Both antifoams and defoamers are used for foam control. Given their similarities in function, they often have similar chemistries. The main difference between them is the timing of application. In order to prevent it, antifoams are designed to be applied before the formation of foam, while defoamers are designed to be applied after foam formation in order to destroy it. Below, we provide a closer look at antifoam and defoamer chemistry.
The Chemistry of Antifoams
Antifoams are typically inert chemicals. They consist of a liquid component (e.g., nonionic surfactant, mineral oil, and/or silicone) and a hydrophobic solid (e.g., wax, fatty acid/alcohol, and/or hydrophobic silica). They must be sufficiently incompatible such that they are insoluble with the medium. Otherwise, they will not mitigate foam as effectively. However, they must also be sufficiently compatible such that they do not cause deposition problems.
There are many types of antifoams available, and they are often lumped into two broad categories:
- Silicone Antifoams. Silicone antifoams are normally composed of hydrophobized silica that is finely dispersed within a silicone fluid. The resulting compound is then stabilized into a water-based or oil-based emulsion. These antifoams are highly effective due to their general chemical inertness, potency even in low concentrations, and ability to spread over a foam film. If needed, they can be combined with other hydrophobic solids and liquids to improve their defoaming properties.
- Non-Silicone Antifoams. Non-silicone antifoams generally contain surfactants, which enhance their dispersal capabilities and effectiveness in foaming water. They can be water-based, oil-based, or surfactant-based. These antifoams can be used for a wide range of industries. Compared to silicone antifoams, they are sometimes more readily biodegradable and less prone to causing certain problems such as discoloration, spotting, and negative membrane effects.
The Chemistry of Defoamers
Defoamers share many of the same chemical characteristics as antifoams. For example, they are typically made of a liquid component and a hydrophobic solid, although some are strictly liquid. Additionally, they are formulated for a balance between solubility and insolubility with the medium that ensures effective foam control performance.
These foam control products come in many variations, of which one type is oil-based defoamers. Oil-based defoamers are typically of the “non-silicone” variety, but their composition can be highly variable and include chemical species ranging from hydrophobic solids to esters to silicones. They offer high efficacy at lower dosages, making them a preferred choice for foam knockdown in many applications.
How Do I Select the Most Effective Antifoam/Defoamer for My Application?
The type of foam generated and the timing of its production vary from process to process. That’s why it is important to choose a foam control solution with a chemistry that is appropriate for your specific application. It is advisable to test a primary and a secondary foam control product. If you want more information on how to select an effective foam control solution or if you would like samples to evaluate, Applied Material Solutions (AMS) is here to help. We have extensive experience producing a broad selection of foam control compounds for use in a wide range of industries and applications. One of the eBooks we’ve put together, “Must-Ask Questions When Choosing a Foam Control Agent,” has many of the answers to any questions you may have about the selection process. Alternatively, you can contact us today.
What Are Silicone Emulsions?
Silicone emulsions are non-toxic and heat-stable compounds that are produced by dispersing silicone oil in a liquid, typically water. This process is accomplished with the introduction of a surfactant. The resulting products exhibit a number of physical characteristics that make them highly beneficial for certain applications. For example, they can be antistatic, non-stick, and/or water-repellant. The properties of a silicone emulsion depend on its formulation; it can come in various pH levels, active levels, and more, all of which influence how it will perform within an application.
Advantages of Silicone Emulsions
There are many advantages to using silicone emulsions over other compound solutions. Below, we highlight some of the key benefits.
- They are easy to use and clean. These compounds are available in numerous viscosities and concentrations, enabling them to be used in a variety of applications. Additionally, if needed, they can be diluted with water or cleaned from surfaces with soap and water.
- They are environmentally friendly. These compounds have less of a negative impact on the environment than solvent-based systems, and tend to be benign and unreactive. Additionally, if it can be recovered, the silicone material can be recycled.
- They are cost-effective. These compounds can protect objects from abrasion, friction, molding and water, enabling them to extend the life of devices and systems. For this reason, they are often used by manufacturing companies to lower repair or replacement costs.
- They are food-safe. These compounds normally have water as their primary volatile compound, which makes them ideal for use in or on products intended for contact with food and beverages. They are formulated to minimize the risk of imparting unwanted flavors or impacting quality.
- They are able to improve equipment efficiency. These compounds can be used on inline equipment, often eliminating the need for offline coating. Additionally, they can improve the efficiency of photovoltaic devices (e.g., solar panels).
Applications of Silicone Emulsions
Due to their many beneficial properties, silicone emulsions find use in a variety of industrial and commercial applications. For example:
- In plastic and rubber materials, they are used as release agents and lubricants.
- In food trays and serving dishes, they are used as release agents and antistats.
- In car polishes and household cleaners, they are used to improve gloss, and impart protective properties and spreadability.
- In textile finishing operations, they are used to enhance the feed, water repellency, and anti-wrinkling properties of products.
- In clay, perlite, vermiculite, and other building materials, they are used to increase water repellency and protect against dampness.
- In printing and papermaking operations, they are used as lubricants and antistatic agents.
- In cosmetics and body care products, they are used to improve untangling properties.
Learn More About Silicone Emulsions From AMS
Want additional information on silicone emulsions? Ask the experts at Applied Material Solutions! We’ve manufactured chemical compound solutions for various processing challenges, including silicone emulsion defoamers and antifoams, for over 45 years. Contact us today to learn more.
Water treatment requires both defoamers and antifoams to prevent foaming and air entrapment that commonly occurs in these applications. Without these additives, the treatment process may slow down significantly or cease entirely if water is unable to travel through filtration systems. Subsequently, without the right products to mitigate foam buildup, facilities could suffer from a lack of productivity and costly downtime.
To avoid potential issues and maintain efficient water treatment processes, there are several types of antifoams and defoamers available. This blog post will review the reasons for using these products and some of the factors to consider when selecting them for a water treatment application.
Water Treatment Antifoam and Defoamer Applications
Apart from excessive foam, waterborne and airborne foam can culminate in public relations issues. Foam that’s not properly contained may also present certain hazards, such as visual obstruction, slippery flooring, or the unmitigated and unwanted transport of chemicals or microorganisms.
To help prevent these problems, defoamers and antifoams are often incorporated into processes to control foam. While antifoam products prevent the formation of foam, defoamers are used to control existing foam as it develops. Some application points where defoamers are applied include:
- Water Equalization Tanks
- Aeration Basins
- Sludge Digesters
- Secondary Treatment Systems
- Final Effluent Processing Systems
- Membrane Systems
- Landfill Leachate Systems
- Boiler Water Treatment Systems
- Manure Pits
- Cooling Towers
Considerations for Choosing a Water Treatment Defoamer
When selecting the appropriate defoamer or antifoam for a specific water treatment process, it’s necessary to determine the ideal chemistry for the application. It’s also important to assess the antifoam’s compatibility with any filtration membranes and microorganisms.
Depending on the needs of a given application, there are multiple types of water treatment antifoams and defoamers available. Some of the most popular solutions include:
- Water-based silicone antifoams
- Water-based silicone-free defoamers
- Oil-based non-silicone defoamers
- Non-aqueous synthetic defoamers
- Powdered or solid defoamers
Regardless of an application’s specific foaming challenge, there’s likely a viable chemical solution available.
Water Treatment Defoamers from Applied Material Solutions
Here at Applied Material Solutions, we provide our customers with a range of defoamers and antifoams that are compatible and effective within many types of water treatment applications. Through the use of our products, users avoid excess foam buildup and the myriad issues that come with it.
Our team specializes in the development and manufacture of numerous types of defoamers and antifoams for a variety of water treatment applications. Our experts can assist you with identifying a defoamer or antifoam that meets your specific requirements. When our customers turn to Applied Material Solutions, they benefit from working with a partner that gives them optimal and economical results.
Get the Defoamer or Antifoam Solution You Need
If you’re in need of defoamer or antifoam products for your water treatment processes, Applied Material Solutions is here to help you select the right additive that will enable you to retain full control over foam levels. For help with locating the right defoamer or antifoam for your water treatment application, please contact us today. Our professionals are ready to assist with product selection and can match your application with the appropriate chemistry.