Toray Succeeds In Development Of Highly Durable Reverse Osmosis Membrane
Stabilizing subnanometer-sized fine pore structure with Toray's proprietary molecular design and interfacial polymerization technology
Toray Industries, Inc. (hereinafter referred to as "the Company") recently announced that it has succeeded in enhancing the durability of reverse osmosis (RO) membrane with high water permeability and high capability for removal of ions and organic compounds by leveraging the Company's original nano-technologies, making it stronger against acids, alkalis, and chlorine used during cleaning.
This new advanced membrane technology that imparts both high durability against chemical cleaning and outstanding separation properties is expected to expand the membrane's use in brackish water and wastewater treatment in which chemical cleaning is required even more frequently because of low quality of raw water. The Company will actively pursue sales expansion of the product in the global market including Europe, North America, Latin America, as well as in China and India among other Asian countries.
In recent years, RO membranes have gained popularity in water treatment plants around the world for addressing water shortage problems. There has been increasing requirement for improving removal properties to secure high quality water and enhancing water permeability to carry out the process with low energy. Demand for enhancement of durability of RO membranes against chemical cleaning and in long-term use has been especially strong to ensure consistent supply of high quality water from raw water with varying qualities, as the use of RO membranes expands significantly.
To meet the demands, the Company made efforts to stabilize pore structure against changing conditions by controlling the pore structure on a sub-nanometer scale. As a result, the Company succeeded in the development of a new membrane with high water permeability and high capability in removing ions and organic compounds as well as superior durability against chemicals used in cleaning.
Technical summary of the RO membrane with high durability is as follows:
- Stabilization of primary structure - molecular design-
Analysis using transmission electron microscope has shown that functional polyamide layer of a reverse osmosis membrane forms protuberance configuration with fine pore structure. The Company in the past has successfully developed membranes with high boron removal capability through control of pore size using positronium annihilation lifetime spectroscopy (PALS) and molecular dynamics simulation method. This time, it carried out in-depth molecular dynamics simulation and succeeded in pluralistic analysis of pore structure (size, volume, number). This technology enabled the Company to predict the pore structure change in changing environment and stabilize primary structure based on molecular design forming cross-linked polyamide pore structure that is stable in changing environment. - Stabilization of higher-order structure -precise interfacial polymerization-
The Company succeeded in quantification of stabilization of higher-order structure of functional polyamide layer through Temperature-Modulated Differential Scanning Calorimetry (TMDSC). Based on the TMDSC analysis data, the Company created precise interfacial polymerization to stably control higher-order structure of functional polyamide layer and realized a new polyamide layer that is highly durable against chemicals used in chemical cleaning.
The Company, by combining its four core technologies such as organic synthetic chemistry, polymer chemistry, biotechnology, and nanotechnology, so far has successfully developed RO membranes with high boron removal capability and low fouling membranes among high-functioning other RO membranes, and these products have won high acclaim around the world as Toray's unique advanced materials.
The development of the highly durable RO membrane further diversifies the solutions the Company offers and is expected to contribute to solving the global water shortage problems.
SOURCE: Toray Industries, Inc.