COLLOIDAL COMPOSITIONS AND METHODS OF PREPARING SAME
FIELD OF THE INVENTION
The present invention generally relates to colloidal compositions and methods
of producing same. More specifically, the present invention relates to colloidal silicas,
such as silicas that have a metal dispersed therein over a wide range of metal content
and that can be dispersed in a controlled manner.
BACKGROUND OF THE INVENTION
The preparation and use of colloidal materials, such as colloidal silica, are
generally known. For example, colloidal silica with a metal-coated surface is
generally known and used. Typically, the silica colloid is first synthesized. The
colloid is then coated with a metal oxide. During this procedure, both negatively and
positively charged surfaces are obtained depending upon the properties of the metallic
starting material and the coating method used. Metal containing silica colloids are
useful in a multitude of applications, such as chemical mechanical polishing agents in
the electronics industry, specialty coating applications, and as support materials in
catalytic processes. Despite this versatility, conventional-type silica colloids have
several disadvantages.
As the metal is typically introduced onto the surface of the colloidal silica
particle, the amount and type of metal component to be added to the silica particle is
effectively limited to the surface area and surface morphology of the particle.
Moreover, conventional surface-treated silica sols arc unstable at neutral pH, i.e., pH
6-8. As is apparent with aluminosilicate colloids, for example, aluminum species
unbound or weakly bound to the colloidal particle surface typically hydrolyze under
neutral pH conditions. This can result in either precipitation or coagulation of the
particle coating material. This is particularly problematic for the electronics industry
as the demand continues to rise for chemical mechanical polishing slurries that are
stable at neutral pH.
A need therefore exists for improved colloidal compositions, such as silica-
based colloids, that have greater metal loads that have enhanced stability over a greater

pH range and/or other suitable characteristics. A need correspondingly exists for an
efficient and cost-effective method of producing such compositions.
SUMMARY OF THE INVENTION
The present invention generally relates to colloidal compositions and methods
of producing same. In particular, the present invention relates to colloidal
compositions that include a silicate with a metal dispersed within the silicate and at
varying metal loadings that can range from as high as about 35 wt% based on silica.
The colloidal compositions can further include a stabilizer, such as a quaternary
compound, that can facilitate the dispersion and loading of the metal within the
silicate.
In this regard, the present invention provides a novel and unique alternative to
conventional surface-treated silica colloids. The colloidal compositions of the present
invention can be made in any suitable way. Preferably, the colloidal compositions are,
in general, synthesized according to two procedures as further detailed below pursuant
to various embodiments of the present invention.
According to the first synthesis procedure, a method of producing a silica
colloid includes providing an alkaline solution having a stabilizing component, adding
a silicic acid solution to the alkaline solution, and forming a colloid of silica particles
wherein the stabilizing component is dispersed throughout each particle. Further, a
cationic metal component can be added to the stabilizer-containing alkaline solution in
an embodiment. Addition of the silicic acid solution to the alkaline solution thus forms
a colloid of silica particles having both the stabilizing component and the metal
component dispersed within one or more of the silicate particles, such as in a
homogenous manner.
In an embodiment, the stabilizer is a quaternary compound, preferably a
quaternary amine, such as a quaternary ammonium hydroxide and the like. The
stabilizer performs several functions in the synthesis of the colloidal silica. For
example, the stabilizer provides the OH- component to the alkaline solution, which
catalyzes the reaction between the silicic acid and metal component to form the
colloid. The stabilizer also enables more of the metal component to bond or

chemically combine with the silica component during formation of the colloid. The
resultant silica colloid demonstrates the capability to carry increased amounts of metal.
The colloid can have a metal content from about .0001wt% to about 35wt% based on
silica. The colloidal particles are amorphous and spherical in shape. In addition, the
colloidal composition can be further processed to produce a crystalline structure as
described in greater detail below. The diameter of the colloidal particles is in the range
of about 2 nm to about 1000 nm according to an embodiment.
According to the second synthesis procedure, a method of preparing a metal-
containing silica colloid is provided wherein a silicic acid solution is reacted with a
cationic metal component to form a metal silicate solution. The metal silicate solution
is subsequently added to an alkaline solution to form a colloid of metal silicate
particles. Reacting the silicic acid solution with the metal component forms a metal-
silicate monomer that is subsequently polymerized as the metal silicate solution is
added to the alkaline solution. The polymerization forms a homogeneous metal-
silicate lattice microstructure or framework throughout the entire solid phase of the
colloid.
The polymerization of the metal-silicate and the utilization of a polyvalent
cationic metal component in formation of the colloid yields a metal silicate colloids
having metal content in the range of about .0001% to as high as 2% by weight silica
according to an embodiment. The lattice metal-silicate structure throughout the entire
solid phase also improves the stability of the colloid. The metal silicate colloid of the
present invention remains soluble throughout the entire pH range, i.e., pH 1-14. The
solid phase of the metal silicate colloid of the present invention is substantially
amorphous having a generally spherical particle shape and size in the range of from
about 2 nm to about 1000 nm according to an embodiment.
With the second synthesis procedure, the location of a metal component within
the metal-containing silica colloid can be effectively controlled. The metal silicate
solution and the silicic acid solution can be selectively added to the alkaline solution to
form a colloid of silica particles containing metal that is dispersed within one or more
of the particles. The sequence and duration in which the metal silicate solution and
the silicic acid solution are added effectively controls the location of the metal within

the solid phase of the colloid. For example, the metal silicate solution can be added to
the alkaline solution before the silicic acid solution to form a colloid of silica particles
having metal dispersed within an interior core layer of each particle. Alternatively, the
silicic acid solution can be added to the alkaline solution before the metal silicate
solution to form a colloid of silica particles having a silica core and metal dispersed
within an outer or exterior layer of each particle. Moreover, the metal silicate solution
and the silicic acid solution can be added to the alkaline solution in an alternating
manner to form a colloid of silica particles having a number of layers, wherein the
layers alternate between metal containing layers and layers containing only silica in a
repeat or successive manner.
To this end, in an embodiment, the present invention provides a colloidal
composition. The colloidal composition includes a silicate doped with a metal, and
a stabilizer dispersed within the silicate.
In an embodiment, the silicate doped with metal includes about 35 wt % or less
of metal based on silica.
In an embodiment, the stabilizer includes a quaternary compound.
In an embodiment, the quaternary compound is a quaternary amine.
In an embodiment, an amount of the stabilizer correlates to an amount of the
metal.
In another embodiment, the present invention provides a colloidal silicate
composition doped with a metal. The colloidal silicate composition includes one or
more silicate particles wherein the metal is dispersed within one or more of the silicate
particles.
In an embodiment, the metal is dispersed in a controlled manner.
In an embodiment, one or more of the silicate particles includes a layered
structure.
In an embodiment, the metal is controllably dispersed within one or more
particle layers of the layered structure.
In an embodiment, the metal includes an alkali metal, an alkaline earth metal, a
1st row transition metal, a 2nd row transition metal, a lanthanide, and combinations
thereof.

In an embodiment, the metal is about 2 wt % or less based on silica.
In yet another embodiment, the present invention provides a method of forming
a colloidal composition. The method includes preparing a heel solution including a
stabilizer; preparing a silicic acid solution; and mixing and further processing the heel
solution and the silicic acid solution to form the colloidal composition.
In an embodiment, a metal is added to the heel solution.
In an embodiment, the colloidal composition includes the stabilizer and a
silicate doped with the metal such that the stabilizer and the metal are dispersed within
one or more particles of the silicate.
In an embodiment, the metal includes about 35 wt % or less based on silica.
In an embodiment, the colloidal composition is further processed to form a
crystalline structure.
In an embodiment, the colloidal composition is further processed by heating.
In an embodiment, a metal is added to the heel solution prior to crystallization.
In an embodiment, the colloidal composition includes a zeolite.
In an embodiment, the stabilizer includes a quaternary amine.
In still yet another embodiment, the present invention provides a method of
forming a colloidal silicate composition. The method includes preparing a silicic acid
solution, a metal silicate solution and an alkaline solution; mixing and further
processing the silicic acid solution and the metal silicate solution with the alkaline
solution; and
forming one or more silicate particles doped with a metal wherein the metal is
dispersed within one or more of the silicate particles.
In an embodiment, the metal is dispersed in a controlled manner.
In an embodiment, the silica doped with metal includes about 2 wt % or less of
the metal based on silica.
In an embodiment, the metal includes an alkali metal, an alkaline earth metal, a
1st row transition metal, a 2nd row transition metal, a lanthanide, and combinations
thereof.
In a further embodiment, a method of controlling a location of a metal within a
metal-containing silica colloid is provided. The method includes preparing a silicic

acid solution, a metal silicate solution and an alkaline solution; and selectively adding
the metal silicate solution and the silicic acid solution to the alkaline solution to form a
colloid of silica particles containing the metal.
In an embodiment, the method further comprises adding the metal silicate
solution before the silicic acid solution and forming the colloid of silica particles
having the metal dispersed within an interior layer of one or more of the silica
particles.
In an embodiment, the method further comprises adding the silicic acid
solution before the metal silicate solution and forming the colloid of silica particles
having the metal dispersed within an outer layer of one or more of the silica particles.
In an embodiment, the method further comprises adding the metal silicate
solution and the silicic acid solution in an alternating manner and forming the colloid
of silica particles having a metal-containing layer and a non-metal containing layer.
In an embodiment, of the silica particles includes a layered structure that has
the non-metal containing layer disposed on the metal containing layer in a repeat
manner.
Additional features and advantages of the present invention are described in
and will be apparent from the following Detailed Description of the Presently
Preferred Embodiments.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED
EMBODIMENTS
The present invention generally relates to colloidal compositions and methods
of preparing same. As used herein, the term "colloid" and other like terms including
"colloidal", "sol", and the like refer to a two-phase system having a dispersed phase
and a continuous phase. The colloids of the present invention have a solid phase
dispersed or suspended in a continuous or substantially continuous liquid phase,
typically an aqueous solution. Thus, the term "colloid" encompasses both phases
whereas "colloidal particles" or "particles" refers to the dispersed or solid phase.
More specifically, the present invention relates to colloidal compositions that
include a silicate and that can be made in a readily and cost effective manner as
described below in greater detail. In general, the present invention provides two types

of synthesis procedures. In one synthesis procedure, the present invention utilizes a
heel solution that includes a stabilizer, such as a quaternary compound. The stabilizer
can enhance the colloidal synthesis in a number of ways, such as by stabilizing and
better enabling a metal to be dispersed within the silicate of the colloidal composition.
It is believed that the stabilizer can also enhance the ability of the silicate to have
higher metal loading, such as about 35wt% or less based on silica. In another synthesis
procedure, silicic acid and a metal silicate solution are selectively added to an alkaline
solution thereby producing a colloid that includes a silicate with a metal dispersed
therein in a controlled manner. The present invention is now described below in
greater detail including specific examples that arc illustrative of the compositions and
methods of the present invention according to various embodiments without limitation.
In one embodiment of the present invention, a method of preparing a colloidal
composition provides adding a silicic acid solution to a reaction vessel that includes a
! heel solutipn having an aqueous solution containing a metal component and a
stabilizing component to form a colloid of silica particles. In an embodiment, the
stabilizer is an amine or quaternary compound. Nonlimiting examples of amines
suitable for use as the stabilizer include dipropylamine, trimethylamine, triethylmine,
tri-n-propylamine, diethanolamine, monoethanolamine, triethanolamine,
diisobutylamine, isopropylamine, diisopropylamine, dimethylamine,
ethylenediaminetetraacetic acid, pyridine, the like and combinations thereof.
Preferably, the stabilizing component is a quaternary amine that forms an alkaline
solution when dispersed in water, such as quaternary ammonium hydroxides. In
addition, it is further preferred that the quaternary amine includes a tetraalkyl
ammonium ion wherein each alky] group has a carbon chain length of 1 to 10, the alkyl
groups being the same or different. Nonlimiting examples of quaternary amines
suitable for use as the stabilizer include tetramethylammonium hydroxide (TMAOH),
tetrapropylammonium hydroxide (TPAOH), tetraethylammonium hydroxide
(TEAOH), tetraburylammonium hydroxide (TBAOH), tetrahexylammonium
hydroxide, tetraoctylammonium hydroxide, tributylmethylammonium hydroxide,
triethylmethylammonium hydroxide, trirnethylphenylammonium hydroxide,
methyltripropylammonium hydroxide, dodecyltrimethylammonium hydroxide,

hexadecyltrimethylammonium hydroxide, dimethyldodecylethylamnionium hydroxide,
diethyldimethylammonium hydroxide, the like and combinations thereof. Also, the
bromide and chloride forms of the above mentioned ammonium salts can be used by
passing through a hydroxide (anion)-exchange column to produce the alkylammonium
hydroxide materials.
The metal can include any suitable material and be derived from any suitable
material including metal salts that are soluble or substantially soluble in an aqueous
solution. In an embodiment, the metal includes an alkali metal, an alkaline earth
metal, a 1st row transition metal, a 2nd row transition metal, a lanthanide, and
combinations thereof. Preferred metal components include aluminum, cerium,
titanium, tin, zirconium, zinc, copper, nickel, molybdenum, iron, rhenium, vanadium,
boron, the like and any combination thereof.
The silicic acid solution can be prepared by passing a sodium silicate solution
through a bed of H+-cation exchange resin. The resulting deionized silicic acid
solution tends to be quite reactive and is typically kept cooled to retard polymerization.
Upon addition of the silicic acid solution to the alkaline solution in the heel, the
disassociated OH" from the stabilizer catalyzes a polymerization reaction between the
cationic metal component and a silicate component from the silicic acid to form the
colloid of silica particles. The reaction thereby yields a solid phase composed of the
metal component, the stabilizer and silica wherein the metal and stabilizer are
dispersed within the silica particles. Utilization of the stabilizer component obviates
the need to provide a heel containing alkaline catalysts, such as NaOH, KOH, NH4OH,
the like, and combinations thereof. It should be appreciated that any suitable type of
silicic acid solution can be utilized.
In addition to catalyzing particle formation, the stabilizer serves as a stabilizing
agent for the metal component. Not wishing to be bound to any particular theory, it is
believed that the quaternary amine cation interacts with the metal oxide anion in the
heel (MO4x- wherein M is the metal cation) ultimately stabilizing the metal. It is
believed that the quaternary amine maintains the metal oxide anion in a four-fold
coordination state or tetrahedral orientation so that silicon-to-metal ratios of four can
be obtained. Stabilizing the metal component in this manner produces a greater

number of silicon-metal linkages allowing the solid phase of the colloid to cany an
increased amount of metal compared to surface treated colloids, for example.
In an embodiment, the resultant silica colloid is capable of supporting from
about 0.000lwt% to about 35wt% metal based on silica. The metal-stabilized silica
solid phase also demonstrates increased stability and remains stable in a pH range of
about 1 to about 14. The skilled artisan will appreciate that "stable" means that the
solid phase of the colloid is present, dispersed through the medium and stable
throughout this entire pH range with effectively no precipitate. The solid phase in an
embodiment is amorphous and has a number of particles that are generally spherical in
shape. The colloidal particles have a diameter in the range of about 2 nanometers (nm)
to about 1000 nm pursuant to an embodiment.
In another embodiment of the present invention, silicic acid is utilized to
incorporate or disperse a metal component into the framework of colloidal silica (i.e.,
doping). The method includes preparing a heel. The heel includes an aqueous solution
that at least includes a quaternary amine as defined herein or an alkaline agent.
Suitable alkaline agents include, for example, NaOH, KOH, NH4OH, the like and
combination thereof. The silicic acid solution (can be prepared as previously discussed
or other suitable manner) is reacted with a cationic metal component to form a metal
silicate solution, represented chemically below:

The metal silicate solution is subsequently added to the heel to form the
colloid. During particle formation, the OH' present in the heel catalyzes the
copolymerization of the cationic metal component and silicate (SiO4-) from the silicic
acid. This produces a colloid with the metal dispersed within the silicate (i.e.,
incorporated into the particle framework as discussed above), such as having a
homogenous distribution of the metal component throughout the entire solid phase of
the colloid. Not wishing to be bound by any particular theory, it is believed that the
dispersion and loading of the metal is obtained as the copolymerization forms a metal-
silicate lattice throughout the microstructure of the solid phase. Nonlimiting examples
of suitable metals that can be used as the cationic metal component include aluminum,
cerium, titanium, tin, zirconium, zinc, copper, nickel, molybdenum, iron, rhenium,

vanadium, boron, 1st and 2nd row transition metals, lanthanides, alkali metals, alkaline
earth metals, the like and any combination thereof. As previously discussed, the metal
component can be derived from any suitable metal source including, for example, any
suitable metal salt that is soluble or substantially soluble in an aqueous solution.
According to this synthesis procedure pursuant to an embodiment, metal
silicate colloids of the present invention can have a metal content from about 0.0001%
to about 2% by weight based on silica. The metal silicate colloids of the present
invention are amorphous and generally spherical in shape, wherein the particles have
an effective diameter or particle size from about 2 run to about 1000 nm in an
embodiment. The metal silicate colloids are stable at a pH range from about 1 to about
14, exhibiting effectively no precipitation in this range. The skilled artisan will
appreciate that the size of the colloidal particles can be adjusted by varying the
addition time of the metal silicate solution to the heel.
As previously discussed, the above-described synthesis procedure can be
utilized to effectively control the location of the method and loading thereof within the
colloidal particles. In an embodiment, the metal silicate solution and the silicic acid
solution are selectively added to the heel to control the position of the metal within the
solid phase of the colloid as desired. Both silicic acid solution and metal silicate
solution can be added to the heel to initiate particle formation or to grow or otherwise
increase the size of a pure silica particle initially added to the heel. For example, the
metal silicate solution is added to the heel before the silicic acid solution in an
embodiment. This addition sequence yields a metal containing silica colloid wherein
the metal is dispersed in a core or interior layer of the colloidal particle. The
subsequent addition of the silicic acid can be used to cover the interior metal-
containing portion of the particle with a layer containing on silica without the metal.
Alternatively, the silicic acid solution can be added to the heel prior to the
addition of the metal silicate solution in an embodiment. This addition sequence yields
colloidal particles having a core or interior composed of silica. The metal silicate
solution can then be added to coat the silica particle to produce a particle containing
metal on an exterior surface or outer layer of the particle wherein the metal is dispersed
within this particle layer. The skilled artisan will appreciate the myriad of possibilities

available for the composition of the colloid solid phase. Addition of only the metal
silicate solution to the heel can yield a colloid having a dispersion or distribution of
metal within one or more of the colloidal particle as previously discussed. Adding the
metal silicate solution and the silicic acid solution in an alternating manner or a
sequence such as metal silicate-silicic acid-metal silicate-silicic acid can yield a
colloidal particle having a number of layers wherein metal containing layers are
separated by layers containing silica and without a metal in an embodiment. It will be
appreciated that the duration of silicic acid and/or metal silicate addition can be varied
as desired to vary the width or thickness of each particle layer in the colloid. The
multiple layered colloid particles of the present invention are generally spherical in
shape and have an effective particle size of about 2 nm to about 1000 nm according to
an embodiment.
It should be appreciated that the colloidal compositions and methods of making
same can be modified in any suitable manner. For example, the colloidal compositions
as described above can be further processed to form a crystalline structure, such as a
crystalline silicate, a crystalline metallosilicate including a zeolite, the like and
combinations thereof. In an embodiment, continued hydrothermal treatment at suitable
temperatures and over a suitable period of time can produce a more crystalline silicate
including metallosilicates, such as zeolites, from the colloidal compositions described-
above wherein the colloidal composition includes silicate and a stabilizer with or
without a metal dispersed within the silicate, specific examples of which are provided
below in greater detail.
According to an embodiment, if the heel in the second synthesis procedure is
replaced with an organic cation such as those used in synthesis procedure one (e.g., a
stabilizer including tetramethylammonium hydroxide (TMAOH),
tetrapropylammonium hydroxide (TPAOH), tetraethylammonium hydroxide (TEAOH)
and/or the like), continued hydrothermal treatment after the silicic acid or metal/silicic
acid containing solution has been added, can result in the formation of a more
crystalline silicate or metallosilicate including a zeolite.
Doped colloidal silica is useful in multitudinous industrial applications
including, for example, dental applications, protein separation, molecular sieves,

nanoporous membranes, wave guides, photonic crystals, refractory applications,
clarification of wine and juice, chemical mechanical planarization of semiconductor
and disk drive components, catalyst supports, retention and drainage aids in
papermaking, fillers, surface coatings, ceramic materials, investment casting binders,
flattening agents, proppants, cosmetic formulations, particularly sunscreens, and
polishing abrasives in the glass, optical and electronics and semiconductor industries.
The form of silica used in a particular application depends in large part on the silica
particle's size and porosity characteristics. Doped colloidal silica having the desired
characteristics is readily prepared according to the method of this invention.
In an embodiment, this invention is a material for use in an industrial
application comprising the colloidal composition described herein.
In an embodiment, the industrial application is selected from the group
consisting of catalyst supports, retention and drainage aids in papermaking, fillers,
flattening agents, proppants and polishing abrasives.
The present invention will be further understood with reference to the
following illustrative examples according to various embodiments without limitation.
Synthesis Procedure One:
A 5 wt% tetramethylammonium hydroxide (20-25 wt%) solution was added to
a 12-gallon reactor along with 10.23 wt% of deionized (DI) water. A 0.70 wt%
aluminum chlorohydrate (50 wt%) solution was added to 19.82 wt% DI water. The
aluminum chlorohydrate solution was then added to the reactor at room temperature at
a rate of 200 mL/min. The reactor was heated to 100 °C. Then, 64.25 wt% silicic acid
was added to the reactor at a ramp rate of 100 - 220 mL/min over 3.25 hours. As
shown below, Table 1 lists the physical characteristics of the colloidal aluminosilicate
made in the 12-gallon reactor after it was concentrated by ultra-filtration;


Synthesis Procedure Two:
1. Preparation of the aluminum containing solutions
Monomelic containing aluminum solution:
A 0.37 M AlCl3.6H2O solution was prepared with a pH of 2.2 and was used as
prepared as further described below.
Polyvalent aluminum containing solution:
A second solution of 0.50 M AlCl3.6H2O was prepared. This solution was
passed through an ion exchange column containing an anion exchange resin (Dowex
550A (OH-)). 100 g of AlCl3.6H2O solution was passed through 100 mL of resin. The
pH of the aluminum containing solution was ca. 3.4 after being passed through the
column. Aluminum chlorohydrate can also be used.
2. Preparation of the silicic acid:
25.00 g of (sodium silicate) was added to 57.37 g of DI water. The solution
was passed through a column containing a cation exchange resin (Dowex 650C (H+)).
About 40 mL of resin for 100 g of diluted sodium silicate solution was used to produce
a silicic acid solution. To the silicic acid solution, a suitable amount of aluminum
containing solution to produce the desired concentration (ppm) of aluminum based on
silica (BOS) was added as detailed below in Table 2.

3. Preparation of the metallosilicate colloids:
Example 1: The silicic acid solution/monomeric aluminum solution (2.93 g of
0.37 M AlCl3.6H2O solution) was added to a caustic heel containing 0.30 g of NaOH
(50 wt%) in 14.40 g of DI water over a 5.0 hours ramp. A total of 68.57 g of silicic
acid solution/aluminum solution was added.
Example 2: The silicic acid solution/polyvalent aluminum solution (3.02 g of
0.50 M AlCl3.6H2O anion-exchanged solution) was added to a caustic heel containing
0.30 g of NaOH (50 wt%) in 14.20 g of DI water over a 5.0 hour ramp. A total of
68.57 g of silicic acid solution/aluminum solution was added.
Example 3: The silicic acid solution/polyvalent aluminum solution (3.02 g of
0.50 M AlCl3.6H2O anion-exchanged solution) was added to a caustic heel containing
0.30 g of NaOH (50 wt%) in 14.20 g of Example 2 over a 5.0 hour ramp. A total of
68.57 g of silicic acid solution/aluminum solution was added.
Example 4: The silicic acid solution/aluminum solution (3.02 g of 0.50 M
AlCl3.6H2O anion-exchanged solution) was added to a caustic heel containing 0.30 g
of NaOH (50 wt%) in 14.20 g of Example 3 over a 5.0 hour ramp. A total of 68.57 g
of silicic acid solution/aluminum solution was added.
Example 5: Pilot Plant synthesis:
The silicic acid solution/aluminum solution (0.67 g of a 0.87 M solution of
aluminum chlorohydrate) was added to a caustic heel containing 0.11 g NaOH (50
wt%) in 3.82 g of 20 nm silica sol in 8.18 g of DI water over a 4.75 hours ramp. The
reaction was heated at 93°C. A total of 87.89 g of silicic acid solution/aluminum
solution was added. The final product was cation-exchanged to remove excess
sodium, large particle filtered (LPC) and pH adjusted to 6.4.
Example 6: Cerium doped silica colloids:
A solution of 0.50 M Ce2(CO3)3 was prepared by adding 46g Ce2(CO3)3 into
100ml DI water then adding 1N HCl until dissolved. The solution was then topped up
to 200ml with DI water.
A silicic acid solution was prepared where 200 g of (sodium silicate) was added
to 1000 g of DI water. The solution was passed through a column containing a cation

exchange resin (Dowex 650C (H+)). About 40 mL of resin for 100 g of diluted sodium
silicate solution was used.
To the silicic acid solution, an amount of the cerium containing solution was
added to provide the desired concentration (ppm) of cerium based on silica (BOS) as
illustrated in Table 2.
The silicic acid solution/cerium solution (6.2 ml of 0.5 M Ce2(CO3)3 solution)
was added to a caustic heel containing 5 g of KOH (45 wt%) in 200 g of DI water over
a 5.0 hours ramp. A total of 1200 g of silicic acid solution/cerium solution was added
to produce the cerium doped silica colloids
Example 7: Titanium doped silica colloids:
A titanium containing solution was prepared. In particular, a solution of 0.50 M TiCl4
was prepared by slowly adding 100ml DI water into a beaker containing 9.4g TiC14
and 10ml isopropyl alcohol.
The silicic acid was prepared in the same fashion as described in Example 6.
To the silicic acid was added an amount of the titanium containing solution to produce
the desired concentration (ppm) of titanium based on silica (BOS) as illustrated below
in Table 2.
The silicic acid solution/titanium solution (12.6 ml of 0.5 M TiC14 solution)
was added to a caustic heel containing 5 g of KOH (45 wt%) in 200 g of DI water over
a 5.0 hours ramp. A total of 1200 g of silicic acid solution/cerium solution was added
to produce the titanium doped silica colloid.
Example 8: Zinc doped silica colloids:
The zinc containing solution used in' this procedure was a commercially-
available product, namely 1N Zn(NO3)2. The silicic acid was prepared in the same
fashion as described in Example 6. To the silicic acid was added an amount of zinc
containing solution to provide the desired concentration (ppm) of zinc based on silica
(BOS) as illustrated below in Table 2. The silicic acid solution/zinc solution (6 ml of 1
M Zn(NO3)2 solution) was added to a caustic heel containing 5 g of KOH (45 wt%) in
200 g of DI water over a 5.0 hours ramp. A total of 1200 g of acid sol/cerium solution
was added to produce the zinc doped silica colloid.

Synthesis Procedure Three. Preparation of crystalline silicate and metallosilicate
colloids:
Example 9: Colloidal Silicalite-1 was synthesized with a narrow particle size
distribution from a mole composition of:
1TPAOH:1.9SiO2:109H2O
The source of silica was silicic acid. The reactor vessel was charged with a 20-25 wt%
solution of TPAOH, which was heated to 90°C. To this, the silicic acid was added
over 3 hours. A clear solution resulted, which was heated for 18 hours.
Example 10: Colloidal ZSM-5 was synthesized with a narrow particle size
distribution from a mole composition of:
65TPAOH: 125SiO2:1A12O3:7000H2O
The source of silica was silicic acid. The reactor vessel was charged with a 20-25 wt%
solution of TPAOH, which was heated to 90°C. To this the aluminum/silicic acid
solution was added over 2 hours. A clear solution resulted, which was heated for 24
hours.
Metallosilicate colloids:
Table 2 shows the various prepared metal doped samples with the different
heels, pH of the different metal containing solutions, amounts of metal added to the
acid sol based on silica (BOS) and a variety of characterization techniques to
determine particle size and the extent, if any, agglomeration. As shown below, Table 2
provides a summary of the synthesis procedures according to Examples 1-10 as
detailed above:


In general, the metal doped colloids described above and made pursuant to
various embodiments exhibit good stability in the pH range 3-9. For example, a
stability test was conducted on the filtered and cation deionized aluminosilicate colloid
of Example 5. The pH was adjusted to 4.1, 6.5 and 8.5 and effective particle diameters
were measured (QELS) before and after heat treatment for two weeks at 60°C. No
gelation occurred with these samples after heat treatment and the particle diameters
remained essentially the same as demonstrated below in Table 3:


The colloidal compositions of the present invention can be utilized in a number
of different and suitable types of applications in any suitable forms and amounts
thereof. For example, the colloidal composition can be used as a chemical mechanical
polishing agent including use for electronic components; a catalyst material and
supports thereof including use in the petrochemical industry, such as cracking to
increase fractions of gasoline; as a detergent or agent thereof to remove calcium ions
and/or the like from solution; and any other types of suitable applications.
It should be understood that various changes and modifications to the presently
preferred embodiments described herein will be apparent to those skilled in the art.
Such changes and modifications can be made without departing from the spirit and
scope of the present invention and without diminishing its attendant advantages. It is
therefore intended that such changes and modifications be covered by the appended
claims.

WE CLAIM:
1. A synthetic metal-containing colloidal silicate
composition comprising:
a metal-silicate lattice solid phase having colloidal
particles. wherein said lattice exists in amorphous and
generally spherical colloidal particles;
a metal covalently copolymerized and incorporated into
said lattice within the colloidal particles and present in
an amount from about 0.01 wt% to about 35 wt%, based on
silica; and
a continuous aqueous phase.
2. The colloidal silicate composition as claimed in claim
1, wherein one or more of the colloidal particles comprises a
layered structure within the amorphous and generally spherical
colloidal particles.

3. The colloidal silicate composition as claimed in claim
1, wherein the copolymerized metal is selected from the group
consisting of an alkali metal, an alkaline earth metal, a 1st row
transition metal, a 2nd row transition metal, a lanthanide, and
combinations thereof.
4. The colloidal silicate composition as claimed in claim
1, wherein the metal-silicate solid phase comprises from about
0.01 wt% to about 2 wt% of the metal based on silica.
5. The colloidal silicate composition as claimed in claim
1, wherein the colloidal particles are generally spherical.
6. The colloidal silicate composition as claimed in claim
1, wherein a stabiliser is dispersed within the metal-silicate
lattice.
7. A synthetic metal—containing colloidal silicate
composition comprising :

a metal-silicate lattice solid phase having colloidal
particles, wherein said lattice exists in both amorphous and
generally spherical colloidal particles; or
a metal covalently copolynerized and incorporated into
said lattice within the colloidal particles and present
within the colloidal particles from about 0.01 wt% to about
35 wt%, based on silica;
a stabilizer dispersed within the metal-silicate
lattice; and
a continuous aqueous phase.
8. The composition as claimed in claim 7, wherein the
stabilizer dispersed with the metal-silicate lattice is selected
from the group consisting of: amines and quaternary amines.
9. The composition as claimed in claim 1, wherein the
particles are further processed into crystalline form.

10. The composition as claimed in claim 1, wherein the
particles are further processed into crystalline form.

The invention relates to metal-containing colliidal silicate
composition comprising a metal-silicate lattice solid phase
having colloidal particles; wherein said lattice exists in
amorphous and generally spherical colloidal particles; a metal
covalently copolymerised and incorporated into said lattice
within the colloidal particles and present in an amount from
about 0.01 wt% to about 35 wt%, based on silica; and a continuous
aqueous phase.