GB2126205A - Preparation of dispersions and gels - Google Patents
Preparation of dispersions and gels Download PDFInfo
- Publication number
- GB2126205A GB2126205A GB08321666A GB8321666A GB2126205A GB 2126205 A GB2126205 A GB 2126205A GB 08321666 A GB08321666 A GB 08321666A GB 8321666 A GB8321666 A GB 8321666A GB 2126205 A GB2126205 A GB 2126205A
- Authority
- GB
- United Kingdom
- Prior art keywords
- dispersion
- chemical compound
- mixed
- oxide
- sol
- 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.)
- Granted
Links
- 239000006185 dispersion Substances 0.000 title claims abstract description 65
- 238000002360 preparation method Methods 0.000 title claims abstract description 14
- 239000000499 gel Substances 0.000 title description 23
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 claims abstract description 51
- 150000001875 compounds Chemical class 0.000 claims abstract description 48
- 239000000908 ammonium hydroxide Substances 0.000 claims abstract description 22
- 125000001453 quaternary ammonium group Chemical group 0.000 claims abstract description 22
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 12
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 10
- 238000000034 method Methods 0.000 claims description 38
- 229910001887 tin oxide Inorganic materials 0.000 claims description 17
- LJCFOYOSGPHIOO-UHFFFAOYSA-N antimony pentoxide Chemical compound O=[Sb](=O)O[Sb](=O)=O LJCFOYOSGPHIOO-UHFFFAOYSA-N 0.000 claims description 16
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 8
- 229910010293 ceramic material Inorganic materials 0.000 claims description 7
- 229910000410 antimony oxide Inorganic materials 0.000 claims description 6
- ADCOVFLJGNWWNZ-UHFFFAOYSA-N antimony trioxide Chemical compound O=[Sb]O[Sb]=O ADCOVFLJGNWWNZ-UHFFFAOYSA-N 0.000 claims description 6
- 238000011065 in-situ storage Methods 0.000 claims description 6
- VTRUBDSFZJNXHI-UHFFFAOYSA-N oxoantimony Chemical compound [Sb]=O VTRUBDSFZJNXHI-UHFFFAOYSA-N 0.000 claims description 6
- KIZQNNOULOCVDM-UHFFFAOYSA-M 2-hydroxyethyl(trimethyl)azanium;hydroxide Chemical compound [OH-].C[N+](C)(C)CCO KIZQNNOULOCVDM-UHFFFAOYSA-M 0.000 claims description 4
- GNTDGMZSJNCJKK-UHFFFAOYSA-N divanadium pentaoxide Chemical compound O=[V](=O)O[V](=O)=O GNTDGMZSJNCJKK-UHFFFAOYSA-N 0.000 claims description 4
- 239000007863 gel particle Substances 0.000 claims description 4
- WGTYBPLFGIVFAS-UHFFFAOYSA-M tetramethylammonium hydroxide Chemical group [OH-].C[N+](C)(C)C WGTYBPLFGIVFAS-UHFFFAOYSA-M 0.000 claims description 4
- 229910052787 antimony Inorganic materials 0.000 claims description 3
- -1 antimony metal Chemical class 0.000 claims description 3
- 229960004029 silicic acid Drugs 0.000 claims description 3
- LLZRNZOLAXHGLL-UHFFFAOYSA-J titanic acid Chemical compound O[Ti](O)(O)O LLZRNZOLAXHGLL-UHFFFAOYSA-J 0.000 claims description 3
- IJGSGCGKAAXRSC-UHFFFAOYSA-M tris(2-hydroxyethyl)-methylazanium;hydroxide Chemical compound [OH-].OCC[N+](C)(CCO)CCO IJGSGCGKAAXRSC-UHFFFAOYSA-M 0.000 claims description 3
- 230000002378 acidificating effect Effects 0.000 claims description 2
- LRCFXGAMWKDGLA-UHFFFAOYSA-N dioxosilane;hydrate Chemical compound O.O=[Si]=O LRCFXGAMWKDGLA-UHFFFAOYSA-N 0.000 claims description 2
- 150000003606 tin compounds Chemical class 0.000 claims description 2
- ZNOKGRXACCSDPY-UHFFFAOYSA-N tungsten trioxide Chemical compound O=[W](=O)=O ZNOKGRXACCSDPY-UHFFFAOYSA-N 0.000 claims description 2
- 229940073455 tetraethylammonium hydroxide Drugs 0.000 claims 1
- LRGJRHZIDJQFCL-UHFFFAOYSA-M tetraethylazanium;hydroxide Chemical compound [OH-].CC[N+](CC)(CC)CC LRGJRHZIDJQFCL-UHFFFAOYSA-M 0.000 claims 1
- 239000000725 suspension Substances 0.000 abstract description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 28
- 235000011114 ammonium hydroxide Nutrition 0.000 description 18
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 15
- 239000000243 solution Substances 0.000 description 12
- 239000002585 base Substances 0.000 description 11
- 238000001935 peptisation Methods 0.000 description 10
- 239000000919 ceramic Substances 0.000 description 8
- OEYIOHPDSNJKLS-UHFFFAOYSA-N choline Chemical compound C[N+](C)(C)CCO OEYIOHPDSNJKLS-UHFFFAOYSA-N 0.000 description 8
- 229960001231 choline Drugs 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 7
- 239000011541 reaction mixture Substances 0.000 description 7
- 239000002253 acid Substances 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 5
- 229910017604 nitric acid Inorganic materials 0.000 description 5
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 238000009835 boiling Methods 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 3
- 239000003153 chemical reaction reagent Substances 0.000 description 3
- 238000001246 colloidal dispersion Methods 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- YHWCPXVTRSHPNY-UHFFFAOYSA-N butan-1-olate;titanium(4+) Chemical compound [Ti+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] YHWCPXVTRSHPNY-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229910001651 emery Inorganic materials 0.000 description 2
- ZSIAUFGUXNUGDI-UHFFFAOYSA-N hexan-1-ol Chemical compound CCCCCCO ZSIAUFGUXNUGDI-UHFFFAOYSA-N 0.000 description 2
- 239000012266 salt solution Substances 0.000 description 2
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 239000010902 straw Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- VKACTUOYRCCNRR-UHFFFAOYSA-K [Sb](O)(O)(O)=O.[Sb]=O Chemical compound [Sb](O)(O)(O)=O.[Sb]=O VKACTUOYRCCNRR-UHFFFAOYSA-K 0.000 description 1
- 230000001476 alcoholic effect Effects 0.000 description 1
- 150000001339 alkali metal compounds Chemical class 0.000 description 1
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 238000001879 gelation Methods 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 230000020477 pH reduction Effects 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- IHBMMJGTJFPEQY-UHFFFAOYSA-N sulfanylidene(sulfanylidenestibanylsulfanyl)stibane Chemical compound S=[Sb]S[Sb]=S IHBMMJGTJFPEQY-UHFFFAOYSA-N 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- BJAARRARQJZURR-UHFFFAOYSA-N trimethylazanium;hydroxide Chemical compound O.CN(C)C BJAARRARQJZURR-UHFFFAOYSA-N 0.000 description 1
- CMPGARWFYBADJI-UHFFFAOYSA-L tungstic acid Chemical compound O[W](O)(=O)=O CMPGARWFYBADJI-UHFFFAOYSA-L 0.000 description 1
- WQEVDHBJGNOKKO-UHFFFAOYSA-K vanadic acid Chemical compound O[V](O)(O)=O WQEVDHBJGNOKKO-UHFFFAOYSA-K 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
- 239000000080 wetting agent 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
- C01B33/152—Preparation of hydrogels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
- B01J13/0004—Preparation of sols
- B01J13/0034—Additives, e.g. in view of promoting stabilisation or peptisation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
- B01J13/0004—Preparation of sols
- B01J13/0047—Preparation of sols containing a metal oxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G19/00—Compounds of tin
- C01G19/02—Oxides
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C1/00—Ingredients generally applicable to manufacture of glasses, glazes, or vitreous enamels
- C03C1/006—Ingredients generally applicable to manufacture of glasses, glazes, or vitreous enamels to produce glass through wet route
- C03C1/008—Ingredients generally applicable to manufacture of glasses, glazes, or vitreous enamels to produce glass through wet route for the production of films or coatings
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Dispersion Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- General Chemical & Material Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Colloid Chemistry (AREA)
Abstract
The preparation of a dispersion comprises treating a chemical compound with a quaternary ammonium hydroxide so as to peptise the chemical compound to form a dispersion. The dispersion may be, for example, a suspension or a sol (i.e. a colloidal solution). The chemical compound may be, for example, a hydrous metal oxide (e.g. hydrous stannic oxide). Mixed dispersions may be formed.
Description
SPECIFICATION
Improvements in or relating to the preparation of materials
The present invention relates to the preparation of materials and finds application in the preparation of dispersions and gels.
According to one aspect of the present invention there is provided a process for the preparation of a dispersion which comprises treating a chemical compound with a quaternary ammonium hydroxide to peptise the chemical compound to form a dispersion.
The peptising may be carried out, for example, to a sufficient extent that a transparent sol (i.e. a colloidal solution) is prepared. Alternatively the peptising may be carried out, for example, to prepare a stable suspension. Thus, before peptisation to a transparent sol is complete a stable suspension may be formed and the peptisation may be arrested at this point.
It is believed, but by no means certain, that a stable suspension thus produced contains both a colloidal component and particles'of larger particle size held in suspension by the colloidal component.
Thus, "dispersion" as used in this specification embraces both a "suspension" and a true "colloidal solution" (i.e. a "sol").
The chemical compound may be, for example, hydrated metal oxide (or hydroxide) or hydrated silica (silicic acid). Preferred hydrated metal oxides are those having an acidic function (i.e. an amphoteric nature) such as hydrous stannic oxide (or stannic acid), hydrous tungstic oxide (tungstic acid), hydrated molybdenic oxide (molybdenic acid), hydrated vanadium pentoxide (vanadic acid), hydrous antimony oxide (antimonic acid) and titanium hydroxide (titanic acid).
Dispersions may be formed from more than one chemical compound in accordance with the present invention.
Thus, a dispersion may be formed which contains more than one of the immediately hereinbefore mentioned hydrated metal oxides or silica. For example, it has been found in accordance with the present invention that sols produced from stannic oxide are compatible with sols produced from silica or the other hydrated metal oxides hereinbefore mentioned.
Where processing conditions permit mixed oxides can be precipitated together and peptised together.
Hydrated oxides (e.g. stannic oxide) for peptising in accordance with the present invention may be prepared by any convenient method. The following methods are given by way of example:
(a) Reaction of metal with aqueous HNO3.
(b) Acidification of suitable alkali metal compounds.
(c) Hydrolysis of suitable salt solutions.
(d) Deanionisation of suitable salt solution.
As hereinbefore disclosed mixed colloidal dispersions may be formed for example by the simultaneous peptisation of oxides or the mixing of previously prepared sols.
However, it has also been found, in accordance with the present invention, that a mixed dispersion can be formed by peptising a first chemical compound with a quaternary ammonium hydroxide and then contacting the resulting dispersion with a second chemical compound such that the second chemical compound is peptised to give a mixed dispersion.
Thus according to another aspect of the present invention there is provided a process for the preparation of a mixed dispersion which comprises treating a first chemical compound with a quaternary ammonium hydroxide to peptise the first chemical compound to form a dispersion and contacting the dispersion with a second chemical compound to peptise the second chemical compound to form a mixed dispersion.
It will be appreciated that "mixed dispersion" as used in this specification embraces both a "mixed suspension" and a true "mixed colloidal solution" (i.e. a "mixed sol").
By way of example, a mixed colloidal dispersion of tin oxide and antimony oxide may be prepared by a process in accordance with the present invention.
Thus, for example, a tin oxide sol may be formed by treating hydrous stannic oxide with a quaternary ammonium hydroxide and subsequently antimony pentoxide may be contacted with the tin oxide sold to peptise the antimony pentoxide to form a mixed tin oxide and antimony oxide sol.
The second chemical compound may in some cases be formed in situ if desired in the dispersion formed from the first chemical compound. For example, when forming a mixed tin oxide and antimony oxide sol a tin oxide sol may be formed by treating a tin compound with a quaternary ammonium hydroxide and subsequently antimony pentoxide formed in situ therein and peptised to give the mixed sol. The antimony pentoxide may be formed in situ by means of reacting antimony metal or antimony trioxide with hydrogen peroxide.
It will be appreciated that the immediately preceding aspect of the present invention may be used advantageously to restrict the use of expensive quaternary ammonium hydroxides to a minimum (i.e. the use of separate quantities of quaternary ammonium hydroxide to produce separate sols which are then mixed can be avoided since the peptisation of the second chemical compound may be effected by the contacting with the dispersion of the first chemical compound).
The peptising of the first chemical compound and the second chemical compound may, for example, be carried out sequentially in one vessel and thus the analytical control of the process facilitated.
Examples of quaternary ammonium bases that may be used in accordance with the present invention are tetramethylammonium hydroxide, tetraethyiammonium hydroxide, methyltriethanolammonium hydroxide and 2-hydroxyethyltrimethylammonium hydroxide (kknown as
Choline Base). A reagent containing 50% methyltriethanoiammonium hydroxide is available as
Quram Base XP61 (marketed by Emery Industries
Inc. of Pennsylvania, USA) (Quarm is a Trade
Mark).
The present invention may be carried out, in accordance with one embodiment by mixing the chemical compound and the quaternary ammonium hydroxide together in water, optionally with heating. It will be appreciated that other solvents may be present as, for example, in the case of Choline Base which is an approximately 45% solution of 2-hydroxyethyltrimethylammonium hydroxide in methanol.
The present invention also provides a process for the formation of a gel which comprises treating a chemical compound with a quaternary ammonium hydroxide to peptise the chemical compound to form a dispersion, and converting the dispersion to a gel.
The dispersion may be converted to a gel by any suitable means (e.g,drying). Where the dispersion is a sol, the gel can be formed by any suitable sol-gel transformation (e.g. drying or dewatering).
The present invention may be carried out, in accordance with one embodiment by mixing a first chemical compound and the quaternary ammonium hydroxide together in water, optionally with heating and subsequently contacting with a second chemical compound. It will be appreciated that other solvents may be present as, for example, in the case of Choline
Base which is an approximately 45% solution of 2-hydroxyethyltrimethylammoniu m hydroxide in methanol.
The present invention also provides a process for the formation of a mixed gel which comprises treating a first chemical compound with a quaternary ammonium hydroxide to peptise the chemical compound to form a dispersion, contacting the dispersion with a second chemical compound to peptise the second chemical compound to form a mixed dispersion, and converting the mixed dispersion to a gel.
Sol to gel conversion in accordance with the present invention can be reversible (i.e. the gel may be redispersible in water to form a colloidal dispersion).
The present invention further provides a process for the preparation of a ceramic material which comprises treating a chemical compound with a quaternary ammonium hydroxide to peptise the chemical compound to form a dispersion, converting the dispersion to a gel and heating the gel to give a ceramic material. Thus,
the present invention finds application in, for example, ceramic and electro-ceramic fields.
The present invention also further provides a process for the preparation of a ceramic material which comprises treating a first chemical compound with a quaternary ammonium hydroxide to peptise the chemical compound to form a dispersion, contacting the dispersion with a second chemical compound to peptise the second chemical compound to form a mixed dispersion, converting the mixed dispersion to a gel and heating the gel to give a ceramic material.
The present invention finds application, in for example, ceramic and electro-ceramic fields.
In known methods for the production-of certain metal oxide sols (e.g. stannic oxide sols) an alkaline sol is produced by peptising a suitable hydrated starting material (e.g. hydrated stannic acid) with an alkali metal hydroxide (usually KOH).
Thus, certain commercially available oxide sols (e.g. stannic oxide sol) contain substantial amounts of sodium or potassium cations which are not easily removed by heating and the presence of which can be deleterious to many ceramic and electro-ceramic applications.
In contrast, the peptising cation of the present invention can be oxidatively removed by heating in air at a relatively low temperature of approximately 5000C.
Dispersions (which includes mixed dispersions) prepared in accordance with the present invention also find application in the coating of materials.
Thus, for example, a dispersion may be applied to a substrate, dried to form a gel layer and then heated to provide a ceramic layer on the other substrate.
By way of further exemplification dispersions (which includes mixed dispersions) in accordance with the present invention may be gelled to form gel particles and the gel particles thus produced heated to give ceramic particles (e.g. suitable for catalyst applications). Spherical gel particles may be made, for example, by dewatering sols in an immiscible alcoholic solvent (e.g. hexanol) in accordance with known processes.
Reference was hereinbefore made to the preparation of a stable dispersion by arresting peptisation before peptisation to a transparent sol
is complete.
It has been found in accordance with the present invention that in some circumstances where it is desired to produce a coating it is preferable to use this stable suspension rather than a transparent sol since, on drying, the stable dispersion gives a coating which is less prone to crazing than a coating produced from a transparent sol.
Hydrated stannic oxide may be fully peptised in accordance with the present invention to give a transparent sols which typically have pH values of
> 7.0 and may be dried to form transparent glassy gels.
When peptising hydrated stannic oxide in
accordance with the present invention to give transparent sols may be obtained when the
quaternary ammonium hydroxide:tin ratio lies between -0.2 and N1.0. Dispersions may be obtained below about 0.2, but this is dependent
on the nature of the stannic oxide used and its
history. Freshly prepared stannic oxide is generally more readily peptised than dried and aged stannic oxide.
It has also been found in accordance with the present invention that a stable dispersion may also be prepared by adding and dispersing (e.g. by ballmilling) a non-peptisable material in a sol prepared by a process in accordance with the present invention; when forming a stable dispersion in this way reagents known to assist suspending and/or wetting properties may be used (e.g. surface active agents or wetting agents). These reagents should be compatible with the sol and generally therefore should be non-ionic or cationic.
By way of example non-peptisable stannic acid or stannic oxide may be dispersed in a sol produced from hydrous stannic oxide in accordance with the present invention to give a stable dispersion.
The invention further provides a dispersion whenever prepared by a process in accordance with the invention.
The invention also further provides a mixed dispersion whenever prepared by a process in accordance with the invention.
Also, the invention provides a gel or a mixed gel whenever prepared by a process in accordance with the invention.
Further, the invention provides a ceramic material whenever prepared by a process in accordance with the present invention.
It has been found that the viscosity of a dispersion in accordance with the present invention tends to vary depending upon the quaternary ammonium hydroxide:chemical compound ratio used in the preparation of the dispersion.
The invention will now be further described, by way of example only, as follows:
Example 1
100 gms of granulated tin metal (A. R. quality) were added in portions to a mixture of 300 mls concentrated nitric acid and 600 mls of water contained in a 2 1 beaker. A vigorous reaction occurred and the reaction mixture was left with occasional stirring for 48 hours. The resulting clear supernate was decanted and the residue diluted with 1 litre of water. The resulting mixture was neutralised with ammonia and allowed to settle. The supernate was decanted and the residue filtered off, using a Buchner funnel and vacuum pump, and washed with water.The resulting washed cake was triturated at room temperature with 45 gms of Quram XP61 (a 46.8 wt% aqueous solution of methyl triethanolammonium hydroxide sold by Emery Industries
Inc. of Pennsylvania, USA).
A limpid, brown tin oxide sol was obtained from which a small quantity (--1.5 g) of a white solid was centrifuged off. The volume of the sol obtained was 250 ml.
Example 2
50 g of granulated tin metal (A.R. quality) were added in portions with slow stirring to 200 ml of concentrated nitric acid diluted with 200 ml of water. A water cooling bath was used to restrict the reaction mixture to < 700 C. When no further
reaction was evident the mixture was diluted with its own volume of water and allowed to stand.
The resulting clear supernate was decanted off and the residue was diluted once again with its own volume of water and allowed to stand. The
resulting clear supernate was decanted and the residue was diluted with water to a volume of 1 litre. Ammonium hydroxide (S.G. 0.880) added
until the pH was 8.0. The reaction mixture was allowed to settle, the supernate decanted and the residue filtered off on a Buchner funnel. The residue was washed with three bed volumes of water containing ammonia solution to pH 8.0.
The cake thus formed was pressed and transferred to a solution of 20 ml Choline base
(approx 45% solution of (2-hydrnxyethyl) trimethylammonium hydroxide in methanol marketed by Sigma London Chemical Co. Ltd.) in 200 mls of water at 600C. Peptisation took place to give a transparent, slightly cloudy, limpid tin oxide sol (380 ml?. This sol was capable of being dried to a glassy, friable gel.
Example 3
The procedure of Example 2 was repeated with the exception that the stannic acid precipitate obtained after reaction with nitric acid was washed with water only and not with ammoniacal solutions. The stannic acid, which was in the hydrogen form, was filtered off, washed with water and pressed. It was transferred to 200 mls of water containing 20 mls of Choline base solution and heated. Peptisation was initially rapid but the viscosity of the mixture increased to gelation. A further 5 ml of Choline Base solution were added to restore fluidity and the peptisation proceeded with the sol boiling. A limpid tin oxide sol was obtained (235 ml).
Example 4
3.4 gm of tetrabutyl titanate were mixed with 100 gm of Choline Base (an approx. 45% solution of 2-hydroxyethyl trimethylammonium hydroxide in methanol) at room temperature. 10 ml of water were added to hydrolyse the ester. The resulting mixture was stirred and a clear two phase system resulted. The phases were heated and the upper (organic) layer (butanol) volatilised. The lower (aqueous) layer was evaporated to a transparent gel which could easily be redispersed in water.
Example 5
Tetrabutyl titanate (3.4 g) was mixed with 1.0 g of 45% Choline Base in methanol and 5 ml of silica sol (Syton X30 manufactured by Monsanto
Ltd.) were stirred in The resulting mixture gelled and 10 mls of water were added. The resulting mixture was heated to volatilise the butanol formed during the reaction. The resulting aqueous, limpid sol could be evaporated on a steam bath to a glassy, brittle gel which was redispersible in water to give a mixed titania-silica sol. This sol was compatible with tin oxide sols produced in Examples 1 to 3 (inclusive) above.
Example 6
Granulated tin metal (50 g-AR quality) was added in portions with slow stirring to concentrated nitric acid (200 mi) diluted with water (200 ml). A water cooling bath was used to restrict the reaction mixture to a temperature of < 700 C. When no further reaction was evident the mixture was diluted with its own volume of water and allowed to stand. The resulting clear supernate was decanted off and the residue was diluted once again with its own volume of water and allowed to stand. The resulting clear supernate was decanted and the residue diluted with water to a volume of 1 litre. Ammonium hydroxide (S.G. 0.880) was added until the pH was 8.0.The reaction mixture was allowed to settle, the supernate decanted and the residue filtered off on a Buchner funnel and washed with three bed volumes of water. The cake thus formed was pressed and added partwise to 20 ml of
Quram XP61 base and stirred at room temperature to effect peptisation to a mobile straw coloured transparent sol.
Example 7
A volume of sol prepared as in Example 6 equivalent to 9.35 gm SnO2 was heated in a beaker with antimony trioxide (0.65 gm) and water (10 ml) to boiling point. The reaction mixture was opaque. Hydrogen peroxide (10 ml; "20 vol") was added portionwise over 5 min when the reaction mixture cleared to a transparent straw coloured mixed sol which could be dried to a glassy friable gel and ignited to a grey mixed oxide solid solution.
Example 8
A volume of the tin oxide sol prepared as in
Example 6, equivalent to 9.35 gm of tin oxide, was heated to boiling with water (10 ml) and powdered antimony metal (0.55 g). Hydrogen peroxide (20 ml; "20 vol") was added portionwise over 20 min to the boiling solution which became translucent as the black antimony metal powder slowly dissolved to form a mixed sol.
Claims (21)
1. A process for the preparation of a dispersion which comprises treating a chemical compound with a quaternary ammonium hydroxide to peptise the chemical compound to form a dispersion.
2. A process as claimed in claim 1 wherein the chemical compound is a hydrated metal oxide or hydrated silica.
3. A process as claimed in claim 2 wherein the hydrated metal oxide is a hydrated metal oxide having an acidic function.
4. A process as claimed in claim 3 wherein the
hydrated metal oxide is hydrous stannic oxide, hydrous tungstic oxide, hydrated molybdenic oxide, hydrated vanadium pentoxide, hydrous antimony oxide or titanium hydroxide.
5. A process as claimed in claim 1 wherein the dispersion is mixed with a sol to form a mixed dispersion.
6. A process as claimed in claim 1 wherein more than one chemical compound is peptised thereby to form a mixed dispersion.
7. A process as claimed in claim 1 wherein a first chemical compound is treated with a quaternary ammonium hydroxide to peptise the first chemical compound to form a dispersion and the dispersion is contacted with a second chemical compound to peptise the second chemical compound to form a mixed dispersion.
8. A process as claimed in claim 7 wherein a tin oxide sol is formed by treating hydrous stannic oxide with a quaternary ammonium hydroxide and subsequently antimony pentoxide is contacted with the tin oxide sol to peptise the antimony pentoxide to form a mixed tin oxide and antimony oxide sol.
9. A process as claimed in claim 7 wherein the second chemical compound is formed in situ in the dispersion formed from the first chemical compound.
10. A process as claimed in claim 9 wherein a mixed tin oxide and antimony oxide sol is formed by forming a tin oxide sol by treating a tin compound with a quaternary ammonium hydroxide and subsequently antimony pentoxide is formed in situ therein and peptised to give the mixed sol.
1 A process as claimed in claim 10 wherein the antimony pentoxide is formed in situ by means of reacting antimony metal or antimony trioxide with hydrogen peroxide.
12. A process as claimed in any one of claims 7 to 9 wherein the peptising of the first chemical compound and the second chemical compound is carried out sequentially in one vessel.
13. A process as claimed in any one of the preceding claims wherein the quaternary ammonium hydroxide base is tetramethylammonium hydroxide, tetraethylammonium hydroxide, methyltriethanolammonium hydroxide or 2-hydroxyethyltrimethylammonium hydroxide.
14. A process as claimed in claim 1 including the further step of converting the dispersion to a gel.
15. A process as claimed in claim 14 wherein the dispersion is formed into gel particles.
16. A process as claimed in claim 14 or 1 5 including the further step of converting the gel to a ceramic material.
1 7. A process for the preparation of a dispersion or mixed dispersion substantially as hereinbefore described with reference to any one of the Examples 1 to 8.
1 8. A dispersion or mixed dispersion whenever prepared by a process as claimed in any one of claims 1 to 13 or claim 17.
1 9. A process for the preparation of a gel or a mixed gel substantially as hereinbefore described with reference to any one of the Examples 2, 4 or 5.
20. A gel or a mixed gel whenever prepared by a process as claimed in any one of claims 14, 1 5 or 19.
21. A ceramic material whenever prepared in accordance with claim 1 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08321666A GB2126205B (en) | 1982-08-13 | 1983-08-11 | Preparation of dispersions and gels |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8223390 | 1982-08-13 | ||
| GB838317565A GB8317565D0 (en) | 1983-06-28 | 1983-06-28 | Preparation of materials |
| GB08321666A GB2126205B (en) | 1982-08-13 | 1983-08-11 | Preparation of dispersions and gels |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8321666D0 GB8321666D0 (en) | 1983-09-14 |
| GB2126205A true GB2126205A (en) | 1984-03-21 |
| GB2126205B GB2126205B (en) | 1986-09-03 |
Family
ID=27261699
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08321666A Expired GB2126205B (en) | 1982-08-13 | 1983-08-11 | Preparation of dispersions and gels |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2126205B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4524051A (en) * | 1983-01-10 | 1985-06-18 | United Kingdom Atomic Energy Authority | Catalyst preparation and oxidation of carbon monoxide with said catalyst |
| EP0134708A3 (en) * | 1983-08-16 | 1986-05-14 | Nissan Chemical Industries Ltd. | Process for preparing colloidal solution of antimony pentoxide |
| US4914071A (en) * | 1987-07-14 | 1990-04-03 | The British Petroleum Company P.L.C. | Method for preparing a catalyst |
| WO2005123255A1 (en) * | 2004-06-21 | 2005-12-29 | Johnson Matthey Public Limited Company | Platinum group metal oxide sols |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114314645B (en) * | 2022-01-11 | 2022-12-16 | 苏州大学 | Preparation method and application of tin dioxide nanoparticles dispersed in alcohol solvent |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1374709A (en) * | 1971-05-18 | 1974-11-20 | Montedison Spa | Stabilisation of aqueous slurries of olefinic rubbery copolymers and terpolymers |
-
1983
- 1983-08-11 GB GB08321666A patent/GB2126205B/en not_active Expired
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1374709A (en) * | 1971-05-18 | 1974-11-20 | Montedison Spa | Stabilisation of aqueous slurries of olefinic rubbery copolymers and terpolymers |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4524051A (en) * | 1983-01-10 | 1985-06-18 | United Kingdom Atomic Energy Authority | Catalyst preparation and oxidation of carbon monoxide with said catalyst |
| EP0134708A3 (en) * | 1983-08-16 | 1986-05-14 | Nissan Chemical Industries Ltd. | Process for preparing colloidal solution of antimony pentoxide |
| US4914071A (en) * | 1987-07-14 | 1990-04-03 | The British Petroleum Company P.L.C. | Method for preparing a catalyst |
| WO2005123255A1 (en) * | 2004-06-21 | 2005-12-29 | Johnson Matthey Public Limited Company | Platinum group metal oxide sols |
| US9126192B2 (en) | 2004-06-21 | 2015-09-08 | Johnson Matthey Public Limited Company | Platinum group metal oxide sols |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8321666D0 (en) | 1983-09-14 |
| GB2126205B (en) | 1986-09-03 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19960811 |