein

the average value R.sub.ave of the R value of the outer surface and the R value of the inside is 1.0 or more and 1.8 or less,

the absolute value ΔR of the difference between the R value of the outer surface and the R value of the inside is 0.05 or less, and

R value is a carbonization progression degree calculated from a Raman spectrum in accordance with the following formula:

R value=(intensity of scattering spectrum at 1360 cm.sup.−1)/(intensity of scattering spectrum at 1600 cm.sup.−1).

An asymmetric hollow fiber (CMS) carbon molecular sieve is made by providing a dope solution comprised of a polvimide and a solvent, at a temperature greater than 250° C. that is less than the storage modulus at a temperature of 250° C., but no more than ten times less as measured using dynamic mechanical thermal analysis from 250° C. to a temperature where the polyimide carbonizes. The polvimide is shaped into a hollow polvimide fiber, the solvent removed and the polyimide hollow fiber is heated to pyroiyze the polvimide and form the asymmetric hollow carbon molecular sieve. The asymmetric hollow fiber carbon molecular sieve has a wall that is defined by an inner surface and outer surface of said fiber and the wall has an inner porous support region extending from the inner surface to an outer raicroporous separation region that extends from the inner porous support region to the outer surface. Surprisingly, when the polyimide has the particular storage modulus characteristics, the method allows for the hollow fiber CMS to be made without any pre-treatmenis or additives to inhibit stractural collapse of the inner microporous region.

A membrane assembly is provided. The membrane assembly includes a non-metallic, porous substrate. A graphene oxide membrane is formed over the non-metallic, porous substrate. A chemical linker interface covalently binds the graphene oxide membrane to the non-metallic, porous substrate.

Disclosed are a CMS membrane, characterized in that it is obtainable by pyrolysis of a polyimide composed of the monomers 1-(4-aminophenyl)-1,3,3-trimethyl-2H-inden-5-amine and 5-(1,3-dioxo-2-benzofuran-5-carbonyl-2-benzofuran-1,3-dione of the following formulae: ##STR00001##
preferably by pyrolysis of the polyimide having the CAS number 62929-02-6, and a supported CMS membrane comprising a CMS membrane obtainable from a polyimide by pyrolysis and a porous support, characterized in that a mesoporous intermediate layer is provided between the CMS membrane and the porous support. Further disclosed are a process for preparing the supported membrane, the use of the membranes for separating gas mixtures or liquid mixtures, an apparatus for gas separation or for liquid separation, and the use of the polyimide for preparing a CMS membrane by pyrolysis.

A membrane distillation (MD) system includes a sweep gas MD (SGMD) module and a knockout chamber. The MD module includes a feed inlet, a feed outlet, a condensing media inlet, and a condensing media outlet. The condensing media is sweep gas. The knockout chamber is positioned after the feed outlet. The knockout chamber includes a liquid inlet, a liquid outlet, and a vapor outlet. Direct gas phase stripping within the SGMD module leads to additional water evaporation at the knockout chamber and contributes to enhanced water or VOCs removal of the MD system.

Methods that expand the properties of laser-induced graphene (LIG) and the resulting LIG having the expanded properties. Methods of fabricating laser-induced graphene from materials, which range from natural, renewable precursors (such as cloth or paper) to high performance polymers (like Kevlar). With multiple lasing, however, highly conductive PEI-based LIG could be obtained using both multiple pass and defocus methods. The resulting laser-induced graphene can be used, inter alia, in electronic devices, as antifouling surfaces, in water treatment technology, in membranes, and in electronics on paper and food Such methods include fabrication of LIG in controlled atmospheres, such that, for example, superhydrophobic and superhydrophilic LIG surfaces can be obtained. Such methods further include fabricating laser-induced graphene by multiple lasing of carbon precursors. Such methods further include direct 3D printing of graphene materials from carbon precursors. Application of such LIG include oil/water separation, liquid or gas separations using polymer membranes, anti-icing, microsupercapacitors, supercapacitors, water splitting catalysts, sensors, and flexible electronics.

A method for manufacturing a porous device (10) is described. The method comprises creating (340) a carbon nanomembrane (40) on a top surface (22) of a base material (20) having latent pores (23) and etching (360) the latent pores (23) in the base material (20) to form open pores (24). The porous device (10) can be used as a filtration device.

Embodiments of the present disclosure provide a carbon molecular sieve membrane (and precursors therefor) including a pyrolysis product of an oxygen-free ladder polymer of intrinsic microporosity. Embodiments of the present disclosure further provide a method of gas separation including contacting a fluid including one or more gas components with a carbon molecular sieve membrane, wherein the carbon molecular sieve membrane includes a pyrolysis product of an oxygen-free ladder polymer of intrinsic microporosity, and separating at least one of said gas components from the fluid. Embodiments of the present disclosure further provide a method of preparing a carbon molecular sieve membrane including heating an oxygen-free ladder polymer of intrinsic microporosity to a pyrolysis temperature in an oxygen-free atmosphere to form, optionally without producing any oxygen-containing gas, a pyrolysis product.

The present disclosure relates, according to some embodiments, to systems, apparatus, and methods for fluid purification (e.g., water) with a ceramic membrane. For example, the present disclosure relates, in some embodiments, to a cross-flow fluid filtration assembly comprising (a) membrane housing comprising a plurality of hexagonal prism shaped membranes (b) an inlet configured to receive the contaminated fluid and to channel a contaminated fluid to the first end of the plurality of hexagonal prism shaped membranes, and (c) an outlet configured to receive a permeate released from the second end of the plurality of hexagonal shaped membranes. The present disclosure also relates to a cross-flow fluid filtration module comprising a fluid path defined by a contaminated media inlet chamber, a fluid filtration assembly positioned in a permeate chamber and a concentrate chamber.

A carbon molecular sieve (CMS) membrane having improved separation characteristics for separating olefins from their corresponding paraffins is comprised of carbon with at most trace amounts of sulfur and a group 13 metal. The CMS membrane may be made by pyrolyzing a precursor polymer devoid of sulfur in which the precursor polymer has had a group 13 metal incorporated into it, wherein the metal is in a reduced state. The pyrolyzing for the precursor having the group 13 metal incorporated into it is performed in a nonoxidizing atmosphere and at a heating rate and temperature such that the metal in a reduced state (e.g., covalently bonded to carbon or nitrogen or in the metal state).