# US 12,005,383 B2 · Method for fluorinating a filter for a pipette tip, pipette tip, associated production method and pipette > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,005,383 B2 - Document ID: US12005383B2 - Status: Granted - Kind: B2 - Application number: 16/969,288 - Filed: 2019-02-18 - Published: 2021-01-14 - Granted: 2024-06-11 - Earliest claimed: 2018-02-20 - Assignees: Gilson, Inc.; Universite Clermont Auvergne; Sigma Clermont; Centre National de la Recherche - Applicants: Gilson SAS; Universite Clermont Auvergne; Centre National De La Recherche Scientifique; Sigma Clermont - Inventors: Nicolas Batisse; Marc Dubois; Jérémy Peyroux; Béatrice Guieu Presle - Web page: https://patentgrep.com/patent/US12005383B2 ## CPC - B01D 39/1653: {of synthetic origin} - B01D 39/1692: {Other shaped material, e.g. perforated or porous sheets} - B01L 3/0217: {of the plunger pump type} - C08L 23/283: Iso-olefin halogenated homopolymers or copolymers - B01D 2239/0428: Rendering the filter material hydrophobic - B01D 2239/10: Filtering material manufacturing - B01L 2300/0681: Filter - 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) - B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract A method for fluorinating a filter for a pipette tip, the filter being made of a solid porous structure made of polyolefin. The method comprises the following steps: (a) placing the filter in an enclosure, (b) creating a vacuum in the enclosure, and (c) bringing the filter into contact with a fluorination agent injected into the enclosure in a gaseous state, the fluorination agent being made up of difluorine F2, the difluorine F2 being injected into the enclosure at a partial pressure between 100 Pa and 10000 Pa and step (c) being done at a temperature between 0° C. and 100° C. A pipette tip comprising a filter modified by the fluorination method, a method for producing such a tip, as well as a withdrawing pipette equipped with such a tip. ## Claims ### Claim 1 Method for fluorinating a filter for a pipette tip, this filter being formed by a porous solid polyolefin structure, characterized in that it comprises the following steps: (a) placing the filter in an enclosure, (b) creating a vacuum in the enclosure, and (c) contacting the filter with a fluorination agent introduced in the gaseous state into the enclosure, in that the fluorination agent consists of difluorine F2, in that the difluorine F2 is introduced into the enclosure at a partial pressure between 100 Pa and 10000 Pa, in that step (c) is conducted at a temperature between 0° C. and 100° C., and further comprising after step (c): (e1) creating a vacuum in the enclosure, followed by (e2) contacting the filter with dihydrogen or a mixture comprising dihydrogen, the dihydrogen or mixture comprising dihydrogen comprising dihydrogen being introduced in the gaseous state into the enclosure. ### Claim 2 (depends on 1) Fluorination method according to claim 1, wherein the polyolefin is chosen from a polyethylene and a polypropylene. ### Claim 3 (depends on 2) Fluorination method according to claim 2, wherein the polyolefin is polyethylene. ### Claim 4 (depends on 1) Fluorination method according to claim 1, wherein the difluorine F2 is introduced into the enclosure at a partial pressure between 500 Pa and 8000 Pa. ### Claim 5 (depends on 1) Fluorination method according to claim 1, wherein step (c) is conducted at a temperature between 10° C. and 60° C. ### Claim 6 (depends on 1) Fluorination method according to claim 1, wherein step (c) is carried out for a duration between 1 min and 60 min. ### Claim 7 (depends on 1) Fluorination method according to claim 1, wherein, during step (c), a number of moles of difluorine greater than or equal to the equivalent number of moles of hydrogen atoms of the polyolefin is introduced. ### Claim 8 (depends on 1) Fluorination method according to claim 1, wherein the mixture comprises dihydrogen and nitrogen. ### Claim 9 (depends on 8) Fluorination method according to claim 8, wherein the volume percentage of dihydrogen in this mixture is greater than or equal to 2% vol. ### Claim 10 (depends on 1) Fluorination method according to claim 1, wherein, during step (e2), a number of moles of dihydrogen less than or equal to the number of moles of difluorine introduced during step (c) is introduced. ### Claim 11 (depends on 1) Fluorination method according to claim 1, wherein step (e2) is carried out for a duration between 10 min and 2 h. ### Claim 12 (depends on 1) Fluorination method according to claim 1, wherein step (e2) is conducted at a temperature between 0° C. and 200° C. ### Claim 13 (depends on 1) Fluorination method according to claim 1, wherein, during steps (b) and (e1), the pressure in the enclosure is less than or equal to 100 Pa. ### Claim 14 (depends on 1) Fluorination method according to claim 1, wherein step (c) is monitored by infrared spectroscopy. ### Claim 15 (depends on 14) Fluorination method according to claim 14, wherein step (c) is stopped when this ratio ACH2/ACFx reaches a value less than or equal to 15. ### Claim 16 (depends on 14) Fluorination method according to claim 14, wherein step (c) is monitored by tracking the evolution of the ratio ACH2/ACFx of the area of the infrared vibration bands corresponding to the —CH2 groups over the sum of the areas of the infrared vibration bands corresponding to the —CHF— groups and to the —CF2 groups. ### Claim 17 (depends on 1) Method for producing a pipette tip comprising a fluorinated filter, the method comprising the following steps: (i) providing a filter formed by a porous solid polyolefin structure, (ii) fitting the filter in the pipette tip, and (iii) fluorinating the filter by implementing the fluorination method according to claim 1. ### Claim 18 (depends on 1) Fluorination method according to claim 1, further comprising a step (d) of removing the by-products formed during step (c), steps (e1) and (e2) being performed after step (d). ### Claim 19 (depends on 18) Fluorination method according to claim 18, wherein step (d) is carried out by degassing the by-products during step (c). ### Claim 20 (depends on 19) Fluorination method according to claim 19, wherein step (d) is carried out by vacuum degassing the by-products formed during step (c). ### Claim 21 (depends on 18) Fluorination method according to claim 18, wherein steps (c) and (d) are carried out successively, step (d) of removing the by-products being carried out at the end of step (c). ### Claim 22 (depends on 18) Fluorination method according to claim 18, wherein step (d) is carried out by chemical trapping of the by-products formed during step (c).