A method for removing microorganisms from liquid samples and a nanofiber containing liquid filtration medium that simultaneously exhibits high liquid permeability and high microorganism retention. Microorganisms such as bacteria, particularly B. Diminuta, are removed from a liquid by passing the liquid through a porous nanofiber containing filtration medium having a B. Diminuta LRV greater than about 9, and the nanofiber(s) has a diameter from about 10 nm to about 1,000 nm. Another method for removing microorganisms such as bacteria and Mycloplasma, includes passing the liquid through a porous nanofiber containing filtration medium having a microorganism LRV greater than about 8, and the nanofiber(s) has a diameter from about 10 nm to about 1,000 nm. The filtration medium can be in the form of a fibrous electro spun polymeric nanofiber liquid filtration medium mat.

Electrospun poly(acrylic) acid (PAA)/poly(vinyl) alcohol PVA nanofibers and integrated filtration membranes generated therefrom are disclosed herein. The membranes are suitable for use in selectively removing heavy metals such as lead and cadmium from water. The surface of the nanofibers is preferably functionalized with one or more chelating agents. The membranes have a high removal efficiency and adsorption capacity with well-distributed high-density heavy metal adsorption sites with strong binding affinities for targeted heavy metals.

Disclosed herein are composite membranes comprising an omniphobic substrate having a reentrant structure. The omniphobic substrate comprises a plurality of pores, the plurality of pores forming the reentrant structure. The omniphobic substrate further comprises a surface, the surface being coated with a dual functional layer that is hydrophilic in air and oleophobic under water, such that the composite membrane has a top portion and a bottom portion, the top portion comprising the coated surface of the omniphobic substrate, such that the top portion of the composite membrane is hydrophilic in air and oleophobic under water and the bottom portion of the composite membrane is omniphobic. The composite membrane can be antiwetting and/or antifouling in the presence of a hydrophobic contaminant, an amphiphilic contaminant, or a combination thereof. The composite membranes can be used for membrane distillation of a contaminated brine solution.

A method of filtering a liquid sample that includes passing a sample comprising at least one biological organism through a filter membrane at a passive water volume flux of at least 10 L/m.sup.2.Math.h.Math.psi, wherein the filter membrane comprises a Bubble Point pore size of no more than 1.0 ?m, thereby retaining at least one biological organism on the surface of the membrane; and detecting the at least one biological organism retained on the surface of the filter membrane.

The filtration material includes a supporting layer, a first selective layer disposed on the supporting layer, and a second selective layer disposed on the first selective layer. The first selective layer includes a polyimide and an ionic polymer intertwined with the polyimide. In particular, the polyimide includes at least one repeat unit having a structure represented by Formula (I) ##STR00001##
wherein A.sup.1 is ##STR00002##
A.sup.2 is ##STR00003##
R.sup.1 and R.sup.2 are independently H, CF.sub.3, OH, Br, Cl, F, C.sub.1-6 alkyl group, or C.sub.1-6 alkoxy group; and X and Y are independently single bond, O, CH.sub.2, C(CH.sub.3).sub.2, or NH.

A filter apparatus includes: a housing having an inlet for supplying sewage or waste water into the housing, and an outlet for discharging purified water from the housing; and filter media arranged inside the housing. Each of the filter media includes: a porous substrate; a nanofiber web laminated on both surfaces of the porous substrate; and a fuse reinforcement material interposed between the nanofiber web and the porous substrate. The porous substrate is surrounded by the nanofiber web except for an upper edge of the porous substrate to form a protruding portion. The apparatus further includes: a discharge pipe connected to the outlet and including a fixing portion fixed to the protruding portion of the porous substrate and a connection tube connected to the fixing portion and connected to the outlet; and a pump connected to the outlet for pumping the purified water out of the housing.

A two-dimensional membrane layered structure may include a support substrate layer having a plurality of substrate passages configured to allow fluid to flow therethrough, a two-dimensional membrane layer disposed on an upper surface of the support substrate layer, and a plurality of flow passages disposed between the support substrate layer and the two-dimensional membrane layer. The two-dimensional membrane layer may have a plurality of pores configured to allow fluid to flow therethrough. The plurality of pores may comprise a first portion of pores that overlap with the plurality of substrate passages and a second portion of pores that do not overlap with the plurality of substrate passages. The plurality of flow passages may be configured to allow fluid to flow through the second portion of pores to the plurality of substrate passages.

A method for removing microorganisms from liquid samples and a nanofiber containing liquid filtration medium that simultaneously exhibits high liquid permeability and high microorganism retention. Microorganisms such as bacteria, particularly B. Diminuta, are removed from a liquid by passing the liquid through a porous nanofiber containing filtration medium having a B. Diminuta LRV greater than about 9, and the nanofiber(s) has a diameter from about 10 nm to about 1,000 nm. Another method for removing microorganisms such as bacteria and Mycloplasma, includes passing the liquid through a porous nanofiber containing filtration medium having a microorganism LRV greater than about 8, and the nanofiber(s) has a diameter from about 10 nm to about 1,000 nm. The filtration medium can be in the form of a fibrous electro spun polymeric nanofiber liquid filtration medium mat.

A nanofiber for a filter medium is provided that includes fiber-forming ingredients including polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) and an emulsifying agent for improving the miscibility of the fiber-forming ingredients. The nanofiber has excellent mechanical strength and chemical resistance and, at the same time, significantly increased hydrophilicity without a separate surface modification/treatment to/on the nanofiber. A filter medium comprising said nanofiber can exhibit improved flux and filtration efficiency and excellent physical properties in a water treatment process in which a pressure equal to or more than a predetermined level is applied and which requires the filter medium to have high mechanical strength and in a water treatment process which requires chemical resistance as the liquid being filtered is strongly acidic or alkaline. Further, since the nanofiber has significantly superior spinnability, the mass productivity of the filter medium is significantly improved, and the unit costs of production can be reduced.

Compositions made of laminate comprised of porous carbon nanotube (CNT) are disclosed. Uses of the Compositions, particularly for reducing a formation of a load of a microorganism or of a biofilm, are also disclosed.