CA1340947C - Method and device for producing pure elemental iodine - Google Patents
Method and device for producing pure elemental iodineInfo
- Publication number
- CA1340947C CA1340947C CA000613953A CA613953A CA1340947C CA 1340947 C CA1340947 C CA 1340947C CA 000613953 A CA000613953 A CA 000613953A CA 613953 A CA613953 A CA 613953A CA 1340947 C CA1340947 C CA 1340947C
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- Prior art keywords
- iodine
- tfi2
- barrier
- solid
- source
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- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
- A01N59/00—Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds
- A01N59/12—Iodine, e.g. iodophors; Compounds thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/36—Pervaporation; Membrane distillation; Liquid permeation
- B01D61/363—Vapour permeation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B7/00—Halogens; Halogen acids
- C01B7/13—Iodine; Hydrogen iodide
- C01B7/14—Iodine
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Water Supply & Treatment (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Organic Chemistry (AREA)
- Pest Control & Pesticides (AREA)
- Agronomy & Crop Science (AREA)
- Plant Pathology (AREA)
- Health & Medical Sciences (AREA)
- Dentistry (AREA)
- General Health & Medical Sciences (AREA)
- Wood Science & Technology (AREA)
- Zoology (AREA)
- Environmental Sciences (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
A method and device for producing pure elemental iodine where a source material containing thermodynamically free iodine is introduced to one side of an iodine solving solid barrier through which said thermodynamically free iodine passes by the process of diffusive mass transfer and is subsequently collected on the product side of the barrier at any desired concentration less than supersaturation, for any given temperature or product stream composition.
Description
FIELD OF THE INVENTION
This invention relates to the production of pure elemental iodine.
BACKGROUND OF THE INVENTION
Iodine (for example in the form of Lugol's solution or tincture of iodine) has long been recognized as an effective biocide. U.S. Pharmacopoeia and other similar publications in many countries have documented this property of iodine since 1830.
Iodophores have bean noted for their similar properties since 1960.
These iodines have been recognized for their bioactivity in man, animals, types of bacteria and in plants and their seeds.
In fact, a deficiency of iodine has been shown to prevent the attainment of maximum health, growth, and reproductive success.
It has been recently shown that the active component in all biocidal iodines is thermodynamically free iodine which is a form of elemental iodine, I2 (which may be microscopic crystals under certain conditions as described by William Schmidt and Murray W. Winicov in U.S. Patent No. 3,028,299 issued April 3, 1962, and extended by others). The term thermodynamically free iodine describes iodine that ins free from complexing. Thermodynamically free iodine in aqueous solution will dissociate into many hydrolysed forms, for e~;ample HIO (or also known as HOI), some of which are biocida:L in nature. If a solution of aqueous iodine could be reliably generated at any concentration of thermodynamically free iodine less than supersaturation, and remain stable at that lE~vel, it would allow the manufacture of many devices useful in water treatment, instrument sterilization, use as a source of nutritional iodine, plus other medicinal and chemical uses.
In an effort t:o produce biocidal iodine compounds, many methods, both chemical and mechanical in nature, have been devised.
To date, however, i:hese rnethods have had limited use and commercial success for reasons attributable to iodine's chemical and physical properties such as low solubility in H20, reactivity easy contamination or the production of poly-halides and iodides and other potentially noxiores adjuvants which inhibit the presence of thermodynamically free iodine.
As shown in the previously mentioned patent to Schmidt and Winicov, thermodynamically free iodine in all iodine solutions, whether alcohol/water, surfactant/water or other complexing agent/water, is confined to the water phase. Further, thermodynamically free iodine is usually found in solution in concentrations less than that of the total titratable iodine of the solution. For example, Lugol's solution, where potassium iodide (KI) is used to create a reservoir of iodine as I3 through the relationship I2 + I ~ 7:3 + In, the solubility of elemental iodine is increased to 1~ (w/v), however, the concentration of thermodynamically free :iodine in solution has a maximum level of circa 0.03$ (w/v) or 300 ppm, and the amount of thermodynamically free iodine detectable :is only circa 0.018 (w/v) or 180 ppm (by Schmidt and Winicov, using an n-heptane test for free iodine).
This invention relates to the production of pure elemental iodine.
BACKGROUND OF THE INVENTION
Iodine (for example in the form of Lugol's solution or tincture of iodine) has long been recognized as an effective biocide. U.S. Pharmacopoeia and other similar publications in many countries have documented this property of iodine since 1830.
Iodophores have bean noted for their similar properties since 1960.
These iodines have been recognized for their bioactivity in man, animals, types of bacteria and in plants and their seeds.
In fact, a deficiency of iodine has been shown to prevent the attainment of maximum health, growth, and reproductive success.
It has been recently shown that the active component in all biocidal iodines is thermodynamically free iodine which is a form of elemental iodine, I2 (which may be microscopic crystals under certain conditions as described by William Schmidt and Murray W. Winicov in U.S. Patent No. 3,028,299 issued April 3, 1962, and extended by others). The term thermodynamically free iodine describes iodine that ins free from complexing. Thermodynamically free iodine in aqueous solution will dissociate into many hydrolysed forms, for e~;ample HIO (or also known as HOI), some of which are biocida:L in nature. If a solution of aqueous iodine could be reliably generated at any concentration of thermodynamically free iodine less than supersaturation, and remain stable at that lE~vel, it would allow the manufacture of many devices useful in water treatment, instrument sterilization, use as a source of nutritional iodine, plus other medicinal and chemical uses.
In an effort t:o produce biocidal iodine compounds, many methods, both chemical and mechanical in nature, have been devised.
To date, however, i:hese rnethods have had limited use and commercial success for reasons attributable to iodine's chemical and physical properties such as low solubility in H20, reactivity easy contamination or the production of poly-halides and iodides and other potentially noxiores adjuvants which inhibit the presence of thermodynamically free iodine.
As shown in the previously mentioned patent to Schmidt and Winicov, thermodynamically free iodine in all iodine solutions, whether alcohol/water, surfactant/water or other complexing agent/water, is confined to the water phase. Further, thermodynamically free iodine is usually found in solution in concentrations less than that of the total titratable iodine of the solution. For example, Lugol's solution, where potassium iodide (KI) is used to create a reservoir of iodine as I3 through the relationship I2 + I ~ 7:3 + In, the solubility of elemental iodine is increased to 1~ (w/v), however, the concentration of thermodynamically free :iodine in solution has a maximum level of circa 0.03$ (w/v) or 300 ppm, and the amount of thermodynamically free iodine detectable :is only circa 0.018 (w/v) or 180 ppm (by Schmidt and Winicov, using an n-heptane test for free iodine).
The gerrr~icida7_ capacity of these iodine formulations is dependent upon the continued release of thermodynamically free iodine from the resE:rvoir of titratable iodine, as the thermodynamically free iodine in solution is depleted through dilution, contamination or biocidal activity. It has therefore been the goal of researchers to develop a practical means of creating this reservoir from which thermodynamically free iodine may be released.
Attempts have: been made to develop a means to mechanically contain an amount of metallic elemental iodine in contact with water', as shown in U.S. Patent No. 3,408,295 issued October 29, 1968 in the name of John A. Vaichulis and in U.S.
Patent No. 4,384,960 issued May 24, 1983 in the name of Richard D.
Polley. These methods, however, have not been totally effective in restraining micro- (and sometimes macro-) particles of iodine crystals from being cre~at.ed in the water flow. Further, these methods cannot prevent the contamination of the iodine reservoir by undesirable substances which may reduce the effectiveness of the reservoir, or facilitate the release of unwanted contaminants into the product stream containing the wanted thermodynamically free iodine.
Attempts have also been made to develop a chemical means of providing a reuiable supply of thermodynamically free iodine.
The chief fault of such systems (for example Lugol's solution, tincture of iodine, iodophores) is that a loss of solvent (i.e.
water lost through evaporation) increases the total percentage of iodine in a volume and therefore, given iodine's relative insolubility, increases the toxic effect of the remaining solution (through recrystal.lization of elemental iodine) and subsequently reduces the availability of thermodynamically free iodine.
Another problem is that by chemical means, the level of thermodynamically free iodine in water is usually restricted to about 60~ of the maximum solubility of thermodynamically free iodine in water (which is circa 0.030 . This is about 180 ppm (0.018$), and is usually found to be much less than that. For example, an iodophore of 3.75 titratable iodine may achieve maximum strength of le:~s than 40 ppm of thermodynamically free iodine after dilution while having 75 ppm of titratable iodine.
Where chemical adjuvants are used to increase the reservoir of titr.atable iodine, the adjuvants may act as an unwanted toxicant., There are many applications for the use of iodine in the medical field (i.e. the irrigation of wounds or incisions during ~;urgery) and one adjuvant mixture used for this purpose was P.V.P.:I. (povidone iodine). Eventually it was realized that the P.V.P. (povidone) macro molecule tended to lodge in the lymph glands of a patient, causing problems with the function of the gland. This _ls one example of adjuvants causing undesirable side effects.
Finally, the ithermodynamically free iodine should be a pure as practically and economically obtainable, for the end uses that it is usually put. Any chemical means of releasing thermodynamically free iodine will likely release undesirable contaminants into the final product.
Attempts have: been made to develop a means to mechanically contain an amount of metallic elemental iodine in contact with water', as shown in U.S. Patent No. 3,408,295 issued October 29, 1968 in the name of John A. Vaichulis and in U.S.
Patent No. 4,384,960 issued May 24, 1983 in the name of Richard D.
Polley. These methods, however, have not been totally effective in restraining micro- (and sometimes macro-) particles of iodine crystals from being cre~at.ed in the water flow. Further, these methods cannot prevent the contamination of the iodine reservoir by undesirable substances which may reduce the effectiveness of the reservoir, or facilitate the release of unwanted contaminants into the product stream containing the wanted thermodynamically free iodine.
Attempts have also been made to develop a chemical means of providing a reuiable supply of thermodynamically free iodine.
The chief fault of such systems (for example Lugol's solution, tincture of iodine, iodophores) is that a loss of solvent (i.e.
water lost through evaporation) increases the total percentage of iodine in a volume and therefore, given iodine's relative insolubility, increases the toxic effect of the remaining solution (through recrystal.lization of elemental iodine) and subsequently reduces the availability of thermodynamically free iodine.
Another problem is that by chemical means, the level of thermodynamically free iodine in water is usually restricted to about 60~ of the maximum solubility of thermodynamically free iodine in water (which is circa 0.030 . This is about 180 ppm (0.018$), and is usually found to be much less than that. For example, an iodophore of 3.75 titratable iodine may achieve maximum strength of le:~s than 40 ppm of thermodynamically free iodine after dilution while having 75 ppm of titratable iodine.
Where chemical adjuvants are used to increase the reservoir of titr.atable iodine, the adjuvants may act as an unwanted toxicant., There are many applications for the use of iodine in the medical field (i.e. the irrigation of wounds or incisions during ~;urgery) and one adjuvant mixture used for this purpose was P.V.P.:I. (povidone iodine). Eventually it was realized that the P.V.P. (povidone) macro molecule tended to lodge in the lymph glands of a patient, causing problems with the function of the gland. This _ls one example of adjuvants causing undesirable side effects.
Finally, the ithermodynamically free iodine should be a pure as practically and economically obtainable, for the end uses that it is usually put. Any chemical means of releasing thermodynamically free iodine will likely release undesirable contaminants into the final product.
It is an object: of the present invent ion to provide a reliable method of obtaining the purest form of thermodynamically free iodine.
It is a further object of the invention to provide a device for obtaining purE~ thermodynamically free iodine.
SUMMARY OF THE INVENTION
According to an aspect of the present invention, there is provided a method for obtaining a desired amount of pure thermodynamic~~lly free iodine (TFI2), comprising the steps of: (a) provj.ding <~ TFI2 solving solid barrier impervious to solvents and contaminants of TFI2; (b) providing a source of TFI2 wr~ich produces a predeterminable amount of TFI2, the source of the 7.'FI2 being located on one side of the solid barrier, the sourcE~ comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressure of the TF7:2 by a predetermined amount; and (c) providing a reservoir means on the other side of the solid barrier for receiv~_ng TF:L2 which passes through the barrier to establish an equil~~brium of TFI2 on both sides of the solid barrier, whereby there is a net flow of TFI2 between both sides of the solid barrier in response to a nonequilibrium condition of TFI2 an both sides of the solid barrier in order to re-establish the desired amount of TFI2 on either side of the solid barrier.
Accordincf to another aspect of the present invention, there i;~ provided a device for producing a desired C
~3~09 4?
amount of pure thermodyn<~mically tree iodine (TFI2), comprising: (a) a TFI2 so:Lving solid barrier impervious to solvents and contaminant: of TFI2; (b) a source of TFI2 which produces a predeterminab:Le amount of TFT2, the source being located on one side of the solid barrier, the source comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressure of the TFI2 by a predetermined amount; and (c) a reservoir means located on the other side of the ~:olid barrier far collection TFI2 which passes through the solid barrier to establish an equilibrium of TFI2 on both sides of the solid barrier, whereby is a net flow of TFIZ between both sides of the solid barrier in response to a nonec~uilibrium condition of TFI2 on both sides of the solid barrier to re-establish the desired amount of TFI2 on either side of the solid barrier.
According to yE~t another aspect of the present invention, there i~; provided a device for producing pure thermodynamically free iodine (TFI2), comprising: (a) a container; (b) a cup opening from the container and defining a sealed cavity between the cup and the container; (c) a source of TFI2 contained within the cavity, the source comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressures of the TFI2 by a predetermined amount; and (d) a TFI2 solving solid barrier lining an outer wall of the cup located within the cavity, the cup being perforated adjacent the barrier lin~.ng, and container and cup being formed of iodine irr~perviaus material.
- 5a -r, BRIEF DESC'.RIPTION OF THE DRAWINGS
Example embodiments of the drawings are shown in the accompanying drawings in which:
Figure Z is a schematic drawing showing a device for producing pure elemental odine;
Figure z is an alternate embodiment of Figure 1;
Figure 3 is an alternate embodiment of Figure 1; and Figure 4 is a <:ross-sect tonal view of an alternate embodiment of Figure 1.
- 5b -C
X3409 4~
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
Elemental iodine, that is, the diatomic molecule I2, is only marginally soluble in water (circa 300 ppm). In many other fluids, iodine may form 2 distinct types of solution, which may be differentiated by their color (i.e. in organic solvents such as carbon tetrachlo~~ide, iodine imparts a violet color upon dissolution, whereas in water, a clear amber color is produced in the absence of polyhalic9es, complexing agents or other colorants.
In the presence of polyhalides, a black color is produced ) . In these liquids, iodine exhibits a vapor pressure and also has a maximum solubility limit. In the presence of polyhalides and/or solubility adjuvants, the iodine's vapor pressure is reduced.
Iodine also has the special property of being soluble in some solids. To iodine, these solids appear to behave as a liquid solvent (in the traditional sense of the properties of a liquid).
When iodine is introduced to these solids, the solid is permeated by the iodine, imp<~rting one of the two colors observed when iodine dissolves in liquids. In addition, over the solid, the iodine exhibits a vapor pressure and within the solid also has a solubility limit.
Many of these apecial solids are impermeable to water and other solvents of iodine. Therefore should a solution containing a quantity of iodine be placed on one side of this solid barrier, and a solvent of iodine be placed on the opposite side of the solid barrier, the I2 will move freely back and forth across the barrier until an equilibrium is reached. This equilibrium is reached when X3409 43~
the vapor pressure of iodine over the fluids on either side of the barrier are equal. Also, by choosing the appropriate thermodynamically free iodine donating product (ie. different adjuvants) to control the vapor pressure over the iodine donating solution, the ultimate concentration on the product side may be accurately controlled for a given temperature and product side solvent.
Figure 1 of the drawings shows a container 10 which iodine molecules cannot penetrate, a solid barrier 12 constructed from an iodine solving :solid, a source of iodine 14 in chamber 16 containing a fluid and a second chamber 18 on the product side of barrier 12 containing a material into which the thermodynamically free iodine, passing through barrier 12, will dissolve. Chamber 18 may be a flu id such as water, a vacuum chamber to produce crystalline iodine, or an iodine solving solid used to retain the thermodynamically free iodine.
One of t:he solid substances which exhibits this iodine solving property is polyethylene; both high and low density. It is preferable that the volume of the solving solid be low to reduce the quantity of iodine needed to achieve an equilibrium concentration, wi~~hin i~he barrier, with respect to the final concentrations of the contents of the two chambers 16 and 18. For this reason, a film of 1. mm thickness of low density polyethylene is preferred.
Figure 2 of the drawings shows an alternate arrangement of the components of Figure 1 where the iodine solving solid 20 '~~~9~ 4~
encapsulates the source quantity of iodine (ie. water plus a quantity of thermodynamically material). The free iodine donating capsule would be capable of releasing a quantity of thermodynamically free iodine for the purposes of achieving a desired level of thermodynamically free iodine n the material i contained in chamber 22. The encapsulating process should be effected using mat.erial:~ which add a minimum of iodine demand and the encapsulation prevents direct physical contact by solvents or contaminants with the contents of the capsule. The capsule may be formed as a ridged or non-ridged pillow. Upon being placed in chamber 22, capsule 20 will facilitate the transfer of I2 molecules to the material in chamber 22 and will do so until the reservoir of iodine is depleted, or an equilibrium is attained between reservoir 14 and chamber' 22. Once equilibrium is attained, should a quantity of thermodynamically free iodine in the reservoir 22 be lost due to biological action, complexing, or for some other reason, and therefore disrupt the balance achieved, then more iodine will diffuse through the capsule wall 20 until the same equilibrium is once again attained.
Figure 3 of the drawings shows an alternate construction in which solid solving barrier 12 is flexible and carries within it an iodine non-solving frangible container 22 containing iodine source 14. Use of this embodiment entails the squeezing of flexible barrier 7.2 in order to fracture the non-solving barrier 22 so that the source solution of iodine has access to the solving barrier. The entire construction is delivered to the material in _ g -1 3 4 09 4~
which the thermodynamically free iodine, which subsequently diffuses through barrier 12, is required.
For thi~~ embodiment, an example of iodine source 14 material would be potassium iodide (KI) and a possible fluid surrounding frangible container 22 and conf fined by solid solving barrier 12 would be chloramine. When frangible container 22 is broken, the chemical rE:action between the potassium iodide and chloramine would produce potassium chloride and thermodynamically free iodine (plus some free amines).
The device shown in Figure 4 of the drawings consists of a unit 30 comprising a ~~up 31 which fits into a container 32, in a manner such that an annular cavity 34 is created between the two.
Both cup 31 and container 32 are constructed of materials impenetrable to iodine (such as F.E.P. (flouroethylpolymer)). A
removable screw ca:p (not shown) fits on cup 31 by engaging a thread 36. Cup 31 has an annular flange 37 which seals onto rim 38 of container 32. The annular cavity between cup 31 and container 32 is filled with an iodine source material 35 from which the thermodynamically free iodine will be extracted.
The outer sur:Eace of cup 31 below flange 37 is coated with an iodine solving solid layer 39. A ring of apertures 42 around cup 31 and .a series of apertures 44 in the bottom of cup 31 exposes the contents of <:up 31 to one surface of the iodine solving solid barrier 39. The bottom of cup 31 is spaced from the surface of container 32 by a ring flange 46 which has notches 48 spaced about its perimeter.
To disinfect a quantity of water, an amount of that water is poured into cup 31 approximately to the level of the apertures 42. The cap is then ~,ecured to cup 31 and the entire unit is shaken. The cap is removed and the water in the cup is now tinted brown with thermoClynamic:ally free iodine in solution. The tinted water may now be tested i~o determine the amount needed to disinfect the required quantity of water. This may be accomplished by dipping an piece o:E starched paper into the iodine containing water in cup 31, and comparing the shade of blue the strip changes to, with a standard co_Lor ch<~rt. Should an appropriate adjuvant/iodine mixture be used for the thermodynamically free iodine donating material, then the concentration testing would not be necessary as a known concentration will exist in the product material.
This method and device have several advantages in that:
1) the iodine charged device has an indefinite shelf life;
2) the iodine cannot become contaminated;
3) as long as the source reservoir is not depleted, the contents of the cup will always achieve the same end concentration of thermodynamically free iodine regardless of the volume of water put into the cup;
4) a loss of wate r from the cup through processes such as evaporation w:i:l1 not increase the toxicity of the end solution, as the excess thermodynamically free iodine will merely diffuse back to the iodine source;
5) there is no need for the use of harmful adjuvants on the product side crf the solving barrier;
6 ) losses of thermodynamically free iodine on the product side of the solving barrier will be automatically replaced by thermodynamically free iodine diffusing from the source side o.f the solving barrier; and 7) when water is used on the product side of the barrier, the resulting solution is unexpectedly non-toxic, non-irritating, non-burning to skin and mucosa, strongly germicidal, and regenerable.
In each of the embodiments described, the iodine solving barrier may be constructed of, but is not restricted to, materials such as linear polyethylene, isotactic polyethylene, polyoxymethylene and pol.ybutylene terephthalate.
In each embodiment, the thermodynamically free iodine source material may be a variety of compounds, including but not restricted to technical grade iodine which contains thermodynamically free iodine. More importantly, adjuvants known to lower the maximum level of thermodynamically free by complexing I2 iodine and therefore lower the vapor pressure of iodine over the adjuvant/iodine mixture, may be used to accurately control the equilibrium concentrations of thermodynamically free iodine on the product side of the barrier.
In each embodiment, the product side of the solid solving barrier, to which i;he thE:rmodynamically free iodine from the source material is to diffuse, may consist of a fluid (liquid or gas) or a iodine solving solid. The product side may also be a vacuum into which the thermodynamically free iodine would form an iodine vapor ~~409 47 which would subsequently be collected as it crystallized upon a cooled surface.
It is a further object of the invention to provide a device for obtaining purE~ thermodynamically free iodine.
SUMMARY OF THE INVENTION
According to an aspect of the present invention, there is provided a method for obtaining a desired amount of pure thermodynamic~~lly free iodine (TFI2), comprising the steps of: (a) provj.ding <~ TFI2 solving solid barrier impervious to solvents and contaminants of TFI2; (b) providing a source of TFI2 wr~ich produces a predeterminable amount of TFI2, the source of the 7.'FI2 being located on one side of the solid barrier, the sourcE~ comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressure of the TF7:2 by a predetermined amount; and (c) providing a reservoir means on the other side of the solid barrier for receiv~_ng TF:L2 which passes through the barrier to establish an equil~~brium of TFI2 on both sides of the solid barrier, whereby there is a net flow of TFI2 between both sides of the solid barrier in response to a nonequilibrium condition of TFI2 an both sides of the solid barrier in order to re-establish the desired amount of TFI2 on either side of the solid barrier.
Accordincf to another aspect of the present invention, there i;~ provided a device for producing a desired C
~3~09 4?
amount of pure thermodyn<~mically tree iodine (TFI2), comprising: (a) a TFI2 so:Lving solid barrier impervious to solvents and contaminant: of TFI2; (b) a source of TFI2 which produces a predeterminab:Le amount of TFT2, the source being located on one side of the solid barrier, the source comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressure of the TFI2 by a predetermined amount; and (c) a reservoir means located on the other side of the ~:olid barrier far collection TFI2 which passes through the solid barrier to establish an equilibrium of TFI2 on both sides of the solid barrier, whereby is a net flow of TFIZ between both sides of the solid barrier in response to a nonec~uilibrium condition of TFI2 on both sides of the solid barrier to re-establish the desired amount of TFI2 on either side of the solid barrier.
According to yE~t another aspect of the present invention, there i~; provided a device for producing pure thermodynamically free iodine (TFI2), comprising: (a) a container; (b) a cup opening from the container and defining a sealed cavity between the cup and the container; (c) a source of TFI2 contained within the cavity, the source comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressures of the TFI2 by a predetermined amount; and (d) a TFI2 solving solid barrier lining an outer wall of the cup located within the cavity, the cup being perforated adjacent the barrier lin~.ng, and container and cup being formed of iodine irr~perviaus material.
- 5a -r, BRIEF DESC'.RIPTION OF THE DRAWINGS
Example embodiments of the drawings are shown in the accompanying drawings in which:
Figure Z is a schematic drawing showing a device for producing pure elemental odine;
Figure z is an alternate embodiment of Figure 1;
Figure 3 is an alternate embodiment of Figure 1; and Figure 4 is a <:ross-sect tonal view of an alternate embodiment of Figure 1.
- 5b -C
X3409 4~
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
Elemental iodine, that is, the diatomic molecule I2, is only marginally soluble in water (circa 300 ppm). In many other fluids, iodine may form 2 distinct types of solution, which may be differentiated by their color (i.e. in organic solvents such as carbon tetrachlo~~ide, iodine imparts a violet color upon dissolution, whereas in water, a clear amber color is produced in the absence of polyhalic9es, complexing agents or other colorants.
In the presence of polyhalides, a black color is produced ) . In these liquids, iodine exhibits a vapor pressure and also has a maximum solubility limit. In the presence of polyhalides and/or solubility adjuvants, the iodine's vapor pressure is reduced.
Iodine also has the special property of being soluble in some solids. To iodine, these solids appear to behave as a liquid solvent (in the traditional sense of the properties of a liquid).
When iodine is introduced to these solids, the solid is permeated by the iodine, imp<~rting one of the two colors observed when iodine dissolves in liquids. In addition, over the solid, the iodine exhibits a vapor pressure and within the solid also has a solubility limit.
Many of these apecial solids are impermeable to water and other solvents of iodine. Therefore should a solution containing a quantity of iodine be placed on one side of this solid barrier, and a solvent of iodine be placed on the opposite side of the solid barrier, the I2 will move freely back and forth across the barrier until an equilibrium is reached. This equilibrium is reached when X3409 43~
the vapor pressure of iodine over the fluids on either side of the barrier are equal. Also, by choosing the appropriate thermodynamically free iodine donating product (ie. different adjuvants) to control the vapor pressure over the iodine donating solution, the ultimate concentration on the product side may be accurately controlled for a given temperature and product side solvent.
Figure 1 of the drawings shows a container 10 which iodine molecules cannot penetrate, a solid barrier 12 constructed from an iodine solving :solid, a source of iodine 14 in chamber 16 containing a fluid and a second chamber 18 on the product side of barrier 12 containing a material into which the thermodynamically free iodine, passing through barrier 12, will dissolve. Chamber 18 may be a flu id such as water, a vacuum chamber to produce crystalline iodine, or an iodine solving solid used to retain the thermodynamically free iodine.
One of t:he solid substances which exhibits this iodine solving property is polyethylene; both high and low density. It is preferable that the volume of the solving solid be low to reduce the quantity of iodine needed to achieve an equilibrium concentration, wi~~hin i~he barrier, with respect to the final concentrations of the contents of the two chambers 16 and 18. For this reason, a film of 1. mm thickness of low density polyethylene is preferred.
Figure 2 of the drawings shows an alternate arrangement of the components of Figure 1 where the iodine solving solid 20 '~~~9~ 4~
encapsulates the source quantity of iodine (ie. water plus a quantity of thermodynamically material). The free iodine donating capsule would be capable of releasing a quantity of thermodynamically free iodine for the purposes of achieving a desired level of thermodynamically free iodine n the material i contained in chamber 22. The encapsulating process should be effected using mat.erial:~ which add a minimum of iodine demand and the encapsulation prevents direct physical contact by solvents or contaminants with the contents of the capsule. The capsule may be formed as a ridged or non-ridged pillow. Upon being placed in chamber 22, capsule 20 will facilitate the transfer of I2 molecules to the material in chamber 22 and will do so until the reservoir of iodine is depleted, or an equilibrium is attained between reservoir 14 and chamber' 22. Once equilibrium is attained, should a quantity of thermodynamically free iodine in the reservoir 22 be lost due to biological action, complexing, or for some other reason, and therefore disrupt the balance achieved, then more iodine will diffuse through the capsule wall 20 until the same equilibrium is once again attained.
Figure 3 of the drawings shows an alternate construction in which solid solving barrier 12 is flexible and carries within it an iodine non-solving frangible container 22 containing iodine source 14. Use of this embodiment entails the squeezing of flexible barrier 7.2 in order to fracture the non-solving barrier 22 so that the source solution of iodine has access to the solving barrier. The entire construction is delivered to the material in _ g -1 3 4 09 4~
which the thermodynamically free iodine, which subsequently diffuses through barrier 12, is required.
For thi~~ embodiment, an example of iodine source 14 material would be potassium iodide (KI) and a possible fluid surrounding frangible container 22 and conf fined by solid solving barrier 12 would be chloramine. When frangible container 22 is broken, the chemical rE:action between the potassium iodide and chloramine would produce potassium chloride and thermodynamically free iodine (plus some free amines).
The device shown in Figure 4 of the drawings consists of a unit 30 comprising a ~~up 31 which fits into a container 32, in a manner such that an annular cavity 34 is created between the two.
Both cup 31 and container 32 are constructed of materials impenetrable to iodine (such as F.E.P. (flouroethylpolymer)). A
removable screw ca:p (not shown) fits on cup 31 by engaging a thread 36. Cup 31 has an annular flange 37 which seals onto rim 38 of container 32. The annular cavity between cup 31 and container 32 is filled with an iodine source material 35 from which the thermodynamically free iodine will be extracted.
The outer sur:Eace of cup 31 below flange 37 is coated with an iodine solving solid layer 39. A ring of apertures 42 around cup 31 and .a series of apertures 44 in the bottom of cup 31 exposes the contents of <:up 31 to one surface of the iodine solving solid barrier 39. The bottom of cup 31 is spaced from the surface of container 32 by a ring flange 46 which has notches 48 spaced about its perimeter.
To disinfect a quantity of water, an amount of that water is poured into cup 31 approximately to the level of the apertures 42. The cap is then ~,ecured to cup 31 and the entire unit is shaken. The cap is removed and the water in the cup is now tinted brown with thermoClynamic:ally free iodine in solution. The tinted water may now be tested i~o determine the amount needed to disinfect the required quantity of water. This may be accomplished by dipping an piece o:E starched paper into the iodine containing water in cup 31, and comparing the shade of blue the strip changes to, with a standard co_Lor ch<~rt. Should an appropriate adjuvant/iodine mixture be used for the thermodynamically free iodine donating material, then the concentration testing would not be necessary as a known concentration will exist in the product material.
This method and device have several advantages in that:
1) the iodine charged device has an indefinite shelf life;
2) the iodine cannot become contaminated;
3) as long as the source reservoir is not depleted, the contents of the cup will always achieve the same end concentration of thermodynamically free iodine regardless of the volume of water put into the cup;
4) a loss of wate r from the cup through processes such as evaporation w:i:l1 not increase the toxicity of the end solution, as the excess thermodynamically free iodine will merely diffuse back to the iodine source;
5) there is no need for the use of harmful adjuvants on the product side crf the solving barrier;
6 ) losses of thermodynamically free iodine on the product side of the solving barrier will be automatically replaced by thermodynamically free iodine diffusing from the source side o.f the solving barrier; and 7) when water is used on the product side of the barrier, the resulting solution is unexpectedly non-toxic, non-irritating, non-burning to skin and mucosa, strongly germicidal, and regenerable.
In each of the embodiments described, the iodine solving barrier may be constructed of, but is not restricted to, materials such as linear polyethylene, isotactic polyethylene, polyoxymethylene and pol.ybutylene terephthalate.
In each embodiment, the thermodynamically free iodine source material may be a variety of compounds, including but not restricted to technical grade iodine which contains thermodynamically free iodine. More importantly, adjuvants known to lower the maximum level of thermodynamically free by complexing I2 iodine and therefore lower the vapor pressure of iodine over the adjuvant/iodine mixture, may be used to accurately control the equilibrium concentrations of thermodynamically free iodine on the product side of the barrier.
In each embodiment, the product side of the solid solving barrier, to which i;he thE:rmodynamically free iodine from the source material is to diffuse, may consist of a fluid (liquid or gas) or a iodine solving solid. The product side may also be a vacuum into which the thermodynamically free iodine would form an iodine vapor ~~409 47 which would subsequently be collected as it crystallized upon a cooled surface.
Claims (28)
1. A method for obtaining a desired amount of pure thermodynamically free iodine (TFI2), comprising the steps of:
(a) providing a TFI2 solving solid barrier impervious to solvents and contaminants of TFI2;
(b) providing a source of TFI2 which produces a predeterminable amount of TFI2, the source of the TFI2 being located on one side of the solid barrier, the source comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressure of the TFI2 by a predetermined amount; and (c) providing a reservoir means on the other side of the solid barrier for receiving TFI2 which passes through the barrier to establish an equilibrium of TFI2 on both sides of the solid barrier, whereby there is a net flow of TFI2 between both sides of the solid barrier in response to a nonequilibrium condition of TFI2 on both sides of the solid barrier in order to re-establish. the desired amount of TFI2 on either side of the solid barrier.
(a) providing a TFI2 solving solid barrier impervious to solvents and contaminants of TFI2;
(b) providing a source of TFI2 which produces a predeterminable amount of TFI2, the source of the TFI2 being located on one side of the solid barrier, the source comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressure of the TFI2 by a predetermined amount; and (c) providing a reservoir means on the other side of the solid barrier for receiving TFI2 which passes through the barrier to establish an equilibrium of TFI2 on both sides of the solid barrier, whereby there is a net flow of TFI2 between both sides of the solid barrier in response to a nonequilibrium condition of TFI2 on both sides of the solid barrier in order to re-establish. the desired amount of TFI2 on either side of the solid barrier.
2. A method as claimed in claim 1 in which the source of TFI2 is encapsulated by the iodine solving solid barrier.
3. A method as claimed in claim 1 in which the thermodynamically free iodine is collected in a liquid.
4. A method as claimed in claim 3 in which said liquid is water.
5. A method as claimed in claim 1 in which the thermodynamically free iodine is collected in a gas.
6. A method as claimed in claim 1 in which said reservoir is a vacuum.
7. A method as claimed in claim 1 in which the thermodynamically free iodine is collected in an iodine solving solid.
8. A method as claimed in claim 1 in which the thermodynamically free iodine is collected on the surface of a solid in which iodine is not soluble.
9. A method as claimed in claim 1 in which the thermodynamically free iodine is collected in an iodine complexing compound.
10. A method as claimed in claim 1 in which the iodine source comprises an iodine/iodine complexing compound mixture.
11. A method as claimed in claim 1 in which the iodine solving barrier is a plastic.
12. A method as claimed in claim 11 in which the plastic is selected from the class consisting of linear polyethylene, isotactic polyethylene, polyoxymethylene and polybutylene terephthalate.
13. A device for producing a desired amount of pure thermodynamically free iodine (TFI2), comprising:
(a) a TFI2 solving solid barrier impervious to solvents and contaminants of TFI2 (b) a source of TFI2 which produces a predeterminable amount of TFI2, the source being located on one side of the solid barrier, the source comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressure of the TFI2 by a predetermined amount; and (c) a reservoir means located on the other side of the solid barrier for collection TFI2 which passes through the solid barrier to establish an equilibrium of TFI2 on both sides of the solid barrier, whereby is a net flow of TFI2 between both sides of the solid barrier in response to a nonequilibrium condition of TFI2 on both sides of the solid barrier to re-establish the desired amount of TFI2 on either side of the solid barrier.
(a) a TFI2 solving solid barrier impervious to solvents and contaminants of TFI2 (b) a source of TFI2 which produces a predeterminable amount of TFI2, the source being located on one side of the solid barrier, the source comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressure of the TFI2 by a predetermined amount; and (c) a reservoir means located on the other side of the solid barrier for collection TFI2 which passes through the solid barrier to establish an equilibrium of TFI2 on both sides of the solid barrier, whereby is a net flow of TFI2 between both sides of the solid barrier in response to a nonequilibrium condition of TFI2 on both sides of the solid barrier to re-establish the desired amount of TFI2 on either side of the solid barrier.
14. A device as claimed in claim 13 in which the iodine source is encapsulated within the iodine solving solid barrier, and in which they means for collecting the thermodynamically free iodine is a container.
15. A device as claimed in claim 13 in which the means to collect the thermodynamically free iodine is a liquid.
16. A device as claimed in claim 15 in which said liquid is water.
17. A device as claimed in claim 13 in which the means for collecting the thermodynamically free iodine is a gas.
18. A device as claimed in claim 13 in which the product side of the iodine solving solid barrier consists of a vacuum.
19. A device as claimed in claim 13 in which the means to collect the thermodynamically free iodine is an iodine solving solid.
20. A device as claimed in claim 13 in which the thermodynamically free iodine is collected on the surface of a solid in which iodine is not soluble.
21. A device as claimed in claim 13 in which the thermodynamically free iodine is collected in an iodine complexing compound.
22. A device as claimed in claim 13 in which the iodine source consists of an iodine/iodine complexing compound mixture.
23. A device as claimed in claim 13 in which the iodine solving solid material is a plastic.
24. A device as claimed in claim 23 in which the iodine solving solid material is selected from a class consisting of linear polyethylene, isotactic polyethylene, polyoxymethylene and polybutylene terephthalate.
25. A device for producing pure thermodynamically free iodine (TFI2), comprising:
(a) a container;
(b) a cup opening from the container and defining a sealed cavity between the cup and the container;
(c) a source of TFI2 contained within the cavity, the source comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressure of the TFI2 by a predetermined amount; and (d) a TFI2 solving solid barrier lining an outer wall of the cup located within the cavity, the cup being perforated adjacent the barrier lining, and container and cup being farmed of iodine impervious material.
(a) a container;
(b) a cup opening from the container and defining a sealed cavity between the cup and the container;
(c) a source of TFI2 contained within the cavity, the source comprising an iodine/iodine complexing compound mixture calibrated to reduce the vapour pressure of the TFI2 by a predetermined amount; and (d) a TFI2 solving solid barrier lining an outer wall of the cup located within the cavity, the cup being perforated adjacent the barrier lining, and container and cup being farmed of iodine impervious material.
26. A device as claimed in claim 25 in which the iodine source comprises an iodine/iodine complexing compound mixture.
27. A device as claimed in claim 25 in which the iodine solving solid material is a plastic.
28. A device as claimed in claim 27 in which the iodine solving solid material is selected from a class consisting of linear polyethylene, isotactic polyethylene, polyoxymethylene and polybutylene terephthalate.
Priority Applications (11)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000613953A CA1340947C (en) | 1989-09-28 | 1989-09-28 | Method and device for producing pure elemental iodine |
| HU9201028A HUT60696A (en) | 1989-09-28 | 1990-08-20 | Process and equipment for obtaining pure elementary iodine |
| CA002066673A CA2066673C (en) | 1989-09-28 | 1990-08-20 | Method and device for producing pure elemental iodine |
| PCT/CA1990/000265 WO1991004940A1 (en) | 1989-09-28 | 1990-08-20 | Method and device for producing pure elemental iodine |
| US07/842,153 US5275736A (en) | 1989-09-28 | 1990-08-20 | Method and device for producing pure elemental iodine |
| JP2511166A JPH05500354A (en) | 1989-09-28 | 1990-08-20 | Method and apparatus for producing pure elemental iodine |
| AU61536/90A AU633616C (en) | 1989-09-28 | 1990-08-20 | Method and device for producing pure elemental iodine |
| FI921354A FI921354A7 (en) | 1989-09-28 | 1990-08-20 | Method and apparatus for producing pure elemental iodine |
| EP90911944A EP0494150A1 (en) | 1989-09-28 | 1990-08-20 | Method and device for producing pure elemental iodine |
| BR909007705A BR9007705A (en) | 1989-09-28 | 1990-08-20 | METHOD AND DEVICE FOR THE PRODUCTION OF PURE ELEMENTARY IODINE |
| NO921168A NO308697B1 (en) | 1989-09-28 | 1992-03-25 | Method and apparatus for producing pure elemental iodine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000613953A CA1340947C (en) | 1989-09-28 | 1989-09-28 | Method and device for producing pure elemental iodine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1340947C true CA1340947C (en) | 2000-04-04 |
Family
ID=4140750
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000613953A Expired - Fee Related CA1340947C (en) | 1989-09-28 | 1989-09-28 | Method and device for producing pure elemental iodine |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0494150A1 (en) |
| JP (1) | JPH05500354A (en) |
| BR (1) | BR9007705A (en) |
| CA (1) | CA1340947C (en) |
| FI (1) | FI921354A7 (en) |
| HU (1) | HUT60696A (en) |
| NO (1) | NO308697B1 (en) |
| WO (1) | WO1991004940A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW482651B (en) * | 1994-12-28 | 2002-04-11 | Baxter Int | Antimicrobial materials. |
| US5948385A (en) * | 1996-09-30 | 1999-09-07 | Baxter International Inc. | Antimicrobial materials |
| DE60037657T2 (en) * | 1999-06-04 | 2009-01-08 | Oxibio, Inc., Portland | INFECTANT CONTAINING MEDICAL DEVICE AND METHOD FOR PRESENTING ITSELF |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE559167C (en) * | 1931-12-12 | 1932-09-16 | Byk Guldenwerke Chem Fab Akt G | Purification of iodine by sublimation |
| US4769143A (en) * | 1987-02-17 | 1988-09-06 | Or-Tsurim | Device for purifying water |
-
1989
- 1989-09-28 CA CA000613953A patent/CA1340947C/en not_active Expired - Fee Related
-
1990
- 1990-08-20 BR BR909007705A patent/BR9007705A/en unknown
- 1990-08-20 FI FI921354A patent/FI921354A7/en not_active Application Discontinuation
- 1990-08-20 EP EP90911944A patent/EP0494150A1/en not_active Withdrawn
- 1990-08-20 WO PCT/CA1990/000265 patent/WO1991004940A1/en not_active Ceased
- 1990-08-20 HU HU9201028A patent/HUT60696A/en unknown
- 1990-08-20 JP JP2511166A patent/JPH05500354A/en active Pending
-
1992
- 1992-03-25 NO NO921168A patent/NO308697B1/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| EP0494150A1 (en) | 1992-07-15 |
| FI921354A0 (en) | 1992-03-27 |
| BR9007705A (en) | 1992-07-21 |
| NO921168D0 (en) | 1992-03-25 |
| FI921354L (en) | 1992-03-27 |
| FI921354A7 (en) | 1992-03-27 |
| AU633616B2 (en) | 1993-02-04 |
| HUT60696A (en) | 1992-10-28 |
| JPH05500354A (en) | 1993-01-28 |
| NO921168L (en) | 1992-05-29 |
| WO1991004940A1 (en) | 1991-04-18 |
| HU9201028D0 (en) | 1992-08-28 |
| NO308697B1 (en) | 2000-10-16 |
| AU6153690A (en) | 1991-04-28 |
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