Abstract: Fabrication methods for selective membranes that include aligned nanotubes can advantageously include a mechanical polishing step. The nanotubes have their ends closed off during the step of infiltrating a polymer precursor around the nanotubes. This prevents polymer precursor from flowing into the nanotubes. The polishing step is performed after the polymer matrix is formed, and can open up the ends of the nanotubes.

Abstract: Membranes for fluid separation are disclosed. These membranes have a matrix layer sandwiched between an active layer and a porous support layer. The matrix layer includes 1-D nanoparticles that are vertically aligned in a porous polymer matrix, and which substantially extend through the matrix layer. The active layer provides species-specific transport, while the support layer provides mechanical support. A matrix layer of this type has favorable surface morphology for forming the active layer. Furthermore, the pores that form in the matrix layer tend to be smaller and more evenly distributed as a result of the presence of aligned 1-D nanoparticles. Improved performance of separation membranes of this type is attributed to these effects.

Abstract: Forward osmosis membranes having a hydrophilic support layer and a polyamide rejection layer in a thin film composite membrane are considered. Preferred support layer materials include aramid polymers and PVDF. A woven or non-woven mesh can be incorporated into the support layer to improve handling properties of the membrane. Flat sheet and hollow fiber configurations are possible. Antifouling techniques are provided. The polyamide layer can be formed on the hydrophilic support layer by interfacial polymerization. Applications include forward osmosis and pressure retarded osmosis applications, such as industrial product and/or waste concentration, hydration bags, energy/pressure generation, and controlled delivery of chemicals (e.g., for pharmaceutical applications).

Abstract: Membranes for fluid separation are disclosed. These membranes have a matrix layer sandwiched between an active layer and a porous support layer. The matrix layer includes 1-D nanoparticles that are vertically aligned in a porous polymer matrix, and which substantially extend through the matrix layer. The active layer provides species-specific transport, while the support layer provides mechanical support. A matrix layer of this type has favorable surface morphology for forming the active layer. Furthermore, the pores that form in the matrix layer tend to be smaller and more evenly distributed as a result of the presence of aligned 1-D nanoparticles. Improved performance of separation membranes of this type is attributed to these effects.

Abstract: Forward osmosis membranes having a hydrophilic support layer and a polyamide rejection layer in a thin film composite membrane are considered. Preferred support layer materials include aramid polymers and PVDF. A woven or non-woven mesh can be incorporated into the support layer to improve handling properties of the membrane. Flat sheet and hollow fiber configurations are possible. Antifouling techniques are provided. The polyamide layer can be formed on the hydrophilic support layer by interfacial polymerization. Applications include forward osmosis and pressure retarded osmosis applications, such as industrial product and/or waste concentration, hydration bags, energy/pressure generation, and controlled delivery of chemicals (e.g., for pharmaceutical applications).