SURFACE, MATERIAL AND PERSONAL CLEANING FORMULATION COMPRISING NANOSTRUCTURED PARTICLES

Abstract

Formulations comprising a nanostructured particles consisting of a solid acid, made of mixed oxides of silica and titania (TiO.sub.2—SiO.sub.2); supporting in its dispersed matrix: copper, silver, gold, iron, rutenium, rhodium, cobalt, zinc, palladium, zinc, manganese, iridium and/or platinum metals at minimal concentrations, and at least one functionalizing agent in contact with the particle, for use as a surface, material and personal cleaner.

Claims

1. A formulation comprising a nanostructured particles consisting of a solid acid, made of mixed oxides of silica and titania (TiO.sub.2—SiO.sub.2); supporting in its dispersed matrix: copper, silver, gold, iron, rutenium, rhodium, cobalt, zinc, palladium, zinc, manganese, iridium and/or platinum metals at minimal concentrations, and at least one functionalizing agent in contact with the particle, for use as a surface, material and personal cleaner.

2. The formulation for use as a surface, material and personal cleaner of claim 1, wherein the metal supported in the dispersed matrix is acetil platinum acetonate (Pt(acac).sub.2).

3. The formulation for use as a surface, material and personal cleaner of claim 1, wherein the functionsalizing agent is selected from polyurethanes, water soluble polymers or hydrophobic polymers.

4. The formulation for use as a surface, material and personal cleaner of claim 1, wherein the formulation is in the form of a gel.

5. The formulation for use as a surface, material and personal cleaner of claim 1, wherein the formulation is in the form of a liquid.

6. The formulation for use as a surface, material and personal cleaner of claim 1, wherein the formulation is in the form of a solid.

Description

DETAILED DESCRIPTION

[0019] The present disclosure includes disclosure of a formulation, comprising a quantity of a silica oxide, a quantity of a titanium oxide, and a quantity (or quantities) of one or more of copper, silver, gold, iron, rutenium, palladium, zinc, manganese, iridium and/or platinum metals, as referenced herein.

[0020] The sol-gel methodology is used to control the physico-chemical properties of the material in a thin, nanometric size and with a wide surface area. The nanoparticle comprised in the disclosed formulation is characterized by being a solid acid consisting of mixed oxides of silica and titania incorporating in its dispersed matrix, copper, silver, gold, iron, rutenium, palladium, zinc, manganese, iridium and/or platinum metals, or mixtures thereof, to minimum concentrations; and at least one functionalizing agent in contact with the particle. The carrier may be in liquid, oil, gel or solid form.

[0021] The functionalizing agent may have several functions. One function is stabilizing the particle in a carrier so that particles do not agglomerate and are uniformly distributed. In addition it may also assist in releasing antimicrobially effective amounts of ions into the environment of a microbe. The functionalizing agents may include polyurethanes and water soluble polymers, they promote dissolution in paints, and also improves adherence to the microbial surfaces. Functionalization agents may also include hydrophobic polymers which are used as emulsions and solutions to modify the particulate surfaces.

[0022] The formulation that comprises the nanostructured particles is effective as a broad-spectrum, fast-acting antimicrobial agent. The antimicrobial effectiveness of the functionalized nanoparticles has been evaluated using standard methods which resulted hi a significant effect in the killing of different types of microbes including bacteria, viruses, molds and fungi.

[0023] The present product can be formulated, depending on the carrier, as a surface cleaner, directed to be applied on any type of surface to eliminate microbial agents and prevent infections. The product can be further formulated as a material cleaner, directed to be applied to any type of material to eliminate microbial agents and prevent infections. Furthermore, the product can be formulated as a personal hygiene product to be applied on the skin, hair, nails and other external tissues to eliminate microbial agents and prevent infections.

[0024] The use of the product is of particular interest, but not limited to the sanitization of surfaces and materials in hospitals, clinics and other health institutions for decreasing transmission of nosocomial infections.

[0025] Sol-gel process using metal alkoxides.

[0026] At the functional group level, three reactions are generally used to describe the sol-gel process: hydrolysis, alcohol condensation, and water condensation. However, the characteristics and properties of a particular sol-gel inorganic network are related to a number of factors that affect the rate of hydrolysis and condensation reactions, such as, pH, temperature and time of reaction, reagent concentrations, catalyst nature and concentration, H.sub.2O/M molar ratio (R), aging temperature and time, and drying. Of the factors listed above, pH, nature and concentration of catalyst, H.sub.2O/M molar ratio (R), and temperature have been identified as most important. Thus, by controlling these factors, it is possible to vary the structure and properties of the sol-gel-derived inorganic network over wide ranges. For example, Sakka et al. observed that the hydrolysis of TEOS utilizing R values of 1-2 and 0.01 M HCl as a catalyst yields a viscous, spinnable solution. It was further shown, that these solutions exhibited a strong concentration dependence on the intrinsic viscosity and a power law dependence of the reduced viscosity on the number average molecular weight.sup.(31-34):

[n]=k(Mn)a  (1)

[0027] Values for a ranged from 0.5 to 1.0, which indicates a linear or lightly branched molecule or chain.

[0028] Values of “a” in eq. 1 ranged from 0.1 to 0.5, indicating spherical or disk shaped particles. These results are consistent with the structures which emerge under the conditions employed by the Ströber process, for preparing SiO.sub.2 powders. It was further shown that with hydrolysis under basic conditions and R values ranging from seven (7) to twenty-five (25), monodisperse, spherical particles could be produced.

##STR00001##

[0029] Generally speaking, the hydrolysis reaction (Eq. 2), through the addition of water, replaces alkoxide groups (OR) with hydroxyl groups (OH). Subsequent condensation reactions are made, involving the silanol groups (Si—OH) produce siloxane bonds (Si—O—Si) plus the by-products water or alcohol in the case of silica. Under most conditions, condensation commences before hydrolysis is complete. However, conditions such as, pH, H.sub.2O/Si molar ratio (R), and catalyst can force completion of hydrolysis before condensation begins. Additionally, because water and alkoxides are immiscible, a mutual solvent is utilized. With the presence of this homogenizing agent, alcohol, hydrolysis is facilitated due to the miscibility of the alkoxide and water. As the number of siloxane bonds increases, the individual molecules are bridged and jointly aggregate in the sol. When the sol particles are aggregate, or inter-knit into a network, a gel is formed. Upon drying, trapped volatiles (water, alcohol, etc.) are driven off and the network shrinks as further condensation can occur. It should be emphasized, however, that the addition of solvents and certain reaction conditions may promote esterification and depolymerization reactions. The hydrolysis/condensation reaction follows two different mechanisms, which depend of the coordination of metallic central atom. When the coordination number is satisfied the hydrolysis reaction occurs by nucleophilic substitution (Se):

##STR00002##

Hydrolysis reaction via nucleophilic substitution (S.sub.n).

[0030] When the coordination number is major, the hydrolysis reaction takes place by nucleophilic addition:

##STR00003##

[0031] Hydrolysis reaction via nucleophilic addition (A.sub.n).

[0032] These mechanisms need that the oxygen coordination is increased from 2 to 3, the additional bond generation involves one electron pair of the oxygen and the new bond can be equivalent to the other bonds. During the condensation step an enormous concentration of hydroxyl groups are formed. This OH can be linked between the metallic atoms or only be simple —OH ligand in the surface.

##STR00004##

Acid-Catalyzed Mechanism

[0033] Under acidic conditions, it is likely that an alkoxide group is protonated in a rapid first step. Electron density is withdrawn from the silicon atom, making it more electrophilic and thus more susceptible to attack from water. This results in the formation of a penta-coordinate transition state with significant SN.sub.2-type character. 13 The transition state decays by displacement of an alcohol and inversion of the silicon tetrahedron, using silica as example:

##STR00005##

Base-Catalyzed Mechanism

[0034] Base-catalyzed hydrolysis of silicon alkoxides proceeds much more slowly than acid-catalyzed hydrolysis at an equivalent catalyst concentration. Basic alkoxide oxygens tend to repel the nucleophile, —OH. However, once an initial hydrolysis has occurred, following reactions proceed stepwise, with each subsequent alkoxide group more easily removed from the monomer then the previous one. Therefore, more highly hydrolyzed silicones are more prone to attack. Additionally, hydrolysis of the forming polymer is more sterically hindered than the hydrolysis of a monomer. Although hydrolysis in alkaline environments is slow, it still tends to be complete and irreversible. Thus, under basic conditions, it is likely that water dissociates to produce hydroxyl anions in a rapid first step. The hydroxyl anion then attacks the silicon atom. Again, an SN.sub.2-type mechanism has been proposed in which the —OH displaces —OR with inversion of the silicon tetrahedron.

##STR00006##

EXAMPLES

Example 1

[0035] 1.6871 g Of acetil platinum acetonate (Pt(acac).sub.2) were mixed with 246 ml of acetone. The mixture was maintained under agitation until the platinum complex was dissolved. To this mixture, 1.2501 g of GABA previously dissolved in 20 ml of deionized water was added. pH was adjusted to 3 with phosphoric acid. Simultaneously, 89 ml of TEOS and 9.8 ml of titanium butoxide dissolved in 70 ml of deionized water were added. Everything was maintained under agitation and at room temperature until de gel was formed.

Example 2

[0036] 1.6871 g Of acetil platinum acetonate (Pt(acac).sub.2) were mixed with 246 ml of acetone. The mixture was maintained under agitation until the platinum complex was dissolved. To this mixture, 1.2501 g of glutamic acid previously dissolved in 20 ml of deionized water was added. pH was adjusted to 3 with phosphoric acid. Simultaneously, 89 ml of TEOS and 9.8 ml of titanium butoxide dissolved in 15 ml of absolute ethanol. 1.7203 g of ammonium sulphate dissolved in 70 ml of deionized water was added. Everything was maintained under agitation and at room temperature until de gel was formed.

Example 3

[0037] 1.6871 g Of acetil platinum acetonate (Pt(acac).sub.2) were mixed with 246 ml of acetone. The mixture was maintained under agitation until the platinum complex was dissolved. To this mixture, 1.2501 g of GABA previously dissolved in 40 ml of deionized water was added. pH was adjusted to 3 with phosphoric acid. Simultaneously, 89 ml of TEOS and 9.8 ml of titanium butoxide dissolved in 15 ml of absolute ethanol were added. 1.7203 g of ammonium sulphate dissolved in 140 ml of deionized water was added. Everything was maintained under agitation and at room temperature until de gel was formed.