Custom Processing Services Blog

How Particle Surface Treatments Can Expand Your Product Possibilities

Justin Klinger, Jan 14, 2021 6:30:00 AM

Particle Surface Treatments

Particle size, morphology, and size distribution are critical factors in a material’s functional performance, or the way the material behaves in its intended use. For example, very finely milled particles can tend to agglomerate, making them tough to handle, disperse, and blend.

And it’s not just physical properties that can complicate particle behavior. Surface chemistry also plays a role in how materials behave on the job. Certain chemical characteristics can make an important constituent difficult to handle, blend, or compound. A material may be hydrophilic, reactive, or conductive, or have some other property that needs to be addressed.

That’s where a toll processor’s particle surface treatment capabilities can be a critical factor in achieving the functional results you need from your materials.

From air jet mill services that alter particle morphology or size, to encapsulation that modifies surface chemistry, particle surface treatments can be a game-changer in your product formulation, overcoming limitations and increasing your R&D options.

Methods for Particle Surface Treatments

Toll processors have a range of equipment options they can access for surface treatments, including blending and milling equipment, air jet mills, fluidized beds, sprayers, and more. A less complex surface treatment, for example, consists of using a fine spray application of oil to prevent dusting in micronized materials.

Jet milling uses physical forces to alter particle surfaces. Particles can be smoothed, or spheronized, in a mill, to achieve characteristics like gloss in a polymer or color tone in a mineral pigment.

Jet mill blending disperses particles in air. In the case of coating a particle surface, it’s critically important to completely encapsulate the particle, essentially replacing the original surface with a new one that has the properties required for the formulation.

In an air jet mill, micronized or nanonized particles can be introduced into the chamber on a jet of air or other gas, coating the larger particles as they circulate within the chamber. A similar procedure can be applied in a fluidized bed, which can allow even finer particles to be surface treated.

Particle Surface Treatments Across Industries

Modifications to particle surfaces make innovation possible in an incredibly broad range of industries, including:

Common to nearly all industries are blendability and handling characteristics like agglomeration and dispersibility. Surface treatments that prevent clumping, improve flowability, or enable easier blending, dispersing, or emulsification can improve the performance of products ranging from agricultural chemicals to beauty products.

Particle surface treatments can achieve specific outcomes with raw materials such as titanium dioxide, a mineral that’s commonly used across industries from pigments and paints to cosmetics, food, and more. 

To improve wettability and get a hydrophilic particle, a surface treatment might involve coating titanium dioxide particles with nanoparticles of silica. As many industries move from using solvents to water-soluble formulations, wettability and dispersion become vital material characteristics.

Surface treatments are commonly used to impart desirable characteristics to paints, pigments, and coatings that can affect both how the product performs in application equipment, as well as how it performs in use, including:

  • Coverage
  • Opacity
  • Lightfastness
  • Brightness
  • Weather Resistance
  • Smudge Resistance
  • Durability
  • Sheen
  • And more

In polymers and pharmaceuticals, surface treatments can be applied to compounded constituents like fillers. In this case, a surface treatment such as a silane coupling agent can help achieve even distribution of fillers, including glass fibers or other reinforcing materials. Silanization is important because fillers play a number of critical functional roles in compounds, such as adding strength and thermal stability, improving moisture resistance or flame retardance, or achieving conductivity or insulating properties.

In more complex applications, multiple surface treatments can be layered on particles in a prescribed order to meet the needs of almost any blending or compounding procedure. Surface treatments can mitigate issues with pH, interaction with reagents, and other formulation considerations.


In fact, different surface treatments can achieve a whole range of different outcomes, starting with the same initial particle. With advancements in particle technology and equipment capabilities, and continuous improvements in the knowledge and experience of material scientists and engineers, your toll processor can help you achieve even more than you might think possible.

You can get started learning more with our Particle Technology Glossary. Just click the link below to get your own copy. You can also reach out any time for answers to your questions about services and capabilities at Custom Processing Services.New call-to-action

Posted in:Toll ProcessingMicronization Services