CN103979545B - The preparation method of a kind of cellular small-bore mesoporous silicon oxide - Google Patents
The preparation method of a kind of cellular small-bore mesoporous silicon oxide Download PDFInfo
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- CN103979545B CN103979545B CN201410061741.0A CN201410061741A CN103979545B CN 103979545 B CN103979545 B CN 103979545B CN 201410061741 A CN201410061741 A CN 201410061741A CN 103979545 B CN103979545 B CN 103979545B
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Abstract
The present invention provides the preparation method of a kind of cellular small-bore mesoporous silicon oxide. The method adopts short chain cats product and sodium salicylate composite as template, water glass is silicon source, obtains cellular small-bore mesoporous silicon oxide by sol-gel method, and aperture is 2.0-2.5nm, specific surface area is 1300-1900m2/g, Kong Rongwei 0.61-0.98cm3/g. The present invention adopts business-like tensio-active agent, reduces synthesis cost, the mesoporous material duct order height of preparation, aperture equal, and specific surface area is big, is conducive to the scale operation of small-bore mesoporous silicon oxide.
Description
Technical field
The invention belongs to inorganic chemistry, physical chemistry, Materials science, field of catalytic chemistry, specifically relate to the preparation method of a kind of cellular small-bore mesoporous silicon oxide.
Background technology
1992, the staff of Mobil oil company of the U.S. used quaternary ammonium alkyl salt form cats product to be template first, successfully synthesized series Jie hole silicate material. Mesoporous material causes rapidly the great attention in the fields such as international chemistry, Materials science, pharmacy, becomes one of research focus of interdiscipline. The relatively good thermostability of the duct of mesopore molecular sieve equal, high-ratio surface sum makes it have very wide application prospect in fields such as fine chemistry industry catalysis, separation of biopolymer and functional materialss.
In practical application, the pore size of mesoporous material and pore passage structure have extremely important meaning. The mesoporous silicon oxide aperture synthesized by ordinary method is at about 3-50nm (D.Y.Zhao, Q.S.Huo, J.L.Feng, B.F.Chmelka, G.D.Stucky, J.Am.Chem.Soc.120 (1998) 6024). Mesoporous silicon oxide for synthesis larger aperture has had more patent and report, it is possible to realize by adding the means such as the block copolymer surfactant of alkane, toluene, trimethylbenzene or employing larger molecular weight in building-up process. And the mesoporous material means synthesizing smaller aperture due (aperture is between 1.5-3nm) are not enriched. The carbochain of the quaternary ammonium alkyl salt form cats product that conventional Jie hole is used in synthesizing is generally between 12-18, and aperture, carbochain more short corresponding Jie hole is more little. More short then its surfactivity of short carbon chain tensio-active agent carbochain is more low, and self-assembly ability and template effect are more poor, causes the mesoporous material order of synthesis poor, mostly is vermiform or unordered duct. The mesoporous silicon oxide of smaller aperture due is considered to have good adsorption selection, shape selective catalysis ability. Therefore, synthesizing ordered small-bore mesoporous silicon oxide has extremely most important theories and practical value.
Zhao Dongyuan academician seminar of Fudan University, taking the poly-oxygen ether tensio-active agent of aliphatic amide as template, adopts the method for solvent volatilization induction interface self-assembly successfully to obtain orderly small-bore mesoporous silicon oxide. (MicroporousandMesoporousMaterials90(2006)23�C31) adopt BJH model to calculate its aperture at 1.6-1.8nm. The people such as S.Shylesh adopt cetyl trimethylammonium bromide to be template, and tetraethyl orthosilicate, 3 chloropropyl triethoxy silane, vinyltriethoxysilane mixture are silicon source, obtained in order containing chromium small-bore mesoporous silicon oxide (AppliedCatalysisA:General318(2007)128�C136). Adopting DFT model nitrogen adsorption curve to calculate this material aperture at about 2.1nm, this material demonstrates good catalytic activity and selectivity and stability in the reaction of catalytic oxidation of cyclohexane. The people such as Yu-ShenLin adopt ten alkyl trimethyl ammonium bromides and propyl carbinol composite as template, water glass be silicon source successfully obtain super large micropore silicon-dioxide (MicroporousandMesoporousMaterials76 (2004) 203 208). Chinese patent CN1608985 adopt carbochain be the alkylamine of 12-18 as template and catalyzer, tetraethyl orthosilicate is silicon source, is hydrolyzed in neutral conditions, successfully obtained high specific surface area silica microballoon, and aperture is between 1.1-1.9nm.
Problem existing for the synthesis small-bore mesoporous silicon oxide reported both at home and abroad at present has: used tensio-active agent is generally by lab design, synthesis, and the not tensio-active agent of commercialization, causes synthesis cost to raise; The material duct order that synthesis obtains is not high, mostly is vermiform duct or macropore, aperture mixture, duct lack of homogeneity.
Summary of the invention
It is an object of the invention to taking lower cost, tensio-active agent ten alkyl trimethyl ammonium bromide of commercialization and sodium salicylate composite as template, prepare the cellular small-bore mesoporous silicon oxide of a kind of high-sequential. Cellular small-bore mesoporous silicon oxide prepared by the present invention has very high duct order and higher specific surface area, and it is cellular that scanning electron microscope image shows this material.
In order to realize above-mentioned purpose, the present invention adopts following technical scheme:
A preparation method for cellular small-bore mesoporous silicon oxide, it comprises the following steps:
First mol ratio is the short chain ionic surfactant of 1:0.3-1.0:1.5:800, aromatic ring compounds, silicon source and water mixing and at room temperature stirs 0.5 hour, wherein said short chain ionic surfactant is ten alkyl trimethyl ammonium bromides, aromatic ring compounds is sodium salicylate, and silicon source is water glass; Then it is 9-10 with the sulphuric acid soln of 2mol/L by the pH regulator of gained mixture, subsequently again by its thermostatically heating 72 hours in the baking oven of 80 DEG C, the solid sediment of gained filtered, wash and dry in atmosphere, obtain combination product; Finally the combination product of gained is placed in retort furnace constant temperature calcining at the temperature of 550 DEG C and within 5 hours, cellular small-bore mesoporous silicon oxide can be obtained.
Preferably, the mol ratio of short chain ionic surfactant, aromatic ring compounds, silicon source and water is 1:0.5:1.5:800.
Preferably, wherein first short chain ionic surfactant and aromatic ring compounds are dissolved in the water of 50% amount stir within 0.5 hour, obtain solution A, and silicon source is dissolved in the water of 50% remaining amount and obtains B solution, then by solution A and B solution short mix.
Preferably, the aperture of cellular small-bore mesoporous silicon oxide prepared by the present invention is 2.0-2.5nm, and specific surface area is 1300-1900m2/ g, Kong Rongwei 0.61-0.98cm3/g��
Metaporous silicon dioxide material duct, cellular small-bore prepared by the present invention is enriched, and presents cellular, see Fig. 1.
Between I type that the nitrogen adsorption-desorption isotherm of cellular small-bore Metaporous silicon dioxide material prepared by the present invention defines between IUPAC and IV type. See Fig. 2, at P/P0The hysteresis loop occurred for about 0.5-1.0 interval is that sample particle piles up the vacancy formed.
Cellular small-bore Metaporous silicon dioxide material prepared by the present invention is measured under 77K by nitrogen adsorption method, and Kong Rong is at P/P0Measuring under=0.98 condition, pore size distribution adopts the U.S. Kang Ta company Autosorb-IQ built-in DFT prototype software of type gas adsorption instrument to calculate.
Cellular small-bore Metaporous silicon dioxide material prepared by the present invention is characterized by small angle x-ray diffraction (SAXD), as shown in Figure 5, has occurred three obvious diffraction peaks within the scope of 2-9 degree, and this represents that this material has the order of height. Relative to the MCM-41 type mesoporous silicon oxide of routine, (100) diffraction surfaces is obviously partial to high angle, shows this material hole road and has less spacing.
The thermogravimetric curve of the material without calcining prepared by the present invention as shown in Figure 6, is the removal of moisture lower than 100 DEG C of weightlessness, and the weightlessness of about 260 DEG C is the removal process of tensio-active agent, and a small amount of weightlessness of 500 DEG C is the condensation course of silicone hydroxyl.
In the building-up process of mesoporous material, suitable micellar system is selected to play key use with regulation and control. Surfactant molecule forms the balance that micella depends on two kinds of power in aqueous: one is the magnetism between hydrophobic grouping, and two is the electric charge between hydrophilic head base or space repulsion. Generally speaking, ten alkyl trimethyl ammonium bromides also are not suitable for doing template synthesizing mesoporous silicon dioxide, because its hydrophobic chain (ten carbon atoms) not sufficiently long, cause the magnetism between hydrophobic grouping big not. If the repulsion effect between hydrophilic head base can correspondingly be reduced, make two kinds of power relative equilibriums, then can the Packing parameter of optimizing surface promoting agent, be beneficial to the formation of micella. Chinese patent CN103058206A have employed ten alkyl trimethyl ammonium bromides and the composite method of short chain sodium octyl sulfate, enhances the ability forming micella. This system belongs to cationic-anionic surfactant mixture, and the hydrophobic chain insertion micella of sodium octyl sulfate is inner, and electronegative hydrophilic head base has neutralized the positively charged hydrophilic head base of ten alkyl trimethyl ammonium bromides effectively. Strong owing to interacting between two kinds of cationic-anionic surfactants, so the ratio between sodium octyl sulfate and ten alkyl trimethyl ammonium bromides to be strict controlled between 0.1-0.4. The present invention adopts ten alkyl trimethyl ammonium bromides and the composite method principle preparing mesoporous silicon oxide of sodium salicylate to be different from the method principle of above-mentioned patent. Sodium salicylate is that one helps water solvent, and the worm-like micelle systems that itself and cetyl trimethylammonium bromide form industrially relatively is widely used as pipeline drag reducer. In the present invention, the head base ion of the positively charged of ten alkyl trimethyl ammonium bromides and the interaction of sodium salicylate aromatic ring ��-electron make sodium salicylate molecule easily permeate the fence district into micella, positive electric repulsion between partly shielding effect hydrophilic head base effectively, so that the sucking action between the hydrophilic head base repulsion of ten alkyl trimethyl ammonium bromides and hydrophobic grouping balances each other, thus facilitate the formation of micella. In addition, relative to sodium octyl sulfate, the interaction of sodium salicylate and ten alkyl trimethyl ammonium bromides is gentleer, therefore in the present invention, sodium salicylate and ten alkyl trimethyl ammonium bromide ratios all can obtain high-quality small-bore mesoporous silicon oxide between 0.3-1.0, namely the present invention synthesizes ratio relative loose, is easy to operation. In addition, sodium salicylate price, lower than sodium octyl sulfate, reduces synthesis cost.
Accompanying drawing explanation
Fig. 1 is the electron scanning micrograph of the cellular small-bore mesoporous silicon oxide of embodiment 1 gained.
Fig. 2 is the high resolution electron microscopy photo of the cellular small-bore mesoporous silicon oxide of embodiment 1 gained.
Fig. 3 is the nitrogen adsorption-desorption isotherm of the cellular small-bore mesoporous silicon oxide of embodiment 1 gained.
Fig. 4 is the pore size distribution curve that the cellular small-bore mesoporous silicon oxide of embodiment 1 gained adopts DFT model to calculate.
Fig. 5 is the small angle x-ray diffraction (SAXD) figure of the cellular small-bore mesoporous silicon oxide of embodiment 1 gained.
Fig. 6 is the thermogravimetric curve of the cellular small-bore mesoporous silicon oxide without calcining of embodiment 1 gained.
Fig. 7 is the small angle x-ray diffraction (SAXD) figure of the mesoporous silicon oxide of comparative example gained.
Also it should be noted that about accompanying drawing, the cellular small-bore mesoporous silicon oxide that embodiment 2-4 obtains and embodiment 1 are very similar, therefore, in order to avoid treatise to repeat, Figure of description part only gives the various test results of the cellular small-bore mesoporous silicon oxide that embodiment 1 obtains as typical case.
Embodiment
The feature that the invention is further illustrated by the following examples, but the present invention is not limited to following embodiment.
In embodiment, the electron scanning micrograph of material adopts U.S.'s FEI company NovaNanoSEM450 type scanning electron microscope to measure.
In embodiment, the transmission electron microscope photo of material adopts U.S.'s FEI company's T ecnaiG2F20S-Twin type transmission electron microscope to measure.
In embodiment, the scanning electron specific surface area of material, aperture, hole hold employing U.S. Kang Ta company Autosorb-IQ type gas adsorption instrument and measure.
In embodiment, the XRD of material adopts Japan's company D/max-rB type X-ray diffractometer of science to measure.
In embodiment, the thermogravimetric curve of material adopts Japan's Shimadzu company DTG-60AH type thermal analyzer to measure.
Embodiment 1
At room temperature get 1.12g ten alkyl trimethyl ammonium bromide and 0.32g sodium salicylate is dissolved in 28.8ml water, stir 0.5h and obtain solution A, separately get 1.70gNa2SiO3��9H2O is dissolved in 28.8ml water to obtain B solution; By solution A and B solution short mix, in said mixture, dropwise drip the sulphuric acid soln into 2mol/L with vigorous stirring, it is 9-10 to pH; Then thermostatically heating 72 hours in the baking oven of 80 DEG C, filter the solid sediment obtained, wash and drying in atmosphere, obtain combination product; The combination product of gained being placed in retort furnace heat up in atmosphere with the speed of 1.5 DEG C/min and be heated to 550 DEG C, namely constant temperature calcining obtains cellular small-bore mesoporous silicon oxide for 5 hours.
Embodiment 2
At room temperature get 1.12g ten alkyl trimethyl ammonium bromide and 0.19g sodium salicylate is dissolved in 28.8ml water, stir 0.5h and obtain solution A, separately get 1.70gNa2SiO3��9H2O is dissolved in 28.8ml water to obtain B solution; By solution A and B solution short mix, in said mixture, dropwise drip the sulphuric acid soln into 2mol/L with vigorous stirring, it is 9-10 to pH; Then thermostatically heating 72 hours in the baking oven of 80 DEG C, filter the solid sediment obtained, wash and drying in atmosphere, obtain combination product; The combination product of gained being placed in retort furnace heat up in atmosphere with the speed of 1.5 DEG C/min and be heated to 550 DEG C, namely constant temperature calcining obtains cellular small-bore mesoporous silicon oxide for 5 hours.
Embodiment 3
At room temperature get 1.12g ten alkyl trimethyl ammonium bromide and 0.51g sodium salicylate is dissolved in 28.8ml water, stir 0.5h and obtain solution A, separately get 1.70gNa2SiO3��9H2O is dissolved in 28.8ml water to obtain B solution; By solution A and B solution short mix, in said mixture, dropwise drip the sulphuric acid soln into 2mol/L with vigorous stirring, it is 9-10 to pH; Then thermostatically heating 72 hours in the baking oven of 80 DEG C, filter the solid sediment obtained, wash and drying in atmosphere, obtain combination product; The combination product of gained being placed in retort furnace heat up in atmosphere with the speed of 1.5 DEG C/min and be heated to 550 DEG C, namely constant temperature calcining obtains cellular small-bore mesoporous silicon oxide for 5 hours.
Embodiment 4
At room temperature get 1.12g ten alkyl trimethyl ammonium bromide and 0.64g sodium salicylate is dissolved in 28.8ml water, stir 0.5h and obtain solution A, separately get 1.70gNa2SiO3��9H2O is dissolved in 28.8ml water to obtain B solution; By solution A and B solution short mix, in said mixture, dropwise drip the sulphuric acid soln into 2mol/L with vigorous stirring, it is 9-10 to pH; Then thermostatically heating 72 hours in the baking oven of 80 DEG C, filter the solid sediment obtained, wash and drying in atmosphere, obtain combination product; The combination product of gained being placed in retort furnace heat up in atmosphere with the speed of 1.5 DEG C/min and be heated to 550 DEG C, namely constant temperature calcining obtains cellular small-bore mesoporous silicon oxide for 5 hours.
Comparative example
At room temperature getting 1.12g ten alkyl trimethyl ammonium bromide is dissolved in 28.8ml water, stirs 0.5h and obtains solution A, separately gets 1.70gNa2SiO3��9H2O is dissolved in 28.8ml water to obtain solution B; By solution A, B short mix, in said mixture, dropwise drip the sulphuric acid soln into 2mol/L with vigorous stirring, it is 9-10 to pH; Then thermostatically heating 72 hours in the baking oven of 80 DEG C, filter the solid sediment obtained, wash and drying in atmosphere, obtain combination product; The combination product of gained being placed in retort furnace heat up in atmosphere with the speed of 1.5 DEG C/min and be heated to 550 DEG C, namely constant temperature calcining obtains mesoporous silicon oxide in 5 hours.
Claims (1)
1. a preparation method for cellular small-bore mesoporous silicon oxide, it comprises the following steps:
First it is the short chain ionic surfactant of 1:0.5:1.5:800 by mol ratio, aromatic ring compounds, silicon source and water mix and at room temperature stir 0.5 hour, wherein first short chain ionic surfactant and aromatic ring compounds are dissolved in the water of 50% amount stir within 0.5 hour, obtain solution A, and silicon source is dissolved in the water of 50% remaining amount and obtains B solution, then by solution A and B solution short mix, wherein said short chain ionic surfactant is ten alkyl trimethyl ammonium bromides, aromatic ring compounds is sodium salicylate, silicon source is water glass, then it is 9-10 with the sulphuric acid soln of 2mol/L by the pH regulator of gained mixture, subsequently again by its thermostatically heating 72 hours in the baking oven of 80 DEG C, the solid sediment of gained filtered, wash and dry in atmosphere, obtain combination product, finally the combination product of gained is placed in retort furnace constant temperature calcining at the temperature of 550 DEG C and within 5 hours, cellular small-bore mesoporous silicon oxide can be obtained.
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| Effect of Hydrotropic Salt on the Assembly Transitions and Rheological Responses of Cationic Gemini Surfactant Solutions;Ting Lu et al.;《Journal of Physical Chemistry B》;20080215;第112卷(第10期);2912页第2栏第12行至第29行 * |
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