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Jump to site search. Journals Books Databases. Search Advanced. Current Journals. Archive Journals. All Journals. New Titles. Pick and Choose. Literature Updates. For Members. For Librarians. RSS Feeds. Chemistry World. Education in Chemistry. The colour change could therefore be used as an indication that the regions containing the active ingredients have mixed and thus, were these regions to also contain molecules which, when in direct contact, caused or enhanced the cleaning properties of the cleaning composition, the colour change would indicate that the cleaning properties had begun or were being enhanced.
Suitably, the phases of the multiple emulsion could additionally comprise active ingredients which function as cleaning aids or agents even before the emulsion collapses.
Alternatively, the same effect could be achieved were one of the active ingredients to be a bleach, the other a colour molecule or dye. Once again, the resulting colour change as the dye and bleach are brought into contact could be used as a visual sign that the originally-separated regions are now in contact such that cleaning or enhancing cleaning properties are in effect. In essence, the mixing of the colour and the bleach will provide the user of the composition with a sensorial cue that the multiple emulsion has broken down.
In a further specific embodiment of the invention, one active ingredient is an oxidising agent, the other a reducing agent. Either or both agents could function as cleaning agents in their own right, i. Generally, the more heat produced by the redox reaction, the greater the increase in temperature of the multiple emulsion system and hence the greater the potential increase in the speed of the cleaning process using the composition.
Examples of suitable oxidising agents for use in this particular embodiment include sodium chlorite and sodium perborate. Examples of suitable reducing agents for use in this particular embodiment include potassium iodide, sodium sulphite and ferrous ammonium sulphate. In the specific embodiment where one active ingredient is an oxidising agent, the other a reducing agent, the mixing of the initially separated phases can lead to the initiation of a clock chemistry reaction.
During such reactions, the pH of the reaction medium will oscillate between acidic and alkaline conditions. In this embodiment, the cleaning action can be based on the pH oscillation of the clock chemistry reaction system. In cleaning compositions, acidic conditions assist in the breaking down of alkaline-based moieties, for example limescale and the like, whilst alkaline conditions will assist in the breaking down of acidic-based moieties, for example in the breaking down of grease and proteinaceous deposits and the like.
Hence, the initiation of clock chemistry will be particularly advantageous as both types of moieties acidic and alkaline can be sequentially attacked by the same composition. Most preferably, the active ingredients can be such that the pH of the composition remains acidic at the end of the clock chemistry reaction. In this case, the composition will continue to assist in the breaking down of alkaline-based moieties, such as limescale, as and until the composition is removed.
Suitable systems for this embodiment of the present invention may include those described in the following references:. Temperature compensation in the oscillatory hydrogen peroxide-thiosulfate-sulfite flow system, G. Rabai et al, Chem. Rabai et al, J. A,, Chaotic pH oscillations in hydrogen peroxide-thiosulfate-sulfite flow system, G. Thus, preferably the multiple emulsion contains components which function as a pH clock.
The chemical composition of a typical pH clock will involve an oxidant and a reductant species.
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Typically, the reductant will be the salt of a weak acid and the corresponding oxidant will be a strong acid. Many different species can be used as partners in these redox systems. In seeking appropriate species, a useful guide for the overall reaction stoichiometry is that the reducing agent should release more protons per electron than the oxidising agent consumes. Within the existing literature, the following species can be identified and may be of use in cleaning compositions:.
Potential Reductant: I all oxyanions of sulfur that contain S-S bonds e. II reducing agents that are significantly more basic than their oxidised counterparts e. The most widely studied and exploited clock reactions are those typified by the Landolt clock reaction. Beyond those combinations mentioned above, there are reports of clock-type reactions with associated pH changes involving the following reagents:.
An example of a clock reaction system starting at low pH and changing to high pH at the end of the induction period involves the reduction of H 2 O 2 by various multidentate complexes of Fe II or Co II ions. In further embodiments of the present invention, enzymes can be one of the active ingredients in the multiple emulsion systems. In such embodiments, the other active ingredient could, for instance, be a catalyst. In this case, the trigger mechanism will lead to a mixing of the enzyme-containing and catalyst-containing phases, thus enabling the cleaning composition to exhibit an improved enzyme efficiency.
It is well-known in the art of cleaning compositions that enzymes play an important role in the cleaning process of both hard and fabric surfaces. Hence, the enzyme could function to one level of cleaning efficiency pre-trigger, and then, post-trigger and after mixing with the catalyst, could function to a different, preferably enhanced, level of cleaning efficiency.
Alternatively one active ingredient could be an enzyme and the other active ingredient could be an agent that terminates enzyme action, for example by degrading it or switching off its action by pH change, for example. Alternatively, one active ingredient could be an enzyme, whilst the other active ingredient could be a bleach, in which case the effect of a mixing of the phases will be to cause a mixing of the enzyme and bleach, leading to a cleaning composition of dual functionality.
Alternatively, but equally applicably, the cleaning composition could function with a sequential action, initially acting by enzyme action, then bleach action. This particular combination of active ingredients is very effective as a cleaning composition but in the absence of the present stabilised multiple emulsion system technology, the enzyme and bleach would tend to react in the formulation and therefore would not be stable in storage and the shelf-life of the product would be adversely affected. A further, and similar, embodiment has an enzyme as one active ingredient, and a peroxide moiety as the other active ingredient.
In normal circumstances, enzymes will not survive under peroxide conditions and therefore this embodiment will allow the production and storage of stable cleaning compositions comprising these two active ingredients. Alternatively, one active ingredient is a bleach, the other a bleach activator. Hence, when the trigger mechanism is activated, the active ingredients will mix, the bleach will be activated, and the cleaning composition will begin to function or will function with an improved efficiency due to the presence of activated bleach.
Improved bleaching efficiency, particularly at lower temperatures, is especially useful for laundry care products or for the bleaching of hard surfaces. Cleaning compositions wherein the bleach and bleach activator are kept apart until the trigger will be stabilised for longer than in conventional formulations, leading to an increased shelf-life. A preferred bleach in this embodiment is hydrogen peroxide, although percarbonates and perborates can also be used.
Moreover, it is possible to use bleach precursors which can be activated with a catalyst to breakdown to give a bleach. Alternatively, a bleach precursor, such as sodium chlorite can be reacted with an acid function to generate chlorine dioxide as a bleaching agent. More preferably, the bleach is in the inner aqueous phase, whilst the enzyme is in the outer aqueous phase. In this preferred embodiment, the fragrance is kept apart from the bleach. Indeed, it is suitably found that the third phase of a three-component multiple emulsion, i.
The ingredient in the third phase will not substantially mix with the active ingredients in the other two phases, which will of course themselves not mix in the stable multiple emulsion system but will mix post-trigger. Nevertheless, the ingredient in the third phase can add to the functioning of the composition by being a moiety that promotes or assists the cleaning process, or improves the properties of the composition in some other way, for example, by improving the fragrance of the composition, or the like.
Alternatively, both active ingredients could be enzymes and in this manner it is possible to keep apart, at least until the trigger mechanism is activated, two enzymes which would react with each other in normal circumstances. It is quite common that two enzymes in a cleaning composition not of the stabilised multiple emulsion type would react with each other in a manner detrimental to the efficiency of the overall composition as a cleaning composition. Therefore, a problem is how to keep such enzymes apart in a convenient cleaning composition. A possible solution is to use the stabilised multiple emulsion systems as herein described.
Hence, cleaning compositions which would normally have a very short shelf-life, can be kept indefinitely, or at least until the trigger mechanism is activated, by using stabilised multiple emulsion systems. Hence, each enzyme will function as a cleaning agent in the stabilised multiple emulsion, without being adversely affected by the presence of the other enzyme, held in a separate phase.
After trigger, the enzymes will be brought into contact and cleaning will continue for a time, as and until the two enzymes react in a manner detrimental to the cleaning efficiency. Nevertheless, without the initial stabilised multiple emulsion system, this detrimental reaction would occur as soon as the composition were made, i. Examples of enzymes which would normally react and therefore could not be kept for any period of time in a conventional cleaning composition are protease on the one hand and lipase or amylase on the other hand.
In this case, the other active ingredient can be a reducing or oxidising moiety, preferably an oxidising moiety. In a yet further embodiment, one active ingredient can be an acidic moiety, or an acid stabilised moiety, whilst the other active ingredient is an alkaline moiety, or an alkaline stabilised moiety. Such pH changes can be utilised in cleaning compositions comprising a dual cleaning functionality, or sequential cleaning functionality, for instance, one cleaning agent being active in acidic conditions, the other in alkaline conditions.
Similarly, the alkaline moiety can be a bicarbonate moiety, which will effervesce when it comes into contact with the acidic moiety, clearly showing when the phases have been mixed. Hence, this embodiment could comprise an alkaline moiety being, or containing, a cleaning agent as the first active ingredient, and an acidic moiety being, or containing, a cleaning agent as the second active ingredient, such that pre-trigger the cleaning composition is overall alkaline, and after-trigger, the cleaning composition is overall acidic in nature. Equally suitably, the composition may pre-trigger be overall acidic, and post-trigger, overall alkaline in nature.
Suitably, the alkaline moiety can be selected from the group comprising inorganic compounds, preferably alkali metal compounds, especially alkali metal carbonates, bicarbonates and hydroxides, and alkali metal peroxy compounds, preferably percarbonates and perborates. Especially preferred are sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium percarbonate and sodium perborate. Sodium hydroxide is most especially preferred. Suitably, the acidic moiety can be selected from the group comprising organic and inorganic acids or precursor compounds thereto.
Particularly suitable acids include organic acids, for example citric acid, formic acid, lactic acid, succinic acid and acetic acid, and inorganic acids, for example hydrochloric acid and sulphamic acid. Sulphamic acid is especially preferred. In a yet further embodiment, one active ingredient can be an acid, for example, acidic moieties as hereinbefore defined, preferably hydrochloric acid or sulphamic acid, whilst the other active ingredient is a chlorite, for example sodium chlorite, NaClO 2. Such chlorite molecules are stable in alkaline conditions. However, when the trigger mechanism is activated, the sodium chlorite will encounter acidic conditions, and both sodium hydroxide and chlorine dioxide will form.
The former is an alkaline agent whilst the latter is a bleaching agent. Both are advantageous in cleaning compositions. In a similar embodiment, one active ingredient can be a peroxide moiety, the other active ingredient an alkaline moiety. It is generally the case that peroxide moieties are stable in acidic conditions, but not in alkaline conditions. In the latter, the peroxide moieties will give off active oxygen molecules, these being useful in cleaning compositions.
Hence, multiple emulsion systems containing a peroxide moiety as a first active ingredient and an alkaline moiety as a second active ingredient will provide a preferred embodiment in that subsequent to the trigger, the peroxide moiety will encounter alkaline conditions, and hence, active oxygen molecules will form. In a yet further embodiment, one active ingredient is a peroxide moiety, the other a hypochlorite molecule.
Once the trigger mechanism is activated, the two moieties can mix, leading to the formation of a mousse in the presence is of a nonionic, cationic, anionic or zwitterionic surfactant, which can be used advantageously in cleaning compositions. In a still further embodiment, one active ingredient is a monomer.enbulibico.cf/codigo-de-profesionales-sanitarios-22-espaa-edicin-2019/se-puede-prevenir-el-sida-divn.pdf
Encapsulation of flavonoid in multiple emulsion using spinning disc reactor technology
The other active ingredient can then be such that a polymer is formed when the phases are mixed, i. For instance, the other active ingredient could be a catalyst. Alternatively, the other active ingredient could be a cross-linking agent, such that the monomer becomes cross-linked after the active ingredients are mixed and thus the cleaning composition will thicken in use, preferably creating a film in situ.
Hence, this particular embodiment would be useful in a method of preventative cleaning. Alternatively, mixing of the actives could thin the external or outer phase.
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In this instance, the internal or inner phase will contain a thinning agent which will act by either physical or chemical means to thin the external phase and hence, the composition overall. Typical cross-linking agents will include agents comprising divalent ions, e. Alternatively, the cross-linking agents may comprise moieties which cause cross-linking either via a change in pH, or wherein the cross-linking is initiated by radicals, UV light, chemical reaction and the like.
In a yet further embodiment, one active ingredient can be a foam-forming moiety, the other a de-foaming moiety. In use as a cleaning composition, a foam will form, and will then be made to collapse when the foam-forming and de-foaming moieties mix after trigger. In a yet further embodiment, the active ingredients can be moieties that together react to form a surfactant, i. Thus, after activation of the trigger mechanism, the phases containing the active ingredients will mix, as will the active ingredients contained therein, and hence a surfactant will form. Surfactants are useful in cleaning compositions, and hence the present embodiment possesses advantages in the cleaning composition field.
Typical examples are soap precursors, for instance an alkali hydroxide, typically sodium hydroxide, and an organic acid, preferably one with a long tail. In a final embodiment, the active ingredients are such that when the trigger mechanism is released, the phases will mix and a reaction takes place which leads to the generation of light, either by chemiluminescence, fluorescence, phosphorescence, or some other light-generating reaction. Thus, if other active ingredients are present in the phases, which, when mixed, cause the cleaning compositions to function as such, then the onset of a cleaning action when the phases mix will be confirmed to the user of the composition by the chemiluminescence, fluorescence, phosphorescence or light-generating effects set out above.
Details of particular active ingredients useful in this embodiment are found in Applied Fluorescence in Chemistry, Biology and Medicine, eds. Rettig, B. Strehmel, S. Schrader, H. Preferably, bleach could be present in the third phase, the water-based phase. In any or all of the specific embodiments noted above, it is preferable that the phases of the multiple emulsion systems, more preferably the phases of the multiple emulsion systems that mix after the external or internal trigger mechanism, further comprise compositions conventionally used in cleaning compositions and the like.
Hence, the active or antagonistic ingredients brought together by the trigger can themselves function as cleaning agents, either before or after the trigger, or at both times, or alternatively, may simply indicate to the user that mixing of the phases has taken place and thus that the cleaning composition is now in the mode where the multiple emulsion system has effectively collapsed and the previously separate phases have mixed, with the further compositions providing some or all of the cleaning action of the cleaning composition.
In addition, the particulate moiety used to stabilise the multiple emulsion system, preferably functionalised silica, may itself exhibit a beneficial cleaning effect, for example by the emulsification or roll-up of soil from a soiled surface. The cleaning compositions hereinbefore described can further comprise other components in any of the phases of the multiple emulsion systems compatible with such systems and which furthermore, may have a beneficial effect on the compositions in cleaning methods.
For instance, the compositions may further comprise at least one of a dessicant, a disintegrant, and one or more surfactants. Such surfactants are well-known in the art and may be anionic, cationic, non-ionic or amphoteric zwitterionic surface active agents.
Of course, such further components should be compatible with the multiple emulsion systems described herein. The compositions of the present invention may include therein one or more organic solvents, such as lower alkyl alcohols, lower alkyl diols or glycol ethers. Such compounds may function as cleaning agents in the compounds of the present invention, and may be especially useful in glass cleaners due to their lack of tendency to smear.
A preferred cleaning composition of the present invention is a hard surface cleaner HSC for cleaning ceramics, glass, stone, plastics, marble, metal, and wood; and particularly for cleaning bathroom and kitchen hard surfaces, for example, sinks, bowls, toilets, panels, tiles and worktops, dishes china, porcelain, etc. A preferred cleaning composition is adapted for cleaning lavatory bowls and for this purpose the composition may be packaged in an ITB In Toilet Bowl or ITC In Toilet Cistern device, preferably in a holder which hangs from the rim of the bowl or cistern.
Equally preferred, the compositions of the present invention can be used as fabric surface cleaners.
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Cleaning compositions of the invention may be used as dishwasher cleaning compositions and may also be used in washing some textile materials. Preferably, the cleaning composition is antimicrobial. Preferably, the antimicrobial effect is generated when the phases of the multiple emulsion system mix after the trigger. Preferably, an antimicrobial chemical is generated in situ or released by dissolution or dispersion. The antimicrobial chemical may, for example, comprise an iodate, bromate, thiocyanate, chlorate or peroxy compound, or chlorine dioxide generated from a chlorite , chlorine, bromine or iodine.
According to a second aspect of the present invention, there is provided the use of a multiple emulsion system as a cleaning composition, wherein said emulsion system comprises at least two active ingredients separated in the emulsion system by an oily or aqueous phase, and wherein said emulsion system is effectively stabilised. Preferably, when said multiple emulsion system is in use as a cleaning composition, said active ingredients previously held separate in the system are brought into contact with each other. Thus, according to this second aspect, the use of multiple emulsion systems as hereinbefore described as cleaning compositions is disclosed.
According to a third aspect of the present invention, there is provided a multiple emulsion system comprising at least two active ingredients separated in the system by an oily or aqueous phase for use as a cleaning composition, and wherein said system is effectively stabilised.