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Unlocking The Full Potential Of Silica
Learn why we made Front Row Si with stabilized monosilicic acid (MSA)
Comparing various methods for stabilizing MSA. The unique advantages of polyol-stabilized MSA solutions, such as Front Row Si.
The Importance Of Stabilizing Monosilicic Acid
Silica products not only increase plant growth rates and yield, but also protect plants from various stresses, making them a valuable addition to any horticulture operation. These products are highly effective against biotic stresses (bacteria, fungi, viruses, insects) and abiotic stresses (heat, drought, acidity, salinity). One way or another, to confer these benefits all silica products must ultimately increase the MSA concentration around the roots or foliage.
It’s important to note that traditional forms of silica (potassium silicate, for example) generally aren’t absorbed via foliar action. While there is evidence of prevention of powdery mildew, applying foliar potassium silicate with this method won’t produce the growth or yield benefits that foliar MSA confers. Potassium silicate must remain at a very high pH to maintain solubility.
This points to another major benefit of stabilized MSA solutions: they don’t contain additional minerals that need to be compensated for in your main fertilizer formulation. For example, using potassium silicate at 0.3 g/gal will add 22ppm of K along with the 20ppm of elemental Si, and this will require compensation. As mentioned, plants benefit greatly from MSA, however it is highly reactive and needs to be stabilized to ensure that its reaching the plant surfaces as monosilicic or disilicic acid. At higher pH levels, MSA disassociates into silicate ions, and at high concentrations, unstabilized MSA polymerizes creating larger molecules. Since only the smaller molecules of mono- and di- silicic acid can be absorbed by plants, this polymerization into oligomeric and polymeric silicic acid needs to be prevented. The commercial availability of MSA products has been made possible with the development of processes that prevent the polymerization of silicic acid, enhancing stability at a variety of concentrations, pH levels, and over longer durations.
Stabilization Methods
One common method of stabilizing MSA solutions include acid stabilizations in combination with molybdenum, zinc, choline, or polyethylene glycol (PEG). These methods allow concentrations of up to 2.5% silicic acids, however these stabilized silica solutions must remain at a very low pH to prevent polymerization in concentrated form. Another method involves using organosilicon precursors, such as tetraethyl ortho-silicate. These products don’t contain water and are very concentrated, allowing up to 40% equivalent concentration of MSA after conversion. As precursors, they don’t actually contain MSA but their components break down into MSA once diluted in water. Unfortunately, they also produce other organic compounds such as ethanol (alcohol) in the solution, which can exert strong negative effects on root growth and plant development.
POLYOL-STABILIZED MSA SOLUTIONS: FRONT ROW Si
Among the various methods of stabilizing silica, polyol-stabilized MSA solutions stand out for their remarkable properties and effectiveness. One such example is Front Row Si, which contains 16% MSA (10% Silicon Dioxide). This product uses sugar alcohols, which form soluble 2/1 (sugar alcohol/silicic acid) silicate complexes with basic silicic acid. Silicate is very selective about the sugar alcohols it reacts with, but certain combinations result in readily soluble complexes at high concentrations.
While potassium silicate solutions require very high pH levels to stay in solution and acid-stabilized MSA products require very low pH to prevent polymerization, the polyol stabilization process used in Front Row Si overcomes this challenge.
Front Row Si has significantly improved mixing properties compared to other silica products on the market; the mono- and disilicic acid components are stabilized to be soluble at all pH levels, making them easier to use in a variety of applications and methods. Additionally, Front Row Si does not contribute any potassium or other minerals that would
The low-molecular weight MSA in monoand di-silicic forms created by the polyol stabilization process in Front Row Si are easily available for plant absorption in contrast to the higher molecular weight Si polymers that are less effective for plant uptake. This superiority in terms of cost, stability, solubility, and availability for plant absorption makes polyol-stabilized MSA solutions like Front Row Si a valuable choice.
MATH INTERLUDE: CALCULATING SOLUTION Si PPM
Much of the research literature reports the effective ppm ranges for elemental Si rather than a silica salt or of MSA. It may be useful to see how to calculate the elemental ppm of Si from MSA in a solution.
1A. WHAT % OF MSA IS Si?
Let’s walk through the steps for deriving the percentage by weight of Si in MSA. MSA’s molecular composition is H4SiO4, or Si(OH)4, meaning it contains silicon, hydrogen, and oxygen.
To find the percentage of Si by weight, you need the molar masses of each of these elements:
• Silicon (Si): 28.085 g/mol
• Hydrogen (H): 1.008 g/mol
• Oxygen (O): 16.00 g/mol
• Calculate the total molar mass of MSA: Take the sum of the molar masses of all elements in the compound multiplied by their respective number of atoms:
• 1 Si atom: 1 × 28.085 g/mol
• 4 H atoms: 4 × 1.008 g/mol
• 4 O atoms: 4 × 16.00 g/mol
• Molar mass of MSA = (1 × 28.085) + (4 × 1.008) + (4 × 16.00) = 28.085 + 4.032 + 64.00 = 96.117 g/mol
• Calculate the percentage of Si by weight: Divide the molar mass of Si by the total molar mass of MSA and multiply by 100% to get the percentage:
• Percentage of Si by weight = (Molar mass of Si / Molar mass of orthosilicic acid) × 100% = (28.085 g/mol / 96.117 g/ mol) × 100% ≈ 29.20%
So, the percentage of Si by weight in MSA is approximately 29.20%.
1B. WHAT % OF SiO2 IS Si?
Many product labels or labs report Si concentrations as SiO2 equivalents.
To determine the percentage of silicon (Si) by weight in silicon dioxide (SiO2), we first need to know the molar masses of silicon and oxygen:
• Molar mass of silicon (Si): 28.0855 g/mol
• Molar mass of oxygen (O): 16.00 g/mol
Silicon dioxide has one silicon atom and two oxygen atoms, so its molar mass can be calculated as:
Molar mass of SiO2 = (1 x 28.0855 g/ mol) + (2 x 16.00 g/mol) = 28.0855 g/ mol + 32.00 g/mol = 60.0855 g/mol
Now we can calculate the percentage of silicon by weight in silicon dioxide:
Percentage of Si = (28.0855 g/mol / 60.0855 g/mol) x 100% ≈ 46.74%
Thus, the percentage of Si by weight in SiO2 is approximately 46.74%
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