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
  • B01J20/28—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
  • B01J20/28023—Fibres or filaments
• • 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
  • B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
  • B01D39/1607—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous
  • B01D39/1623—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous of synthetic origin
• • 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
  • B01J20/30—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
  • B01J20/3206—Organic carriers, supports or substrates
  • B01J20/3208—Polymeric carriers, supports or substrates
  • B01J20/321—Polymeric carriers, supports or substrates consisting of a polymer obtained by reactions involving only carbon to carbon unsaturated bonds
• • 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
  • B01J20/324—Inorganic material layers containing free carbon, e.g. activated carbon
• • 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
  • B01J20/3293—Coatings on a core, the core being particle or fiber shaped, e.g. encapsulated particles, coated fibers
• • 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
  • B01D2239/0241—Types of fibres, filaments or particles, self-supporting or supported materials comprising electrically conductive fibres or particles
• • 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
  • B01D2239/04—Additives and treatments of the filtering material
  • B01D2239/0471—Surface coating material
  • B01D2239/0492—Surface coating material on fibres
• • 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
  • B01J2220/00—Aspects relating to sorbent materials
  • B01J2220/50—Aspects relating to the use of sorbent or filter aid materials
  • B01J2220/62—In a cartridge

Definitions

• the present invention provides a method for production of conductive polymer filters and a filter obtained using said method.
• the common method for liquid clarification is filtration with use of candle filters, also called filter cartridges. These filters are of cylindrical shape and are installed inside an appropriate housing, through which the filtrated liquid passes. Contaminations are retained on the filter, which is periodically replaced with a new one.
• Filtration cartridges are usually made of polypropylene using the melt-blown technology. Polypropylene is used in filtration layer formation composed of thin polymer fibres.
• This phenomenon may be prevented by elimination of electrostatic charges accumulating on the filter.
• Production of a filter with conductive material, such as metal, is difficult since it is really difficult to produce inexpensive metallic fibres of micrometer thickness.
• CN 103846011 discloses porous membrane made of conductive polymer with specific surface resistance higher then ⁇ . ⁇ .
• Method for production of such membrane comprises the following steps: carrying out ultrasonic dispersion on carbon black for 1-3 hours in water at 25°C, then stirring, adding a binding agent into the mixture, and fully stirring to obtain a uniform dynamic membrane casting solution; washing a polymer basement membrane with water; continuously running under the operation pressure of 0.1- 0.3 MPa, at 25-90°C.
• This method uses sedimentation and the uniform, dynamic casting solution with a membrane obtained in the first stage as a solution which is to be filtered, and a membrane obtained in step (1) as the filtering material, followed by natural drying in order to obtain a conductive, polymer-based porous membrane.
• the production method according to CN 103846011 is simple, leads to no environmental pollution and no special requirement on equipment, is low in cost and achieves convenience for industrial application.
• CN102671551 describes a conductive membrane for microfiltration and a method for production thereof.
• This membrane is made by mixing a substrate made of polymer macromolecules containing conductive particles, powdered graphite or carbon paper.
• the substrate material in the form of a membrane is combined with conductive macromolecules of the carbon-based material, ensuring higher separation efficiency.
• a production method for a polymer layer with applied ions is described in a CN103214689.
• the method comprises preparation of an aqueous solution of a monomer for polymer generation, an electrolyte solution, a protonic acid solution, a solution of ions to be applied and a solution of enhancing ions, followed by mixing of all five solutions, performing in situ polymerisation on a conductive substrate using the method of electrolytic monopolar impulse deposition in order to combine the applied ions with the polymer layer without the ferrocyanide group in a single step.
• WO2013039895 discloses a filter which is modified by a polymer-carbon system based on a nanocomposite material, designed for a significant increase of filtration efficiency, separation and removal of many chemicals, heavy metal ions, organic substances and living organisms.
• Polymer materials such as e.g., poli-N-vinylcarbazol (PVK) are attached to graphene and/or materials similar to graphene based on nanomaterials and to graphene oxide chemically modified with a chelating agent, e.g. EDTA.
• the nanocomposite is deposited uniformly on the surface of the membrane.
• the technique of stable application of such a layer in submicron order sizes was developed.
• This layer is stably and permanently attached to the polymeric substrate.
• initial activation of the polymer surface in order to enable strong adhesion of the actual conductive layer applied in the next step.
• Additional difficulty of the process included use of a relatively small amount of material applied to the surface of element fibres in order not to limit the space available for the flow of the filtered liquid and for retained contamination particles to be collected in.
• the subject of the present invention is a method for production of a conductive surface layer on fibres of a non-conductive polymer, preferably a polypropylene polymer, wherein fibre surfaces are initially activated in a reaction with an activating mixture containing water and an organic solvent, followed by coating of fibre surfaces with a conductive microlayer including products of carbohydrate carbonisation or other products of substances undergoing carbonisation in presence of mineral acids.
• an organic solvent partially soluble in water and in the mineral acid is used.
• a solvent selected from a group including esters, such as butyl acetate, ketons such as methyl-butyl ketone, dipropyl ketone, ethers such as dibutyl ether, aromatic solvents such as benzene, toluene, xylene, cumene, ethybenzene or mixtures thereof is used as the organic solvent.
• the activating mixture is used, comprising an aqueous solution containing 3-9 parts of ethyl acetate and 10-30 parts of nitric acid per 100 parts of water. More preferably, an activation mixture comprises 40- 60% solution of mixture of sulphuric and nitric acid in molar ratio of 3: 1 to 1 :3, saturated with benzene or toluene.
• activation is carried out at a temperature close to the boiling point of the activation mixture, but lower than softening temperature of polymeric fibres.
• the filtration material is soaked completely in solution, in a temperature range of 45-80°C, preferably 50-95 °C, for 5-32 hours.
• carbohydrate carbonisation is carried out in a medium of mineral acid with its concentration being 15 %wt. or higher.
• the mineral acid is selected from a group comprising: nitric acid, sulphuric acid, hydrochloric acid, phosphoric acid and mixtures thereof, and the temperature is at least 45°C, preferably 70-90°C, for 5-32 hours.
• sugars soluble in water are used in carbonisation step, that are selected from: C 3 -C 7 monosaccharides, including ketoses and aldoses, disaccharides, including sucrose, oligosaccharides and polysaccharides.
• the aqueous solution in the method is used containing 2-8 %wt. of sucrose or glucose and 45-60% sulphuric acid.
• cartridge conductivity is increased by introduction of at least one metal additive to the surface carbon layer, in the form of oxides, hydroxides, hydroxyoxides, preferably metals introduced to the carbon layer include metals selected from the group including: iron, copper, nickel, chromium, zinc, cobalt, manganese and silver.
• the cartridge rinsed with water and dried is preferably submerged in a CuS0 4 solution, wetting the element completely, and after drying it is again submerged again but in a hot aqueous NaOH solution, instead.
• an aqueous NaOH solution with temperature of 90-100°C is used and the filter is soaked in this solution for 0.5-3 hours.
• the subject of the present invention is also a filter cartridge with activated fibre surface coated with carbonised carbohydrate, preferably this layer includes at least one metal selected from the group including: iron, copper, nickel, chromium, cobalt, manganese and silver as oxides, hydroxides and hydroxyoxides, as well as a filter cartridge with activated fibre surface obtained in the method according to the invention.
• a filter cartridge made of a polypropylene fibre layer deposited on a mesh core also made of polypropylene was submerged in an aqueous solution containing 8 parts of ethyl acetate, 20 parts of nitric acid per 100 parts of water.
• the filter cartridge was kept fully submerged at 60°C for 24 hours. Then the element was taken out and flushed with clean water. Then, thus activated element was submerged in an aqueous solution containing 5 %wt. of sucrose and 55% of sulphuric acid and kept in these conditions for 13 hours at 100°C, in a closed vessel in order to limit water losses.
• Sucrose carbonised in such conditions, according to equation (1).
• Polypropylene filter cartridge for filtration of 5 -micron particles was activated by soaking in a 50% aqueous solution of sulphuric and nitric acid in a molar ratio of 3: 1 , saturated with benzene and toluene. The activation process lasted 12 hours at 75°C. Then the filter was removed from the activating solution and flushed with water. The element turned brown. Next, the filter cartridge was soaked in an aqueous solution containing 6% of glucose and 50% of sulphuric acid at 80°C for 24 hours. During this time, glucose underwent dehydration to carbon products which covered surfaces of fibres of the filter cartridge, making the element black. The element was cooled down and flushed with water, followed by drying. The mass increase in comparison to the initial mass of the element was 6.9 g. Element resistance was measured according to Example 1 and resistivity of the obtained, fibrous layer of the element was calculated, yielding a result of 2.38 ⁇ 10 "5 [ ⁇ -m].
• the filter cartridge was activated and coated with a carbon layer as in Example 2.
• the dried element was submerged in a 1% CuS0 4 solution to achieve complete wetting, after which the element was removed and dried again.
• the element was then submerged in a hot, 2% aqueous NaOH solution of temperature close to 100°C and subjected to soaking lasting 1 hour.
• the element was then flushed with water and dried. Element resistance was measured according to Example 1 and resistivity of the obtained, fibrous layer of the element was calculated, yielding a result of 4.51 ⁇ 10 "6 [ ⁇ -m].
• Mass of the filter does not increase more than 3%-5% as a result of the described production method.
• the obtained filtration layer is very cohesive and its wetting e.g. using non-polar naphtha does not limit its electric conductivity.
• the application technique may be executed without the need of using expensive and complicated equipment. This allows the price of the final product to be kept low.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Analytical Chemistry (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Filtering Materials (AREA)
• Water Treatment By Sorption (AREA)

Applications Claiming Priority (2)

Publications (1)

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Cited By (1)

Citations (6)

• 2015
  • 2015-06-22 PL PL412800A patent/PL412800A1/pl unknown
  • 2015-06-29 WO PCT/PL2015/000102 patent/WO2016209096A1/en active Application Filing

Patent Citations (6)

Non-Patent Citations (1)

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