Sol-Gel Material Absorbing Aldehydes And Ketones, And The Process For Its Preparation

Abstract

The present invention concerns an adsorbent porous sol-gel material comprising at least -silane oxides; —an inorganic and/or organic acid with a boiling temperature higher than 100° C.; —a molecular probe of general formula (I) or one of the salts of same in which R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 separately represent a hydrogen atom, a (C1-C6) alkyl group, a (C3-C7) cycloalkyl group, an alkyl-(C3-C7) cycloalkyl group; in which Z represents a spacer group chosen from a (C1-C16) alkyl group, a (C2-C16) alkenyl group, a (C2-C16) alkynyl group, a (C1-C16) halogenoalkyl group, an aryl group, an aryloxy group, a carbocycle group, or an aryl-(C1-C16) alkyl group.

Claims

1. A process for the preparation of a porous sol-gel adsorbent material, comprising: casting an aqueous composition into a desired shape, wherein the aqueous composition comprises at least an alkoxysilane type sol-gel precursor, an inorganic and/or organic acid having a boiling temperature of more than 100° C., and a probe molecule represented by the following General Formula (I) or a salt thereof; reacting the casted aqueous composition at a temperature above 20° C. to form a porous sol-gel adsorbent material a hydrolysis/condensation reaction; and drying the porous sol-gel adsorbent material ##STR00006## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 independently represents a hydrogen atom, a (C1-C6)alkyl group, a (C3-C7)cycloalkyl group, or an alkyl-(C3-C7)cycloalkyl group, wherein Z represents a spacer group selected from the group consisting of a (C1-C16)alkyl group, a (C2-C16)alkenyl group, a (C2-C16)alkynyl group, a (C1-C16)haloalkyl group, an aryl group, an aryloxy group, a carbocyclic group and an aryl-(C1-C16)alkyl group.

2. The process according to claim 1, wherein the alkoxysilane precursor is selected from the group consisting of tetramethyl orthosilicate (TMOS), methyltrimethoxysilane (MTMS), tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), dimethyldimethoxysilane and mixtures thereof.

3. The process according to claim 1, wherein the acid is selected from the group consisting of sulphamic acid, phosphoric acid, paratoluenesulphonic acid, parahydroxybenzoic acid and mixtures thereof.

4. The process according to claim 1, wherein the probe molecule is adipic acid dihydrazide (C.sub.6H.sub.14N.sub.4O.sub.2), sebacic acid dihydrazide (C.sub.10H.sub.22N.sub.4O.sub.2) or terephthalic acid dihydrazide (C.sub.8H.sub.10N.sub.4O.sub.2), or salts thereof.

5. The process according to claim 1, characterized in that wherein, in the aqueous composition, a molar ratio of the alkoxysilane precursor to the probe molecule ranges from 1:0.1 to 1:0.001.

6. The process according to claim 1, further comprising: baking the dried porous sol-gel adsorbent material.

7. A porous sol-gel adsorbent material, comprising at least: a silane oxide; at least one of an inorganic acid or an organic acid having a boiling temperature of more than 100° C.; and a probe molecule represented by the following General Formula (I) or a salt thereof, ##STR00007## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 independently represents a hydrogen atom, a (C1-C6)alkyl group, a (C3-C7)cycloalkyl group or an alkyl-(C3-C7)cycloalkyl group, and wherein Z represents a spacer group selected from the group consisting of a (C1-C16)alkyl group, a (C2-C16)alkenyl group, a (C2-C16)alkynyl group, a (C1-C16)haloalkyl group, an aryl group, an aryloxy group, a carbocyclic group,and an aryl-(C1-C16)alkyl group.

8. The porous sol-gel adsorbent material according to claim 7, wherein the porous sol-gel adsorbent material in the form of cylindrically shaped granules, and wherein a ratio of a length (L) of the granule to a diameter (D) of the granule is greater than 1.

9. A method for capturing at least on of an aldehyde or a ketone, comprising: contacting the porous sol-gel adsorbent material of claim 7 with at least one of the aldehyde or the ketone.

10. The method according to claim wherein the aldehydes is selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, acrolein, pentanal, hexanal, benzaldehyde and mixtures thereof.

11. An air purification device comprising the porous sol-gel adsorbent material of claim 7.

12. The process according to claim 2, wherein the alkoxysilane precursor is tetramethyl orthosilicate (TMOS).

13. The process according to claim 5, wherein, in the aqueous composition, a molar ratio of the alkoxysilane precursor to the probe molecule ranges from 1:0.08 to 1:0.002.

14. The process according to claim 5, wherein, in the aqueous composition, a molar ratio of the alkoxysilane precursor to the probe molecule ranges from 1:0.075 to 1:0.010.

15. The process according to claim 5, wherein, in the aqueous composition, a molar ratio of the alkoxysilane precursor to the probe molecule ranges from 1:0.05 to 1:0.015.

Description

EXAMPLES

Example 1

TMOS MATRIX Doped With Adipic Acid Dihydrazide and Sulphamic Acid (Formulation E1).

[0099] Reagents: Adipic acid dihydrazide (CAS No. 1071-93-8, molar mass=174.2 g.mol.sup.−1, purity 98%), TMOS (CAS number: 681-84-5, molar mass=152.2 g.mol.sup.−1, density d=1.023 mg.cm.sup.−3), Sulphamic acid (CAS number 5329-14-6, molar mass =97.1 g g.mol.sup.−1, technical grade purity). Plastic honeycomb mold with cylindrical shafts with a diameter of 6 mm and a depth of 10 mm.

[0100] V(TMOS)=1,463 mL

[0101] V(H20)=2,927 mL

[0102] adipic acid dihydrazide=90.5 g (0.12M)

[0103] sulphamic acid=51.2 g (0.12M)

[0104] V(total)=4,390 mL

[0105] Procedure: 90.5 g adipic acid dihydrazide and 51.2 g sulphamic acid are placed in a 5,000 mL bottle and 2,927 mL of water is added. The mixture is stirred until the adipic acid dihydrazide and sulphamic acid are completely dissolved. The aqueous solution is placed in a 5 L double-shell reactor thermostatically kept at 25° C. 1,463 mL of TMOS is added. The mixture is left under mechanical agitation. The formation of 2 phases can be observed. The mixture is left to stir until it becomes homogeneous (10 min). The mixture is poured into a PTFE tray fitted with a honeycomb mold. The tray is placed in a drying cabinet thermostatically controlled at 40° C. The tray is brushed with a flow of nitrogen (N.sub.2) with a flow rate of 10 L/min. Drying is stopped after one or more days.

[0106] The dry granules obtained are translucent. These granules are rebaked at 70° C. for 4 hours.

[0107] In this example the molar proportions of the reagents TMOS/H.sub.2O/adipic acid dihydrazide/sulphamic acid are equal to 1/16.5/0.052/0.054.

Example 2

TMOS Matrix Doped With Adipic Acid Dihydrazide and Sulphamic Acid (Formulation E2).

[0108] Reagents: Adipic acid dihydrazide (CAS number 1071-93-8, molar mass=174.2 g.mol.sup.−1, purity 98%), TMOS (CAS number: 681-84-5, molar mass=152.2 g.mol.sup.−1, density d=1.023 mg.cm.sup.−3), sulphamic acid (CAS number 5329-14-6, molar mass=97.1 g g.mol.sup.−1, technical grade purity). Plastic honeycomb mold with cylindrical shafts with a diameter of 6 mm and a depth of 10 mm.

[0109] V(TMOS) =1,463 mL

[0110] V(H20) =2,927 mL

[0111] adipic acid dihydrazide =30.2 g (0.04M)

[0112] sulphamic acid =17.1 g (0.04M)

[0113] V(total) =4,390 mL

[0114] Procedure: 30.2 g adipic acid dihydrazide and 17.1 g sulphamic acid are placed in a 5,000 mL bottle and 2,927 mL of water is added. The mixture is stirred until the adipic acid dihydrazide and sulphamic acid are completely dissolved. The aqueous solution is placed in a 5 L double-shell reactor thermostatically kept at 25° C. 1,463 mL of TMOS is added. The mixture is left under mechanical agitation. The formation of 2 phases can be observed. The mixture is left to stir until it becomes homogeneous (10 min). The mixture is poured into a PTFE tray fitted with a honeycomb mold. The tray is placed in a drying cabinet thermostatically controlled at 40° C. The tray is brushed with a flow of nitrogen (N.sub.2) with a flow rate of 10 L/min. Drying is stopped after one or more days.

[0115] The dry granules obtained are translucent. These granules are rebaked at 70° C. for 24 hours.

[0116] In this example, the molar proportions of the reagents TMOS/H2O/adipic acid dihydrazide/sulphamic acid are equal to 1/16.5/0.017/0.018.

Example 3

TMOS Matrix Doped With Adipic Acid Dihydrazide and Phosphoric Acid (Formulation E3)

[0117] Reagents: Adipic acid dihydrazide (CAS No. 1071-93-8, molar mass=174.2 g.mol.sup.−1, purity 98%), TMOS (CAS number: 681-84-5, molar mass=152.2 g.mol.sup.−1, density d=1.023 mg.cm.sup.−3), phosphoric acid (CAS number 7664-38-2, molar mass =98 g.mol.sup.−1, purity 85%). Plastic honeycomb mold with cylindrical shafts with a diameter of 6 mm and a depth of 10 mm.

[0118] V(TMOS)=1,446 mL

[0119] V(H20)=2,909 mL

[0120] adipic acid dihydrazide=90.5 g (0.12M)

[0121] phosphoric acid=35.52mL (0.12M)

[0122] V(total)=4,390 mL

[0123] Procedure: 90.5 g adipic acid dihydrazide and 35.52 mL phosphoric acid are placed in a 5,000 mL vial and 2,909 mL of water are added. The mixture is stirred until the adipic acid dihydrazide and sulphamic acid are completely dissolved. The aqueous solution is placed into a 5 L double-shell reactor thermostatically kept at 25° C. 1,446 mL of TMOS is added. The mixture is left under mechanical agitation. The formation of 2 phases is observed. The mixture is left to stir until it becomes homogeneous (10 min). The mixture is poured into a PTFE tray fitted with a honeycomb mold. The tray is placed in a drying cabinet thermostatically controlled at 40° C. The tray is brushed with a flow of nitrogen (N2) with a flow rate of 10 L/min. Drying is stopped after one or more days.

[0124] The dry granules obtained are translucent. These granules are rebaked at 70° C. for 24 hours.

[0125] In this example the molar proportions of the reagents TMOS/H20/adipic acid dihydrazide/phosphoric acid are equal to 1/16.5/0.052/0.054.

Example 4

TMOS MATRIX Doped With Adipic Acid Dihydrazide and Sulphamic Acid (Formulation E4)

[0126] Reagents: Adipic acid dihydrazide (CAS No. 1071-93-8, molar mass=174.2 g.mol.sup.−1, purity 98%), TMOS (CAS number: 681-84-5, molar mass=152.2 g.mol.sup.−1, density d=1.023 mg.cm.sup.3), MTMS (CAS number: 1185-55-3, molar mass=136.22 g.mol.sup.−1, density d=0.955mg.cm.sup.3), sulphamic acid (CAS number 5329-14-6, molar mass=97.1 g g.mol.sup.−1, technical grade purity). Plastic honeycomb mold with cylindrical shafts with a diameter of 6 mm and a depth of 10 mm.

[0127] V(TMOS)=1,028 mL

[0128] V(MTMS)=423 mL

[0129] V(H20)=2,939 mL

[0130] adipic acid dihydrazide=90.5 g (0.12M)

[0131] sulphamic acid=51.2 g (0.12M)

[0132] V(total)=4,390 mL

[0133] Procedure: 90.5 g adipic acid dihydrazide and 51.2 g sulphamic acid are placed in a 5,000 mL bottle and 2,927 mL of water is added. The mixture is stirred until the adipic acid dihydrazide and sulphamic acid are completely dissolved. The aqueous solution is placed in a 5 L double-shell reactor thermostatically kept at 25° C. 1,028 mL of TMOS and 423 mL of MTMS are added. The mixture is left under mechanical agitation. The formation of 2 phases is observed. The mixture is left to stir until it becomes homogeneous (10 min). The mixture is poured into a PTFE tray fitted with a honeycomb mold. The tray is placed in a drying cabinet thermostatically controlled at 40° C. The tray is brushed with a flow of nitrogen (N.sub.2) with a flow rate of 10 L/min. Drying is stopped after one or more days.

[0134] The dry granules obtained are translucent. These granules are rebaked at 70° C. for 24 hours.

[0135] In this example the molar proportions of the reagents TMOS/H.sub.2O/adipic acid dihydrazide/sulphamic acid are equal to 1/16.5/0.3/0.052/0.054.

Example 5

TMOS MATRIX Doped With Adipic Acid Dihydrazide and Paratoluene Sulphonic Acid (Formulation E5)

[0136] Reagents: Adipic acid dihydrazide (CAS No. 1071-93-8, molar mass=174.2 g.mol.sup.−1, purity 98%), TMOS (CAS number: 681-84-5, molar mass=152.2 g.mol.sup.−1, density d=1.023 mg.cm.sup.3), paratoluene sulphonic acid monohydrate (CAS number 6192-52-5, molar mass=190.2 g g.mol.sup.−1, purity>98%). Plastic honeycomb mold with cylindrical shafts with a diameter of 6 mm and a depth of 10 mm.

[0137] V(TMOS)=1,463 mL

[0138] V(H.sub.2O)=2,927 mL

[0139] adipic acid dihydrazide=45.25 g (0.06M)

[0140] paratoluene sulphonic acid monohydrate=52.9 g (0.06M)

[0141] V(total)=4,390 mL

[0142] Procedure: 90.5 g adipic acid dihydrazide and 52.9 g paratoluene sulphonic acid monohydrate are placed in a 5,000 mL bottle and 2,927 mL of water is added. The mixture is stirred until the adipic acid dihydrazide and paratoluene sulphonic acid monohydrate are completely dissolved. The aqueous solution is placed in a 5 L double-shell reactor thermostatically kept at 25° C. 1,463 mL of TMOS is added. The mixture is left under mechanical agitation. The formation of 2 phases is observed. The mixture is left to stir until it becomes homogeneous (10 min). The mixture is poured into a PTFE tray fitted with a honeycomb mold. The tray is placed in a drying cabinet thermostatically controlled at 40° C. The tray is brushed with a flow of nitrogen (N.sub.2) with a flow rate of 10 L/min. Drying is stopped after one or more days.

[0143] The dry granules obtained are translucent. These granules are rebaked at 70° C. for 24 hours.

[0144] In this example the molar proportions of the reagents TMOS/H.sub.2O/adipic acid dihydrazide/paratoluene sulphonic acid monohydrate are equal to 1/16.5/0.026/0.027.

Example 6

TMOS MATRIX Doped With Terephthalic Acid Dihydrazide and Sulphamic Acid (Formulation E6)

[0145] Reagents: Terephthalic acid dihydrazide (CAS No. 136-64-1, molar mass=194.194 g.mol.sup.−1), TMOS (CAS number: 681-84-5, molar mass=152.2 g.mol.sup.−1, density d=1.023 mg.cm.sup.−3), Sulphamic acid (CAS number 5329-14-6, molar mass =97.1 g g.mol.sup.−1, technical grade purity. Plastic honeycomb mold with cylindrical shafts with a diameter of 6 mm and a depth of 10 mm.

[0146] V(TMOS)=1,463 mL

[0147] V(H.sub.2O)=2,927 mL

[0148] terephthalic dihydrazide=25.58 g (0.03M)

[0149] sulphamic acid=25.58 g (0.06M)

[0150] V(total)=4,390 mL

[0151] Procedure: 25.58 g of terephthalic acid dihydrazide and 25.58 g of sulphamic acid are placed in a 5,000 mL bottle and 2,927mL of water is added. The mixture is stirred until the terephthalic acid dihydrazide and sulphamic acid are completely dissolved. The aqueous solution is placed in a 5 L double-shell reactor thermostatically kept at 25° C. 1,463 mL of TMOS is added. The mixture is left under mechanical agitation. The formation of 2 phases is observed. The mixture is left to stir until it becomes homogeneous (10 min). The mixture is poured into a PTFE tray fitted with a honeycomb mold. The tray is placed in a drying cabinet thermostatically controlled at 40° C. The tray is brushed with a flow of nitrogen (N.sub.2) with a flow rate of 10 L/min. Drying is stopped after one or more days.

[0152] The dry granules obtained are translucent. These granules are rebaked at 70° C. for 24 hours.

[0153] In this example the molar proportions of the reagents TMOS/H.sub.2O/terephthalic acid dihydrazide/sulphamic acid are equal to 1/16.5/0.013/0.027.

Example 7

TMOS MATRIX Doped With Sebacic Acid Dihydrazide and Sulphamic Acid (Formulation E7)

[0154] Reagents: Sebacic acid dihydrazide (CAS No. 925-83-7, molar mass=230.31 g.mol.sup.−1), TMOS (CAS number: 681-84-5, molar mass=152.2 g.mol.sup.−1, density d=1.023 mg.cm.sup.−3), sulphamic acid (CAS number 5329-14-6, molar mass=97.1 g g.mol.sup.−1, technical grade purity). Plastic honeycomb mold with cylindrical shafts with a diameter of 6 mm and a depth of 10 mm.

[0155] V(TMOS)=1,463 mL

[0156] V(H20)=2,927 mL

[0157] sebacic acid dihydrazide=30.33 g (0.03M)

[0158] sulphamic acid=25.58 g (0.06M)

[0159] V(total)=4,390 mL

[0160] Procedure: 30.33 g of sebacic acid dihydrazide and 25.58 g of sulphamic acid are placed in a 5,000 mL bottle and 2,927mL of water is added. The mixture is stirred until the sebacic acid dihydrazide and sulphamic acid are completely dissolved. The aqueous solution is placed in a 5 L double-shell reactor thermostatically kept at 25° C. 1,463 mL of TMOS is added. The mixture is left under mechanical agitation. The formation of 2 phases is observed. The mixture is left to stir until it becomes homogeneous (10 min). The mixture is poured into a PTFE tray fitted with a honeycomb mold. The tray is placed in a drying cabinet thermostatically controlled at 40° C. The tray is brushed with a flow of nitrogen (N.sub.2) with a flow rate of 10 L/min. Drying is stopped after one or more days.

[0161] The dry granules obtained are translucent. These granules are rebaked at 70° C. for 24 hours.

[0162] In this example the molar proportions of the reagents TMOS/H.sub.2O/sebacic acid dihydrazide/sulphamic acid are equal to 1/16.5/0.013/0.027.

Measurement of the Trapping Capacity of Formulations E1 to E7

[0163] The materials to be tested were exposed to formaldehyde concentrations of about 400 ppbv at a flow rate of 4 l/min. These conditions were obtained using the ETHERA generation bench shown in FIG. 1.

[0164] Formaldehyde is generated in a permeation oven with regulated temperature and nitrogen flow. The formaldehyde obtained at contents in the order of several ppmv is diluted by a flow of dry compressed air and another of wet compressed air (HR 100%) in order to obtain an air flow calibrated at 400 ppbv formaldehyde and 50% humidity. This gas flow is then separated into three streams and sent to sampling tanks B1, B2 and B3. On the lines leading to B2 and B3 are test cartridges containing the materials to be studied. The formaldehyde-polluted gas therefore passes through the cartridges before arriving in the B2 and B3 tanks.

[0165] Once or twice a day a gaseous sample is taken from each of the tanks to determine the formaldehyde concentrations passing through each of them. The value obtained for B1 gives us the formaldehyde concentration upstream of the test cartridges whereas the values obtained for B2 and B3 give us the concentrations downstream of the test cartridges. The formaldehyde concentrations are determined using the Profil'air Dynamic kit method.

[0166] The average concentration upstream and downstream of the cartridges is determined for each measuring point, and these concentrations are converted into the formaldehyde mass per minute that arrives upstream of the cartridges and exits downstream. The difference between these two values determines the mass of the formaldehyde trapped per minute of exposure.

[0167] To calculate the quantity of formaldehyde trapped, a linear evolution of the amount trapped as a function of time is assumed between each measuring point. The corresponding line between the two points is drawn and its equation is determined. This equation is then integrated between the two measuring points to determine the area under the line and thus the amount of formaldehyde trapped between the two measuring points. The sum of the areas thus determined represents the total quantity of formaldehyde trapped during the test period.

[0168] The trapping capacity of each porous sol-gel material obtained, formulations E1 to E7, was determined:

TABLE-US-00001 Formulation Trapping capacity (mg/g) E1 11.1 E2 3.2 E3 7.0 E4 6.5 E5 5.3 E6 3.1 E7 7.2