CN116692881A - Preparation method of hydrophobic rare earth-based silica aerogel - Google Patents
Preparation method of hydrophobic rare earth-based silica aerogel Download PDFInfo
- Publication number
- CN116692881A CN116692881A CN202310908262.7A CN202310908262A CN116692881A CN 116692881 A CN116692881 A CN 116692881A CN 202310908262 A CN202310908262 A CN 202310908262A CN 116692881 A CN116692881 A CN 116692881A
- Authority
- CN
- China
- Prior art keywords
- rare earth
- silica aerogel
- doped silica
- ethanol
- hydrophobic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims abstract description 125
- 229910052761 rare earth metal Inorganic materials 0.000 title claims abstract description 97
- 239000004965 Silica aerogel Substances 0.000 title claims abstract description 84
- 150000002910 rare earth metals Chemical class 0.000 title claims abstract description 82
- 230000002209 hydrophobic effect Effects 0.000 title claims abstract description 29
- 238000002360 preparation method Methods 0.000 title claims abstract description 20
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 122
- 239000002904 solvent Substances 0.000 claims abstract description 25
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 claims abstract description 24
- 238000000034 method Methods 0.000 claims abstract description 20
- -1 phenyl-alkoxy silane Chemical compound 0.000 claims abstract description 20
- 229910000077 silane Inorganic materials 0.000 claims abstract description 17
- 230000007062 hydrolysis Effects 0.000 claims abstract description 11
- 238000006460 hydrolysis reaction Methods 0.000 claims abstract description 11
- 239000000741 silica gel Substances 0.000 claims abstract description 11
- 229910002027 silica gel Inorganic materials 0.000 claims abstract description 11
- 239000002243 precursor Substances 0.000 claims abstract description 8
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 claims abstract description 7
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000012266 salt solution Substances 0.000 claims abstract description 7
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 7
- 239000010703 silicon Substances 0.000 claims abstract description 7
- 239000007788 liquid Substances 0.000 claims abstract description 6
- 230000003197 catalytic effect Effects 0.000 claims abstract description 5
- 239000003377 acid catalyst Substances 0.000 claims abstract description 4
- 239000002019 doping agent Substances 0.000 claims abstract description 4
- 239000000499 gel Substances 0.000 claims description 30
- 238000003756 stirring Methods 0.000 claims description 27
- 238000001035 drying Methods 0.000 claims description 25
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical group CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 claims description 19
- 239000011259 mixed solution Substances 0.000 claims description 18
- 230000032683 aging Effects 0.000 claims description 10
- 230000003301 hydrolyzing effect Effects 0.000 claims description 9
- 239000011240 wet gel Substances 0.000 claims description 9
- JCVQKRGIASEUKR-UHFFFAOYSA-N triethoxy(phenyl)silane Chemical compound CCO[Si](OCC)(OCC)C1=CC=CC=C1 JCVQKRGIASEUKR-UHFFFAOYSA-N 0.000 claims description 8
- 229910052746 lanthanum Inorganic materials 0.000 claims description 7
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims description 7
- 229910052727 yttrium Inorganic materials 0.000 claims description 7
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 claims description 7
- ZNOCGWVLWPVKAO-UHFFFAOYSA-N trimethoxy(phenyl)silane Chemical compound CO[Si](OC)(OC)C1=CC=CC=C1 ZNOCGWVLWPVKAO-UHFFFAOYSA-N 0.000 claims description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 4
- 238000002791 soaking Methods 0.000 claims description 4
- 229910052769 Ytterbium Inorganic materials 0.000 claims description 3
- 150000003839 salts Chemical class 0.000 claims description 3
- LFQCEHFDDXELDD-UHFFFAOYSA-N tetramethyl orthosilicate Chemical compound CO[Si](OC)(OC)OC LFQCEHFDDXELDD-UHFFFAOYSA-N 0.000 claims description 3
- NAWDYIZEMPQZHO-UHFFFAOYSA-N ytterbium Chemical compound [Yb] NAWDYIZEMPQZHO-UHFFFAOYSA-N 0.000 claims description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 2
- 229910052693 Europium Inorganic materials 0.000 claims description 2
- 229910052688 Gadolinium Inorganic materials 0.000 claims description 2
- 229910002651 NO3 Inorganic materials 0.000 claims description 2
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims description 2
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 2
- 229910052772 Samarium Inorganic materials 0.000 claims description 2
- 229910052771 Terbium Inorganic materials 0.000 claims description 2
- 229910021529 ammonia Inorganic materials 0.000 claims description 2
- ZZNQQQWFKKTOSD-UHFFFAOYSA-N diethoxy(diphenyl)silane Chemical compound C=1C=CC=CC=1[Si](OCC)(OCC)C1=CC=CC=C1 ZZNQQQWFKKTOSD-UHFFFAOYSA-N 0.000 claims description 2
- AHUXYBVKTIBBJW-UHFFFAOYSA-N dimethoxy(diphenyl)silane Chemical compound C=1C=CC=CC=1[Si](OC)(OC)C1=CC=CC=C1 AHUXYBVKTIBBJW-UHFFFAOYSA-N 0.000 claims description 2
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 claims description 2
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 claims description 2
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 claims description 2
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 claims description 2
- 238000007789 sealing Methods 0.000 claims description 2
- GZCRRIHWUXGPOV-UHFFFAOYSA-N terbium atom Chemical compound [Tb] GZCRRIHWUXGPOV-UHFFFAOYSA-N 0.000 claims description 2
- 239000000243 solution Substances 0.000 abstract description 16
- 239000000377 silicon dioxide Substances 0.000 abstract description 13
- 238000004140 cleaning Methods 0.000 abstract description 9
- 238000009833 condensation Methods 0.000 abstract description 4
- 230000005494 condensation Effects 0.000 abstract description 4
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 abstract description 4
- 238000005903 acid hydrolysis reaction Methods 0.000 abstract description 3
- 230000003075 superhydrophobic effect Effects 0.000 abstract description 3
- 238000010438 heat treatment Methods 0.000 description 21
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 18
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 13
- 239000007864 aqueous solution Substances 0.000 description 9
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 8
- 239000004964 aerogel Substances 0.000 description 8
- 235000011114 ammonium hydroxide Nutrition 0.000 description 8
- 230000003068 static effect Effects 0.000 description 8
- 239000003085 diluting agent Substances 0.000 description 7
- 229910001873 dinitrogen Inorganic materials 0.000 description 7
- 238000007599 discharging Methods 0.000 description 7
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- NGDQQLAVJWUYSF-UHFFFAOYSA-N 4-methyl-2-phenyl-1,3-thiazole-5-sulfonyl chloride Chemical compound S1C(S(Cl)(=O)=O)=C(C)N=C1C1=CC=CC=C1 NGDQQLAVJWUYSF-UHFFFAOYSA-N 0.000 description 5
- KUBYTSCYMRPPAG-UHFFFAOYSA-N ytterbium(3+);trinitrate Chemical compound [Yb+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O KUBYTSCYMRPPAG-UHFFFAOYSA-N 0.000 description 5
- 229910052814 silicon oxide Inorganic materials 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- 239000003054 catalyst Substances 0.000 description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 3
- 238000009413 insulation Methods 0.000 description 3
- GJKFIJKSBFYMQK-UHFFFAOYSA-N lanthanum(3+);trinitrate;hexahydrate Chemical compound O.O.O.O.O.O.[La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O GJKFIJKSBFYMQK-UHFFFAOYSA-N 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 235000012239 silicon dioxide Nutrition 0.000 description 3
- 238000006555 catalytic reaction Methods 0.000 description 2
- 238000011049 filling Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000002105 nanoparticle Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- XIOPWXFTXDPBEY-UHFFFAOYSA-N ytterbium(3+);trinitrate;pentahydrate Chemical compound O.O.O.O.O.[Yb+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O XIOPWXFTXDPBEY-UHFFFAOYSA-N 0.000 description 2
- QBAZWXKSCUESGU-UHFFFAOYSA-N yttrium(3+);trinitrate;hexahydrate Chemical compound O.O.O.O.O.O.[Y+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O QBAZWXKSCUESGU-UHFFFAOYSA-N 0.000 description 2
- OBOSXEWFRARQPU-UHFFFAOYSA-N 2-n,2-n-dimethylpyridine-2,5-diamine Chemical compound CN(C)C1=CC=C(N)C=N1 OBOSXEWFRARQPU-UHFFFAOYSA-N 0.000 description 1
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 235000013877 carbamide Nutrition 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical class [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- NNMXSTWQJRPBJZ-UHFFFAOYSA-K europium(iii) chloride Chemical compound Cl[Eu](Cl)Cl NNMXSTWQJRPBJZ-UHFFFAOYSA-K 0.000 description 1
- 239000005357 flat glass Substances 0.000 description 1
- MWFSXYMZCVAQCC-UHFFFAOYSA-N gadolinium(iii) nitrate Chemical compound [Gd+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O MWFSXYMZCVAQCC-UHFFFAOYSA-N 0.000 description 1
- 150000004702 methyl esters Chemical class 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 125000005375 organosiloxane group Chemical group 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- LHBNLZDGIPPZLL-UHFFFAOYSA-K praseodymium(iii) chloride Chemical compound Cl[Pr](Cl)Cl LHBNLZDGIPPZLL-UHFFFAOYSA-K 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- YZDZYSPAJSPJQJ-UHFFFAOYSA-N samarium(3+);trinitrate Chemical compound [Sm+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O YZDZYSPAJSPJQJ-UHFFFAOYSA-N 0.000 description 1
- 238000003980 solgel method Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- YJVUGDIORBKPLC-UHFFFAOYSA-N terbium(3+);trinitrate Chemical compound [Tb+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O YJVUGDIORBKPLC-UHFFFAOYSA-N 0.000 description 1
- 239000004753 textile Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
- C01B33/14—Colloidal silica, e.g. dispersions, gels, sols
- C01B33/157—After-treatment of gels
- C01B33/158—Purification; Drying; Dehydrating
- C01B33/1585—Dehydration into aerogels
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
Abstract
The application provides a preparation method of hydrophobic rare earth-based silica aerogel, which comprises the following steps: phenyl-alkoxy silane and tetraalkoxy silane are used as silicon sources and common precursors, rare earth salt solution is used as an acid catalyst and a doping agent to be added into the precursors, and hydrolysis is carried out under an ethanol solvent to obtain rare earth doped silica sol; standing the rare earth doped silica sol in alkaline catalytic liquid diluted by ethanol to form rare earth doped silica gel; the rare earth doped silica gel is aged, subjected to solvent exchange and dried to obtain the rare earth doped silica aerogel. The super-hydrophobic property generated by introducing phenyl can endow the silica aerogel with self-cleaning capability; in the process of catalyzing acid hydrolysis by the rare earth solution, rare earth ions are uniformly introduced into the silica framework in the condensation process, so that the high temperature resistance of the silica aerogel is further improved.
Description
Technical Field
The application belongs to the technical field of aerogel preparation, and particularly relates to a preparation method of hydrophobic rare earth-based silica aerogel.
Background
The silica aerogel is a light and porous material constructed by a three-dimensional network structure formed by interconnecting silica nanoparticles, and the pores of the silica aerogel are mostly mesoporous with the thickness of 2-50nm and have extremely high porosity. The characteristics of the silica aerogel are endowed with the characteristics of high specific surface area, low density, low thermal conductivity and the like, so that the silica aerogel has wide application prospects in the fields of heat insulation, sound insulation, catalysis, adsorption and the like. The surface of the silica aerogel prepared based on the sol-gel method is rich in hydroxyl groups, so that water molecules in the air are easily absorbed, the self skeleton structure is collapsed, and even the surface of the aerogel is cracked. On the other hand, the hydroxyl groups on the surface of the silicon dioxide are further condensed at high temperature, and the high-temperature sintering (more than 800 ℃) is easily generated by the combination of the point-to-point connection mode of the nano particles. The above drawbacks seriously affect the practical application of silica aerogel, especially in the field of thermal insulation.
The self-cleaning mechanism of the material relies on the tiny contact area of the water droplets with the surface where the water forms nearly spherical droplets, which can easily roll away with the dust. Only when the contact angle of the material is sufficiently high and has a small contact angle hysteresis (difference between the advancing angle and the receding angle), the water droplets do not adhere to the material surface but roll on the surface. At this point, the water droplets have the ability to transport and remove surface contaminants and the material has self-cleaning ability. Therefore, the super-hydrophobic material with a very small rolling angle shows potential self-cleaning capability, and the excellent self-cleaning performance enables various materials to play an important role in work, for example, the self-cleaning paint is applied to the fields of window glass, textiles and the like, and labor can be saved. Co-hydrolytic condensation of an organosiloxane with ethyl orthosilicate (methyl ester) is an effective method for preparing hydrophobic silica aerogel. The patent CN 108502893A, CN 104556964A takes organic siloxane as a co-precursor, and is modified by an acid-base two-step catalysis method, so that the silica aerogel with certain hydrophobicity can be obtained. However, the introduction of the general organic alkoxy silane can reduce the high temperature resistance of the silica aerogel, obtain a limited water contact angle, and influence the application of the silica aerogel in the high temperature and high hydrophobicity fields.
Disclosure of Invention
In order to solve the problems in the prior art, the application provides a preparation method of hydrophobic rare earth-based silica aerogel, which takes phenyl alkoxy silane and methyl/ethyl orthosilicate as co-precursors, takes rare earth solution as an acid catalyst and a doping agent to prepare rare earth doped phenyl modified silica aerogel, on one hand, the unique hydrophobicity of the silica aerogel can be endowed by introducing phenyl groups, and the self-cleaning capability of the silica aerogel can be endowed; on the other hand, in the process of catalyzing acid hydrolysis by the rare earth solution, rare earth ions are uniformly introduced into the silica framework in the condensation process, and the rare earth elements are uniformly distributed in the silica aerogel, so that the high-temperature sintering of the silica aerogel can be inhibited, and the high-temperature resistance of the silica aerogel is further improved.
The application solves the technical problems by adopting the following technical scheme:
the application aims to provide a preparation method of hydrophobic rare earth-based silica aerogel, which is characterized by comprising the following steps:
phenyl-alkoxy silane and tetraalkoxy silane are used as silicon sources and common precursors, rare earth salt solution is used as an acid catalyst and a doping agent to be added into the precursors, and hydrolysis is carried out under an ethanol solvent to obtain rare earth doped silica sol; standing the rare earth doped silica sol in alkaline catalytic liquid diluted by ethanol to form rare earth doped silica gel; the rare earth doped silica gel is aged, subjected to solvent exchange and dried to obtain the rare earth doped silica aerogel.
The preparation method of the hydrophobic rare earth-based silica aerogel is characterized by comprising the following steps of:
1) Under the condition of stirring, adding phenyl-alkoxy silane and tetraalkoxy silane into ethanol solvent to obtain mixed solution; dropwise adding a rare earth salt solution into the mixed solution, continuously stirring, standing, and hydrolyzing to obtain rare earth doped silica sol;
2) Preparing rare earth doped silica gel: adding alkaline catalytic liquid diluted by ethanol into the rare earth doped silica sol obtained in the step 1) under the stirring condition, and sealing and standing until gel is formed;
3) Adding ethanol into the wet gel obtained in the step 2), soaking and aging, performing solvent exchange, then placing into an autoclave, and preparing the rare earth doped silica aerogel by adopting a supercritical ethanol drying method.
Further, the phenyl-alkoxysilane in the step 1) is one or more of Phenyltrimethoxysilane (PTMS), phenyltriethoxysilane (PTES), diphenyldimethoxysilane (DMDPS), and diphenyldiethoxysilane (MPDES).
Further, the tetraalkoxysilane is tetraethyl orthosilicate (TEOS) or methyl orthosilicate (TMOS).
Further, the rare earth salt in the step 1) is nitrate, chloride or hydrate of the corresponding salt of the rare earth element.
Further, the rare earth element is selected from any one of lanthanum, ytterbium, yttrium, gadolinium, terbium, samarium, praseodymium and europium.
Preferably, the rare earth salts include, but are not limited to, lanthanum nitrate, ytterbium nitrate, yttrium nitrate, gadolinium nitrate, terbium nitrate, samarium nitrate, praseodymium chloride, europium chloride, yttrium chloride.
Further, the molar ratio of the phenyl-alkoxysilane to the tetraalkoxysilane is 0.125-1.25:1.
preferably, the molar ratio of the phenyl-alkoxysilane to the tetraalkoxysilane is 1:1.
Further, the mass fraction of the phenyl-alkoxysilane and the tetraalkoxysilane after being dissolved in ethanol is 10 to 60%.
Further, the mass fraction of the rare earth salt solution is 6-50%, and the dissolution temperature is 25-80 ℃.
Further, in step 1), the molar ratio of rare earth ions to silicon is 0.05-0.25:1.
further, in step 1), the hydrolysis time is greater than 18 hours.
Further, ethanol is added into an alkaline catalyst to dilute to obtain an alkaline catalyst liquid, wherein the alkaline catalyst is one or more of ammonia water, ammonium carbonate or urea.
Further, the molar ratio of ammonia to silicon in the rare earth doped silica gel is 0.01-2.5:1.
Further, the aging time in the step 3) is 2-3 days, and the ethanol is replaced every 12 hours during the solvent exchange for 4-6 times so as to remove water molecules introduced by the hydrated salt.
Further, the supercritical ethanol drying method comprises the following steps: nitrogen replacement is carried out before nitrogen pre-filling to ensure an anaerobic environment, then nitrogen filling is carried out to ensure that the pressure is not less than 2MPa, and heat preservation and drying are carried out for 1-4 h under the conditions that the temperature is 260-300 ℃ and the pressure is more than 7 MPa.
Compared with the prior art, the application has the beneficial technical effects that:
the super-hydrophobic property generated by introducing phenyl can endow the silica aerogel with self-cleaning capability; in the process of catalyzing acid hydrolysis by the rare earth solution, rare earth ions are uniformly introduced into the silica framework in the condensation process, so that the high temperature resistance of the silica aerogel is further improved. The preparation process and the operation steps of the application are simple, the raw materials are easy to obtain, and the mass production can be realized. The specific surface area of the prepared rare earth doped phenyl modified silica aerogel is 450-850 m 2 Between/g; the introduction of rare earth elements inhibits the sintering of the silicon dioxide aerogel at 1000 ℃, and the maximum specific surface areas can respectively reach 190m after heat treatment at 1000 ℃ for 2 hours 2 And/g. The phenyl groups with low surface energy are introduced to endow the silica aerogel with superhydrophobicity, the water static contact angle is higher than 150 degrees, the hysteresis angle is smaller than 2 degrees, and the silica aerogel has excellent self-cleaning performance.
The foregoing description is only an overview of the present application, and is intended to be implemented in accordance with the teachings of the present application in order that the technical means thereof may be more clearly understood, and in order that the present application may be more readily understood, its objects, features and advantages be more particularly described below.
Drawings
FIG. 1 is a flow chart of a process for preparing a hydrophobic rare earth-based silica aerogel according to the present application.
FIG. 2 is a graph showing the change of specific surface area of example 4 after heat treatment at different temperatures for 2 hours in the preparation method of the hydrophobic rare earth-based silica aerogel according to the present application.
FIG. 3 is an optical photograph of 4. Mu.L water droplets on the surface of the aerogel of example 1 in a preparation method of a hydrophobic rare earth-based silica aerogel according to the present application.
FIG. 4 is an optical photograph of 4. Mu.L water droplets on the surface of the aerogel of example 1 after heat-treating at 500℃for 1 hour in a preparation method of a hydrophobic rare earth-based silica aerogel according to the present application.
Detailed Description
The technical scheme of the application is further described in detail below with reference to the attached drawings and specific embodiments. It is to be understood that the following examples are illustrative only and are not to be construed as limiting the scope of the application. All techniques implemented based on the above description of the application are intended to be included within the scope of the application.
In addition, unless otherwise specifically indicated, the various raw materials, reagents, instruments and equipment used in the present application may be obtained commercially or prepared by existing methods.
Example 1:
a preparation method of hydrophobic rare earth-based silica aerogel comprises the following steps:
3g of PTES and 2.6g of TEOS were dissolved in 7.66g of ethanol under stirring to obtain a mixed solution; 0.11g of ytterbium nitrate pentahydrate was dissolved in 1.13g of water at room temperature to obtain an aqueous ytterbium nitrate solution having a mass fraction of 6.7%. Dropwise adding ytterbium nitrate aqueous solution into the mixed solution, stirring for a period of time, standing and hydrolyzing for 24 hours to obtain rare earth doped silica sol, wherein TEOS and Yb are prepared 3+ The molar ratio of (2) is 1:0.02. After the hydrolysis is completed, adding 1.38g of ammonia water/ethanol diluent into the rare earth doped silica sol under stirring, and standing until the gel is formed, wherein the gel time is within 3 hours. Soaking the ytterbium-doped silica wet gel after gel in ethanol solution, aging for 3 days at room temperature, and then carrying out solvent exchange: the ethanol was replaced every 12h, 4 times. Then placing the gel subjected to solvent exchange into an autoclave, and adopting a supercritical ethanol drying method to prepare ytterbium doped ceramicSilica aerogel, drying conditions are: adding 600ml of ethanol as a drying medium into a sample to be dried, pre-charging nitrogen gas for 2MPa, heating to 260 ℃ at a speed of 1 ℃/min, keeping the temperature for 2 hours under a pressure of about 8MPa, and then discharging the pressure at a speed of 1MPa/30min to obtain the blocky ytterbium-doped silica aerogel.
The ytterbium-doped silica aerogel prepared in example 1 had superhydrophobicity, a static contact angle of 159.8 °, and a contact angle hysteresis (difference between advancing contact angle and receding contact angle) of 0.9 °; its original specific surface area is 531m 2 Per g, the specific surface area after heat treatment at 1000 ℃ for 2 hours is 77m 2 /g。
Example 2:
a preparation method of hydrophobic rare earth-based silica aerogel comprises the following steps:
3g of PTES and 2.6g of TEOS were dissolved in 7.66g of ethanol under stirring to obtain a mixed solution; 0.55g of ytterbium nitrate pentahydrate was dissolved in 1.10g of water at room temperature to obtain an aqueous ytterbium nitrate solution having a mass fraction of 25%. Dropwise adding ytterbium nitrate aqueous solution into the mixed solution, stirring for a period of time, standing and hydrolyzing for 24 hours to obtain rare earth doped silica sol, wherein TEOS and Yb are prepared 3+ The molar ratio of (2) is 1:0.1. After the hydrolysis is completed, adding 2.79g of ammonia water/ethanol diluent into the rare earth doped silica sol under stirring, and standing until the gel is formed, wherein the gel time is within 3 hours. Soaking the ytterbium-doped silica wet gel after gel in ethanol solution, aging for 3 days at room temperature, and then carrying out solvent exchange: the ethanol was replaced every 12h, 6 times. Then placing the gel subjected to solvent exchange into an autoclave, and preparing ytterbium-doped silica aerogel by adopting a supercritical ethanol drying method, wherein the drying conditions are as follows: adding 600ml of ethanol as a drying medium into a sample to be dried, pre-charging nitrogen gas for 2MPa, heating to 260 ℃ at a speed of 1 ℃/min, keeping the temperature for 2 hours under a pressure of about 8MPa, and then discharging the pressure at a speed of 1MPa/30min to obtain the blocky ytterbium-doped silica aerogel.
The ytterbium-doped silica aerogel prepared in example 2 had superhydrophobicity with a static contact angle of 156.9 ° and a contact angle hysteresis of 1.1 °; its original specific surface area is 472m 2 Per g, warp 1Heat treatment at 000deg.C for 2h, specific surface area of 94m 2 /g。
Example 3:
a preparation method of hydrophobic rare earth-based silica aerogel comprises the following steps:
3g of PTES and 2.6g of TEOS were dissolved in 7.66g of ethanol under stirring to obtain a mixed solution; 1.06g of lanthanum nitrate hexahydrate was dissolved in 1.10g of water at 80℃to obtain a 36.8% by mass aqueous lanthanum nitrate solution. Dropwise adding a lanthanum nitrate aqueous solution into the mixed solution, stirring for a period of time, standing and hydrolyzing for 24 hours to obtain rare earth doped silica sol, wherein TEOS and La are prepared 3+ The molar ratio of (2) is 1:0.2. After the hydrolysis is completed, adding 4.56g of ammonia water/ethanol diluent into the rare earth doped silica sol under stirring, and standing until the gel is formed, wherein the gel time is within 3 hours. Immersing the gel lanthanum-doped silica wet gel in ethanol solution, aging for 3 days at room temperature, and then carrying out solvent exchange: the ethanol was replaced every 12h, 6 times. Then placing the gel subjected to solvent exchange into an autoclave, and preparing the lanthanum-doped silica aerogel by adopting a supercritical ethanol drying method, wherein the drying conditions are as follows: adding 600ml of ethanol as a drying medium into a sample to be dried, pre-charging nitrogen gas for 2MPa, heating to 260 ℃ at a speed of 1 ℃/min, keeping the temperature for 2 hours under a pressure of about 8MPa, and then discharging the pressure at a speed of 1MPa/30min to obtain the massive lanthanum-doped silica aerogel.
The lanthanum doped silica aerogel prepared in example 3 had superhydrophobicity with a static contact angle of 157.8 ° and a contact angle hysteresis of 1.3 °; its original specific surface area is 531m 2 Per g, a specific surface area of 67m after heat treatment at 1000℃for 2h 2 /g。
Example 4:
a preparation method of hydrophobic rare earth-based silica aerogel comprises the following steps:
1.5g of PTES and 2.6g of TEOS were dissolved in 7.66g of ethanol under stirring to obtain a mixed solution; 0.53g of lanthanum nitrate hexahydrate was dissolved in 1.10g of water at room temperature to obtain a 24.4% by mass aqueous lanthanum nitrate solution. Dropwise adding lanthanum nitrate aqueous solution into the mixed solution, stirring for a period of timeStanding and hydrolyzing for 24 hours after the reaction to obtain rare earth doped silica sol, wherein TEOS and La 3+ The molar ratio of (2) is 1:0.1. After the hydrolysis is completed, adding 2.75g of ammonia water/ethanol diluent into the rare earth doped silica sol under stirring, and standing until the gel is formed, wherein the gel time is within 5 hours. Immersing the gel lanthanum-doped silica wet gel in ethanol solution, aging for 3 days at room temperature, and then carrying out solvent exchange: the ethanol was replaced every 12h, 6 times. Then placing the gel subjected to solvent exchange into an autoclave, and preparing the lanthanum-doped silica aerogel by adopting a supercritical ethanol drying method, wherein the drying conditions are as follows: adding 600ml of ethanol as a drying medium into a sample to be dried, pre-charging nitrogen gas for 2MPa, heating to 260 ℃ at a speed of 1 ℃/min, keeping the temperature for 2 hours under a pressure of about 8MPa, and then discharging the pressure at a speed of 1MPa/30min to obtain the massive lanthanum-doped silica aerogel.
The lanthanum doped silica aerogel prepared in example 4 had superhydrophobicity with a static contact angle of 153.2 ° and a contact angle of 1.7 ° after contact angle; its original specific surface area is 840m 2 Per g, the specific surface area after heat treatment at 1000 ℃ for 2 hours is 174m 2 /g。
Example 5:
a preparation method of hydrophobic rare earth-based silica aerogel comprises the following steps:
0.75g of PTES and 2.6g of TEOS were dissolved in 7.66g of ethanol under stirring to obtain a mixed solution; 0.53g of lanthanum nitrate hexahydrate was dissolved in 1.10g of water at room temperature to obtain a 24.4% by mass aqueous lanthanum nitrate solution. Dropwise adding a lanthanum nitrate aqueous solution into the mixed solution, stirring for a period of time, standing and hydrolyzing for 24 hours to obtain rare earth doped silica sol, wherein TEOS and La are prepared 3+ The molar ratio of (2) is 1:0.1. After the hydrolysis is completed, adding 2.03g of ammonia water/ethanol diluent into the rare earth doped silica sol under stirring, and standing until the gel is formed, wherein the gel time is within 5 hours. Immersing the gel lanthanum-doped silica wet gel in ethanol solution, aging for 3 days at room temperature, and then carrying out solvent exchange: the ethanol was replaced every 12h, 6 times. Then placing the gel after solvent exchange into an autoclave, and adopting a supercritical ethanol drying method to prepare the gelThe lanthanum doped silica aerogel has the following drying conditions: adding 600ml of ethanol as a drying medium into a sample to be dried, pre-charging nitrogen gas for 2MPa, heating to 260 ℃ at a speed of 1 ℃/min, keeping the temperature for 2 hours under a pressure of about 8MPa, and then discharging the pressure at a speed of 1MPa/30min to obtain the massive lanthanum-doped silica aerogel.
The lanthanum doped silica aerogel prepared in example 5 had superhydrophobicity with a static contact angle of 154.4 ° and a contact angle hysteresis of 1.5 °; its original specific surface area is 799m 2 Per g, the specific surface area is 180m after heat treatment at 1000 ℃ for 2 hours 2 /g。
Example 6:
a preparation method of hydrophobic rare earth-based silica aerogel comprises the following steps:
1.24g of PTMS and 2.6g of TEOS were dissolved in 7.66g of ethanol under stirring to obtain a mixed solution; 0.47g of yttrium nitrate hexahydrate was dissolved in 1.10g of water at room temperature to obtain an aqueous solution of yttrium nitrate with a mass fraction of 21.5%. Dropwise adding yttrium nitrate aqueous solution into the mixed solution, stirring for a period of time, standing and hydrolyzing for 24 hours to obtain rare earth doped silica sol, wherein TEOS and Y are prepared 3+ The molar ratio of (2) is 1:0.1. After the hydrolysis is completed, adding 2.68g of ammonia water/ethanol diluent into the rare earth doped silica sol under stirring, and standing until the gel is formed, wherein the gel time is within 5 hours. Immersing the yttrium doped silicon oxide wet gel after gel into ethanol solution, aging for 3 days at room temperature, and then carrying out solvent exchange: the ethanol was replaced every 12h, 6 times. Then placing the gel subjected to solvent exchange into an autoclave, and preparing yttrium doped silicon oxide aerogel by adopting a supercritical ethanol drying method, wherein the drying conditions are as follows: adding 600ml of ethanol as a drying medium into a sample to be dried, pre-charging nitrogen gas for 2MPa, heating to 260 ℃ at a speed of 1 ℃/min, keeping the temperature for 2 hours under a pressure of about 8MPa, and then discharging the pressure at a speed of 1MPa/30min to obtain the bulk yttrium doped silica aerogel.
The yttrium doped silica aerogel prepared in example 6 had superhydrophobicity with a static contact angle of 154 ° and a contact angle hysteresis of 1.9 °; its original specific surface area is 849m 2 Per g, specific surface area after heat treatment at 1000℃for 2h190m 2 /g。
Example 7:
a preparation method of hydrophobic rare earth-based silica aerogel comprises the following steps:
0.62g of PTMS and 2.6g of TEOS were dissolved in 7.66g of ethanol under stirring to obtain a mixed solution; 0.47g of yttrium nitrate hexahydrate was dissolved in 1.10g of water at room temperature to obtain an aqueous solution of yttrium nitrate with a mass fraction of 21.5%. Dropwise adding yttrium nitrate aqueous solution into the mixed solution, stirring for a period of time, standing and hydrolyzing for 24 hours to obtain rare earth doped silica sol, wherein TEOS and La are prepared 3+ The molar ratio of (2) is 1:0.1. After the hydrolysis is completed, adding 2.14g of ammonia water/ethanol diluent into the rare earth doped silica sol under stirring, and standing until the gel is formed, wherein the gel time is within 5 hours. Immersing the gel lanthanum-doped silica wet gel in ethanol solution, aging for 3 days at room temperature, and then carrying out solvent exchange: the ethanol was replaced every 12h, 6 times. Then placing the gel subjected to solvent exchange into an autoclave, and preparing the lanthanum-doped silica aerogel by adopting a supercritical ethanol drying method, wherein the drying conditions are as follows: adding 600ml of ethanol as a drying medium into a sample to be dried, pre-charging nitrogen gas for 2MPa, heating to 260 ℃ at a speed of 1 ℃/min, keeping the temperature for 2 hours under a pressure of about 8MPa, and then discharging the pressure at a speed of 1MPa/30min to obtain the massive lanthanum-doped silica aerogel.
The yttrium doped silica aerogel prepared in example 7 had superhydrophobicity with a static contact angle of 155.2 ° and a contact angle hysteresis of 2 °; its original specific surface area is 825m 2 Per g, the specific surface area after heat treatment at 1000 ℃ for 2 hours is 177m 2 /g。
The rare earth doped silica aerogel has good specific surface area, and the original specific surface area reaches 400-900 m 2 And/g. For the lanthanum doped silica aerogel of example 4, the specific surface area was measured after heat treatment at 300 ℃, 400 ℃, 500 ℃, 800 ℃, 1000 ℃, 1100 ℃ for 2 hours, respectively, and referring to the specific surface area change chart in fig. 2, it can be seen that the specific surface area of the silica aerogel drastically decreases with increasing heat treatment temperature after 400 ℃, especially at 800 °cThe specific surface area of the silica aerogel is obviously reduced, and the specific surface area of the silica aerogel is 174m after heat treatment for 2 hours at 1000 DEG C 2 And/g, the hydroxyl groups on the surface of the silicon dioxide are further condensed at high temperature mainly because the introduction of the rare earth elements is uniformly distributed in the silicon oxide framework, so that the high-temperature sintering of the silicon oxide aerogel is inhibited. Therefore, the rare earth doped silica aerogel obtained by the method can not be sintered at high temperature, and still has a good specific surface area at high temperature.
Referring to fig. 3 and 4, the optical photographs of the ytterbium-doped silica aerogel obtained in example 1 and the ytterbium-doped silica aerogel obtained in 500 ℃ after heat treatment for 1 hour are respectively dripped with one drop of 4 μl of water, and it can be seen that the contact angle of the ytterbium-doped silica aerogel obtained in example 1 is 159.8 °, the contact angle of the ytterbium-doped silica aerogel obtained in example 1 after heat treatment for 1 hour at 500 ℃ is 149.7 °, the hydrophobicity of the thermal silica gel is basically unchanged after heat treatment, and the hydrophobicity of the rare earth-doped silica aerogel has excellent high temperature resistance.
The foregoing embodiment numbers of the present application are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.
The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are to be protected by the present application.
Claims (10)
1. The preparation method of the hydrophobic rare earth-based silica aerogel is characterized by comprising the following steps of:
phenyl-alkoxy silane and tetraalkoxy silane are used as silicon sources and common precursors, rare earth salt solution is used as an acid catalyst and a doping agent to be added into the precursors, and hydrolysis is carried out under an ethanol solvent to obtain rare earth doped silica sol; standing the rare earth doped silica sol in alkaline catalytic liquid diluted by ethanol to form rare earth doped silica gel; the rare earth doped silica gel is aged, subjected to solvent exchange and dried to obtain the rare earth doped silica aerogel.
2. The method for preparing hydrophobic rare earth based silica aerogel according to claim 1, comprising the steps of:
1) Under the condition of stirring, adding phenyl-alkoxy silane and tetraalkoxy silane into ethanol solvent to obtain mixed solution; dropwise adding a rare earth salt solution into the mixed solution, continuously stirring, standing, and hydrolyzing to obtain rare earth doped silica sol;
2) Preparing rare earth doped silica gel: adding alkaline catalytic liquid diluted by ethanol into the rare earth doped silica sol obtained in the step 1) under the stirring condition, and sealing and standing until gel is formed;
3) Adding ethanol into the wet gel obtained in the step 2), soaking and aging, performing solvent exchange, then placing into an autoclave, and preparing the rare earth doped silica aerogel by adopting a supercritical ethanol drying method.
3. The method for preparing the hydrophobic rare earth-based silica aerogel according to claim 1 or 2, wherein: the phenyl-alkoxy silane is one or more of phenyl trimethoxy silane, phenyl triethoxy silane, diphenyl dimethoxy silane and diphenyl diethoxy silane.
4. The method for preparing the hydrophobic rare earth-based silica aerogel according to claim 1 or 2, wherein: the tetraalkoxysilane is tetraethoxysilane or tetramethylsilicate.
5. The method for preparing the hydrophobic rare earth-based silica aerogel according to claim 1 or 2, wherein: the rare earth salt in the step 1) is nitrate, chloride or hydrate of corresponding salt of rare earth element.
6. The method for preparing the hydrophobic rare earth-based silica aerogel according to claim 5, wherein: the rare earth element is selected from any one of lanthanum, ytterbium, yttrium, gadolinium, terbium, samarium, praseodymium and europium.
7. The method for preparing the hydrophobic rare earth-based silica aerogel according to claim 1 or 2, wherein: the molar ratio of the phenyl-alkoxy silane to the tetraalkoxy silane is 0.125-1.25:1.
8. the method for preparing the hydrophobic rare earth-based silica aerogel according to claim 2, wherein: the mass fraction of the phenyl-alkoxy silane and the tetraalkoxy silane after being dissolved in ethanol is 10-60%, and the mass fraction of the rare earth salt solution is 6-50%.
9. The method for preparing the hydrophobic rare earth-based silica aerogel according to claim 2, wherein: in the step 1), the molar ratio of rare earth ions to silicon is 0.05-0.25:1.
10. the method for preparing the hydrophobic rare earth-based silica aerogel according to claim 2, wherein: the molar ratio of ammonia to silicon in the rare earth doped silica gel is 0.01-2.5:1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310908262.7A CN116692881A (en) | 2023-07-24 | 2023-07-24 | Preparation method of hydrophobic rare earth-based silica aerogel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310908262.7A CN116692881A (en) | 2023-07-24 | 2023-07-24 | Preparation method of hydrophobic rare earth-based silica aerogel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116692881A true CN116692881A (en) | 2023-09-05 |
Family
ID=87839371
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310908262.7A Pending CN116692881A (en) | 2023-07-24 | 2023-07-24 | Preparation method of hydrophobic rare earth-based silica aerogel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116692881A (en) |
-
2023
- 2023-07-24 CN CN202310908262.7A patent/CN116692881A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3375757B1 (en) | Silica aerogel blanket for ultra-high temperature, manufacturing method thereof, and installation method thereof | |
| CN113716572B (en) | Preparation method of alumina-silica aerogel composite material | |
| WO2022148460A1 (en) | Fiber composite aerogel material, preparation method therefor and use thereof | |
| CN101616726B (en) | Gas separation membranes containing a microporous silica layer based on silica doped with a trivalent element | |
| JP3401570B2 (en) | Method for producing glass substrate with improved long-term stability at high temperatures | |
| KR101409884B1 (en) | Preparation method of hydrophobic monolith type silica aerogel | |
| CN110643141B (en) | Preparation method of silicon oxide/phenolic aldehyde binary composite aerogel | |
| JP2008208019A (en) | Porous material and method for preparing the same | |
| CN104418331A (en) | Block hydrophobic silicon dioxide aerogel and preparation method thereof | |
| CN106495169A (en) | A kind of hydrophobic type aerosil and preparation method thereof | |
| CN101774592A (en) | High heat insulation transparent SiO2 aerogel film material and preparation method thereof | |
| CN113135732B (en) | Chopped glass fiber silicon dioxide aerogel composite material and preparation method thereof | |
| CN105036143B (en) | Preparation method of nano silicon dioxide aerogel | |
| CN101817980A (en) | Sol-gel preparation method of silica-based superhydrophobic thin films | |
| CN101654348A (en) | Preparation of high-temperature resistant hole sealing agent and hole sealing technique | |
| CN112456961B (en) | Composite aerogel heat insulation material and preparation method and application thereof | |
| JPWO2019069494A1 (en) | Coating liquid, coating film manufacturing method and coating film | |
| CN110436953B (en) | High-temperature-resistant Al-Si-B-O ceramic aerogel material and synthesis method thereof | |
| CN114960192A (en) | Hydrophobic rate controllable and adjustable silica aerogel felt and preparation method thereof | |
| CN111072037A (en) | Preparation method of silicon dioxide aerogel with good flexibility | |
| CN116692881A (en) | Preparation method of hydrophobic rare earth-based silica aerogel | |
| CN102872725A (en) | Method for preparing CO2 catching membrane material with high hydrothermal stability | |
| KR101111662B1 (en) | Method for Preparing Large-area Silica Aerogel Coatings by Using DCCA | |
| CN112320833B (en) | High temperature resistant SiO 2 -Gd 2 O 3 Composite aerogel and preparation method thereof | |
| JP3273957B2 (en) | Method for producing airgel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |