Precipitated silica serves a dual function as both a suspending agent and a carrier in pesticide formulations. Its mechanism of action is based on its high specific surface area, porous structure, and strong adsorption properties, significantly improving the physical stability and application efficiency of the formulations.

Mechanism of Action as a Suspending Agent
Inhibiting Sedimentation and Stabilizing the System: Precipitated silica particles increase the viscosity of the pesticide suspension, forming a three-dimensional network structure that effectively prevents the sedimentation of pesticide active ingredient particles under gravity. This conforms to Stokes' law, which states that "sedimentation velocity is inversely proportional to the viscosity of the system," reducing drug efficacy loss due to sedimentation by more than 30%.
Improving Flowability and Anti-clogging Properties: In liquid suspensions, its fine particles prevent the aggregation of active ingredients, maintaining a uniform dispersion of the liquid. In the process of mixing wettable powders with water, it can quickly deaggregate and prevent clumping, significantly reducing the risk of sprayer nozzle clogging and improving application efficiency.
Adjustable Particle Size for Different Scenarios: By controlling the particle size distribution of precipitated silica, droplet characteristics can be optimized—larger particle sizes are used for fruit tree spraying to reduce drift, while smaller particle sizes are used for greenhouse crops to enhance coverage on the underside of leaves, enabling precise application.
Functional Characteristics as a Carrier
Efficient Loading of Active Ingredients: As a highly adsorbent carrier, the porous structure of precipitated silica acts like a "miniature warehouse," adsorbing pesticide active ingredient molecules, achieving uniform loading and stable storage of active ingredients, especially suitable for wettable powders (WP) and water-dispersible granules (WG).
Enhancing Efficacy and Sustained Release Performance: Through the adsorption-sustained release mechanism, precipitated silica extends the retention time of pesticides on the target surface, slows down the photolysis and volatilization of active ingredients, improves utilization, reduces the amount of pesticide applied per unit area, and contributes to green agriculture.
Strong Environmental Tolerance: Its chemical inertness and hydrophilicity allow it to maintain structural stability even under rainwater erosion and high temperature and humidity environments, ensuring long-lasting efficacy. Technological Advantages and Application Value
Function Dimension | Technological Advantages | Practical Benefits
Physical Stability | Increased viscosity and anti-settling, anti-flocculation | Extended shelf life, reduced stratification
Application Efficiency | Rapid dispersion, anti-clogging of nozzles | Saves operating time, improves uniformity
Environmental Friendliness | Sustained release and reduced dosage, lower residue | Reduces pesticide use by more than 30%, reduces water pollution
Adaptability | Controllable particle size, strong hydrophilicity | Adaptable to different crop leaf characteristics (hydrophobic/hydrophilic)
Actual Application Feedback and Technological Extensions
When formulating wettable powders, pesticide manufacturers often use precipitated silica in combination with dispersants and wetting agents to form a "adsorption-dispersion-stabilization" integrated system. The optimal addition ratio is usually 1%-5%, depending on the properties of the active ingredient.
Although no direct farmer feedback notes were found in the current search, studies have confirmed that formulations containing precipitated silica show higher leaf retention and better pest and disease control effects in field trials.