Hydrogel with Selective Absorption for Separation of Liquid Mixtures
This invention provides a method for synthesizing a novel hydrogel that can switch its wettability and absorption for polar liquids and maintain its non-polar liquid repellency while requiring minimal heat input. The invention enables a separation method has the potential to reduce energy costs for some industrial processes and has been employed to separate immiscible polar-non-polar liquid mixtures (water and oil) and a completely miscible liquid mixture (ethanol and heptane) at room temperature.
Hydrogels are synthetic materials that can absorb and retain large quantities of water, up to 90%. Hydrogels are three-dimensional network hydrophilic structures derived from synthetic and/or natural polymers. The compounds swell in water and retain the water while maintaining its structure due to cross-linking of individual polymer chains. There is a need to improve the energy and efficiency of hydrogels.
This invention is potentially useful a material for making sorbents and membranes for filtration and separation processes for a broad range of industrial processes as it enables improved separation and cost efficiencies over existing methods and materials used for the applications such as biofuel purification filtration, oil spill cleanup, ethanol-water separation, and jet fuel separation.
How it works:
The invention is made with a free radical polymerization method initiated with ultraviolet (UV) light to synthesize a fluorinated Poly N-isopropylacrylamide (FPNIPAM). Oil-repellency at low and elevated temperatures has been demonstrated by the hydrogel, which makes it ideal for separating polar-non-polar liquid mixtures.
This invention enables significantly improved separation and cost efficiencies over existing methods and materials used for industrial separations of immiscible polar-non-polar liquid mixtures and completely miscible liquid mixtures.
Why it is better:
Because of the significantly improved separation and cost efficiencies over existing methods and materials used for industrial separations, it can be used lower the cost of industrial separation processes and for applications not previously cost feasible.
The materials provided by this invention can be used as media for separation and filtration devices.