Method for sol-gel coating of textile materials

Abstract

The invention relates to a method for the coating of a textile material, said method comprising the following steps: d) providing a coating composition comprising an aqueous solvent and an organosilicon precursor; e) impregnating the textile material with the coating composition by means of pad finishing; f) drying the impregnated textile material; characterized in that the coating composition contains no polycarboxylic acid or catalyst.

Claims

1. A method for coating a textile material with a sol-gel material, said method comprising the steps of: a) providing a coating composition comprising an aqueous solvent and an organosilicon precursor, b) impregnating the textile material with the coating composition by means of pad finishing, c) drying the impregnated textile material, characterized in that the coating composition contains no polycarboxylic acid or catalyst.

2. The method according to claim 1, wherein the coating composition also contains no surfactant.

3. The method according to claim 1, wherein the textile material is a woven fabric, a nonwoven fabric, or a knit, preferably a woven fabric.

4. The method according to claim 1, wherein the textile material comprises fibers having hydrolysable functional groups, such as hydroxyl functional groups.

5. The method according to claim 1, wherein the aqueous solvent is water or a mixture of water and an organic solvent.

6. The method according to claim 1, wherein the organosilicon precursor is selected among tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), methyl trimethoxysilane (MTM), methyl triethoxysilane (MTE), phenyltrimethoxysilane (PhTMOS), phenyltriethoxysilane (PhTEOS), a fluoroalkyltrimethoxysilane, a fluoroalkyltriethoxysilane, a chloroalkylmethoxysilane, a chloroalkylethoxysilane, an aminopropyltrimethoxysilane (APTES), aminopropyltriethoxysilane (APTMS), (3-glycidyloxypropyl)trimethoxysilane (GPTMOS), (3-glycidyloxypropyl) triethoxysilane (GPTEOS), and mixtures thereof preferably among tetramethoxysilane (TMOS), methyl trimethoxysilane (MTM), phenyltrimethoxysilane (PhTMOS), a fluoroalkyltrimethoxysilane, a chloroalkylmethoxysilane, an aminopropyltriethoxysilane (APTES), (3-glycidyloxypropyl) trimethoxysilane (GPTMOS), and mixtures thereof.

7. The method according to claim 6, wherein the organosilicon precursor is tetramethoxysilane (TMOS).

8. The method according to claim 6, wherein the organosilicon precursor is a mixture of tetramethoxysilane (TMOS) with one or more precursors selected among methyl trimethoxysilane (MTM), methyl triethoxysilane (MTE), phenyltrimethoxysilane (PhTMOS), phenyltriethoxysilane (PhTEOS), a fluoroalkyltrimethoxysilane, a fluoroalkyltriethoxysilane, a chloroalkylmethoxysilane (ClTMOS), a chloroalkylethoxysilane, an aminopropyltriethoxysilane (APTES), (3-glycidyloxypropyl) trimethoxysilane (GPTMOS), and mixtures thereof.

9. The method according to claim 8, wherein the organosilicon precursor is a mixture of tetramethoxysilane (TMOS) with (3-glycidyloxypropyl) trimethoxysilane (GPTMOS).

10. The method according to claim 1, wherein it comprises several successive cycles of impregnation by pad finishing.

11. The method according to claim 1, wherein it comprises, before step b), a step of applying a precoating composition comprising an organic solvent and a zirconium alkoxide, said precoating composition containing no polycarboxylic acid or catalyst.

12. The method according to claim 1, wherein it further comprises a step of immobilizing sol-gel pellets on at least one of the two sides of the impregnated textile material.

13. The method according to claim 12, wherein the step of immobilizing the sol-gel pellets is carried out after the drying step c).

14. The method according to claim 12, wherein it comprises, after the drying step c), the application of a second layer of textile material on the impregnated textile material.

15. The method according to claim 14, wherein the second layer of textile material is secured to the impregnated textile material, in particular by stitching, welding, or gluing.

16. A coating composition, comprising an aqueous solvent and an organosilicon precursor, characterized in that it contains no polycarboxylic acid or catalyst.

17. The coating composition according to claim 16, wherein the aqueous solvent is water or a mixture of water and an organic solvent.

18. The coating composition according to claim 16, wherein the organosilicon precursor is selected among tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), methyl trimethoxysilane (MTM), methyl triethoxysilane (MTE), phenyltrimethoxysilane (PhTMOS), phenyltriethoxysilane (PhTEOS), a fluoroalkyltrimethoxysilane, a fluoroalkyltriethoxysilane, a chloroalkylmethoxysilane, a chloroalkyltriethoxysilane, an aminopropyltriethoxysilane, (3-glycidyloxypropyl)trimethoxysilane (GPTMOS), and mixtures thereof; preferably among tetramethoxysilane (TMOS), methyl trimethoxysilane (MTM), phenyltrimethoxysilane (PhTMOS), a fluoroalkyltrimethoxysilane, a fluoroalkyltriethoxysilane, a chloroalkylmethoxysilane, an aminopropyltriethoxysilane, (3-glycidyloxypropyl) trimethoxysilane (GPTMOS), and mixtures thereof.

19. The coating composition according to claim 18, wherein the organosilicon precursor is tetramethoxysilane (TMOS).

20. The coating composition according to claim 18, wherein the organosilicon precursor is a mixture of tetramethoxysilane (TMOS) with a precursor selected among methyl trimethoxysilane (MTM), methyl triethoxysilane (MTE), phenyltrimethoxysilane (PhTMOS), phenyltriethoxysilane (PhTEOS), fluoroalkyltrimethoxysilane, fluoroalkyltriethoxysilane, chloroalkylmethoxysilane, chloroalkyltriethoxysilane, aminopropyltriethoxysilane, (3-glycidyloxypropyl)trimethoxysilane (GPTMOS), and mixtures thereof.

21. The coating composition according to claim 20, wherein the organosilicon precursor is a mixture of tetramethoxysilane (TMOS) with (3-glycidyloxypropyl) trimethoxysilane (GPTMOS).

22. The coating composition according to claim 20, wherein the organosilicon precursor is a mixture of tetramethoxysilane (TMOS) with phenyltrimethoxysilane (PhTMOS).

23. An impregnated textile material obtained using the coating method according to claim 1.

24. The impregnated textile material according to claim 23, wherein the sol-gel material forms a sheathing around the fibers of the textile material.

25. The impregnated textile material according to claim 23, wherein it has a specific surface area S.sub.BET, determined from adsorption isotherms using the Brunauer, Emmet and Teller (BET) model, between 330±30 and 880±30 m.sup.2.Math.g.sup.−1, in particular between 540±30 and 880±30 m.sup.2.Math.g.sup.−1.

26. The impregnated textile material according to claim 23, wherein it has a micropore proportion greater than 0%, preferably greater than 30%, and even more preferably greater than 50%.

27. The impregnated textile material according to claim 23, wherein it has a mesopore proportion of less than 100%, preferably less than 70%, and even more preferably less than 50%.

28. The impregnated textile material according to claim 23, wherein it has a mass per unit area of 1 to 500 g/m.sup.2, preferably from 5 to 400 g/m.sup.2, more preferably from 10 to 300 g/m.sup.2.

29. The impregnated textile material according to claim 23, wherein it further comprises sol-gel pellets immobilized on at least one of its sides.

30. The impregnated textile material according to claim 29, wherein it has a mass per unit area of 60 to 500 g/m.sup.2, preferably 80 to 400 g/m.sup.2, and more preferably from 100 to 300 g/m.sup.2.

31. A gas filter, comprising the impregnated textile material according to claim 23.

32. A personal protective equipment, comprising the impregnated textile material according to claim 23.

33. The personal protective equipment according to claim 32, wherein it is NBC personal protective equipment.

Description

FIGURES

(1) FIG. 1: Comparison of normalized methyl salicylate breakthrough curves with a deposition of 20 g/m.sup.2 for the original fabric, formula H (strategy I), formula H′ (strategy II), and formula H″ (strategy III). Also illustrates the measurement of t.sub.1/2 for sample H″ where T.sub.max is the final methyl salicylate content and t.sub.1/2 is the total trapping period having T.sub.max/2 as the ordinate.

(2) FIG. 2: (A) Comparison of normalized methyl salicylate breakthrough curves with successive depositions of 20 g/m.sup.2 for the original fabric and formula J (strategy I); (B) Comparison of normalized methyl salicylate breakthrough curves with successive depositions of 20 g/m.sup.2 for the original fabric and formula A′ (strategy II).

(3) FIG. 3: Comparison of methyl salicylate breakthrough curves obtained with activated carbon, formula L′, and formulas N′+L′.

(4) FIG. 4: (A) Schematic view of the components of the tool for measuring the drape of the fabric; (B) Schematic diagram of measuring the drape of the fabric.

(5) FIG. 5: (A) Photo of the original fabric in the tool for measuring the drape of the fabric; (B) photo of the fabric impregnated with formulation K′.

(6) FIG. 6: (A) Photo from top view: fabric+A′ sol-gel (left)/fabric (right): (B) Photo from side view: fabric+A′ sol-gel (left)/fabric (right).

(7) FIG. 7: Top view using SEM (scanning electron microscopy) of the deposition of formulation A′.

(8) FIG. 8: Cross-sectional view using SEM of the deposition of formulation A′.

(9) FIG. 9: (A) unprocessed IR spectrum: original fabric, fabric+A′ sol-gel before abrasion, fabric+A′ sol-gel after abrasion; (B) differential IR spectrum: A′ sol-gel before abrasion, A′ sol-gel after abrasion.

(10) FIG. 10: Illustration of the immobilization of sol-gel pellets in Example 5: (A) photo of the textile material used for the immobilization process: two layers sewn together on which lines have been defined, (B1) and (B2) system used to introduce the pellets within the lines defined by stitching, using a cut pipette, (C1) and (C2) textile material obtained by immobilization method: seams defining containment areas.

(11) FIG. 11: Graphs of the results of filtration tests with the methyl salicylate of Example 5 over 10 minutes.

(12) FIG. 12: Graphs of the results of filtration tests with the methyl salicylate of Example 5 over 300 minutes.

EXAMPLES

(13) Chemicals Used Tetramethoxysilane (CAS: 681-84-5) (TMOS, Acres Organics, 99%); Tetraethoxysilane (CAS 78-10-4) (TEOS, Acres Organics, 98%); Methyl trimethoxysilane (CAS 1185-55-3) (MTM, Sigma-Aldrich, 98%); Trifluoropropyl trimethoxysilane (CAS: 429-60-7) (3FTMOS, TCI, >98%); 1H,1H,2H,2H-Perfluorodecyltriethoxysilane (CAS 51851-37-7) (13FTEOS, Sigma-Aldrich, 98%); 1H,1H,2H,2H-Perfluoroheptadecyltriethoxysilane (CAS: 101947-16-4) (17FTEOS, Sigma-Aldrich, 97%); Aminopropyl triethoxysilane (CAS: 919-30-2) (APTES, Acros Organics, 99%); Phenyl trimethoxysilane (CAS: 2996-92-1) (PhTMOS, TCI, >98%). Phenyl triethoxy silane (CAS: 780-69-8) (PhTEOS, Sigma-Aldrich, ≥Sigma-Aldrich); (3-glycidyloxypropyl)trimethoxysilane (CAS: 2530-83-8) (GPTMOS, Sigma-Aldrich, ≥98%); Tetrapropyl zirconate 70% .sub.wt in 1-propanol (CAS: 23519-77-9) (TPOZ. Sigma-Aldrich); Bis(diethyl citrato)-dipropyl zirconate (CAS: 308847-92-9) (DPOZ, Sigma-Aldrich); Ethanol (CAS: 64-17-5) (Merck, Uvasol for spectroscopy); Acetonitrile (CAS: 75-05-8) (Merck, Lichrosolv gradient grade for liquid chromatography); Succinic acid (CAS: 110-15-6) (Sigma-Aldrich, Reagent Plus≥99.0%); Sodium hypophosphite (CAS: 123333-67-5) (Sigma-Aldrich, hydrate).

(14) Measurement of Dynamic Viscosity

(15) The dynamic viscosity of the various formulations of Example 1 was measured with a Physica MCR 301 rheometer available from Anton Paar.

(16) The analysis volume is 700 μL deposited without deburring on a support heat controlled to 20° C. The viscosity is measured with a cone-plate in constant shear rotation (γ=100 s−1). The measurement method used generates 20 viscosity points 20 seconds apart. Each viscosity measurement therefore corresponds to an average of 20 points. The measurements are expressed in Pa.Math.s.

Example 1: Preparation of Coated Fabrics

(17) I. Preparation of Coated Fabrics According to the Strategy Described in FR 2984343 A1 (with Polybasic Carboxylic Acid and Catalyst)

(18) Formulations A to K described below are deposited on pieces of 5 cm×10 cm to 21 cm×30 cm of 50:50 Kermel®/Lenzing FR® fabric (Kernel, Colmar, France; Lenzing AG, Lenzing, Austria) by bath impregnation and squeezing (principle of pad finishing), then the fabrics are dried in an oven for 2 min at 120° C. and allowed to stand 24 h at room temperature and atmospheric pressure in the laboratory. In another embodiment, the textile material is nonwoven, in particular a felt. An example of such a felt is the one from Duflot Industries in Nomex®.

(19) The initial amount deposited varies between 15 and 31 g/m.sup.2. The mass per unit area of the sol-gel material is derived by weighing the fabric before and after impregnation.

(20) Formulation A

(21) In a hermetically scalable glass flask, 0.164 g succinic acid and 0.174 g sodium hypophosphite are mixed in a volume of 22.13 mL ultrapure water. The mixture is stirred at room temperature (20-22° C.) until dissolution of the poly acid and catalyst at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm). Then 2.873 mL TMOS are added to the initial mixture.

(22) Dynamic viscosity: 2.1 cP (mPa.Math.s)

(23) Deposition of this formula on textile indicates a mass per unit area of 24 g/m.sup.2.

(24) Formulation B

(25) In a hermetically scalable glass flask, 0.164 g succinic acid and 0.175 g sodium hypophosphite are mixed in a volume of 22.15 mL ultrapure water. The mixture is stirred at room temperature (20-22° C.) until dissolution of the poly acid and catalyst at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm). Then 1.438 mL TMOS and 1.415 mL MTM are added to the initial mixture.

(26) Dynamic viscosity: 2.0 cP (mPa.Math.s)

(27) Deposition of this formula on textile indicates a mass per unit area of 18 g/m.sup.2.

(28) Formulation C

(29) In a hermetically sealable glass flask, 0.164 g succinic acid and 0.174 g sodium hypophosphite are mixed in a volume of 22.14 mL ultrapure water. The mixture is stirred at room temperature (20-22° C.) until dissolution of the polyacid and catalyst at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm). Then 2.012 mL TMOS and 0.848 mL MTM are added to the initial mixture.

(30) Dynamic viscosity: 1.7 cP (mPa.Math.s)

(31) Deposition of this formula on textile indicates a mass per unit area of 18 g/m.sup.2.

(32) Formulation D

(33) In a hermetically sealable glass flask, 0.111 g succinic acid and 0.119 g sodium hypophosphite are mixed in 11.51 mL ultrapure water and 11.51 mL ethanol. The mixture is stirred at room temperature (20-22° C.) until dissolution of the polyacid and catalyst at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm). Then 1.896 mL TMOS and 0.085 mL APTES are added to the initial mixture

(34) Dynamic viscosity: 19.6 cP (mPa.Math.s)

(35) Deposition of this formula on textile indicates a mass per unit area of 31 g/m.sup.2.

(36) Formulation E

(37) In a hermetically sealable glass flask, 0.111 g succinic acid and 0.119 g sodium hypophosphite are mixed in 11.50 mL ultrapure water and 11.50 mL ethanol. The mixture is stirred at room temperature (20-22° C.) until dissolution of the polyacid and catalyst at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm). Then 1.836 mL TMOS and 0.170 mL APTES are added to the initial mixture.

(38) Dynamic viscosity: 65 cP (mPa.Math.s)

(39) Deposition of this formula on textile indicates a mass per unit area of 25 g/m.sup.2.

(40) Formulation F

(41) In a hermetically scalable glass flask, 0.151 g succinic acid and 0.161 g sodium hypophosphite are mixed in 19.40 mL ultrapure water and 2.91 mL acetonitrile. The mixture is stirred at room temperature (20-22° C.) until dissolution of the polyacid and catalyst at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm). Then 2.516 mL TMOS and 0.175 mL 3FTMOS are added to the initial mixture.

(42) Dynamic viscosity: 2.1 cP (mPa.Math.s)

(43) Deposition of this formula on textile indicates a mass per unit area of 15 g/m.sup.2.

(44) Formulation G

(45) In a hermetically sealable glass flask, 0.150 g succinic acid and 0.160 g sodium hypophosphite are mixed in 19.26 mL ultrapure water and 2.89 mL acetonitrile. The mixture is stirred at room temperature (20-22° C.) until dissolution of the polyacid and catalyst at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm). Then 2.499 mL TMOS and 0.348 mL 13FTEOS are added to the initial mixture.

(46) Dynamic viscosity: 2.2 cP (mPa.Math.s)

(47) Deposition of this formula on textile indicates a mass per unit area of 16 g/m.sup.2.

(48) Formulation H

(49) In a hermetically sealable glass flask, 0.149 g succinic acid and 0.159 g sodium hypophosphite are mixed in 19.13 mL ultrapure water and 2.87 mL acetonitrile. The mixture is stirred at room temperature (20-22° C.) until dissolution of the polyacid and catalyst at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm). Then 2.481 mL TMOS and 0.524 mL 17FTEOS are added to the initial mixture.

(50) Dynamic viscosity: 4.8 cP (mPa.Math.s)

(51) Deposition of this formula on textile indicates a mass per unit area of 19 g/m.sup.2.

(52) Formulation I

(53) In a hermetically sealable glass flask, 0.111 g succinic acid and 0.118 g sodium hypophosphite are mixed in 11.49 mL ultrapure water and 11.49 mL ethanol. The mixture is stirred at room temperature (20-22° C.) until dissolution of the poly acid and catalyst at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm). Then 1.7% mL TMOS, 0.129 mL 3FTMOS, and 0.095 mL APTES are added to the initial mixture.

(54) Dynamic viscosity: 3.6 cP (mPa.Math.s)

(55) Deposition of this formula on textile indicates a mass per unit area of 23 g/m.sup.2.

(56) Formulation J

(57) In a hermetically scalable glass flask, 0.111 g succinic acid and 0.118 g sodium hypophosphite are mixed in 11.43 mL ultrapure water and 11.43 mL ethanol. The mixture is stirred at room temperature (20-22° C.) until dissolution of the poly acid and catalyst at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm). Then 1.787 mL TMOS, 0.257 mL 13FTEOS, and 0.094 mL APTES are added to the initial mixture.

(58) Dynamic viscosity: 3.7 cP (mPa.Math.s)

(59) Deposition of this formula on textile indicates a mass per unit area of 23 g/m.sup.2.

(60) Formulation K

(61) In a hermetically scalable glass flask, 0.111 g succinic acid and 0.118 g sodium hypophosphite are mixed in 11.41 mL ultrapure water and 11.41 mL ethanol. The mixture is stirred at room temperature (20-22° C.) until dissolution of the polyacid and catalyst at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm). Then 1.784 mL TMOS, 0.294 mL 17FTEOS, and 0.094 mL APTES are added to the initial mixture.

(62) Dynamic viscosity: 18 cP (mPa.Math.s)

(63) Deposition of this formula on textile indicates a mass per unit area of 21 g/m.sup.2.

(64) II. Preparation of Coated Fabrics According to the Invention (without Polybasic Carboxylic Acid and without Catalyst) in One Step

(65) Formulation A′

(66) In a hermetically sealable glass flask, 2.873 mL TMOS are added to a volume of 22.13 mL ultrapure water. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(67) Dynamic viscosity: 6.8 cP (mPa.Math.s)

(68) Deposition of this formula on textile indicates a mass per unit area of 29 g/m.sup.2.

(69) Formulation B′

(70) In a hermetically sealable glass flask, 1.438 mL TMOS and 1.415 mL MTM are added to a volume of 22.15 mL ultrapure water. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(71) Dynamic viscosity: 2.3 cP (mPa.Math.s)

(72) Deposition of this formula on textile indicates a mass per unit area of 27 g/m.sup.2.

(73) Formulation C′

(74) In a hermetically sealable glass flask, 2.012 mL TMOS and 0.848 mL MTM are added to a volume of 22.14 mL ultrapure water. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(75) Dynamic viscosity: 2.4 cP (mPa.Math.s)

(76) Deposition of this formula on textile indicates a mass per unit area of 27 g/m.sup.2.

(77) Formulation D′

(78) In a hermetically sealable glass flask, 1.896 mL TMOS and 0.085 mL APTES are added to a mixture of 11.51 mL ultrapure water and 11.51 mL ethanol. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(79) Dynamic viscosity: 3.4 cP (mPa.Math.s)

(80) Deposition of this formula on textile indicates a mass per unit area of 27 g/m.sup.2.

(81) Formulation E′

(82) In a hermetically sealable glass flask, 1.836 mL TMOS and 0.170 mL APTES are added to a mixture of 11.50 mL ultrapure water and 11.50 mL ethanol. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(83) Dynamic viscosity: 3.8 cP (mPa.Math.s)

(84) Deposition of this formula on textile indicates a mass per unit area of 24 g/m.sup.2.

(85) Formulation F′

(86) In a hermetically sealable glass flask, 2.516 mL TMOS and 0.175 mL 3FTMOS are added to a mixture of 19.40 mL ultrapure water and 2.91 mL acetonitrile. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(87) Dynamic viscosity: 2.7 cP (mPa.Math.s)

(88) Deposition of this formula on textile indicates a mass per unit area of 23 g/m.sup.2.

(89) Formulation G′

(90) In a hermetically sealable glass flask, 2.499 mL TMOS and 0.348 mL 13FTEOS are added to a mixture of 19.26 mL ultrapure water and 2.89 mL acetonitrile. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rmp).

(91) Dynamic viscosity: 3.6 cP (mPa.Math.s)

(92) Deposition of this formula on textile indicates a mass per unit area of 21 g/m.sup.2.

(93) Formulation H′

(94) In a hermetically sealable glass flask, 2.481 mL TMOS and 0.524 mL 17FTEOS are added to a mixture of 19.13 mL ultrapure water and 2.87 mL acetonitrile. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(95) Dynamic viscosity: 3.7 cps (mPa.Math.s)

(96) Deposition of this formula on textile indicates a mass per unit area of 23 g/m.sup.2.

(97) Formulation I′

(98) In a hermetically sealable glass flask, 11.49 mL ultrapure water and 11.49 mL ethanol are mixed. Then 1.7% mL TMOS, 0.129 mL 3FTMOS, and 0.095 mL APTES are added to the solvent mixture. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(99) Dynamic viscosity: 3.4 cP (mPa.Math.s)

(100) Deposition of this formula on textile indicates a mass per unit area of 21 g/m.sup.2.

(101) Formulation J′

(102) In a hermetically sealable glass flask, 11.43 mL ultrapure water and 11.43 mL ethanol are mixed. Then 1.787 mL TMOS, 0.257 mL 13FTEOS, and 0.094 mL APTES are added to the solvent mixture. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(103) Dynamic viscosity: 3.5 cP (mPa.Math.s)

(104) Deposition of this formula on textile indicates a mass per unit area of 21 g/m.sup.2.

(105) Formulation K′

(106) In a hermetically sealable glass flask, 11.41 mL ultrapure water and 11.41 mL ethanol are mixed. Then 1.784 mL TMOS, 0.294 mL 17FTEOS, and 0.094 mL APTES are added to the solvent mixture. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(107) Dynamic viscosity: 3.9 cP (mPa.Math.s)

(108) Deposition of this formula on textile indicates a mass per unit area of 22 g/m.sup.2.

(109) Formulation L′ (L′, L′, and L′)

(110) In a hermetically scalable glass flask, 4.900 mL TMOS and 0.683 mL PhTMOS are added to a volume of 40.88 mL ultrapure water (formulation L′) or to a mixture of 20.44 mL ultrapure water and 20.44 mL ethanol (formula L′). In a hermetically sealable glass flask, 57.26 mL TMOS and 13.01 mL PhTMOS are added to a volume of 129.72 mL ultrapure water (formula L′). The formulas are stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(111) Deposition of formulas L′, L′ on textile respectively indicate a mass per unit area of 16 and 17 g/m.sup.2. Deposition of formula L′ on a Nomex® felt indicates a mass per unit area of 510 g/m.sup.2.

(112) Formulation M′

(113) In a hermetically sealable glass flask, 1.000 mL TMOS and 0.418 mL PhTMOS are added to a volume of 10.010 mL ultrapure water. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(114) Dynamic viscosity: 1.7 cP (mPa.Math.s)

(115) Deposition of this formula on textile indicates a mass per unit area of 18 g/m.sup.2.

(116) Formulation N′

(117) In a hermetically sealable glass flask, 4.000 mL TMOS and 0.660 mL GPTMS are added to a volume of 33.37 mL ultrapure water. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(118) Dynamic viscosity: 4.7 cP (mPa.Math.s)

(119) Deposition of this formula on textile indicates a mass per unit area of 13 g/m.sup.2.

(120) Formulation O′

(121) In a hermetically scalable glass flask, 2.277 mL TMOS, 0.367 mL PhTMOS, and 0.434 mL GPTMOS are added to a volume of 21.93 mL ultrapure water. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(122) Dynamic viscosity: 1.9 cP (mPa.Math.s)

(123) Deposition of this formula on textile indicates a mass per unit area of 17 g/m.sup.2.

(124) Formulation P′

(125) In a hermetically sealable glass flask, 2.158 mL TMOS, 0.552 mL 17FTEOS, and 0.3% mL GPTMOS are added to a mixture of 19.04 mL ultrapure water and 2.86 mL acetonitrile. The formula is stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(126) Dynamic viscosity: 3.9 cP (mPa.Math.s)

(127) Deposition of this formula on textile indicates a mass per unit area of 15 g/m.sup.2.

(128) III. Preparation of Coated Fabrics According to the Invention (without Polybasic Carboxylic Acid and without Catalyst) in Two Steps

(129) Formulation H″

(130) In a first hermetically sealable glass flask, 2.00 mL TPOZ are diluted in 23.0 mL ethanol (formula H′1). In a second hermetically sealable glass flask, 19.13 mL ultrapure water and 2.87 mL acetonitrile are mixed. Then 2.481 mL TMOS and 0.524 mL 17FTEOS are added to the solvent mixture (formula H″2). The formulas are stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm).

(131) Dynamic Viscosity: H″1: 1.5 cP (mPa.Math.s) H″2: 2.6 cP (mPa.Math.s)

(132) Successive depositions of formulas H″1 and H″2 on textile indicate a mass per unit area of 14 g/m.sup.2.

(133) Formulation L″

(134) In a first hermetically scalable glass flask, 11.28 mL TPOZ are diluted in % 82 mL ethanol (formula L″1). In a second hermetically sealable glass flask, 16.415 mL TMOS and 2.290 mL PhTMOS are added to a volume of 137.0 mL ultrapure water (formula L″2). The formulas are stirred at room temperature (26-27° C.) at about three increments of the BIBBY HG 1202 hotplate magnetic stirrer (about 400 rpm).

(135) Sequenced depositions of formulas L″1 and L″2 (=L″) on textile indicate a mass per unit area of 10 g/m.sup.2.

(136) Formulation M″

(137) In a first hermetically sealable glass flask, 2.76 mL TPOZ are diluted in 22.2 mL ethanol (formula M″1). In a second hermetically sealable glass flask, 8.55 mL TMOS and 3.67 mL PhTMOS are mixed with 87.8 mL ultrapure water (formulation M″2). The formulations are stirred at room temperature (20-22° C.) at setting 4 of the IKA WERKE RO10 Power multistirrer plate (about 500 rpm)

(138) Dynamic Viscosity: M″1: 1.5 cP (cps) M″2:1.9 cP (mPa.Math.s)

(139) Successive depositions of formulas M″1 and M″2 on textile indicate a mass per unit area of 20 g/m.sup.2. Sequenced deposits of formulas M″1 and M″2 on textile indicate a mass per unit area of 17 g/m.sup.2.

(140) Table 1 below summarizes the weights per unit area obtained for different formulations Recall that: Adhesion strategy I according to FR 2984343 A1 is carried out with the addition of succinic acid and sodium hypophosphite; One-step adhesion strategy II according to the invention is direct adhesion with the silica precursors used; Two-step adhesion strategy III according to the invention is adhesion via a Zr alkoxide.

(141) TABLE-US-00001 TABLE 1 Formula Formula Formula according according according to Deposit. to Deposit. to Deposit strategy of sol-gel strategy of sol-gel strategy of sol-gel Sol-gel precursors I (g/m.sup.2) II (g/m.sup.2) III (g/m.sup.2) TMOS A 24 A′ 29 — — TMOS/MTM B 18 B′ 27 — — TMOS-MTM C 18 C′ 77 — — TMOS/APTES D 31 D′ 27 — — TMOS/APTES E 75 E′ 24 — — TMOS/3FTMOS F 15 F′ 73 — — TMOS/13FTEOS G 16 G′ 21 — — TMOS/17FTEOS H 19 H′ 23 H″ 14 TMOS/APTES/3FTMOS I 23 I′ 21 — — TMOS/APTES/13FTEOS J 23 J′ 74 — — TMOS/APTES/17FTEOS K 21 K′ 77 — — TMOS/PhTMOS — — L′  16 L″ = 10 L″   + L″  TMOS/PhTMOS — — L′  17 — — TMOS/PhTMOS — — M′ 18 M″  20 TMOS/PhTMOS — — — — M″  17 TMOS/GPTMOS — — N′ 13 — — TMOS/GPTMOS/PhTMOS — — O′ 17 — — TMOS/GPTMOS/17FTEOS — — P′ 15 — —

Example 2: Exposure to Pollutants

(142) Fabrics impregnated with each sol-gel formulation were exposed to gas mixtures containing toluene or methyl salicylate, in order to test trapping efficiency versus the porosity properties of the sol-gel materials and the intrapore polarity. The breakthrough curves under gas flow were established for each pollutant.

(143) 2.1 Materials and Methods

(144) Gas Permeability of Fabrics

(145) To test the gas permeability of the fabrics, a test bench was installed in the laboratory. For this purpose, a Quantachrome Porometer 3G with 37 mm sample holder was used. The Porometer can test fabric 37 mm in diameter (cut out with a punch). The seal is provided by O-rings. The flow of gas thus passes through the entire fabric tested.

(146) The fabric test bench consists of two 4-way valves, upstream and downstream of the sample holder, which make it possible to measure gas flow's upstream and downstream of the sample holder. Tests showed that there is no (or little) pressure drop when the tested fabric is present. The pollutant content is measured in the flow of gas upstream and downstream of the sample holder, using a PID (Photoionization Detector) to obtain the pollutant breakthrough curve. Fabric permeability is tested using two pollutants: toluene and/or methyl salicylate. Each pollutant has its own specific exposure conditions. These conditions are described below.

(147) Toluene Permeability Test:

(148) For the toluene exposure tests, the pollutant is obtained from a cylinder calibrated for 100 ppm (the flow range of the flow meter used is within 0-100 mL/min) then diluted in dry nitrogen (the flow range of the flow meter used is within 0-1 L/min). The flow of diluted gas is brought into contact with the tested fabric. A toluene content of 3-4 ppm is conventionally used for permeability tests.

(149) Methyl Salicylate Permeability Test:

(150) For the methyl salicylate exposure tests, the vapor of this pollutant is generated by bubbling dry nitrogen (the flow range of the flow meter used is within 0-1 L/min). The flow of gas enriched with methyl salicylate is brought into contact with the tested fabric. A thermostat/cryostat to regulate the temperature of the bubbler containing the methyl salicylate (coil) is used to ensure reproducibility of the exposure tests. The bubbler containing the methyl salicylate is thus kept at 20° C. Using a dry nitrogen flow rate of 300 mL/min. an initial content of 55-00 ppm of methyl salicylate is obtained.

Methods for Processing Methyl Salicylate Permeability Data

(151) The methyl salicylate permeability tests consist of measuring the salicylate content (ppm) over time. This tracing is called a breakthrough curve, for which the “S” shape is more or less pronounced. The comparison of normalized methyl salicylate breakthrough curves with a deposition of 20 g/m.sup.2 for the original fabric, formula H (strategy I), formula H′ (strategy II), and formula H″ (strategy III) is shown in FIG. 1. The comparison of normalized methyl salicylate breakthrough curves with successive depositions of 20 g/m.sup.2 for the original fabric and formula J (strategy I) and for the original fabric and formula A′ are shown in FIGS. 2A and 2B respectively.

(152) The resulting breakthrough curves are processed using two methods breaking down the breakthrough curve and modeling the breakthrough curve. Both methods are detailed below.

(153) Method 1: Breaking Down the Breakthrough Curve

(154) The first method for evaluating the filtration consists of breaking down the breakthrough curve and analyzing the total trapping times. The total trapping times are determined for a methyl salicylate content of 0 ppm (t@0 ppm), a methyl salicylate content of less than 1 ppm (t<1 ppm), less than 5 ppm (t<5 ppm), and less than 20 ppm (t<20 ppm). These total trapping times are the characteristic times of the decomposition method.

(155) Method 2: Modeling the Breakthrough Curve

(156) The second method for evaluating the filtration consists of modeling the breakthrough curve by a sigmoid function according to the Hill model described below. This model was selected because, by definition, it allows modeling that starts from point (0.0), meaning a salicylate content of 0 ppm at t=0 min. This model, which comes from enzyme catalysis, models strictly positive data following a sigmoid function (S-shaped curve) which nicely corresponds to the breakthrough curves obtained by exposing sol-gel impregnated fabrics to methyl salicylate.

(157) The characteristic time of the breakthrough curve modeling method is therefore: t.sub.1/2. In addition, the slope of the curve can be calculated using the parameters of the model. Two points are required for this: A (t.sub.A; T.sub.A) and B (t.sub.B; T.sub.B). The calculation of the coordinates and slope are summarized in the table below.

(158) Data Comparison: Normalization of Characteristic Times

(159) The masses per unit area of the sol-gel depositions vary between 15 and 30 g/m.sup.2. However, a data comparison is only possible at the same mass. To eliminate the differences in mass per unit area, the characteristic limes of the two methods described above were normalized to an average deposition of 20 g/m.sup.2. In practice, the normalization is calculated as follows:

(160) $.Math.t\left(\min \right).Math.=\frac{T_{\mathrm{characteristic}}\left(\min \right)}{\mathrm{Experimental}\mathrm{mass}\mathrm{per}\mathrm{unit}\mathrm{area}\left(g\text{/}{m}^2\right)}\times \mathrm{Mass}\mathrm{per}\mathrm{unit}\mathrm{area}\mathrm{of}20g\text{/}{m}^2$

(161) In this manner, the data are correlated to identical weights: it is then possible to compare formulas.

(162) 2.2 Results

(163) Exposure to Methyl Salicylate

(164) The results of adhesion strategies I, II, and III are reported in Tables 2, 3, and 4 below for the methyl salicylate trapping efficiency.

(165) TABLE-US-00002 TABLE 2 I Strategy Slope Time (min) |t.sub.@0 ppm| |t .sub.<1 ppm| |t .sub.<5 ppm| |t .sub.<20 ppm| |t .sub.1/2 | (ppm/min) Original fabric 0.0 1.0 1.5 3.0 4.2 6.4 Formula A 0.0 5.0 8.3 14.2 16.0 2.1 B 0.0 1.1 1.7 3.3 4.3 5.7 C 0.0 2.2 3.9 6.1 9.1 5.6 D 0.0 4.4 6.3 8.8 13.4 4.9 E 0.0 8.8 11.9 16.3 21.7 3.9 F 0.0 0.6 1.6 6.1 12.9 1.8 G 0.0 0.8 3.2 10.0 15.8 1.7 H 0.0 8.0 11.3 17.3 21.5 3.0 I 6.1 8.7 11.3 16.5 18.9 2.1 J 2.6 4.3 6.1 9.6 12.6 5.3 K 0.0 3.8 5.2 8.1 11.8 3.2

(166) TABLE-US-00003 TABLE 3 II Strategy Slope Time (min) |t.sub.@0 ppm| |t .sub.<1 ppm| |t .sub.<5 ppm| |t .sub.<20 ppm| |t .sub.1/2 | (ppm/min) Original fabric 0.0 1.0 1.5 3.0 4.2 6.4 Formula A 21.6 23.7 27.2 34.1 37.3 2.1 B′ 2.6 4.2 5.7 9.1 11.4 2.8 C′ 14.9 17.1 20.1 26.8 30.3 2.2 D′ 17.1 18.0 21.3 27.0 30.3 2.7 E′ 13.8 15.1 17.2 21.6 24.5 3.1 F′ 20.7 21.5 23.7 28.9 31.3 2.7 G′ 20.4 21.5 23.7 31.5 35.7 2.1 H′ 17.2 18.1 20.3 25.0 28.0 3.0 I′ 20.2 21.2 24.0 31.7 35.1 2.2 J′ 11.3 15.1 17.5 23.6 26.5 2.6 K′ 8.0 10.7 13.4 17.9 20.4 3.3 L′  34.0 38.6 47.3 63.5 72.9 1.4 L′  28.7 35.3 44.0 58.6 62.6 1.3 M′ 24.4 25.2 35.2 50.9 64.6 0.9 N′ 28.4 38.0 48.4 61.3 69.3 1.9 O′ 18.9 20.1 22.5 30.9 35.0 2.0 P′ 7.9 11.1 16.3 23.0 33.0 1.5

(167) TABLE-US-00004 TABLE 4 III Strategy Slope Time (min) |t.sub.@0 ppm| |t .sub.<1 ppm| |t .sub.<5 ppm| |t .sub.<20 ppm| |t .sub.1/2 | (ppm/min) Original fabric 0.0 1.0 1.5 3.0 4.2 6.4 Formula H″ 26.4 29.2 32.5 38.9 41.7 3.1 L″ 45.0 56.8 102.6 133.3 151.5 1.1

(168) The results obtained for methyl salicylate filtration show that all the formulations tested using adhesion strategy II according to the invention have better filtration performance than formulations prepared using adhesion strategy I according to the prior art based on the same sol-gel precursors. These results clearly demonstrate that the incorporation of polycarboxylic acid and catalyst modifies the sol-gel, making it unsuitable for a gas filtration application. The best result for methyl salicylate permeability is obtained with formulation L″ using strategy ill.

(169) Successive depositions were tested to increase the mass per unit area of the filtering material.

(170) From 1 to 4 successive depositions of formulas J and A′ were conducted as well as two different successive depositions of formulas N′ and L′. These resulted in masses per unit area of between 12 and 47 g/m.sup.2 for formulation J and 11 to 32 g/m.sup.2 for A′. It should be noted that although adhesion is better with formulation J which contains poly basic carboxylic acid and catalyst (strategy I), the presence of the polyacid and catalyst has the effect of greatly reducing the filtration property in comparison to formulation A. The mass per unit area is 36 g/m.sup.2 for N′+L′. Adhesion strategies I and II are compared in Table 5 below for their methyl salicylate trapping efficiency.

(171) TABLE-US-00005 TABLE 5 Successful depositions with strategy I Successful depostions with strategy II Num. Slope Num. Slope of t.sub.@0 ppm t.sub.1/2 (ppm/ of t.sub.@0 ppm t.sub.1/2 (ppm/ Formula depos. (min) (min) min) Formula depos. (min) (min) min) Original 0 0.0 4.2 6.4 Original 0 0.0 4.2 6.4 fabric fabric J 1 5.2 11.8 5.1 A′ 1 8.0 21.1 2.6 2 7.3 18.5 4.2 2 14.3 38.2 2.1 3 5.0 18.9 2.8 3 24.0 69.3 1.4 4 7.3 24.6 2.0 4 32.3 83.9 1.1 N′ + 1 + 1 44.0 81.2 0.8 L′ 

(172) A deposition of formula L′ and two successive depositions of formulas N′+L′ were earned out on a Nomex® felt. These depositions resulted in masses per unit area of 510 (formula N′ only) and 588 g/m.sup.2 (N′: 173 g/m.sup.2+L′: 415 g/m.sup.2) respectively. These sol-gel impregnated materials were compared to a filtering layer using a technology based on activated carbon beads, representing the prior art and having a mass per unit area of 150 g/m.sup.2 activated carbon and a specific surface area of 1770 m.sup.2/g. Exposures to a concentration of 140 ppm methyl salicylate over 8 h resulted in the breakthrough curves given in FIG. 3.

(173) The results show that without activated carbon, the formulations based on sol-gel alone can filter a high concentration of methyl salicylate in a similar manner to the prior art. More particularly, this trapping capacity is even greater in the case of successive depositions of N′ and L′. Indeed, the trapping time t @0 ppm is 2.3 h for activated carbon, while it is 3.0 hours for the successive depositions of N′ and L′. The slope of the breakthrough curve is also better, as values of 22 and 32 ppm/h are obtained for formula L′ and N′+L′, while the prior art has a slope of 35 ppm/hr.

(174) Exposure to Toluene

(175) The adhesion strategies I, II, and III are compared in Tables 6, 7, and 8 below for their toluene trapping efficiency.

(176) TABLE-US-00006 TABLE 6 Strategy I Time (min) |t .sub.@0 ppm| |t.sub.<1 ppm| |t.sub.<2 ppm| |t.sub.<3 ppm| Original fabric 0.0 0.2 0.3 0.4 Formula A 0.0 0.4 1.7 25.0 B 0.0 0.2 0.2 0.3 C 0.0 0.3 0.4 11.7 D 0.0 0.7 0.9 1.7 E 0.2 0.5 2.1 15.0 F 0.0 0.2 34.2 88.3 G 0.0 0.2 27.5 70.8 H 0.2 0.4 16.7 68.3 I 0.0 0.2 0.5 20.8 J 0.0 0.3 5.0 51.7 0.4 13.3 48.3

(177) TABLE-US-00007 TABLE 7 Strategy II Time (min) |t .sub.@0 ppm| |t.sub.<1 ppm| |t.sub.<2 ppm| |t.sub.<3 ppm| Original fabric 0.0 0.2 0.3 0.4 Formula A′ 0.1 0.3 22.8 49.7 B′ 0.0 0.2 0.5 12.4 C′ 0.1 0.6 8.3 20.7 D′ 0.2 0.4 0.5 3.0 E′ 0.4 1.7 4.0 11.0 F′ 0.1 0.5 14.5 35.9 G′ 0.2 0.9 23.4 46.9 H′ 0.2 3.4 21.4 55.2 I′ 0.5 5.9 22.1 77.2 J′ 0.2 0.4 0.5 1.7 K′ 0.8 4.4 8.3 15.9 L′  4.5 20.2 38.4 85.6 L′  0.7 20.1 43.1 94.8 M′ 0.0 4.0 11.1 26.6 N′ 0.0 5.7 12.0 23.9

(178) TABLE-US-00008 TABLE 8 Strategy III Time (min) |t .sub.@0 ppm| |t.sub.<1 ppm| |t.sub.<2 ppm| |t.sub.<3 ppm| Original fabric 0.0 0.2 0.3 0.4 Formula H″ 0.3 0.4 0.8 28.0 L″ 0.0 4.0 8.2 96.0

(179) The results differ more for the toluene permeability than those obtained for the methyl salicylate permeability. In fact, the results indicate that the adhesion strategy used has an influence on filtration performance, with the exception of formulas G and H where the results are similar for both strategies I and II. Improved toluene filtration performance is observed with adhesion strategy II in 6 tests out of 9. The best results for toluene permeability are obtained with formulation L′, which also gave the best performance for methyl salicylate.

(180) Successive depositions were tested in order to increase the mass per unit area of the filtering material.

(181) From 1 to 4 successive depositions of formulas J and A′ were performed. These resulted in masses per unit area of between 12 and 47 g/m.sup.2 for formulation J and 11 to 32 g/m.sup.2 for A′. Adhesion strategies I and II are compared in Table 9 below for their toluene trapping efficiency.

(182) TABLE-US-00009 TABLE 9 Successful depositions with Successful depositions with strategy I strategy II Num. Num. of |t.sub.@0 ppm| of |t.sub.@0 ppm| Formula depos. (min) t .sub.< 2 ppm t .sub.< 3 ppm Formula depos. (min) t .sub.< 2 ppm t .sub.< 3 ppm Orginal 0 0.0 0.3 0.4 Original 0 0.0 0.3 0.4 fabric fabric J 1 0.0 0.5 15.0 A′ 1 0.3 1.0 2.1 2 0.0 10.3 76.3 2 0.3 1.6 15.8 3 0.0 56.0 135.0 3 0.2 15.8 28.7 4 0.0 68.0 182.0 4 0.2 29.5 46.0

(183) The same results are observed as for methyl salicylate exposure. Despite a higher mass per unit area for formulation J than for A′, the presence of polybasic carboxylic acid and catalyst has the effect of reducing the filtration properties of media J.

Example 3: Polarity and Porosity of Sol-Gel Materials

(184) The porosity of the sol-gel materials was determined from nitrogen adsorption isotherms (specific surface area, pore volume, pore size distribution). The intrapore polarity is revealed by the capacity of the material to trap methyl salicylate more efficiently in comparison to toluene.

(185) 3.1 Materials and Methods

(186) Nitrogen adsorption consists of the physisorption of nitrogen on the surface of a solid: it is a reversible process (adsorption/desorption). Nitrogen adsorption is a volumetric technique: a volume of gas of known temperature and pressure is sent over the previously degassed sample, and maintained at the temperature of liquid nitrogen. An adsorption isotherm corresponding to the adsorbed volume of gas as a function of the partial pressure of nitrogen is established. Interpretation of the adsorption isotherm is based on various analytical models: the Brunauer, Emmett and Teller (BET) model which is a model of the adsorption of a monolayer of nitrogen molecules into the pores, and a model based on the theory of functional density which uses Monte Carlo methods to reproduce the adsorption isotherm for pores of a given size. These analyses provide three pieces of information: the adsorption specific surface area, the pore volume, and the pore size distribution. The analyses were performed using the Quantachrome “Autosorb-1” porosity analyzer.

(187) 3.2 Results

(188) Table 10 below summarizes the polarity and porosity of monolith sol-gel materials obtained from the formulation of Example 1, by nitrogen adsorption (specific surface area, pore volume, pore size distribution).

(189) TABLE-US-00010 TABLE 10 Pore Specific surface volume Pore size distribution of micro-, area (m.sup.2/g) (cm.sup.3/ meso-, macropores (%) Formula S.sub.BET S.sub.DFT g) <20 Å 20-500 Å >500 Å A 472 ± 30 316 ± 20 0.310 0 100 0 G 290 ± 30 200 ± 20 0.14 0 100 0 I  81 ± 30  62 ± 20 0.038 8 92 0 A′ 760 ± 30 711 ± 20 0.405 43 57 0 B′ 735 ± 30 581 ± 20 0.565 5 95 0 C′ 865 ± 30 640 ± 20 0.504 0 99 1 D′ 422 ± 30 399 ± 20 0.753 0 100 0 E′ 340 ± 30 346 ± 20 0.690 0 100 0 F′ 877 ± 30 820 ± 20 0.475 59 41 0 G′ 743 ± 30 755 ± 20 0.376 48 52 0 I′ 546 ± 30 459 ± 20 0.694 8 92 0 J′ 366 ± 30 371 ± 20 0.751 0 100 0 K′ 387 ± 30 364 ± 20 0.765 0 100 0 L′  545 ± 30 644 ± 20 0.257 74 26 0 N′ 332 ± 30 291 ± 20 0.163 50 50 0

Example 4: Properties of the Impregnated Fabrics

(190) Flexibility

(191) The flexibility of the fabrics impregnated with the sol-gel formulations was evaluated using the flexibility measurement tool represented in FIG. 4A. The tool 1 consists of two parts, a lower part 2 serving as a support for the fabric T and an upper part 3 which fits onto the lower part to immobilize the fabric T. FIG. 4B shows the functional diagram for the measurement. To obtain a measurement, 5 cm of fabric are positioned “in vacuo” (in other words outside the measurement tool), a picture from a side view is taken, and in this side view the angle α formed between the fabric and the vertical is measured using a protractor to assess the drape of the fabric.

(192) This tool makes it possible to compare samples against a reference sample (fabric without sol-gel), as is shown in the photos in FIG. 5.

(193) Table 11 below summarizes the flexibility measurements before/after the sol-gel deposition.

(194) TABLE-US-00011 TABLE 11 α α α Adhesion (Original (Fabric + (Fabric + strategy fabric) preparation) sol-gel) I 18° N/A 37° (Fabric + Formula H) II 18° N/A 38° Fabric + Formula H′ III 18° 23° 23° Fabric + Fabric + Formula H″ Deposition (Depositions of H″.sub.1 of H″.sub.1 and H″.sub.2)

(195) Air Permeability

(196) The concept of breathability is related to air permeability. Air permeability measurements were performed according to standard ISO9237:1995 at 100 Pa. Table 12 below summarizes the data for the original fabrics and the fabrics impregnated with formulation H with the various adhesion strategies.

(197) TABLE-US-00012 TABLE 12 Adhesion Air permeability (L/m.sup.2 .Math. s) Mean Max- CV* strategy Formula Test Meas. 1 Meas. 2 Meas. 3 Meas. 4 (L/m.sup.2 .Math. s) min (%) Original fabric — 128 142 147 139 139 19 5.0 Strategy Type H A 113 110 118 120 115 10 4.0 H B 118 138 138 N/A 131 20 8.8 Strategy II H′ C 206 208 211 204 207 7 1.4 H′ D 212 201 206 205 206 11 2.2 Strategy III H″ E 162 168 165 158 163 10 2.6 H″ F 149 170 169 182 168 33 4.5 *The CV (coefficient of variation) is calculated as follows: CV (%) = Standard deviation/Mean × 100

(198) Note that the air permeability of fabrics impregnated with formulation H (strategy I) suffers a slight loss. However, in a remarkable and reproducible manner, the permeability values of fabrics impregnated with the H′ (strategy II) and H′ (strategy III) formulations are higher than that of the original fabric. This highly reproducible phenomenon was interpreted as a sheathing of the fibers which leaves them perfectly smooth by reducing the inter-fiber irregularities which could reduce the rate of the air penetration. This increase in permeability does not affect the filtration properties (H<H′<H″).

(199) Washing Resistance

(200) Fabrics impregnated with formulas H, H′, and H″ were evaluated for their resistance to washings at 60° C. with intermediate tumble drying according to the ISO 6330:2012 standard.

(201) Appearance

(202) Sol-gel deposition does not change the appearance of the original fabric. Similarly, the successive washings do not affect the appearance of the fabric.

(203) Hydrophobia

(204) The hydrophobic properties of the fabrics impregnated with the H (strategy I), H′ (strategy II), and H″ (strategy III) formulations were determined by contact angle measurements using the DataPhysics OCA 15EC goniometer and the SCA20 software in dynamic mode, capturing 4 measurements per second for 1 min in order to determine the stability of the water drop (10 μL) on the fabric. The data are presented as follows: before washing/after 1-5-10-25 washes. Table 13 below summarizes the mean contact angles for 1 min. accompanied by photos taken at the end of the measurement in dynamic mode.

(205) TABLE-US-00013 TABLE 13 Mean contact angle for 1 min (°)/CV (%) Fabric Before washing 1 wash 5 washes 10 washes 25 washes H 147°/0.24% 142°/0.35% From 133 to 82° — — H′ 145°/0.11% 142°/0.27% From 127 to 0° — — P′ 145°/0.57% .sup. 141/0.49% .sup. 130/0.06% 128/1.68% From 113 to 91° H″ 131°/0.30% 134°/0.78% 134°/0.56% From 122 to 88° —

(206) Based on the hydrophobic properties, the adhesion strategy of the invention without poly carboxylic acid and without catalyst is better than the adhesion strategy of the prior art, because the contact angle remains stable at 10 washes in comparison to one wash for the prior art.

(207) Energy Dispersive Analysis (SEM/EDS)

(208) To quantify the amount of filtering medium remaining after each series of washes, the fabrics impregnated with fluorinated sol-gel H, H′, O′, P′ and H″ were characterized by energy-dispersive analysis (combined SEM/EDS) before and after washing.

(209) Scanning electron microscopy (SEM) is a powerful technique for observing the surface topography. It is based primarily on the detection of secondary electrons emerging from a surface under the impact of a very fine beam of primary electrons that scans the observed surface and provides images with a resolving power often under 5 nm and a large depth of field. The instrument makes it possible to form a near-parallel beam, very thin (to a few nanometers), of electrons that are highly accelerated by voltages adjustable from 0.1 to 30 keV in order to focus it on the area to be examined, and to scan it progressively. Appropriate sensors collect significant signals while scanning the surface and form a variety of significant images from them. Images of the fabric samples were collected using the Zeiss “Ultra 55” SEM. The samples are observed directly without any particular deposition (metal, carbon). A low acceleration voltage of 3 keV and an InLens detector (detector of backscattered and secondary electrons) are used for the sample observations and to prevent a phenomenon of too much load due to the nature of the fabrics.

(210) Energy dispersive X-ray analysis (EDS) constitutes an electron microanalysis. The impact of the electron beam on the sample produces X-rays characteristic of the sample elements. In practice, this involves using an X-ray detector (energy detector) installed on the SEM (Zeiss Ultra 55). This characterization technique provides morphological information (images) and chemical information (elemental composition). The elemental composition can be obtained as a spectrum or a map. In a context of analyzing textile materials, the elemental composition is determined by spectrum acquisition. Two to three sample areas are analyzed in order to obtain representative average quantifications. Analysis of the reference materials (fabric without sol-gel and with sol-gel only in monolith form) was performed to ensure consistency in the results obtained for the samples before/after washing. The Broker Quantax detector and the “Esprit” EDS analytical software were used to obtain the EDS results for the fabrics tested.

(211) Table 14 below summarizes the mass percentages of silicon that were obtained from three measurement areas on each sample (H, H′, H″), as well as the amount of silicon remaining after the washes which is calculated as follows:

(212) $\mathrm{Silicon}\mathrm{remaining}\mathrm{after}x\mathrm{washes}\left(\%\right)=\frac{{\%}_{\mathrm{weight}}\mathrm{Si}\mathrm{after}x\mathrm{washes}}{{\%}_{\mathrm{weight}}\mathrm{Si}\mathrm{before}x\mathrm{washes}}\times 100$

(213) TABLE-US-00014 TABLE 14 Mass percentage of Si Si remaining after washes (% by weight) (% by weight) Number of washes Number of washes Fabric 0 1 5 10 25 1 5 10 25 H 4.16 2.52 0.06 0.17 0.05 61 1 4 1 H′ 7.52 0.58 0.83 0.33 0.16 8 11 4 2 O′ 8.14 2.94 0.29 0.12 0.03 36 4 2 0 P′ 10.73 1.49 0.56 0.14 0.15 14 5 1 1 H″ 3.45 0.71 0.44 0.89 0.14 21 13 26 4

(214) The SEM images of the invention show the presence of sol-gel material at the fiber surface even after 10 washes. The elemental composition by EDX analysis confirms this presence and indicates ˜20% Silicon by weight after 1, 5, and 10 washes. Furthermore, composition H″ (strategy II) is based on zirconium, an element that is also qualifiable and quantifiable. The line Lα for zirconium has an energy of 2.04 keV. It is still detectable and quantifiable after 25 washes (0.68% by weight which corresponds to 14% of the Zr remaining after 25 washes).

(215) Exposure to Pollutants Before/after Washing

(216) TABLE-US-00015 TABLE 15 Breakdown of Modeling of breakthrough breakthrough Filtration capacity of methyl curves curves salicylate after washes (%) |t .sub.0ppm|* |t .sub.1/2|* Number of washes Fabric (min) (min) 0 1 5 10 25 H 7.7 15.6 100 75 0 — — H′ 20.0 37.1 100 0 — — — O′ 18.9 35.0 100 45 14 7 4 P′ 7.9 33.0 100 55 34 0 — H″ 26.4 41.7 100 11 1 — — N′ + L′   24.2 44.6 100 31 8 3 — *The characteristic times were normalized for a mean deposition of 20 g/m.sup.2.

Example 4: Abrasion Test

(217) Appearance

(218) Abrasion of the deposition of formula A′ was tested according to the NF EN ISO 12947-2:1998 standard, and compared to the original fabric without sol-gel. The results obtained after 10,000 abrasion revolutions (10× 1000 revolutions) with a pressure of 9 kPa are show n in FIG. 6.

(219) Viewed from above, fabrics with or without sol-gel have the same appearance: the presence of sol-gel therefore does not affect the abrasion resistance. Viewed from the side, the photo shows that the original fabric (without sol-gel) is more hairy than the same fabric covered with formula A′. This observation is an advantage for the deposition of sol-gel on textiles.

(220) Scanning Electron Microscopy

(221) The deposition of formula A′ was characterized by SEM, in a top view and cross-sectional view before and after abrasion.

(222) The fabric used for the depositions is made of threads, and a thread of this fabric is made of an intimate mixture of textile fibers of Kennel and viscose. The SEM images before abrasion show the formation of a sol-gel sheath around the textile fibers (FIG. 7, cross-sectional view) and not around the threads. This sol-gel sheath is uniform (FIG. 8, top view), in other words it does not present any cracks. After abrasion, one can see the appearance of cracks but material remains on the surface of the fibers.

(223) FTIR-ATR Spectroscopy

(224) The fabric impregnated with sol-gel A′ was characterized by FTIR-ATR spectroscopy in reflection mode before and after abrasion. Spectra were recorded following 100 scans with a resolution of 4 cm.sup.−1 using the Broker “Alpha-P” FTIR-ATR module.

(225) The IR spectrum (FIG. 9) confirms the presence of sol-gel after abrasion. The IR spectrum obtained after abrasion is less intense than the one obtained before abrasion, as is logical. Integration of the differential spectra in the 1000-1300 cm.sup.−1 region is used to evaluate the amount of sol-gel remaining after abrasion. Table 15 below summarizes the results.

(226) TABLE-US-00016 TABLE 16 Area obtained by integration Sol-gel remaining of the 1000-1300 cm.sup.−1 region after abrasion Sol-gel A′ 3.22 before abrasion Sol-gel A′ 1.36 42% (1.36/3.22 × after abrasion 100 = 42)

(227) These measurements confirm the presence of sol-gel after abrasion. The use of FTIR-ATR spectroscopy indicates the presence of about 40% of the sol-gel on the fabric based on the differential spectra.

Example 5: Textile Material Impregnated with Immobilized Sol-Gel Pellets

(228) 5.1 Preparation of Sol-Gel Pellets

(229) In order to obtain the sol-gel pellets, a honeycomb mold of polycarbonate having a diameter of 3.0 mm (±0.3) available from Plascore (reference PC-3.0-CL) was used. The 3 mm diameter honeycomb plates were cut in order to fit into Petri dishes 11.5 and 10.8 cm in diameter.

(230) In parallel, the TMOS/PhTMOS 85/15 sol-gel formula was prepared in the manner described below. In a hermetically sealable glass flask, 40.41 mL TMOS and 9.184 mL PhTMOS are added to a mixture of 45.83 mL ultrapure water and 4.58 mL ethanol. The formula is stirred at room temperature (20-22° C.) at setting 10 of the IKA WERKE RO10 Power multistirrer plate (about 1000 rpm). The reactants are not miscible when added, then as the reaction advances the formula becomes clear. Before deposition in a Petri dish, the viscosity of the formula is 19.9 mPa.Math.s and the pH is 4.0-4.5.

(231) In Petri dishes 11.5 and 10.8 cm in diameter, a sol-gel volume of 31.1 and 27.5 cm.sup.3 respectively is necessary in order to obtain a sol-gel height of 0.3 cm in the honeycomb mold. Once the sol-gel formula (liquid) is placed in the Petri dish containing the honeycomb, a sealing film (aluminized) is adhered to the Petri dish. The three prepared Petri dishes are then placed on a multilevel rack and introduced into a desiccator with no gas flow. After two weeks at room temperature, the sol-gel has detached from the honeycomb. To complete the drying of the pellets, a breathable film is placed on the Petri dishes and the dessicator is flushed with a stream of argon gas of about IL/min.

(232) The sol-gel pellets obtained are uniform in size. Weighing the flask indicates 14.3 g of sol-gel pellets. Measurement of a cylindrical pellet indicates a diameter of about 18 mm and a thickness of about 1.7 mm, which is a reduction of about 45% compared to the dimensions of the mold. The pellets have a BET surface area of 497 m.sup.2/g and a DFT surface area of 469 m.sup.2/g. The pore volume is 0.270 cm.sup.3/g. The pore size distribution indicates 46% microporosity and 54% mesoporosity.

(233) 5.2 Pellet Deposition on Textile

(234) In order to increase the mass per unit area of sol-gel, the intended deposition consists of immobilizing the sol-gel pellets by trapping them between two lay ers of textile materials within containment areas defined by stitching.

(235) The photos shown in FIG. 10 illustrate this method of immobilizing the sol-gel pellets. Photo (A) shows the containment rows defined by stitching on an area of approximately 10×10 cm. Two layers of 50/50 Kermel/viscose having an air permeability of approximately 680 L/m.sup.2.Math.s are used. The sol-gel pellets are introduced into each row using a pipette that can reach the end of the containment row (photos (B1) and (B2)). After fixe pellets are introduced into each containment row, a line of stitching finishes defining the containment area. In the same manner, five pellets are introduced all the way to the new end so defined, and then a new line of stitching defines a new containment area. In this manner, the entire initial area of about 10×10 cm has been covered with 11×11 cm of containment areas each holding five pellets of sol-gel. Photos (C1) and (B2) show the final result.

(236) The resulting textile material is homogeneous, regular, and flexible, having a mass of 2.94 g of TMOS/PhTMOS 85/15 pellets over a surface area of 112 cm.sup.2 of 50/50 Kermel/viscose fabric, which is a mass per unit area of 262 g/m.sup.2 of sol-gel.

(237) The air permeability of the fabric with the sol-gel pellets indicates an average value of 702 L/m.sup.2.Math.s, while the same fabric without the sol-gel pellets indicates a value of 680 L/m.sup.2.Math.s (applying the ISO 9237 standard at 100 Pa). Despite the significant mass per unit area of sol-gel, incorporation of the pellets does not influence air permeability.

(238) A filtration test for methyl salicylate was carried out with the above prepared fabric with and without sol-gel pellets. This previously sewn fabric was cut using a punch of 37 mm diameter.

(239) Weights for the cut circles were:

(240) TABLE-US-00017 Item Mass Original fabric without sol-gel pellets 354 mg Fabric with sol-gel pellets 704 mg Sol-gel pellets (mg) 350 mg Sol-gel pellets (g/m.sup.2) 325 g/m.sup.2

(241) The filtration results show that a clear difference in filtration performance is observed between the original textile and the textile incorporating the pellets (FIG. 11). However, the breakthrough curve obtained with the textile incorporating the pellets does not have the usual S-shape. To attempt to quantify the results, a calculation of the area under the breakthrough curve was used. For this, the areas of the breakthrough curves of the original textile without pellets and of the textile incorporating the sol-gel pellets were compared to the area without fabric in order to determine the passage of methyl salicylate as a percentage. Calculations performed using Origin software at 10 min and 300 min and the corresponding curves are presented below.

(242) TABLE-US-00018 Integration Methyl Integration Methyl over salicylate over salicylate 10 min passage 300 min passage after Test Area (a.u.) after 10 min Area (a.u.) 300 min Without fabric 520 100% 15990 100% Fabric alone 337  78% 15668  98% Fabric + pellets 81  16% 10830  68%

(243) The filtration results for methyl salicylate clearly show the advantage of the immobilization of sol-gel pellets between two layers of textile materials. It will be even more significant when at least one of the two layers is an impregnated textile material according to the invention.