Silver composites

Figure 12.7. Top—Micrograph of a suspension containing nanosized silver particles. Bottom—Micrograph of a micron-sized silver composite ink. 

To determine the silver composition of an alloy, a piece of alloy weighing 10-48g was dissolved in nitric acid and the resulting solution was diluted to 1-00 litre in a standard flask. 0-20 moll hydrochloric acid was added to 100-0 cm of this solution until precipitation of silver(l) chloride was complete. 

Kumar R, Munstedt H. Silver ion release from antimicrobial polyamide/silver composites. Biomaterials 2004, 26, 2081-2088. 

The present invention describes the use of a silver composition in water to treat certain human ailments. An embodiment of the invention is a silver composition comprising small particles of silver which comprise an interior of metallic silver and an exterior of ionic silver which particles are suspended in water. A preferred embodiment of the invention is a silver composition comprising particles of silver wherein more than 50% of the particles are less than 0.015 micrometers in size and the particles are colloidally suspended in water. 

The compositions all have the size characteristics described below and unlike conventional silver compositions are completely colorless and stable to light and temperature changes without use of any additives. The compositions are unreactive towards added hydrogen peroxide. 

The analysis of the silver content in the silver compositions of this invention may be done by atomic absorption (AA), inductively coupled plasma/atomic emission (ICP/AES), or other techniques known to one of ordinary skill in the art to be sensitive to silver in the appropriate concentration range. If the particles of the silver composition are small and uniformly sized (for example, 0.01 micrometers or less), a reasonably accurate assay may be obtained by running the colloid directly by AA or ICP/AES. This is because the sample preparation for AA ionizes essentially all of the silver allowing its ready detection. 

If the compositions comprise particles as large as 0.2 micrometers, it is preferred to use a digestion procedure. The digestion procedure is not necessarily ideal for silver compositions that may have been manufactured or stored in contact with halides or other anionic species that may react with finely divided silver, or combined with protein or other gelatinous material. An embodiment of the digestion procedure is as follows ... 

Take a 10 ml aliquot of a thoroughly mixed or shaken silver composition to be analyzed, and place it in a clean polycarbonate bottle or other container of suitable material (generally, the bottle) with a tight fitting lid. A size of 30-100 ml is preferred. 

With a micropipette or dropper, add 0.1 ml of nitric acid, reagent grade to the silver composition in the bottle. 

With the lid of the bottle tightly in place, heat the silver composition to 80° C. with mild agitation for a time sufficient to dissolve the silver—dissolution is essentially instantaneous. 

A few drops of the 22 ppm inventive silver composition were evaporated to dryness on a silicon substrate at ambient temperature. The residue was analyzed by TOF-SIMS, and is denoted as the sample. A reference silver (II) oxide (AgO) material was analyzed by placing a few particles of the reference powder as received from the vendor on a silicon substrate, and is denoted as the reference. 

Evidence of Efficacy of 22 PPM Silver Composition Against Bacillus Subtilis... 

Evidence of Efficacy of 10 PPM Silver Composition as a Broad Spectrum Antimicrobial... 

The 10 ppm silver composition of the present invention was tested and found to be both bacteriostatic and bactericidal for all organisms tested. In other studies, this composition was compared to other commercially available colloidal silver products and found to have a superior activity to all other preparations tested (data not shown). The most interesting observation was the broad spectrum that the 10 ppm silver composition possesses. The antimicrobial activity that was observed was fairly constant independent of the particular organism tested. With the exception of Streptococcus faecalis and Streptococcus aureus (which had MIC values of 10 ppm and 5 ppm, respectively), MIC values ranged between 1.25 ppm and 2.5 ppm for both gram... 

Evidence of Efficacy of 32 PPM Silver Composition Against Pseudomonas Aeruginosa, Salmonella Chol-eraesuis and Staphylococcus Aureus... 

The beef samples were then hung vertically on stainless steel hooks attached to a motorized track that pulled the beef samples through a model spray cabinet (Kansas State University, Food Safety Laboratory) while spray treatments were applied. Treatments with either the silver compositions of this invention or deionized water were applied to the beef at 20 psi from a distance of 13 cm in the model pressure rinse cabinet for 20 seconds. The spray nozzle (BETE NF0580 303) delivered approximately 20 ml of solution to the surface of the beef sample. The temperature of solutions and treatment application room was approximately 14° C. After treatment, duplicate 3.5 cm2 core samples were randomly drawn from the lateral surface of the beef sample at 0, 20, 60 and 240 minutes. Samples were cultivated and enumerated on selective differential and... 

Results with Silver Composition in Water. For Salmonella, for the lower initial bacteria level (104), the following log reductions were recorded 0.38 at 0 minutes, 0.41 at 20 minutes, 0.39 at 60 minutes, and 0.61 at 240 minutes. For the higher initial bacteria level (106), the following log reductions were recorded 0.24 (at 0 minutes, 0.21 at 20 minutes, 0.41 at 60 minutes and 0.54 at 240 minutes. The results indicate that the 10 ppm silver embodiment of this invention provides an effective bactericidal effect for Salmonella on beef steak. 

Abdominal pain and Diarrhea. The method comprises the step of administering approximately 5-25 ml of silver composition, one to five times a day orally until there was a response. One patient was treated with about 10 ml (about two teaspoons) of a composition of the present invention three times in one day. The patient had a full recovery in one day. 

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