A method is disclosed for preventing carbon nanotube degradation in ionizable environments. The method includes immersing a porous thin-film nanotube (CNT)/polymer composite Joule heating element in an ionizable environment; and applying an alternating current at a frequency of at least 100 Hz to the porous thin-film nanotube (CNT)/polymer composite Joule heating element in the ionizable environment.

A filtration membrane coating comprising a hydrophilic polymer, a surfactant, and one or more charged compounds, each containing one or more sulfonate functionalities and one or more linkable functionalities selected from the group consisting of amine, monochlorotriazine, and dichlorotriazine. The hydrophilic polymer and surfactant form a thin primer layer which is also superhydrophilic. The primer layer improves flux, and enables improved adhesion of the one or more charged compounds, which form a charged dye layer on top of the primer layer when enhances rejection of charged divalent ions. The coating can be applied while the membrane is packaged in its final form, such as in a spiral wound or other configuration.

This invention relates generally to a chitosan-graphene oxide membrane and process of making the same. The nanocomposite membrane can filter water and remove contaminants without fouling like other commercially-available polymer-based water filters. The membrane can be used as a flat sheet filter or can be engineered in a spiral filtration module. The membrane is scalable and tunable for many water contaminants including pharmaceuticals, pesticides, herbicides, and other organic chemicals. The membrane uses chitosan, which is low-cost, renewable biopolymer typically considered to be a waste product and the second most abundant biopolymer on Earth, thus making the membrane an environmentally-friendly product choice.

A conventional media filter such as a gravity sand filter is converted into a membrane filter. The media is removed and replaced by immersed membrane modules. Transmembrane pressure is created by a static head pressure differential, without a suction pump, thereby creating a membrane gravity filter (MGF). Preferred operating parameters include transmembrane pressure of 5-20 kPa, 1-3 backwashes per day, and a flux of 10-20 L/m.sup.2/h. The membranes are dosed with chlorine or another oxidant, preferably at 700 minutes*mg/L as Cl.sub.2 equivalent per week or less. The small oxidant does is believed to provide a porous biofilm or fouling layer without substantially removing the layer. The media filter may be modified so that backwash wastewater is removed from near the bottom of the tank rather than through backwash troughs above the membrane modules. Membrane integrity testing may be done while the tank is emptied after a backwash.

The present disclosure provides for a water treatment system including a water tank and a polymer membrane. The water tank includes an inlet in fluid communication with an outlet. The polymer membrane is contained within the water tank and includes Arabic gum so as to minimize biofouling. The polymer membrane may include 0.1% to 7% by weight of Arabic gum. The water tank is configured such that an untreated water stream entering at the inlet is treated by passing the untreated water stream through the polymer membrane before exiting at the outlet.

A two-layer photo-responsive membrane including a polymer layer and a support layer, the polymer layer being disposed on a surface of the support layer. The polymer layer is formed of a graft copolymer that contains a hydrophobic backbone and multiple side chains, the side chains each consisting of repeat units that switch between a hydrophobic form and a hydrophilic form upon exposure to a light of a specific wavelength. The polymer layer has a molecular weight cut-off of 3,000 to 250,000 Daltons and a thickness of 50 nm to 10 m; and the support layer has a molecular weight cut-off of 50 to 250,000 Daltons. Also disclosed is a method of preparing this two-layer photo-responsive membrane.

Polyethers (A), whose main chain essentially consists of repeating units of the formulae (1) and (2) in alternating order, are useful as an additive to a porous polymer membrane, or as the main polymer constituent of a porous polymer membrane, for stabilizing said membrane against detrimental effects of oxidizing agents and/or for improving the stability of a filtration module comprising said membrane against detrimental effects of oxidizing agents. ##STR00001##

The present invention relates to a porous sheet product, to a filter element comprising the porous sheet product, to a method for producing the porous sheet product, to a method for producing the filter element, and to the use of the sheet product and of the filter element.

The present invention relates to a method of preparing a nanocomposite membrane, comprising: (a) providing a nanocomposite solution comprising a polymer solution and nanomaterials; (b) subjecting the nanocomposite solution to a cold water bath to produce the nanocomposite membrane in a gel-like form; and (c) subjecting the gel nanocomposite membrane to a heat treatment to solidify the nanocomposite membrane, wherein the nanomaterials are dispersed within the polymer matrix of the nanocomposite membrane.

In one aspect, the invention relates to chlorine-resistant filtration membranes comprising n-alkyl substituted polyaniline derivatives for use in, for example, water purification, and methods for making and using same. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.