Compositions: ceramic – Ceramic compositions – Pore-forming
Patent
1996-06-04
1999-06-08
Bell, Mark L.
Compositions: ceramic
Ceramic compositions
Pore-forming
501103, 264 42, 264 43, C04B 3548, C04B 35653, C04B 3804
Patent
active
059104627
DESCRIPTION:
BRIEF SUMMARY
INTRODUCTION
The present invention relates, generally, to porous articles, and in particular to porous zirconia or zirconium containing articles, to methods of making such articles, and to methods of using such articles. One example of the porous articles are porous particles. More particularly, the present invention relates to porous particles containing zirconia and other metallic oxides including silica in combination and to the manufacture and use of such particles. Even more particularly, the present invention relates to the use of particles containing zirconia and other metallic oxides including optionally containing silica, in separation applications, particularly in chromatographic applications. One particular aspect of the present invention relates to derivatisation processes whereby the surface of the porous zirconia or zirconium containing particles are modified and to the use of such modified particles in chemical processes, particularly in chromatographic applications.
Porous articles find use in certain applications because of their properties, such as for example, their high surface area per unit volume. Such uses include use as supports for a wide variety of chemical substances, such as catalyst supports and as chemical sorbents. Where the porosity and the pore size of the particles can be controlled, the porous particles also find particular use in chromatography applications and in chemical separation applications generally. Porous silica, one example of a porous particle, finds particular use in chromatographic applications, such as High Performance Liquid Chromatography (HPLC). However, the use of porous silica is limited by the chemical reactivity of the particles since porous silica is susceptible to reactions in alkaline media and therefore is of only limited use in applications which require resistance to alkaline attack or for operations conducted in alkaline media. Thus, there is a need for a porous material which is not susceptible to alkaline attack and can be used in alkaline media.
Another example of porous articles are organic polymers which are particularly useful in a wide variety of applications due to their pore size or to the pore sizes being readily controllable. However, at high temperatures and in certain organic solvents, or when subjected to certain mechanical stress, the organic polymers have limited strength, and can distort altering their pore sizes which in turn changes the separation characteristics of the polymers and thus reduces their effectiveness and usefulness in many applications. Disadvantages of using polymers are particularly prevalent in situations where the polymer particles are mixed with liquids, since the low density of the organic polymer particles, being similar to that of the liquids, prevents their ready separation from the liquid. In particular, low density polymeric particles are difficult to handle in fluidised beds due to the similarities of the densities of the particles and of the liquids being treated in the fluidised bed. Thus, there is a need to provide porous particles which retain their shape in a wide variety of chemical and mechanical environments in order to prolong the useful working life of the particles and to increase the variety of applications in which the particles may be used. Additionally, there is a need to provide porous particles which can be readily separated from the liquids being treated by the particles on the basis of the difference in densities of the particles and liquids.
In the past there has been a proposal to use porous zirconia particles as the support phase for chromatography applications (Rigney, Webber and Carr, Journal of Chromatography 484 (1989) 273-291). However, this proposal was not entirely successful due to the particles being unstable in some mechanical environments encountered in chromatographic applications and due to the inability to modify the surface properties of the particles. Such disadvantages arose primarily from the method used in making the particles. The present invention sets ou
REFERENCES:
patent: 3421914 (1969-01-01), Hare
patent: 3892580 (1975-07-01), Messing
patent: 4203772 (1980-05-01), Davis, Jr. et al.
patent: 4735922 (1988-04-01), Ray
patent: 4888309 (1989-12-01), Araya
patent: 4923830 (1990-05-01), Everhart et al.
patent: 5023217 (1991-06-01), Everhart et al.
patent: 5384290 (1995-01-01), Brezny
patent: 5399535 (1995-03-01), Whitman
patent: 5563106 (1996-10-01), Binner et al.
Tsugio, Stao, et al, Transformation of Yittria-Diped Tetragonal ZrO.sub.2 Polycrystals by Annealing under Controlled Humidity Conditions:, pp. c-320-c-322. No month.
Verre, 1987, 1(5), (Paris), Johnson, PJ, et al, "Glass Ceramic rich in Lanthanum oxide (La.sub.2 O.sub.3)-Zirconium dioxide with interconnected pores", pp. 565-570. No month.
South African Journal of Physics, 8, (3), 1985 (Pretoria), Hart, S, et al, "ZrO.sub.2 -rich glass ceramic with interconnected pores", pp. 50-55. No month.
Derwent Abstract Accession No. 89-097552, Class S03, Jp, A, 01-046646 (Shimadzu Seisakusho KK) Feb. 21, 1989 (abstract). Robert R. Hughan and Richard H.J. Hannink, "Precipitation During Controlled Cooling of Mangesia-Partially-Stabilized Zirconia", pp. 556-563. No month. A.H. Heuer, "Transformation Toughening in ZrO.sub.2 -Containing Ceramics", pp. 689-698. No month.
Aguilar Marie Isabel
Cheang Philip Hong Ning
Eriksson Kjell-Ove
Gani Mary Susan Jean
Hearn Milton Thomas William
Bell Mark L.
Sample David
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