WO2013008019A1 - Filtre - Google Patents

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Publication number
WO2013008019A1
WO2013008019A1 PCT/GB2012/051654 GB2012051654W WO2013008019A1 WO 2013008019 A1 WO2013008019 A1 WO 2013008019A1 GB 2012051654 W GB2012051654 W GB 2012051654W WO 2013008019 A1 WO2013008019 A1 WO 2013008019A1
Authority
WO
WIPO (PCT)
Prior art keywords
substrate
metal
filter element
nps
nanoparticles
Prior art date
Application number
PCT/GB2012/051654
Other languages
English (en)
Inventor
Thomas Bligh SCOTT
James William MACFARLANE
Original Assignee
University Of Bristol
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB1111951.8A external-priority patent/GB201111951D0/en
Priority claimed from GBGB1205823.6A external-priority patent/GB201205823D0/en
Application filed by University Of Bristol filed Critical University Of Bristol
Publication of WO2013008019A1 publication Critical patent/WO2013008019A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/34—Regenerating or reactivating
    • B01J20/3433—Regenerating or reactivating of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/20—Other self-supporting filtering material ; Other filtering material of inorganic material, e.g. asbestos paper, metallic filtering material of non-woven wires
    • B01D39/2027—Metallic material
    • B01D39/2031—Metallic material the material being particulate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/20—Other self-supporting filtering material ; Other filtering material of inorganic material, e.g. asbestos paper, metallic filtering material of non-woven wires
    • B01D39/2068—Other inorganic materials, e.g. ceramics
    • B01D39/2072—Other inorganic materials, e.g. ceramics the material being particulate or granular
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
    • B01J20/0225—Compounds of Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt
    • B01J20/0229—Compounds of Fe
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
    • B01J20/0233—Compounds of Cu, Ag, Au
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
    • B01J20/024—Compounds of Zn, Cd, Hg
    • B01J20/0244—Compounds of Zn
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/06—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/06—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04
    • B01J20/08—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04 comprising aluminium oxide or hydroxide; comprising bauxite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/20—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising free carbon; comprising carbon obtained by carbonising processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28002—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their physical properties
    • B01J20/28004—Sorbent size or size distribution, e.g. particle size
    • B01J20/28007—Sorbent size or size distribution, e.g. particle size with size in the range 1-100 nanometers, e.g. nanosized particles, nanofibers, nanotubes, nanowires or the like
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28014—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
    • B01J20/28042—Shaped bodies; Monolithic structures
    • B01J20/28045—Honeycomb or cellular structures; Solid foams or sponges
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/3085—Chemical treatments not covered by groups B01J20/3007 - B01J20/3078
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
    • B01J20/3202—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the carrier, support or substrate used for impregnation or coating
    • B01J20/3204—Inorganic carriers, supports or substrates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
    • B01J20/3231—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the coating or impregnating layer
    • B01J20/3234—Inorganic material layers
    • B01J20/3236—Inorganic material layers containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
    • B01J20/3291—Characterised by the shape of the carrier, the coating or the obtained coated product
    • B01J20/3295—Coatings made of particles, nanoparticles, fibers, nanofibers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D15/00—Electrolytic or electrophoretic production of coatings containing embedded materials, e.g. particles, whiskers, wires
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D21/00—Processes for servicing or operating cells for electrolytic coating
    • C25D21/10—Agitating of electrolytes; Moving of racks
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/007—Electroplating using magnetic fields, e.g. magnets
    • C25D5/009—Deposition of ferromagnetic material
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/18—Electroplating using modulated, pulsed or reversing current
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/20—Electroplating using ultrasonics, vibrations
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/48—After-treatment of electroplated surfaces
    • C25D5/50—After-treatment of electroplated surfaces by heat-treatment
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/60—Electroplating characterised by the structure or texture of the layers
    • C25D5/605—Surface topography of the layers, e.g. rough, dendritic or nodular layers
    • C25D5/611—Smooth layers
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/60—Electroplating characterised by the structure or texture of the layers
    • C25D5/615—Microstructure of the layers, e.g. mixed structure
    • C25D5/617—Crystalline layers
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/67—Electroplating to repair workpiece
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D7/00—Electroplating characterised by the article coated
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D7/00—Electroplating characterised by the article coated
    • C25D7/001—Magnets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/02—Types of fibres, filaments or particles, self-supporting or supported materials
    • B01D2239/0258—Types of fibres, filaments or particles, self-supporting or supported materials comprising nanoparticles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/065—More than one layer present in the filtering material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/065—More than one layer present in the filtering material
    • B01D2239/0654—Support layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/10—Filtering material manufacturing
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/20—Electroplating: Baths therefor from solutions of iron

Definitions

  • the present application relates to filters, particularly water filters, methods used to deposit composite surface coatings for filters and the use of them to remove contaminants from fluids.
  • Contaminants include heavy metals,
  • a foam substrate is coated with an adherent composition, such as a polyurethane , an acrylic, a silicone or another inherently tacky material, which dries to a water resistant coating.
  • an adherent composition such as a polyurethane , an acrylic, a silicone or another inherently tacky material, which dries to a water resistant coating.
  • a reactive absorbent powder such as powdered zero-valent iron, carbon, copper, zinc or zeolite, is then applied to the coated surface of the substrate which is subsequently shaken or moved to spread the powder over the coated surfaces of the foam substrate. This coated substrate is then proposed as a water filtration substrate.
  • the present proposals relate generally to a filter element comprising a substrate with a composite layer on a surface of the substrate, the composite layer comprising nanoparticles (NPs) comprising a first metal or a first metal oxide and a layer of a second metal, a second metal oxide or a combination thereof between the NPs on the substrate surface.
  • NPs nanoparticles
  • the present invention relates to a filter element comprising a substrate with a composite metal layer on a surface of the substrates, the composite layer comprising
  • nanoparticles comprising a first metal and a layer of a second metal between the NPs on the substrate surface.
  • the NPs comprise a first metal.
  • the NPs comprise a first metal oxide.
  • the NPs may comprise a combination of a first metal and a first metal oxide.
  • the layer between the NPs on the substrate surface comprises a second metal.
  • substrate surface comprises a second metal oxide.
  • substrate surface comprises a second metal and a second metal oxide.
  • nanoparticles in a liquid comprising a first metal or a first metal oxide and the liquid comprising second metal ions, and electrochemically depositing a composite layer of NPs and second metal on a substrate surface.
  • the present invention relates to a method of forming a composite metal layer on a substrate surface by providing a suspension of nanoparticles in a liquid, the
  • nanoparticles comprising a first metal and the liquid
  • the present proposals also include a fluid (e.g. water) treatment system and method comprising removal of a contaminant from a fluid (e.g. water) system using the filter and/or filter element of the present proposals, and regenerating the filter element to release the contaminant and restore contaminant-removal potential of the filter element.
  • a fluid e.g. water
  • Fig 1 shows a SEM image of a carbon foam surface treated according to the method described in Example 1. Scale bar 200nm.
  • Fig 2 shows a SEM image of a carbon foam surface treated according to the method described in Example 2. Scale bar 200nm.
  • Fig 3 shows a SEM image of a carbon foam surface treated according to the method described in Example 3. Scale bar 200nm.
  • Fig 4 shows a carbon foam surface at various stages of treatment according to the method described in Example 4.
  • Scale bars (L-R top row then L-R bottom row) 200 ⁇ , ⁇ , ⁇ , 200nm, lOOnm.
  • Fig. 5 shows a STEM image of a carbon foam surface treated according to the method described in Example 4.
  • Fig. 6 shows a bright-field STEM image of a cross-section through a carbon foam surface treated according to the method described in Example 4 also showing a cross section through the nanoparticles deposited on the surface.
  • Fig. 7a shows a SEM image of a carbon foam surface treated according to the method described in Example 6. Scale bar ⁇ .
  • Fig. 7b shows a SEM image of a carbon foam surface treated according to the method described in Example 7. Scale bar 50 ⁇ .
  • Fig. 8a shows a SEM image of a carbon foam surface treated according to the method described in Example 8. Scale bars (L/R)
  • Fig. 8b shows a SEM image of a carbon foam surface treated according to the method described in Example 9. Scale bars (L/R)
  • Fig. 8c shows a SEM image of a carbon foam surface treated according to the method described in Example 10.
  • Fig. 8d shows a SEM image of a carbon foam surface treated according to the method described in Example 11. Scale bars (L/R)
  • Fig. 9a shows a SEM image of a carbon foam surface treated according to the method described in Example 12. Scale bar ⁇ .
  • Fig. 9b shows a SEM image of a carbon foam surface treated according to the method described in Example 13. Scale bar 4 ⁇ .
  • Fig. 10 shows the experimental apparatus used to perform the electrodeposition described in Example 14.
  • Fig. 11 shows SEM images of the nano-structure on a top surface of the treated RVC substrate (top and bottom left) and a section approximately 3.8mm from the top surface (top and bottom right) . Scale bars 300nm (top row) , 500nm (bottom row) .
  • Fig. 12 shows an XPS spectrum of Fe 2p3/2 peak with fitted curves for before (top) and after (bottom) vacuum annealing.
  • Fig. 13 shows percentage of organic removed normalised by surface area of reactive material (iron nano-composite 12m 2 g _1 , granulated activated carbon 65m 2 g _1 , organo-clay 825m 2 g _1 ) .
  • the filter element of the present proposals or substrate surface coated according to the present methods may provide improved contaminant removal activity compared to known filter elements .
  • reaction speed e.g. fluid has to pass over a smaller area of the filter surface for the
  • increased reaction potential e.g. a given area of the filter surface can remove a larger amount of contaminant before the reactive composite layer on the surface of the filter element is depleted to the extent that the filter element no longer effectively removes contaminants from the fluid system
  • increased lifespan of the filter element e.g. a larger volume of fluid can be treated by a single filter element before the reactive composite layer on the surface of the filter element is depleted to the extent that the filter element no longer effectively removes contaminants from the fluid system
  • the filters and coated surfaces of these proposals comprise a substrate with a composite layer on a surface of the substrate, the composite layer comprising nanoparticles (NPs) comprising a first metal or a first metal oxide and a layer of a second metal, second metal oxide or a combination thereof between the NPs on the
  • the filters and coated surfaces of these proposals comprise a substrate with a composite metal layer on a surface of the substrate, the composite layer comprising nanoparticles (NPs) comprising a first metal and a layer of a second metal between the NPs on the substrate surface.
  • NPs nanoparticles
  • the substrate component can be made from any material that forms a porous substrate body.
  • the substrate has a high surface area.
  • Exact surface area may depend on the application of the final filter element but a preferred surface area is between about 4 and 40 m 2 /g.
  • substrate is preferably a material having a solid foam structure, preferably an open-cell foam, and preferred substrates are formed from an electrically conductive material because this allows the methods of the present proposals to be used to manufacture the filter element.
  • materials for the substrate include porous metallic bodies such as porous copper, porous carbon
  • the substrate is formed from porous carbon materials and most preferably from reticulated vitreous carbon foam.
  • the substrate may be a particulate substrate on which the composite coating of the present proposals may be formed.
  • Such particulate substrates may include silica or silicate particles (such as sand) , alumina particles, graphite or carbon particles, metallic particles, and glass, plastic or resin particles or beads.
  • the particulate substrate preferably has a particle diameter of between about 1 ⁇ and 5 mm, more preferably between about 0.5 mm and 2mm.
  • a preferred particulate substrate may be particulate carbon such as granular activated carbon (GAC) .
  • GAC granular activated carbon
  • an open cell foam structure as the substrate has an advantage that as fluid flow through an initial path of the filter element is restricted over time, the fluid can divert to travel via a different pathway through the filter element rather than blocking the filter itself and requiring higher head pressure to force the fluid through restricted pathways. This is particularly
  • the composite material deposited on the surface of the substrate increases in volume on reaction with contaminants in a fluid system causing the pores in a porous substrate body to become blocked or flow through them restricted over time.
  • a discrete porous substrate body is preferred, although a particulate substrate can also be useful if packed into a filter housing so that fluid to be filtered flows through the packed coated particles and contacts the coated
  • the composite layer on the surface of the substrate comprises both NPs comprising a first metal or a first metal oxide (preferably a first metal) and a layer of a second metal, second metal oxide or combination thereof (preferably a second metal) between the NPs on the surface of the substrate.
  • the second metal layer, second metal oxide layer or combination of second metal and second metal oxide layer also covers the NPs, i.e. it forms a layer covering both the surface of the substrate between the NPs and the NPs themselves (in such situations, the NPs may be referred to as being "overgrown" by the metal layer) .
  • the NPs are metallic, they are preferably formed from at least one metal but may comprise more than one metal, e.g.
  • bimetallic NPs i.e. the "first metal” combined with another metal
  • trimetallic NPs i.e. the "first metal” combined with two additional metals
  • the metallic NPs may have a thin outer coating of oxidised material, e.g. if they have been exposed to atmospheric oxygen or other oxidising environment.
  • the first metal may be any metal that has the ability to react with contaminants but is preferably a transition metal and
  • the first metal is Fe .
  • Fe is particularly preferred because Fe NPs are cheap to make and the size of the NPs can be easily controlled to give a narrow size distribution in a target size range. Fe is also shown to be effective for the treatment of fluids, especially water, to remove contaminants.
  • the NPs are formed from a mixture of metals (i.e. the first metal and one or more others), they preferably include one or more of the elements: Fe, Ni, Ag, Au, Cu, Zn and Co; combined in any proportions.
  • Preferred mixtures include Fe in combination with one or more of Ni, Cu and Co.
  • NPs formed from a mixture of metals are an alloy of Fe and Ni, more preferably in an 80:20 w/w Fe:Ni ratio.
  • the first metal oxide may be any metal oxide but is preferably a transition metal oxide, for example Ti0 2 , ZnO, Fe 2 0 3 , Fe 3 0 4 or CrO, preferably Ti0 2 .
  • a transition metal oxide for example Ti0 2 , ZnO, Fe 2 0 3 , Fe 3 0 4 or CrO, preferably Ti0 2 .
  • Ti0 2 is a semiconductor, and in addition when Ti0 2 nanoparticles are used to form the composite layer the material property of Ti0 2 allows the formation of reactive oxygen species (ROS) with UV illumination.
  • ROS reactive oxygen species
  • the NPs preferably have a particle size of about 1 - ⁇ 1000nm, preferably 2-100nm and more preferably 5-25nm. Above about lOOOnm reactivity of the particles diminishes undesirably.
  • the second metal (forming the layer between the NPs) may be any metal but is typically one with the ability to react with contaminants and is preferably a transition metal and more
  • the second metal is Fe .
  • the layer between the NPs on the substrate surface may comprise one or more metals in addition to the second metal.
  • the layer comprising the second metal may further comprise one or more metals selected from Fe, Ni, Ag, Au, Cu, Zn and Co.
  • both the first metal and the second metal are the same and more preferably are both Fe .
  • the NPs are formed from and Fe/Ni mixture and the layer between the NPs is formed from Fe .
  • first metal or first metal oxide, second metal, second metal oxide or combination thereof and the composition of the NPs and metal layer between them can be tailored to provide the most effective and efficient removal of desired, target contaminants.
  • the thickness of the composite layer is about the diameter of the NPs (or slightly thicker if the NPs are
  • the thickness of the composite layer is preferably less than 1 ⁇ , more preferably about 10-500 nm, more preferably about 50-300nm. If the composite layer is too thick, little or no additional active surface area or catalytic activity is gained but the layer takes longer to form and uses more material so is economically less desirable.
  • the use of the composite coating on the substrate surface i.e. a coating comprising NPs comprising a first metal or a first metal oxide (preferably a first metal) and a layer of a second metal, a second metal oxide or a combination thereof (preferably a second metal) between the NPs on the surface of the substrate, provides a filter element having a high capacity for removal of contaminants from a fluid system (e.g. a water system) .
  • a fluid system e.g. a water system
  • this capacity for contaminant removal is higher than for known filter elements. This may be due to the very high reactive surface area achieved by the composite coating. This reactive surface area is typically higher than simple metal-plated surfaces or surfaces on which metallic NPs have been deposited.
  • Simple metal-plating of a substrate can achieve a reactive surface but typically this has a similar surface area to the underlying substrate.
  • Deposition of metallic NPs on a substrate surface can provide a higher active surface area than the underlying substrate, due to the NPs standing up from the substrate surface, but between the NPs the substrate surface is usually exposed unreactive substrate.
  • the composite coating of the present proposals provide a higher reactive surface area than either of these two known situations because the NPs stand up from the substrate surface so exposing a high active surface area and in addition, an active surface layer is provided between the NPs so the exposed active surface is increased still further.
  • the present proposals also relate to a method of forming a composite layer on a substrate surface. These methods involve providing a suspension of NPs in a liquid, the NPs comprising a first metal or a first metal oxide and the liquid comprising second metal ions, and electrochemically depositing a composite layer of NPs and second metal on a substrate surface.
  • these methods involve providing a suspension of NPs in a liquid, the NPs comprising a first metal and the liquid comprising second metal ions, and electrochemically depositing a composite layer of NPs and second metal on a substrate surface.
  • the electrochemical deposition of the composite layer on a substrate surface typically involves providing an electrically conductive substrate as the cathode in an electrochemical cell with the liquid comprising second metal ions as the electrolyte.
  • the electrochemical deposition involves immersing an electrically conductive substrate in the suspension of NPs in the liquid comprising the second metal ions within an electrically conductive vessel.
  • An electrolytic cell is then set up with the substrate acting as the cathode and the electrically conductive vessel acting as the anode.
  • Application of an electric current moves the second metal ions out of the liquid to deposit on the substrate.
  • the small size of the NPs suspended in the liquid means that they are also manipulated by the electric field in the vessel and deposit on the surface of the substrate with the ions of the second metal from the liquid to form the composite coating. Due to the use of nano-sized particles, an electrostatically charged region forms around the surface of the NPs allowing them to be manipulated by the electrical field (set up in the electrochemical cell) .
  • This electrochemical arrangement is preferred to one in which a sacrificial anode is used (i.e. where the metal for deposition on the substrate is provided by the anode itself which is consumed during the electrochemical deposition) because it provides a more uniform coating on the substrate surface and is a more robust and scalable process because the deposition is not significantly influenced by pH or concentration gradients in the electrochemical cell (which can be influential and problematic in sacrificial anode arrangements and can lead to uneven deposition on the substrate) .
  • the electrochemical deposition current has a current density of less than 3 Acm -2 , preferably less than 1 Acm "2 , more preferably less than 0.6 Acm -2 , more preferably less thar 0.4 Acm -2 , more preferably less than 0.2 Acm -2 , and most preferably less than 0.1 Acm -2 , for example, a current density of 0.09 Acm -2 has been found useful in providing a suitable composite layer.
  • the current density of the electrochemical deposition current has been found to affect the formation of the composite layer; a greater current density causes a larger flux of metal ions towards the cathode, but this also causes more rapid evolution of hydrogen at the cathode as H + ions are generated.
  • the production of hydrogei bubbles at the cathode may prevent or impede the second metal ions from binding to the substrate.
  • the use of a deposition current with a current density of less than 1 Acm -2 can improve the adhesion of the NPs and/or second metal ions to the substrate and can help to prevent uneven deposition of the composite layer so that a stable and regular surface may be obtained.
  • the rate of deposition may be too low to be commercially useful, for example a current density of less than 0.001 Acm -2 may be too low to be commercially useful.
  • the ratio of the concentration of NPs to the concentration of the metal salt in the liquid is less than 80:2 and greater than 20:80, more preferably less than 75:25 and greater than 25:75, more preferably 50:50 (for example 5 gL -1 NPs: 5 gL -1 metal salt) . It has been found that a ratio of the concentration o NPs to the concentration of the metal greater than 80:20, or less than 20:80 may have a detrimental effect on the composite layer formed. Therefore the ratio of the concentration of NPs to the concentration of the metal salt in the liquid may help to provide a uniform composite layer.
  • a preferred concentration of NPs in the liquid is about 1 - ⁇ 10 gL -1 , preferably about 1-8 gL -1 , more preferably about 2-5 gL -1 .
  • the liquid electrolyte is an aqueous solution containing the second metal ions.
  • solvents such as organic solvents e.g. glycerol, or high purity volatile organic compounds.
  • the exact preferred solvent is typically dependent on the dissolution characteristics of the metal ions in question, although the preferred water solvent is widely applicable .
  • the electrolyte liquid may also contain other optional components such as surfactants (e.g. carboxymethyl cellulose (CMC), guar gum, polyacrylic acid, sodium dodecyl sulphate (SDS), block copolymers such as Triton X-100 (RTM) , ammonium laureth sulphate, sodium laureth sulphate, benzalkonium chloride, fatty alcohols such as stearyl alcohol or cetyl alcohol, polyoxyethylene glycol alkyl ethers, poloxamers etc.) .
  • surfactants e.g. carboxymethyl cellulose (CMC), guar gum, polyacrylic acid, sodium dodecyl sulphate (SDS), block copolymers such as Triton X-100 (RTM) , ammonium laureth sulphate, sodium laureth sulphate, benzalkonium chloride, fatty alcohols such as stearyl alcohol or cetyl alcohol, polyoxyethylene glycol
  • the polarity of the electrolytic cell is reversed periodically, preferably in a cycle of alternative forward and reverse polarity. This can help to prevent uneven deposition of the composite layer resulting in a more even thickness and improved coverage of composite layer across the surface of the substrate. It is preferred that the period of time for which the polarity is reversed is less than or equal to (preferably less than) the time for which the polarity is in the forward direction. Preferably the ratio of the time for which the polarity is in the forward direction to the time for which the polarity is reversed is between 1:0.1 - ⁇ 1, preferably about 1:0.2 - 0.5 and most preferably about 1:1/3. Below a ratio of about 1:0.1, i.e.
  • the current flows in the forward direction for between 0.5 s and 5 min, preferably between 1 and 120 s, or between 1 and 60 s, more preferably between about 15 and 45 s, most
  • the length of the period of reverse current determined according to the ratios above. If the current flows in the forward direction for longer than 5 min without a period of reverse current, there is a risk that the quality and uniformity of the coating may be degraded. If the current flows in the forward direction for less than 0.5 s before a period of reverse polarity, the rate of deposition is low and the overall coating takes an undesirably long time to form. Most preferably, the
  • electrodeposition cycle includes a repeated cycle of current flowin in the forward direction for about 30 s followed by current with th reverse polarity for about 10 s.
  • the liquid is agitated intermittently during the electrochemical deposition process.
  • This agitation can help to keep the NPs in suspension in the liquid which results in a more uniform coverage of NPs on the surface of the substrate.
  • This agitation is preferably ultrasonic agitation, e.g. using an ultrasonic bath or probe to agitate the liquid, although other agitation methods may also be effective to keep the NPs in
  • the electric current through the electrochemical cell is switched off during agitation of the liquid to prevent any interference of the agitation with the deposition of a uniform coating; typically adhesion of the NPs to the surface of the substrate is reduced if the agitation is performed at the same time as the electrodeposition process. It is preferred that the period of time for which the liquid is agitated is less than or equal to (preferably less than) the time for which the current flows in the forward direction. This preference is primarily for efficiency reasons; longer periods of agitation are possible and do not have a detrimental effect on the surface coating.
  • the ratio of the time for which the current is in the forward direction to the agitation time is between about 1:0.01 - ⁇ 1, preferably 1:0. - ⁇ 1, more preferably about 1:0.2 - 0.5 and most preferably about 1:1/3.
  • the current flows in the forward direction for between 0.5 and 5 min, preferably between 1 and 120 s, or between 1 and 60 s, more preferably between about 1 and 45 s, most preferably 30 s, with the length of the period of agitation of the liquid determined according to these ratios.
  • the electrodeposition cycle includes a repeated cycle of current flowing in the forward direction, followed by a period of current flowing with the reverse polarity, followed by a period of agitation of the liquid (with no current flowing) , preferably with the time periods determined by the ranges and ratios described above.
  • the electrodeposition cycle includes a repeated cycle of current flowing in the forward direction for 30 s, followed by a period of current flowing with the reverse polarity for 10 s, followed by a period of agitation of the liquid (with no current flowing) for 10 s.
  • the electrodeposition cycle includes a repeated cycle of a first period of current flowing in the forward direction alternating with a period of agitation (with no current flowing) followed by a second period of current flowing in the reverse direction alternating with a period of agitation (with no current flowing) .
  • a preferred example of this method may use a repeating cycle of a first period of 40s comprising 5s agitation alternating with 5s forward current, alternating with a second period of 20s comprising 5s agitation alternating with 5s reverse current .
  • the composite coating tends to lack uniformity and can flake away from the substrate surface.
  • NPs being "overgrown", i.e. covered with a layer of metal from the electro-deposition of the second metal ions from the liquid.
  • This overgrowth tends to reduce the overall available surface area for reaction and also covers the NPs which means that the any surface of the NPs that is overgrown is not available as a reactive surface. This can negate or reduce the effectiveness of any careful selection of the composition of the NPs to target particular contaminants so impairing performance of the coating .
  • the first metal or first metal oxide, the second metal and NP sizes are as described in relation to the composite layers above.
  • the deposition of NPs on the substrate surface can be enhanced by placing a magnet inside the substrate which attracts the ferromagnetic NPs towards the surface of the substrate. Therefore, some methods also include the step of providing a magnet inside the substrate during the electrochemical deposition. In preferred methods, the magnet is an electromagnet because these typically provide a stronger attractive magnetic force than permanent magnets .
  • the performance of the composite layer (e.g. composite metal layer) on the surface of the substrate can also be enhanced by annealing the layer in a vacuum or inert atmosphere following deposition.
  • This annealing step can improve the crystallinity of a deposited composite coating and can improve the electron transfer between the coating and the substrate surface. It also has the effect of driving impurities in the originally deposited composite coating to the grain boundaries in the metallic layer where they are concentrated which means that the metal layer between the grain boundaries is improved in purity.
  • the annealing preferably involves heating the composite layer in a vacuum (e.g. ⁇ lxlO ⁇ 3 mbar and preferably ⁇ lxl0 ⁇ 4 mbar) or inert atmosphere (such as He, Ne, Ar or dry N 2 ) at a temperature up to the lower melting point of the NPs and second metal layer of the composite layer.
  • a vacuum e.g. ⁇ lxlO ⁇ 3 mbar and preferably ⁇ lxl0 ⁇ 4 mbar
  • inert atmosphere such as He, Ne, Ar or dry N 2
  • the annealing temperature is between about 200°C and 50°C below the lower melting point of the NPs and second metal layer.
  • the annealing temperature between about 100 °C and about 1000 °C, more preferably between about 200°C and about 800°C, most preferably between about 300°C and about 600°C, such as about 500°C.
  • the annealing time is not particularly critical but is typically at least about 2 hours, preferably at least about 6 hours, more preferably at least about 12 hours, most preferably between about 12 and 24 hours. Less than 2 hours may not be sufficient time to achieve the benefits mentioned above, e.g. improved crystallinity of the metal layer; and annealing times of more than 24 hours may not achieve significantly better results but do incur additional production costs.
  • the performance of the composite layer on the surface of the substrate can also be enhanced by oxidation of the second metal layer.
  • the degree of oxidation of the second metal layer can be varied depending on the target contaminant for filtration.
  • oxidation of the second metal layer produces a composite layer with a second metal oxide layer. In other methods oxidation of the second metal layer produces a composite layer with a second layer comprising a second metal and a second metal oxide.
  • the second metal oxide may be any oxide of the second metals described above, for example a transition metal oxide.
  • a further aspect of the present proposals is the use of a filter element of these proposals or a coated substrate formed by the present methods, in a method of treating a fluid to remove contaminants.
  • These proposals also include a filter comprising one or more filter elements as described herein or coated substrates formed by a method as described herein.
  • the filter typically includes one or more filter elements as described herein or coated substrates formed by the present methods, and a filter housing which has a fluid inlet, a fluid outlet and a fluid flow pathway between the two, the fluid flow pathway passing through a filtering region which contains the one or more filter elements as described herein or coated substrates formed by the present methods.
  • the substrate of the filter element is a discrete porous substrate body
  • the fluid flow pathway typically passes through that body in the filtering region.
  • the substrate is a coated particulate substrate
  • the fluid flow pathway typically passes through a region of packed coated particles in the filtering region.
  • the filters of the present proposals may also contain
  • filter components such as screen filters
  • additional filter components upstream of the filtering region to remove particulate impurities from the incoming fluid prior to treatment with the filter elements and coated substrates described herein.
  • the fluid is preferably a liquid and most preferably is water.
  • contaminants involves flowing a fluid over the composite coating on the surface of the substrate.
  • the fluid may be pre-filtered before passing over the coated surface to remove particulate contaminants .
  • the fluid is water and the filter elements and substrates coated according to the methods described can remove contaminants from the water.
  • the present proposals provide effective methods and products for the removal of contaminants from aqueous systems.
  • contaminant may, for example be present in, groundwater flow, drinking water, water treatment plants, industrial plant waters both pre- and post-treatment, or mine tailings.
  • a possible application includes the removal of Uranium from deep mine waters, by the adsorption and chemical reduction of U 6+ U 4+ on a substrate coated with a composite coating in which both first and second metals are Fe .
  • the contaminants that can be removed depend on the particular coating, e.g. on the exact composition of the NPs and the metal layer between them, and the coatings can be tailored to be most effective at removal of particular targeted contaminants.
  • some typical contaminants that may be removed from water systems include heavy metals (such as Cd, Hg, Cr, Cu, U, As, Sn, and Pb) , pesticides, residues and metabolites from pharmaceuticals (such as hormones e.g. estrogen), compounds that interfere with the endocrine system in animals, e.g. any endocrine disruptor compounds, waste products from industrial processes, bacteria (such as Pseudomonas aeruginosa or Escherichia coli) , and many others.
  • the present proposals also include the regeneration or restoration of filters, filter elements and coated surfaces formed according to the present methods.
  • the composite coatings of these proposals have been used to remove contaminants from a fluid system, the composite coating can become occluded by the products of the reaction between the coating and the contaminants or can show a reduced activity for removing contaminants.
  • Many filter systems simply have to be discarded at this stage because it is not possible (or is commercially not viable) to remove the surface contamination to restore or revive the contaminant-removing activity.
  • the electrodeposition methods used to form the present composite coatings mean that it is straightforward to remove the coating by reverse electroplating. This involves placing the contaminated surface or filter element in the same apparatus as used for the present coating methods and applying an electric current with the opposite polarity to that used for the plating step, i.e. wherein the contaminated, coated substrate is the anode in the
  • electrochemical cell and an electrolyte liquid is provided.
  • the electrolyte liquid is water.
  • This reverse electroplating removes the composite surface from the substrate along with any contaminants deposited on the composite surface.
  • An advantage of this regeneration is for systems where the composite surface has been used to filter out valuable components from a fluid system.
  • the reverse electroplating can release the valuable components along with the composite surface components into the electrolyte form which they can be chemically isolated or simply dried into a solid deposit which may in itself have commercial value. For example, this could be used in the mining industry as a method for concentrating minerals or a
  • the substrate can of course be re-coated (using the present methods) and re-used.
  • the ability to perform this reverse electroplating method to remove the coating and associated contaminants is due to the same physical properties that are required for the electroplating methods. So the use of an electrically conductive substrate makes this reverse electroplating step possible.
  • the present methods may also include a step of removing the composite surface and any associated contaminants by reverse electroplating and isolating the contaminants from the electrolyte solution.
  • a 10 x 10 x 30 mm carbon foam block (commercially available from ERG Materials and Aerospace corporation (Oakland, CA, USA) was suspended in FeCl 3 , 2 g/L salt solution in a 316 stainless steel beaker.
  • 0.2 g of bimetallic nanoparticles 80% Fe, 20% Ni were added to the electrolyte solution (a concentration of 2 g/L Fe NPs in the electrolyte solution) .
  • a current of 0.3 A was applied for 0.5 minutes, with ultrasound sonication in place continuously to keep the nano particles in suspension.
  • the substrate was removed from solution, washed in high purity methanol and stored under ultra-high vacuum.
  • the surface of the carbon foam block is shown in fig 1.
  • a carbon foam block was treated as in Example 1. However during the electrochemical treatment, ultrasound sonication and electric current were pulsed alternately with 5 s of electro- deposition followed by 5 s of sonication for a total treatment time of 60 s.
  • the surface of the carbon foam block is shown in fig 2.
  • fig 2 the improved NP morphology and uniformity can be seen compared to fig 1 where the electro-deposition current was not stopped during the ultrasound sonication.
  • the NPs (1) are still largely "overgrown", i.e. covered with a layer of metal from the electro-deposition from the metal ions in the liquid. This overgrowth tends to reduce the overall available surface area for reaction .
  • a carbon foam block was treated as in Example 1. However during the electrochemical treatment the forward and reverse polarity current periods were interspersed with periods of
  • the forward polarity current was 0.3 A and the reverse polarity current was 0.3 A. No current flowed during the ultrasound sonication steps.
  • the surface of the carbon foam block is shown in fig 3.
  • a carbon foam block was treated as in Example 3. However, following the electro-deposition treatment, the treated carbon foam was vacuum annealed at 500 °C for 12-24 hrs at a vacuum pressure of ⁇ 1 x 10 ⁇ 4 mbar .
  • the surface of the treated carbon foam block is shown (at various magnification levels) in fig 4 and shows no significant change in surface structure or topography compared to the surface prior to vacuum annealing.
  • measurements of surface chemistry using X-ray photoelectron spectroscopy (XPS) demonstrate a surface refinement, wherein the proportion of Fe(II) in the surface oxide film is significantly increased as shown in Table 1.
  • the XPS system was a Thermo Fisher Scientific Escascope equipped with a dual anode X-ray source ( ⁇ 1 ⁇ 1486.6 eV and Mg Ka 1253.6 eV) . Samples were analysed under high vacuum ( ⁇ 5xl0 ⁇ 8 mbar) with ⁇ 1 ⁇ radiation at 400W(15 kV, 23 mA) .
  • Fig. 5 shows a STEM image of a carbon foam surface treated according to the method described in Example 4 showing good surface coverage with a coating including well defined, discrete NPs (2) .
  • Fig. 6 shows a bright-field STEM image of a cross-section through a carbon foam surface (3) treated according to the method described in Example 4 also showing a cross section through the nanoparticles deposited on the surface (3) .
  • the discrete NPs (1) can be clearly seen deposited on the surface (3) .
  • the treated carbon foam block formed in Example 4 was suspended in 200 ml of various aqueous solutions containing the following contaminants: Cr lOppm; Cu lOppm; and As lOppm, for 300 minutes at an ambient room temperature.
  • liquid samples were prepared for analysis by inductively coupled plasma atomic emission spectroscopy
  • ICP-AES ICP-AES by diluting 10 times in 1% nitric acid (analytical quality concentrated HN0 3 in Milli-Q water) . Blanks and standards for analysis were also prepared in 1% nitric acid. ICP-AES analysis
  • a 10 x 10 x 30 mm carbon foam block (commercially available from ERG Materials and Aerospace corporation (Oakland, CA, USA) was suspended in FeCl 3 ,5 g/L salt solution in a 316 stainless steel beaker. 5g/L of Fe nanoparticles were added to the electrolyte solution. The carbon foam block was treated electrochemically .
  • the forward polarity current was 0.1 A (current density of 0.03 Acrrf 2 ) and the reverse polarity current was 0.1 A (current density of 0.03 Acrrf 2 ) .
  • the substrate was removed from solution, washed in high purity methanol and stored under ultra-high vacuum. The surface of the carbon foam block is shown in Fig. 7a.
  • a carbon foam block was treated as in Example 6. However, the forward polarity current and the reverse polarity current used during electrochemical treatment were 1 A (current density of 0.3 Acrrf 2 ) .
  • the surface of the carbon foam block is shown in Fig. 7b.
  • FIGS. 7a and 7b show the effect of current used during
  • Figures 7a and 7b show that the current used must be high enough to draw the ions to the surface of the substrate; however H + ions may also be drawn to the cathode and result in the generation of hydrogen gas. This evolution of gas can cause cracks in the surface and hinder even deposition of the composite layer.
  • a 10 x 10 x 30 mm carbon foam block (commercially available from ERG Materials and Aerospace corporation (Oakland, CA, USA) was suspended in AgN, 5g/L salt solution in a 316 stainless steel beaker. 5g/L of Ag nanoparticles were added to the electrolyte solution. The carbon foam block was treated electrochemically .
  • the forward polarity current was 0.3 A and the reverse polarity current was 0.3 A. No current flowed during the ultrasound sonication steps.
  • the substrate was removed from solution, washed in high purity methanol and stored under ultra-high vacuum.
  • the surface of the carbon foam block is shown in Fig. 8a.
  • a carbon foam block was treated as in Example 8. However, the salt solution used was PtCl and the nanoparticles added to the electrolyte solution were Pt NPs .
  • the surface of the carbon foam block is shown in Fig. 8b.
  • a carbon foam block was treated as in Example 8. However, the nanoparticles added to the electrolyte solution were Ti0 2 NPs. The surface of the carbon foam block is shown in Fig. 8c.
  • a carbon foam block was treated as in Example 8. However, the salt solution used was FeCl 3 and Pt and Fe nanoparticles were added to the electrolyte solution. The surface of the carbon foam block is shown in Fig. 8d.
  • Fig. 8d shows that for this mixed phase PtNP/INP system a uniform structure was also observed.
  • a carbon foam block was treated as in Example 3.
  • Example 13 A carbon foam block was treated as in Example 3.
  • Figures 9a and 9b were formed under the same conditions as the surface of figure 3 except for the ratio of Fe salt to Fe NPs used.
  • the surface of Fig. 9a is much smoother, and therefore has a much smaller surface area, than that of the surface of Fig. 3 due to the low ratio of the concentration of NPs to concentration of metal salt used in the liquid. It is thought that the low concentration of NPs provide only a small number of
  • Fig. 9b has conglomerates of fluff like structures on its surface. These structures are the result of uneven deposition caused by the high ratio of concentration of NPs to concentration of metal salt in the liquid in the method of Example 13.
  • Filter substrate disks 9mm thick and 47mm in diameter, of Reticulated Vitreous Carbon (RVC) foam (ERG Aerospace, U.S.A.) with a porosity of 45 pores per inch (PPI), were washed ultrasonically in acetone and MilliQ water as a preparatory cleaning step.
  • RVC Reticulated Vitreous Carbon
  • the RVC foam disks were maintained in contact with a stainless steel plate forming the cathode.
  • a stainless steel beaker acted as the anode and container for an electrolyte solution, which was a combination of 0.4g FeCl 3 (99.9%, Sigma) and lg Iron Nanoparticles (INP) s (Nanolron Ltd., Czech Republic) in 200ml deionised water (pH4) .
  • the beaker was held within a sonic bath to assist suspension of the INPs and prevent them aggregating.
  • the electrolyte was purged of oxygen using argon to reduce the oxidation of the INPs.
  • the RVC disk was sonicated in the electrolyte to allow the INPs to penetrate the foam before beginning the deposition. Electrodeposition was performed using a 9 minute treatment consisting of 40s of 5s sonication and 5s forward current pulses, alternating with 20s of 5s sonication and 5s reverse current pulses. The RVC substrate was then turned over and the cycle repeated. The samples were rinsed with acetone to remove any excess INPs and they placed immediately in a vacuum desiccator to dry.
  • Control samples were formed using electrolyte solutions void of nanoparticles (0.0086mol FeCl 3 ) under the same treatment
  • the formation of the nano-coating was found to be influenced by the electrodeposition conditions.
  • Current density was identified as an important variable; increased potential difference between electrodes causes an increase in ion/INP flux due to the larger electrostatic attraction.
  • Another important variable is the length of electrodeposition; longer deposition times, although producing a thicker layer, forfeit the structural integrity of the coating and it becomes easily detached from the substrate.
  • the presence of both iron salt and INPs in the electrolyte is also important; the iron ions cement the INPs to the surface, whilst the INPs cause
  • Fig. 11 shows SEM images of the nano-structure on a top surface of the treated RVC substrate (top and bottom left) and a section approximately 3.8mm from the top surface (top and bottom right) .
  • the coating consists primarily of quasi spherical features, approximately 20nm in size, created by the deposition of INPs cemented to the surface by the dissociated iron from FeCl 3 . These features are interspersed by faceted metallic crystals, resulting from the INPs acting as nucleation sites for heterogeneous crystal growth .
  • Example 14 A sample of the coated RVC foam formed in Example 14 was vacuum annealed at 600°C for 24hrs in a vacuum. XPS analysis was performed both before and after the vacuum annealing to investigate the change in physicochemistry .
  • the vacuum annealing process improves the structure of both the metallic NPs that are deposited and any oxide layer on the outside of the NPs.
  • Vacuum annealing of iron NPs causes the metallic core to recrystallise into a more ordered structure, grain sizes to increase and impurities to migrate to the surface and grain boundaries.
  • the surface oxide is also significantly improved with an improvement in crystallinity to a thinned uniform and conductive magnetite (Fe 3 0 4 ) layer. The improved layer allows for more
  • the vacuum annealed iron NPs therefore demonstrate improved reactivity whilst reducing the aqueous
  • Fig. 12 shows an XPS spectrum of Fe 2p3/2 peak with fitted curves for before (top) and after (bottom) vacuum annealing.
  • the ratio of Fe(II) :Fe(III) increases (from 0.160 to 0.373) in accordance with the thermal decomposition of Fe(III) .
  • This physiochemical improvement implies that vacuum annealing the nano-composite will increase the
  • Fig. 13 shows percentage of organic removed normalised by surface area of reactive material (INC 12m 2 g _1 , GAC 65m 2 g _1 , OC 825m 2 g _1 ) .
  • the mechanism involved for BTEX removal onto the INC is thought to be adsorption followed by degradation caused by the organic-iron coordination weakening of the benzene ring. This is compared to OC and GAC which are typically thought to remove organics via adsorption alone.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Electrochemistry (AREA)
  • Metallurgy (AREA)
  • Analytical Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Nanotechnology (AREA)
  • Life Sciences & Earth Sciences (AREA)
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Abstract

La présente invention porte sur des éléments filtrants comprenant un substrat doté d'une couche composite sur une surface du substrat, la couche composite comprenant des nanoparticules comprenant un premier métal, un premier oxyde métallique ou une association de ceux-ci ; et une couche comprenant un second métal, un second oxyde métallique ou une association de ceux-ci entre les particules disposées sur la surface du substrat. L'invention porte également sur des procédés de formation de tels éléments filtrants ainsi que sur des filtres incorporant ces éléments filtrants, sur des procédés de traitement d'un fluide utilisant l'élément filtrant et sur des procédés de régénération de l'élément filtrant. Les premier et second métaux préférés sont Fe, Ni, Ag, Au, Cu, Zn, Pt, Co, Ce ou Al.
PCT/GB2012/051654 2011-07-12 2012-07-12 Filtre WO2013008019A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GB1111951.8 2011-07-12
GBGB1111951.8A GB201111951D0 (en) 2011-07-12 2011-07-12 Filter
GB1205823.6 2012-03-30
GBGB1205823.6A GB201205823D0 (en) 2012-03-30 2012-03-30 Filter

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Cited By (5)

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EP2979741A1 (fr) * 2013-03-29 2016-02-03 Korea University Research and Business Foundation Filtre à nanocatalyseur et son procédé de production
WO2018193249A1 (fr) * 2017-04-18 2018-10-25 University Of Bath Filtres à air
WO2019054214A1 (fr) * 2017-09-13 2019-03-21 株式会社大阪ソーダ Agent de traitement de métaux lourds et procédé de fabrication d'un agent de traitement de métaux lourds
GB2567695A (en) * 2017-10-23 2019-04-24 Pro 1 Nanosolutions Ou Cobalt metal nanoparticles for heavy metal extraction from water
US11071946B2 (en) 2013-03-29 2021-07-27 Korea University Research And Business Foundation Nano-catalyst filter and production method for same

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WO2009137694A2 (fr) * 2008-05-09 2009-11-12 University Of Kentucky Research Foundation Inc. Dépôt électrolytique régulé de nanoparticules
WO2010027868A2 (fr) * 2008-08-26 2010-03-11 Nanoscale Corporation Procédé et appareil pour le contrôle et l'élimination de substances indésirables
US20100297904A1 (en) * 2007-07-19 2010-11-25 Sigrid Obenland Ultrahydrophobic substrate provided on its surface with metallic nanoparticles, method of production and use of same
US20100307978A1 (en) 2009-04-25 2010-12-09 John Sawyer Apparatus and method for contaminant removal from aqueous solution
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US20020006867A1 (en) * 1997-01-17 2002-01-17 The Penn State Research Foundation Powerful reductant for decontamination of groundwater and surface streams
WO2006072784A2 (fr) * 2005-01-04 2006-07-13 Nanotecture Ltd Filtre
US20090246528A1 (en) * 2006-02-15 2009-10-01 Rudyard Lyle Istvan Mesoporous activated carbons
US20080105560A1 (en) * 2006-11-08 2008-05-08 Industrial Technology Research Institute Method for Preparing Nano Metallic Particles
US20100297904A1 (en) * 2007-07-19 2010-11-25 Sigrid Obenland Ultrahydrophobic substrate provided on its surface with metallic nanoparticles, method of production and use of same
WO2009137694A2 (fr) * 2008-05-09 2009-11-12 University Of Kentucky Research Foundation Inc. Dépôt électrolytique régulé de nanoparticules
WO2010027868A2 (fr) * 2008-08-26 2010-03-11 Nanoscale Corporation Procédé et appareil pour le contrôle et l'élimination de substances indésirables
US20100307978A1 (en) 2009-04-25 2010-12-09 John Sawyer Apparatus and method for contaminant removal from aqueous solution
EP2261398A1 (fr) * 2009-06-10 2010-12-15 Universität des Saarlandes Mousses métalliques

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2979741A1 (fr) * 2013-03-29 2016-02-03 Korea University Research and Business Foundation Filtre à nanocatalyseur et son procédé de production
EP2979741A4 (fr) * 2013-03-29 2017-03-29 Korea University Research and Business Foundation Filtre à nanocatalyseur et son procédé de production
US11071946B2 (en) 2013-03-29 2021-07-27 Korea University Research And Business Foundation Nano-catalyst filter and production method for same
WO2018193249A1 (fr) * 2017-04-18 2018-10-25 University Of Bath Filtres à air
US11779874B2 (en) 2017-04-18 2023-10-10 University Of Bath Air filters
WO2019054214A1 (fr) * 2017-09-13 2019-03-21 株式会社大阪ソーダ Agent de traitement de métaux lourds et procédé de fabrication d'un agent de traitement de métaux lourds
JPWO2019054214A1 (ja) * 2017-09-13 2020-10-29 株式会社大阪ソーダ 重金属処理剤および重金属処理剤の製造方法
GB2567695A (en) * 2017-10-23 2019-04-24 Pro 1 Nanosolutions Ou Cobalt metal nanoparticles for heavy metal extraction from water

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