Will not precipitate over time and therefore unopened it has an indefinite shelf life, it does not react to light and can therefore be stored in clear plastic or glass bottles. They should not however be subjected to freezing or excessively high temperatures. For this reason although they are not light sensitive storage in direct sunlight is not advisable.
True colloids will ideally contain over 80% of the total silver content as silver particles the rest usually being ionic silver. It is generally accepted that over 50%of particulate silver can be considered a colloid. Obtaining a stable silver colloid is a complex process, which is why most manufacturers simply cannot do it. Groups of atoms are charged particles and depending on the substance they are dispersed in they may attract or repel one another. The charge that keeps particles separate may be negative or positive and is known as the Zeta Potential (http://www.silver-colloids.com/Tutorials/tutorials.html). If all particles carry an equal charge of the same polarity they will always repel one another, in that case the colloid remains stable. If particles do not carry a sufficient charge they will eventually coalesce and precipitate in the form of large particles.
TRUE SILVER COLLOIDS ARE NOT EASY TO MANUFACTURE
Colour
They are generally coloured from light yellow, often described as straw coloured to dark brown. They are NEVER clear.
Dark colour was previously thought to indicate large particle size, but in fact this is not the case.
Dark colour can also be produced by high concentration of very small particles. Particle size is accurately measured by a Photon Correlation Spectrometer but most manufacturers do not posses one ( they are in the $30,000 to $40,000 price range ) A TEM electron microscope is not sufficiently accurate.
DARK COLOUR DOES NOT ALWAYS INDICATE LARGE PARTICLES IF IT IS CLEAR IT IS AN IONIC SOLUTION
Particle size
Particle size is extremely important, as the reactivity of any particle is determined by its surface.
Material in the centre of any particle is effectively useless. The relationship between particle size and surface area is inversely proportional. Large particles will have a low efficiency index because their reactive surface in relation to total concentration will be low. Smaller particles for the same concentration will have larger total surface area. It is therefore true that the most effective product would be a high concentration true colloid with the smallest particle size. See the particle size comparison page here ( page to be created )
SMALLER IS BETTER
PPM
This term means – Parts Per Million, it is an expression of the total silver content in relation to the total product volume. It is equal to Mg/Lt milligrams per litre of water.
1ppm = 1Mg/Lt. The practical limit to a true silver colloid in water is between 10 and 20 PPM.
HIGH PPM IS NOT ALWAYS GOOD AND GENERALLY INDICATES THE PRESENCE OF ADDITIVES OR HIGH CONCENTRATION IONIC SOLUTIONS.
Ionic Silver Solutions
These are relatively cheap and comparatively easy to manufacture employing a technology known as electrolysis. There are often references to the purity of the water or something like HVAC process ,but it is still electrolysis. Many manufacturers still label these products as Colloid silver and then refer to ions as tiny or microscopic particles. To be absolutely clear ions are NOT particles. Ions are created by electrolysis (https://en.wikipedia.org/wiki/Electrolysis) using silver electrodes in water, current can be direct or alternating and voltage may be from 9 to several thousands of volts.
SIMPLE TO MAKE LOW COST OF MANUFACTURE
Colour
Ionic solutions are clear because ions do not absorb light from the visible spectrum. They are often packaged in coloured bottles. Ionic solutions will turn cloudy white if mixed with pure sodium chloride (Table salt). * elsewhere * this reaction may not occur if the salt contains additives such as anti caking agents used in some table salt brands.
IONIC PRODUCTS ARE CLEAR SOLUTIONS
Not Particles
Ions are not metallic particles they are silver atoms missing one electron from their outer electron orbital. This means they do not behave as metallic silver and are extremely reactive. They quickly form compounds in the presence of other ions. Some particles are usually produced during the process of manufacturing ionic products, but these tend to be large and of random size. Total particle content can be as high as 20% For more information on ionic solutions click here >>
SOMETIMES CONTAIN UP TO 20% OF LARGE PARTICLES OF 25 to 800 nanometers (25 nanometers is very large in nanoparticle terms).
Silver Gels and Mild Silver Protein
Protein based products generally contain very high concentrations of very large silver particles suspended in a protein polymer such as gelatine or a vegetarian equivalent. This is required because the particles are often so large they would precipitate and coagulate into even larger particles if the viscosity of the protein or gel did not prevent them from doing so.
They are highly susceptible to bacterial contamination particularly after opening and are not recommended by anyone except the manufacturers of these products.
Gels formed from Ionic solutions or from true Colloid silver may be useful externally where a liquid application would not stay on the area to be treated.
PROTEIN BASED PRODUCTS NOT RECOMMENDED FOR ANY APPLICATION
