CN1298821C

CN1298821C - Cerium ion doped mesopore titanium dioxide electrorheological fluid materials

Info

Publication number: CN1298821C
Application number: CNB2004100259544A
Authority: CN
Inventors: 赵晓鹏; 尹剑波
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2004-03-16
Filing date: 2004-03-16
Publication date: 2007-02-07
Anticipated expiration: 2024-03-16
Also published as: CN1670142A

Abstract

The present invention relates to electrorheological fluid material, particularly to cerium ion doped mesopore titanium dioxide electrorheological fluid material. Compared with the previous mesopore rare earth doped modified titanium dioxide electrorheological fluid material induced by amine surface active agents, the present invention selects a triblock copolymer of polyethylene glycol-polyxypropylene-polyethylene glycol as a template agent; an advanced evaporation induction self-assembly technique is used for preparing cerium ion doped titanium dioxide electrorheological fluid material with large holes, thick walls and good thermal stability. The material not only has high mechanical property (an accompanying diagram displays the relation (31%, 25DEG. C)of the yield stress and the direct-current electric field intensity of mesopore titanium dioxide electrorheological fluid) and simultaneously has good thermal stability.

Description

A kind of novel doped with cerium ion mesopore electric titania rheological liquid material

Technical field the present invention relates to a kind of electro-rheologic fluid material, particularly doped with cerium ionic mesopore electric titania rheological liquid material.

The background technology electrorheological fluid is made up of in transformer oil the particles dispersed of high-k usually.The electrorheological fluid oneself viscosity can be undergone mutation when being subjected to electric field action, when strength of electric field during greater than a certain value electrorheological fluid can change into by liquid state solid-state, thereby have stronger anti-shear ability.Particularly these variations of electrorheological fluid can be subjected to the outfield size modulations, have the characteristics such as fast reversible that respond.Therefore electrorheological fluid is with a wide range of applications at many industrial circles, as vibroshock, deoscillator, robot control, moment transmitting device etc.The late nineteen eighties, anhydrous electric rheological liquid was succeeded in developing, as electrorheological fluid such as polyaniline that English Patent 1501635,2100740A, 2170510B etc. reported and modified polyanilines; United States Patent (USP) 4,879, the 056 Aluminosilicates electrorheological fluid of being reported; The carbon containing class electrorheological fluid that Japanese Patent 63-97694,7-90287 etc. are reported, the electric titania rheological liquid of the rare-earth-doped modification that Chinese patent 99115944.6 is reported etc.The electrorheological fluid that these materials are prepared has overcome the shortcoming of moisture electrorheological fluid temperature stability difference preferably.But the mechanical strength of these electrorheological fluid (＜10kPa) low, still can not satisfy the industrial application requirement.We have prepared a kind of novel mesopore electric titania rheological material with nano-scale recently, its yielding stress can reach 15kPa, yet because the preparation process employing is that the amine tensio-active agent is induced central hole structure, the mesopore electric titania rheological particle hole wall that is obtained is thin partially, crystallization degree is low, cause poor heat stability, thereby make the bad stability of ER properties.The mechanical strength of this er material (15kPa) still is in traditional level simultaneously, can't satisfy most application requiring.

Summary of the invention is the low mechanical strength of solution traditional electrical rheology liquid and the shortcoming of amine tensio-active agent inductive mesopore electric titania rheological particle poor heat stability, the present invention adopts the triblock polymer self-assembling technique of advanced evaporation under inducing to prepare a kind of not only Heat stability is good, and has the doped with cerium ionic mesopore electric titania rheological liquid material of superelevation electric rheological effect.The aperture that is characterized in the mesoporous cerium doped titanium dioxide of disperse phase of this electrorheological fluid is that 5.64nm, specific surface area are 204m ²/ g, pore volume are 0.46m ³/ g, hole wall are anatase-type titanium oxide, and particulate density is 3.23g/cm ³, particle size distribution is between 0.5～5.0 micron, and the electrorheological fluid of preparing with silicone oil has the yield strength of 63kPa (4kV/mm), improves nearly order of magnitude than existing traditional electrical rheology liquid; Owing to adopted the inductor of triblock polymer as central hole structure, particle to have thicker and the higher hole wall of crystallization degree, show good thermostability simultaneously.

Description of drawings

Fig. 1 mesopore electric titania rheological liquid electrorheological fluid (18%) is at shearing rate 3.0S ^-1Under shear-stress and timing relationship (25 ℃)

The relation of Fig. 2 mesopore electric titania rheological liquid electrorheological fluid yielding stress and strength of electric field (direct current) (25 ℃)

The relation of Fig. 3 mesopore electric titania rheological liquid electrorheological fluid current density and strength of electric field (direct current) (25 ℃)

The relation (25 ℃) of the shearing resistance of Fig. 4 mesopore electric titania rheological liquid (18%) electrorheological fluid and shearing rate

Fig. 5 mesopore electric titania rheological liquid electrorheological fluid (23%) is at shearing rate 3.0S ^-1Under shear-stress and timing relationship (25 ℃)

Fig. 6 mesopore electric titania rheological liquid electrorheological fluid (31%) is at shearing rate 3.0S ^-1Under shear-stress and timing relationship (25 ℃)

Embodiment is raw materials used to be had: the chemical pure titanium tetrachloride, and the analytical pure dehydrated alcohol, the analytical pure Cerium II Chloride, secondary deionized water and polyoxyethylene-polyoxypropylene tensio-active agent Pluronic P-123, its molecular formula is HO (CH ₂CH ₂O) ₂₀(CH ₂CH (CH ₃) O) ₇₀(CH ₂CH ₂O) ₂₀H, Pluronic F-I27, its molecular formula is HO (CH ₂CH ₂O) ₁₀₆(CH ₂CH (CH ₃) O) ₇₀(CH ₂CH ₂O) ₁₀₆H.The tensio-active agent heating for dissolving is obtained to contain the ethanolic soln of tensio-active agent in dehydrated alcohol; Titanium tetrachloride and Cerium II Chloride be dissolved in the solvent with a certain amount of concentrated hydrochloric acid and ethanol configuration obtain sol precursor; Under stirring at room sol precursor slowly is added among the ethanolic soln that contains tensio-active agent, dropwises the back and continue to stir 5～10 minutes so that the reactant mixing is more even, the pH value of solution forms clear solution less than 1 at this moment; This clear solution poured into deposit the gelation process that 7-14 days solvent flashing, water and hydrochloric acid are finished titanium salt under 40 ℃ of the constant temperature in the open culture dish; Block gel is changed in the chamber type electric resistance furnace, handle continuously by 1 ℃ of/minute intensification and at 400 ℃ or 450 ℃ and took off template in 6 hours, obtained the doped titanium dioxide electrorheological fluid discrete state material of mesopore; At last this particle is mixed with agate mortar by certain particle/silicone oil volume ratio with silicone oil through smoking after 8 hours 150 ℃ of dryings, promptly obtain the doped titanium dioxide electrorheological fluid of mesopore.

The performance of implementation procedure of the present invention and material is by embodiment and description of drawings:

Embodiment one:

5 gram tensio-active agent F-I27 heating for dissolving are obtained to contain the ethanolic soln of tensio-active agent in 20 milliliters of dehydrated alcohols; 17 gram titanium tetrachlorides and 1.11 gram Cerium II Chlorides are dissolved in the solvent that disposes with 20 milliliters concentrated hydrochloric acid and ethanol (1: 1) obtain sol precursor; Under stirring at room sol precursor slowly is added among the ethanolic soln that contains tensio-active agent, dropwises that the back continue to be stirred 5～10 minutes so that reactant mixes more evenly, and to regulate pH value with concentrated hydrochloric acid be 1, the formation clear solution; Then this clear solution being put into baking oven deposits 7-14 days solvent flashings and obtains spissated even gel under 40 ℃; Change gel over to crucible and put into chamber type electric resistance furnace, handle continuously by 1 ℃ of/minute intensification and at 400 ℃ and took off tensio-active agent in 6 hours, promptly obtained the doped titanium dioxide electrorheological fluid discrete state material of mesopore; At last this particle is mixed by particle/silicone oil volume ratio 18% usefulness agate mortar with silicone oil through smoking after 8 hours 150 ℃ of dryings, promptly obtain the doped titanium dioxide electrorheological fluid of mesopore.Fig. 1 is shear-stress and the timing relationship of this electrorheological fluid under fixed shear speed; Fig. 2 is the shear-stress of this electrorheological fluid under fixed shear speed and the relation of strength of electric field; The relation of this electrorheological fluid electrorheological fluid current density of Fig. 3 and strength of electric field; The shearing resistance of this electrorheological fluid electrorheological fluid of Fig. 4 and the relation of shearing rate

Embodiment two:

To handle down more than 8 hours at 150 ℃ by the mesopore rare earth-doped titanium dioxide particle of embodiment one preparation and press grain volume fraction 23% preparation electrorheological fluid with the silicone oil of handling 2 hours through 150 ℃.Shear-stress and the strength of electric field relation of this electrorheological fluid under fixed shear speed seen Fig. 2; Fig. 5 is shear-stress and the timing relationship of this electrorheological fluid under fixed shear speed.

Embodiment three:

To handle down more than 8 hours at 150 ℃ by the mesopore rare earth-doped titanium dioxide particle of embodiment one preparation and press grain volume fraction 31% preparation electrorheological fluid with the silicone oil of handling 2 hours through 150 ℃.Shear-stress and the strength of electric field relation of this electrorheological fluid under fixed shear speed seen Fig. 2; Fig. 6 is shear-stress and the timing relationship of this electrorheological fluid under fixed shear speed.

Claims

1, a kind of doped with cerium ion mesopore electric titania rheological liquid material, the disperse phase that it is characterized in that this material are to induce porous titanium dioxide dielectric grain in the doped with cerium ion of self-assembling technique preparation with evaporation, and the external phase base fluid is a silicone oil; Wherein the aperture of mesoporous cerium doped titanium dioxide is that 5.64nm, specific surface area are 204m ²/ g, pore volume are 0.46m ³/ g, hole wall are anatase-type titanium oxide, and particulate density is 3.23g/cm ³, particle size distribution is between 0.5～5.0 micron.

2, a kind of according to claim 1 doped with cerium ion mesopore electric titania rheological liquid material, the mol ratio that it is characterized in that cerium and titanium is 0.07.

3, a kind of according to claim 1 doped with cerium ion mesopore electric titania rheological liquid material, it is characterized in that the cerium ion-doped titanium dioxide of disperse phase mesopore is to make template with the polyoxyethylene-poly-oxypropylene polyoxyethylene segmented copolymer, the butter of titanium is made the titanium precursor system and is equipped with acquisition.

4, a kind of according to claim 1 doped with cerium ion mesopore electric titania rheological liquid material is characterized in that the mesopore titanium dioxide granule adopts evaporation to induce the self-assembling technique preparation, and technology comprises the steps:

(1) raw materials used have: the chemical pure titanium tetrachloride, and the analytical pure dehydrated alcohol, the analytical pure Cerium II Chloride, secondary deionized water and polyoxyethylene-polyoxypropylene tensio-active agent Pluronic P-123, its molecular formula is HO (CH ₂CH ₂O) ₂₀(CH ₂CH (CH ₃) O) ₇₀(CH ₂CH ₂O) ₂₀H, Pluronic F-I27, its molecular formula is HO (CH ₂CH ₂O) ₁₀₆(CH ₂CH (CH ₃) O) ₇₀(CH ₂CH ₂O) ₁₀₆H;

(2) the tensio-active agent heating for dissolving is obtained to contain the ethanolic soln of tensio-active agent in dehydrated alcohol; Titanium tetrachloride and Cerium II Chloride be dissolved in the solvent with a certain amount of concentrated hydrochloric acid and ethanol configuration obtain sol precursor; Under stirring at room sol precursor slowly is added among the ethanolic soln that contains tensio-active agent, dropwises the back and continue to stir 5～10 minutes so that the reactant mixing is more even, the pH value of solution forms clear solution less than 1 at this moment;

(3) this clear solution is poured into deposited the gelation process that 7-14 days solvent flashing, water and hydrochloric acid are finished titanium salt under 40 ℃ of the constant temperature in the open culture dish;

(4) block gel is changed in the chamber type electric resistance furnace, handle continuously by 1 ℃ of/minute intensification and at 400 ℃ or 450 ℃ and took off template in 6 hours, obtained the doped titanium dioxide electrorheological fluid discrete state material of mesopore;

(5) the titania-doped electrorheological particle of mesopore is mixed with agate mortar by certain particle/silicone oil volume ratio with silicone oil through smoking after 8 hours 150 ℃ of dryings, promptly obtain the doped titanium dioxide electrorheological fluid of mesopore.