# US 12,109,537 B1 · Bi-layered superhydrophobic membrane for water filtration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,109,537 B1 - Document ID: US12109537B1 - Status: Granted - Kind: B1 - Application number: 18/444,479 - Filed: 2024-02-16 - Granted: 2024-10-08 - Earliest claimed: 2024-02-16 - Assignees: King Faisal University - Applicants: King Faisal University - Inventors: Junaid Saleem; Safdar Hossain Sk; Zubair Khalid Baig Moghal; Gordon McKay - Web page: https://patentgrep.com/patent/US12109537B1 ## CPC - B01D 69/02: characterised by their properties - B01D 17/04: Breaking emulsions - B01D 61/147: {Microfiltration} - B01D 69/12: Composite membranes; Ultra-thin membranes - B01D 69/1218: {Layers having the same chemical composition, but different properties, e.g. pore size, molecular weight or porosity} - B01D 71/262: {Polypropylene} - B01D 2325/0233: with clearly distinguishable layers - B01D 2325/04: Characteristic thickness - B01D 2325/06: Surface irregularities - B01D 2325/20: Specific permeability or cut-off range - B01D 2325/24: Mechanical properties, e.g. strength - B01D 2325/38: Hydrophobic membranes - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## Abstract A bi-layered superhydrophobic membrane includes top and base layers formed from polypropylene. The bi-layered superhydrophobic membrane can have a thickness ranging from about 100 μm to about 1 mm. When subjected to oil-water emulsion separations, the superhydrophobic membrane can achieve an organic solvent flux of 14,000 Lm−2h−1 with a 96% water rejection. The bi-layered superhydrophobic membrane can be effectively used for water filtration, providing both selectivity and permeability, while offering an eco-friendly solution for reuse of polypropylene plastic waste. ## Claims ### Claim 1 A bi-layered superhydrophobic membrane, comprising: a porous top layer formed from about 75% to about 100% polypropylene; and a porous base layer formed from about 75% to about 100% polypropylene, the porous base layer being less porous than the porous top layer, wherein a thickness of the bi-layered superhydrophobic membrane ranges from about 100 μm to about 1 mm, wherein a surface roughness of the bi-layered superhydrophobic membrane ranges from about 120 nm to about 130 nm, and wherein a thickness of the top layer of the bi-layered superhydrophobic membrane ranges from about 60 μm to about 600 μm. ### Claim 2 (depends on 1) The bi-layered superhydrophobic membrane of claim 1, wherein a thickness of the base layer of the bi-layered superhydrophobic membrane ranges from about 40 μm to about 400 μm. ### Claim 3 (depends on 1) The bi-layered superhydrophobic membrane of claim 1, wherein the bi-layered superhydrophobic membrane has a tensile strength ranging from about 13 MPa to about 28 MPa. ### Claim 4 (depends on 1) The bi-layered superhydrophobic membrane of claim 1, wherein the polypropylene comprises at least one polypropylene selected from the group consisting of virgin polypropylene, waste polypropylene, and recycled polypropylene. ### Claim 5 (depends on 1) The bi-layered superhydrophobic membrane of claim 1, wherein the top layer of the bi-layered superhydrophobic membrane is more hydrophobic than the base layer of the bi-layered superhydrophobic membrane. ### Claim 6 (depends on 1) A method of separating water from a water-in-organic solvent emulsion, comprising: contacting the water-in-organic solvent emulsion with the top layer of the bi-layered superhydrophobic membrane of claim 1, whereby the organic solvent passes through micropores in the bi-layered superhydrophobic membrane and water flows off the top layer of the bi-layered superhydrophobic membrane. ### Claim 7 (depends on 6) The method of claim 6, wherein a level of water rejection from the top layer of the bi-layered superhydrophobic membrane ranges from about 91% to about 100%. ### Claim 8 (depends on 7) The method of claim 7, wherein the organic solvent is selected from the group consisting of toluene, hexane, oil, dichloromethane, heptane, and a combination thereof. ### Claim 9 (depends on 8) The method of claim 8, wherein the oil is diesel oil. ### Claim 10 A bi-layered superhydrophobic membrane, comprising: a porous top layer comprising polypropylene, the porous top layer having a thickness ranging from about 60 μm to about 600 μm and a surface roughness ranging from about 120 nm to about 130 nm; and a porous base layer comprising polypropylene, the porous base layer having a thickness ranging from about 40 μm to about 400 μm. ### Claim 11 (depends on 10) The bi-layered superhydrophobic membrane of claim 10, wherein the top layer is formed from about 75% to about 100% polypropylene; and the base layer is formed from about 75% to about 100% polypropylene. ### Claim 12 (depends on 10) The bi-layered superhydrophobic membrane of claim 10, wherein the porous base layer is less porous than the porous top layer. ### Claim 13 (depends on 10) The bi-layered superhydrophobic membrane of claim 10, wherein a thickness of the bi-layered superhydrophobic membrane ranges from about 100 μm to about 1 mm. ### Claim 14 (depends on 10) The bi-layered superhydrophobic membrane of claim 10, wherein the porous top layer imparts high surface roughness, leading to superhydrophobicity for selective separation, and simultaneously provides micropores to ensure effective liquid passage. ### Claim 15 (depends on 10) The bi-layered superhydrophobic membrane of claim 10, wherein the porous base layer serves as a substrate for the porous top layer, offering structural support and strength, while also including sufficient micropores to maintain high permeability.