CN104229806B

CN104229806B - A kind of method for being catalyzed nucleation process synthesis magadiite

Info

Publication number: CN104229806B
Application number: CN201410458274.5A
Authority: CN
Inventors: 戈明亮; 王雁武; 陈萌
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2014-09-10
Filing date: 2014-09-10
Publication date: 2018-01-16
Anticipated expiration: 2034-09-10
Also published as: CN104229806A

Abstract

The present invention discloses a kind of method for being catalyzed nucleation process synthesis magadiite, and the preparation method comprises the following steps：Silicon source, alkali source, catalysis nucleator and water are mixed, obtain mixture；Silicon source is met with the component in molar ratio computing mixture：Alkali source=3~7；Water：Alkali source=20~100；Mixture is put into closed container at autogenous pressures, 110~170 DEG C of crystallization 6~72 hours；The good product of crystallization is taken out, it is filtered, be washed to behind pH=7~8 in 60 DEG C~100 DEG C drying 4~12 hours, obtained two-dimensional layered-structure material magadiite.The synthesis cycle of the invention compared with the existing synthetic method for being not added with catalysis nucleator shortens 12~108 hours, synthesis temperature reduces 30~40 DEG C, and the magadiite can be used as catalyst, adsorbent, pillared composite, ion-exchanger, the filler etc. of nano composite material.

Description

A kind of method for being catalyzed nucleation process synthesis magadiite

Technical field

The present invention relates to magadiite synthetic method, and in particular to a kind of side for being catalyzed nucleation process synthesis magadiite Method.

Background technology

Magadiite is a kind of two-dimensional layered-structure material, and its laminate is by electronegative SiO₄Tetrahedron forms, and has Preferably chemistry and heat endurance, interlayer have the hydration sodium ion that can be exchanged, have preferable dilatancy between laminate, can be with Accommodate it is small arrive high-polymer molecular or group greatly to proton, these properties promote magadiite as cation-exchanger, absorption The application of agent, pillared composite, catalyst, nano composite material filler etc..

The document on magadiite synthesis focuses mostly on different in the difference of silicon source, silicon source, alkali source, the proportioning of water at present And itself and modenite, β zeolites, ZSM-35 one or more are compounded to form coexisting material, on catalysis nucleation process synthesis Magadiite technique is not yet seen in word.

The content of the invention

The technical problems to be solved by the invention are that the synthesis cycle of magadiite in the prior art is longer, synthesis temperature The problem of higher, there is provided a kind of method for being catalyzed nucleation process synthesis magadiite, the method is characterized in that improving nucleation speed Also generation magadiite chemical reaction rate, the technique and the existing synthesis for being not added with being catalyzed nucleator are accelerated while rate Method shortens 6~72 hours compared to synthesis cycle, and synthesis temperature reduces 6~20 DEG C.

To solve the above problems, the technical solution adopted by the present invention is as follows.

A kind of method for being catalyzed nucleation process synthesis magadiite, comprises the following steps：

(1) silicon source, alkali source, catalysis nucleator and water are mixed, obtains mixture；With the component in molar ratio computing mixture Meet silicon source：Alkali source=3~7；Water：Alkali source=20~100；It is catalyzed two points that nucleator volume is no more than all volume of mixture One of, and more than 1/6th of all volume of mixture；

(2) mixture that step (1) obtains is put into closed container at autogenous pressures, 110~170 DEG C of crystallization 6~144 Hour；

(3) the good product of crystallization is taken out, it is filtered, be washed to it is small in 60 DEG C~100 DEG C dryings 4~12 behind pH=7~8 When, two-dimensional layered-structure material magadiite is made.

In the above method, silicon source described in step (1) in aerosil or precipitated silica it is a kind of with On.

In the above method, the alkali source described in step (1) is sodium hydroxide and the mixture of sodium carbonate；With molar ratio computing, Wherein Na₂CO₃：NaOH=2~5.

In the above method, in step (1), described is catalyzed nucleator as one kind in bead, ceramic bead or steel ball, institute State a diameter of 2mm~7mm of catalysis nucleator.

In the above method, in step (1), described catalysis nucleator is not involved in chemosynthesis reaction, reuses.

In the above method, concretely comprised the following steps described in step (1) by what silicon source, alkali source, catalysis nucleator and water mixed：First Alkali source and water are mixed into solution, then mixed with silicon source, is finally mixed with catalysis nucleator.

Synthesis temperature reduces 6~20 DEG C degrees Celsius in the present invention, and its principle can be construed to：Its catalytic action is due to The addition of catalysis nucleator makes some groups of reactant fix to form intermediate product with nucleating agent haptoreaction first, it Carry out into nuclear reaction again afterwards, intermediate product is reduced to be nucleated catalytic machine and generates target product, and the generation of such intermediate product changes Become response path, reduced the activation energy of reaction, and then reduced reaction temperature, improve reaction rate；Nucleation can It is interpreted as in the case of no catalysis nucleator, as homogeneous nucleation, nucleation rate are：

N in formula --- the atomicity in unit volume liquid phase；

κ --- Boltzmann constant；

ΔG_A--- atom crosses the activation energy through liquid-solid interface：

α --- nucleus form factor, to spherical nucleus, π/3 of α=16；

ΔG_v--- volume free energy is poor.

The free Δ G of forming core of heterogeneous nucleation_sAnd the forming core speed μ in the unit area of heterogeneous nucleus_sCalculating formula difference For：

ΔG_s=Δ G·f(θ)

In formula

The contact angle of θ --- nascent crystals and heterogeneous nucleus

N_s--- the atomicity in unit area

Remaining symbol is identical with the homogeneous nucleation formula without nucleator.

From three formula above, unless θ=180 °, otherwise f (θ) is always less than 1, so volume needed for Heterogeneous Nucleation Forming core free energy is always less than the free energy of average forming core, and nucleation rate is always higher than the nucleation rate of homogeneous nucleation, and θ angles are got over Small, difference is bigger, that is to say, that when reactant solution shows that wellability is better with nucleator, nucleation rate is higher.[Xing Jiandong, Epitaxis [M], publishing house of Xi'an Communications University, 2008.5,5-7].So there is catalysis and the effect of nucleation simultaneously, Tentatively it is referred to as " catalysis nucleation ".

Compared with prior art, the invention has the advantages that and technique effect：

The present invention adds catalysis nucleator, has synthesized the magadiite of simple phase under the process conditions limited, This method synthesis cycle compared with the existing synthetic method for being not added with catalysis nucleator shortens 6~96 hours, and synthesis temperature reduces 6~20 DEG C degrees Celsius.Obtained material is with two-dimensional layered structure and interlayer is with tradable cation, is handed in ion Change, be catalyzed, adsorbing etc. is widely used.

Brief description of the drawings

Fig. 1 is the X-ray diffracting spectrum of gained magadiite in embodiment 1.

Fig. 2 is the X-ray diffracting spectrum of gained magadiite in embodiment 2.

Fig. 3 is the X-ray diffracting spectrum of gained magadiite in embodiment 3.

Fig. 4 is the X-ray diffracting spectrum of gained magadiite in embodiment 4.

Fig. 5 a and Fig. 5 b are the ESEM collection of illustrative plates of gained magadiite in embodiment 4.

Embodiment

The present invention is described in detail below by embodiment, but protection scope of the present invention is not limited to these embodiments.

Fume colloidal silica (the SiO arrived used in following examples₂Content wt.% >=99.8), buy in Jiang Xijia Prompt new material Co., Ltd；Precipitated silica (93%SiO₂, 7%H₂O), buy in Shanghai Zhen Jiang Chemical Co., Ltd.s.

Embodiment 1

Take 0.40 gram of sodium hydroxide and 2.12 grams of sodium carbonate to be successively dissolved in 53.05 grams of water and mixed solution is made, will mix Solution and 13.55 grams of precipitated silicas (aqueous 7wt%) add 15 points of 50 ceramic beads (diameter 5mm) and stirring after being sufficiently mixed Clock, it is stirring evenly and then adding into autoclave and hydrothermal crystallizing is carried out at 110 DEG C 36 hours.Product is filtered, is washed to pH Dried 6 hours at 80 DEG C after=7~8, produce magadiite.Qualitative analysis (its X-ray is carried out by X-ray diffraction method Diffraction spectrogram is shown in accompanying drawing 1), it is known that the magadiite is simple phase, and with plus catalysis nucleator and method the same terms not Same product is the same, and crystallization degree is suitable, it is known that the catalysis nucleation of ceramic bead makes reaction is approximate to shorten synthesis at 110 DEG C Time 108h.

Embodiment 2

Take 0.40 gram of sodium hydroxide and 2.12 grams of sodium carbonate to be successively dissolved in 42.39 grams of water and mixed solution is made, will mix Solution and 11.61 grams of precipitated silicas (aqueous 7wt%) add 15 points of 50 ceramic beads (diameter 5mm) and stirring after being sufficiently mixed Clock, it is stirring evenly and then adding into autoclave and hydrothermal crystallizing is carried out at 110 DEG C 36 hours.Product is filtered, is washed to pH Dried 6 hours at 80 DEG C after=7~8, produce magadiite, (electron-microscope scanning figure of the present embodiment products obtained therefrom can refer to figure 5b).Qualitative analysis (its X-ray diffraction spectrogram is shown in accompanying drawing 2) is carried out by X-ray diffraction method, it is known that the magadiite is single Pure phase, crystallization degree are suitable, it is known that the product synthesized under the conditions of 150 DEG C, 36h ceramic bead catalysis nucleation under 110 DEG C, 36h cans are synthesized, and approximation reduces by 40 DEG C of synthesis temperature.

Embodiment 3

Take 0.40 gram of sodium hydroxide and 2.12 grams of sodium carbonate to be successively dissolved in 26.32 grams of water and mixed solution is made, will mix Solution and 9.68 grams of precipitated silicas (aqueous 7wt%) add 15 points of 50 beades (diameter 5mm) and stirring after being sufficiently mixed Clock, it is stirring evenly and then adding into autoclave and hydrothermal crystallizing is carried out at 130 DEG C 24 hours.Product is filtered, is washed to pH Dried 6 hours at 80 DEG C after=7~8, produce magadiite, (electron-microscope scanning figure of the present embodiment products obtained therefrom can refer to figure 5b).Qualitative analysis (its X-ray diffraction spectrogram is shown in accompanying drawing 3) is carried out by X-ray diffraction method, it is known that the magadiite is single Pure phase, and with without plus catalysis nucleator and the different product of method the same terms as, and with no plus catalysis nucleator and The different product of method the same terms is the same, it is known that the product synthesized under the conditions of 160 DEG C, 24h is nucleated in the catalysis of ceramic bead Lower 130 DEG C, 24h cans be synthesized, approximation reduce by 30 DEG C of synthesis temperature.

Embodiment 4

Take 0.40 gram of sodium hydroxide and 2.12 grams of sodium carbonate to be successively dissolved in 10.26 grams of water and mixed solution is made, will mix Solution and 7.74 grams of precipitated silicas (aqueous 7wt%) add 50 steel balls (diameter 5mm) and stirred 15 minutes after being sufficiently mixed, It is stirring evenly and then adding into autoclave and hydrothermal crystallizing is carried out at 170 DEG C 6 hours.Product is filtered, be washed to pH=7~ Dried 6 hours at 80 DEG C after 8, produce magadiite, (electron-microscope scanning figure of the present embodiment products obtained therefrom can refer to Fig. 5 b). Such as the magadiite electron-microscope scannings soil in Fig. 5 a and Fig. 5 b (wherein Fig. 5 a are not add 170 DEG C of hydrothermal crystallizing 18h of catalysis nucleator) In it can be seen that it has the rose valvular structure of stratiform, i.e., with two-dimensional layered structure, by contrast as can be seen that adding The product of nucleating agent has more perfect crystallization structure and more orderly layer structure, is entered by X-ray diffraction method Row qualitative analysis (its X-ray diffraction spectrogram is shown in accompanying drawing 4), it is known that the magadiite is simple phase, and is catalyzed into not adding Core agent and method the same terms it is different product it is the same, it is known that the catalysis nucleation of steel ball makes the approximate contracting of reaction at 170 DEG C Short generated time 12h.

The above embodiment of the present invention is only intended to clearly illustrate example of the present invention, and is not to the present invention Embodiment restriction.For those of ordinary skill in the field, can also make on the basis of the above description Other various forms of changes or variation.There is no necessity and possibility to exhaust all the enbodiments.It is all the present invention All any modification, equivalent and improvement made within spirit and principle etc., should be included in the protection of the claims in the present invention Within the scope of.

Claims

A kind of 1. method for being catalyzed nucleation process synthesis magadiite, it is characterised in that comprise the following steps：

（1）Silicon source, alkali source, catalysis nucleator and water are mixed, obtain mixture；Met with the component in molar ratio computing mixture Silicon source：Alkali source=3~7；Water：Alkali source=20~100；The half that nucleator volume is no more than all volume of mixture is catalyzed, And more than 1/6th of all volume of mixture；Described catalysis nucleator is one in bead, ceramic bead or steel ball Kind, a diameter of 2mm~7mm of the catalysis nucleator；Described alkali source is the mixture of sodium hydroxide and sodium carbonate；With mole Than meter, wherein Na₂CO₃：NaOH=2~5；It is described to be concretely comprised the following steps what silicon source, alkali source, catalysis nucleator and water mixed：First will Alkali source and water are mixed into solution, are then mixed with silicon source, are finally mixed with catalysis nucleator；Described silicon source is gas phase titanium dioxide One or more of silicon or precipitated silica;Described catalysis nucleator is not involved in chemosynthesis reaction, reuses；

（2）By step（1）Obtained mixture is put into closed container at autogenous pressures, and 110~170 DEG C of crystallization 6~144 are small When；

（3）The good product of crystallization is taken out, it is filtered, be washed to behind pH=7~8 in 60 DEG C~100 DEG C drying 4~12 hours, make Obtain two-dimensional layered-structure material magadiite.