Hydrophilic Coatings: The Ultimate Guide – Types, Benefits, Uses

Hydrophilic coatings are thin surface treatments used for reducing friction while increasing lubricity. They have an ability to attract and retain water. These “slippery when wet” coatings create smooth and slippery surfaces, which make them ideal for applications like medical device coatings. A hydrophilic coating layer stays thin, bonds to many different materials, and can be tuned for lubricity, biocompatibility, or durability as per the application.

Medical grade formulations are used as lubricious coatings for medical devices, such as guidewires and catheters. Industrial serve many functions. For example, they can cut drag on a boat hull, reduce fouling inside pipelines and valves, and keep lenses, windshields, and goggles clear of fog. They have a wide range of uses across diverse industries, including medical, automotive, aerospace, marine, optical, and consumer goods.

In this article, we use Hydromer®, Inc.’s 40+ years of hydrophilic coatings expertise to explore this technology in depth. We will look at what hydrophilic coatings are, the materials behind them, the substrates and processes involved, and where they are used across industries. It also covers the benefits they bring, what to look for when choosing one, and how suppliers like Hydromer fit into this space.

Brief History of Hydrophilic Coatings

Hydrophilic coatings have drastically evolved over the last decade, but the need for them is much older. For a long time, many industries needed materials that could reduce friction, shed fog, or manage moisture. However, early efforts relied mainly on simple substances and oils to change how a surface interacted with water. Such materials were hard to control and did not stay in place. 

The first real step came in 1956. DuPont built a two-layer hydrophilic coating system that consisted of a bonding coat and a binding coat. Soon, coatings based on synthetic polymers such as polyvinylpyrrolidone (PVP) and polyurethane were formulated. Such coatings stayed dry and stable until they touched water, at which point the surface turned smooth and slippery.

Early hydrophilic coatings were not perfect. They were costly, needing expensive plasma processing equipment. They were sometimes difficult to apply or easily scratched off the device. Over time, the bonding process and application methods improved, and faster manufacturing brought the cost down. Hydromer®, founded in 1980 by Manfred F. Dyck, grew alongside this progress and helped improve the technology as well as move it from just the medical sector into industrial and marine uses.

So what exactly are hydrophilic coatings? We discuss this in detail below. 

What Are Hydrophilic Coatings?

A hydrophilic coating is a thin surface layer that has a strong attraction to water, applied to a surface to reduce friction while increasing lubricity.

The term “hydrophilic” means “water-loving.” In turn, a hydrophilic coating is a thin surface layer (coating) that has a strong attraction to water. The coating is applied to a surface in order to make the surface hydrophilic. When the coating comes in contact with water or liquids, it absorbs the water molecules. Because of its wettability it spreads the liquid into a thin film across the surface instead of making the water bead up. This is one main difference when comparing hydrophilic vs hydrophobic coatings. 

Such water-binding action is what gives hydrophilic coatings their useful surface behavior. That the surface stays dry and easy to handle until it is wetted. Once wetted, it forms a low-friction, smooth layer.

In most cases, the coating is only a few microns thick and sits on top of a substrate without changing the part underneath. It can be applied to nearly any material, including metals, plastics, glass, and many other substrates. Primers can be used to enhance adhesion as well with some substrates. 

What Are the Key Properties of Hydrophilic Coatings?

Below are the properties that make a hydrophilic coating useful across industries:

• High Wettability: The coating has a low water contact angle, which means water spreads across the surface as a thin film rather than forming droplets. This even spreading behavior is the basis for many of its other benefits.
• Excellent Lubricity: Once wet, the surface of these lubricious coatings becomes smooth and slippery, which lowers the coefficient of friction. This helps parts slide, insert, or move with less resistance and less wear.
• Anti-Fog and Condensation Control: Because water spreads into a clear film instead of tiny fog droplets, the surface stays transparent. This property is beneficial when the coatings are used on lenses, mirrors, visors, and other optical parts.
• Anti-Fouling and Deposit Resistance: The hydration layer makes it harder for proteins, dirt, and other materials to stick to the surface. As such, coated parts tend to stay cleaner and need less maintenance. The coatings are widely used as antithrombogenic coatings for blood contact devices. 
• Thin and Substrate-Friendly: The coating stays very thin and can bond to many materials without changing their shape or core properties. This allows it to coat existing parts with little design change.
• Customization: The hydrophilic formulations can be adjusted for lubricity, durability, or biocompatibility as per the application. Formulations can also be created to add additional functionalities, such as antimicrobial properties in medical coatings. This flexibility is one reason the same class of coating fits so many different fields.

The Chemistry of Hydrophilic Coatings

Hydrophilic coatings polymers carry polar groups such as hydroxyl, amide, carboxyl, and ether groups. These have a natural attraction to water. When the surface is dry the coating feels normal to handle. Once water or moisture reaches the surface, the groups begin to bond with the water molecules and pull them in. 

As the coating takes up water, it activates. Specifically, it swells slightly and forms a thin, gel-like hydration layer on the coated surface. This layer holds a large amount of bound water and provides a high level of lubricity. The two surfaces are now separated by a gel-like layer, and the coefficient of friction of the surface drops sharply. This allows the coated surface to glide smoothly along other surfaces with much less friction. 

Note that the effect is reversible. When the surface dries, it returns to its stable state. Then it turns slippery again the next time it is wetted. 

For the coating to be durable, it has to stay bonded to the base material. This is usually done through a tie or primer layer, or by cross-linking the coating so it holds together and resists wet abrasion.

If you are interested in learning more about hydrophilic coating chemistry, be sure to read our article: Hydrophilic Coating Polymers and Chemistries: Complete Guide.

Different Types of Hydrophilic Coatings

There are many variations of Hydrophilic coatings. They are classified based on their operational characteristics. They all share the same water-loving behavior, but each type is formulated and tuned for a different functionality depending on where it will be used.

Below are the main types of hydrophilic coatings:

• Lubricious Hydrophilic Medical Coatings are the most common use. They are designed to reduce friction once the surface is wet. These have many uses, but are most commonly used on medical guidewires, catheters, seals, and other parts that need to slide or insert smoothly. They can be customized to add many other medical functions, such as providing antimicrobial, drug-eluting, antithrombogenic, and other properties.
• Anti-Fog Coatings spread condensation into a thin, clear film instead of tiny fog droplets. They keep lenses, visors, mirrors, and clear packaging see-through in humid or changing conditions.
• Anti-Fouling or Antimicrobial Coatings use the hydration layer to stop proteins, dirt, and organisms from gripping the surface. They help keep devices, membranes, and equipment cleaner and lower the risk of contamination.
• Condensation Control Coatings manage how moisture and frost form on a surface. They are used on optics, refrigeration parts, and glass where clear visibility and moisture control matter.
• Drag-Reducing Coatings create a smooth, water-bound surface that lowers resistance as an object moves through water. Boat hulls and fluid-handling parts use them to improve flow and efficiency.

Note that advanced hydrophilic medical device coatings can be formulated to provide more than one of these functions into a single formulation. The coatings are highly customizable. 

Designing Hydrophilic Coatings

When it comes to hydrophilic coatings, there are three things to consider: choosing the right materials, building and curing the coating system, and applying coatings to the surface. Each of them affects the final result, such as how slippery, durable, and well-bonded the coating turns out.

Materials Used to Formulate Hydrophilic Coatings

A hydrophilic coating is formulated from a water-loving polymer along with a set of supporting materials that help with adhesion, durability, etc. Both natural and synthetic materials are used, and the exact mix depends on the surface and the function the coating is intended to perform.

Below are the main materials.

• Hydrophilic Base Polymers: This is the water-loving component that forms the slippery hydration layer. Common choices are PVP, PEG, PEO, PVA, and polyacrylic acid, along with natural polymers such as polysaccharides.
• Binder and Backbone Polymers: Materials such as polyurethane (PU) give the coating its structure, flexibility, and grip on the surface. They hold the hydrophilic polymer in place so it does not simply wash away.
• Cross-linkers: These bond the coating together and to the substrate, which improves durability and resistance to wet abrasion. Isocyanates are often used for this purpose.
• Primers and Tie Layers: A base coat helps the hydrophilic layer stick to surfaces that are otherwise hard to bond. This step is important for metals and low-energy plastics.
• Functional Additives: Extra ingredients such as antimicrobial agents or photoinitiators add properties or support a specific curing method.

Types of Hydrophilic Coating Systems: Single-Layer vs Multi-Layer Coatings

Once the materials are chosen for the formulation, the coating is built as a system and cured so it stays fixed to the surface. The method depends on the coating chemistry and the substrate involved.

• Single-Layer Systems: The coating is applied in one pass, which keeps the process simple and lower in cost. It suits surfaces that bond easily and do not need heavy-duty durability.
• Multi-Layer Systems: A primer or tie coat is applied first, followed by the hydrophilic top coat. This gives stronger adhesion and better durability on parts that are hard to bond with the coatings.

Types of Curing Methods: UV vs Thermal Cure

Hydrophilic coatings can be cured in multiple ways. As a result, they are formulated differently based on the curing method selected. 

• Thermal Curing: The part is coated and then heated so the coating cross-links and bonds firmly to the surface. This is a common curing method for many formulations, although it takes longer than UV curing versions. The substrate materials also need to have a high enough heat resistance to withstand the temperatures. 
• UV Curing: UV-cure hydrophilic coatings are cured quickly under UV light with the help of photoinitiators. It is fast and well suited to high-volume production lines.

Surface preparation is another important step during hydrophilic coating manufacturing. It includes treatments such as plasma or chemical activation to prepare the surface before coating. This helps the coating adhere better and last longer.

Application Methods For Hydrophilic Coating

These coatings are applied as a liquid in order to ensure controlled deposition. Application drastically affects the thickness and uniformity of the final layer.

Hydrophilic coatings can be applied via dip, spin, spray, and flow coating application methods. Hydromer, Inc. also applies their coatings via a proprietary meniscus method suitable for very long, thin tubing applications. 

• Dip Coating: The part is lowered into the coating and withdrawn at a controlled speed. This gives an even layer and is well suited to wires, tubes, and similar shapes.
• Spin Coating: The part is spun so the coating spreads into a thin, uniform film. It works best for flat or small components.
• Spray Coating: The coating is sprayed onto the surface, which makes it flexible for larger or complex shapes. Spray settings can be adjusted to control thickness.
• Flow Coating: The coating is flowed across the surface, and the excess is allowed to drain off. This produces even films on larger parts.
• Proprietary Meniscus Coating: This is Hydromer’s proprietary method, which places the coating precisely on selected areas of a part. It is best suited where only certain sections need to be coated more precisely.

Hydrophilic Coatings Are Used in Many Applications

Hydrophilic coatings are used across many industries. They are helpful wherever a water-attracting, low coefficient of friction surface adds value. These coatings help solve different problems in different applications.

Below are some of the most common uses of hydrophilic coatings, starting with the most common – medical devices. 

1. Medical Devices

Medical devices were the first major use of hydrophilic coatings, and they remain the largest one today. These devices need to pass through blood vessels, ducts, and other narrow pathways with minimal resistance. Hydrophilic coatings’ slippery-when-wet surface lets devices move through the most tedious pathways with less resistance and less tissue trauma.

These coatings also need to be biocompatible and antithrombogenic for blood contact devices. Hydrophilic coatings excel in both these areas.  

Earlier, the medical field lubricated devices with simple substances such as glycerin, silicone oils, and even olive oil. These worked to a point, but the lubrication was hard to control and often came off the device after insertion. Early attempts with fluoropolymers such as PTFE ran into similar limits.

Hydromer® has been supplying high-performance, reliable hydrophilic medical device coatings for 40+ years. Its formulations can coat both inner and outer surfaces, including micro- and multiple lumens and complex geometries.

Common Medical Devices Coated Using Hydrophilic Formulations

• Vascular and Cardiovascular Devices: hydrophilic coatings allow guidewires, catheters, balloons, stents, and pacemaker leads to move smoothly through blood vessels.
• Urology Devices: Urinary catheters and related devices are coated so they insert more comfortably.
• Neurovascular Devices: Fine guidewires and microcatheters used in the brain and small vessels rely on very low friction surfaces to navigate tight, winding paths.
• Dialysis and Vascular Access: Shunts, needles, and access devices use these coatings to ease insertion and reduce trauma at the access site.
• Ophthalmic Devices: Intraocular lens inserters and similar tools use hydrophilic coatings for smooth, controlled delivery during eye procedures.

Benefits of Hydrophilic Coatings for Medical Devices

• Smoother Insertion and Navigation: The coating turns slippery when wet, which lowers friction as the device passes through the body.
• Reduced Tissue Trauma: Lower friction means less rubbing against vessel walls and tissue during insertion and removal. 
• Thromboresistance: Some hydrophilic coatings are non-leaching and are generally considered to lower the tendency for blood platelets to stick to the device. 
• Better Biocompatibility: Hydrophilic surfaces are generally considered biocompatible and can reduce protein adhesion on the device.
• Support for Antimicrobial Function: The coating can carry antimicrobial agents to help lower the risk of device-related infection.
• More Efficient, More Comfortable Procedures: Because devices move more easily, procedures can be smoother and quicker.

2. Automotive

Hydrophilic coatings are used on vehicles mainly to manage water and keep surfaces clear. Moisture spreads into a thin, even film instead of forming droplets or fog on surfaces. In turn, drivers get better visibility, and sensors are kept cleaner.

Common Automotive Parts Coated with Hydrophilic Formulations

• Windshields or Windows: A hydrophilic layer spreads rain and condensation into a thin sheet, which improves clarity and view.
• Mirrors and Cameras: Side mirrors and reverse view cameras stay clearer when water does not bead on them.
• Headlights and Sensor Covers: Fogging on the inside of lamp and sensor housings can dim output or block a sensor. A hydrophilic surface keeps these covers clear so they work as intended.
• ADAS Sensors and Lenses: Driver-assist systems rely on cameras and sensors that need a clear, unobstructed view. Hydrophilic coatings help keep these surfaces free of fog and water spots.
• Interior Glass and Displays: Coatings reduce fogging on interior glass and screens during temperature swings.

Benefits of Hydrophilic Coatings for Automotive Applications

• Better Visibility: Water and fog spread into a clear film instead of droplets. This gives the driver a clearer view in rain and humidity.
• Improved Safety: Clearer glass, mirrors, and sensors support safer driving and better driver-assist performance. This matters most in poor weather.
• Reliable Sensor and Camera Function: A fog-free, water-free surface keeps cameras and sensors reading accurately.

3. Life Sciences & Diagnostics

Hydrophilic coatings play a quiet but important role in the lab. Many diagnostic and research tools depend on moving very small amounts of liquid in a precise and predictable way, and a water-loving surface helps the fluid wet, spread, and flow as intended.

Common Diagnostic and Research Tools Coated with Hydrophilic Formulations

• Microfluidic and Lab-on-Chip Devices: Tiny channels rely on capillary action to pull liquid through without pumps. A hydrophilic surface keeps the flow smooth and steady, which supports accurate results.
• Diagnostic Assays and Test Strips: Lateral flow tests and similar assays need the sample to travel evenly across the material. Hydrophilic surfaces help the fluid wick in a controlled way for reliable readings.
• Biosensors and Membranes: Sensor surfaces and filtration membranes use hydrophilic coatings to keep the surface wet and reduce fouling. This helps maintain a stable and repeatable response.

Benefits of Hydrophilic Coatings for Life Sciences & Diagnostics

• Predictable Fluid Flow: The coating helps liquids wet and move in a controlled way for consistent capillary flow in small channels and test strips.
• Improved Accuracy: Even wetting and less liquid cling reduce sample loss and dosing error. As such, results become more repeatable across tests.
• Consistent, Repeatable Performance: Stable surface behavior means less variation from one run to the next. This is important for accurate diagnostics and research data.

4. Industrial Manufacturing

In industrial settings, hydrophilic coatings are used to control friction, moisture, and buildup on working parts. A water-attracting surface can make components move more smoothly, help liquids spread and drain, and keep deposits from sticking to equipment. This supports cleaner operation and less downtime across a range of machinery and processes.

Common Industrial Parts and Components Coated with Hydrophilic Formulations

• Seals, Bearings, and Moving Parts: A slippery-when-wet surface lowers friction and wear between contacting parts.
• Fluid Handling and Pipes: Coated inner surfaces help liquids flow evenly and reduce buildup along the walls.
• Filtration and Membranes: Hydrophilic membranes wet quickly and resist clogging from particles and deposits.
• Heat Exchangers: Even water spreading and controlled condensation improve heat transfer on exchanger surfaces.

Benefits of Hydrophilic Coatings for Industrial Manufacturing

• Lower Friction and Wear: The wet surface reduces the coefficient of friction between moving parts. This helps components run smoothly and extends their working life.
• Reduced Fouling and Buildup: The hydration layer makes it harder for deposits and particles to stick. As such, equipment stays cleaner and needs less frequent servicing.
• Better Fluid and Heat Management: Even wetting supports steady flow, drainage, and heat transfer. This helps processes run more consistently.

5. Aerospace

Aerospace applications use hydrophilic coatings to manage water, fog, and ice on surfaces where clear visibility and clean airflow are important.

At altitude, aircraft face large temperature swings and constant moisture, which can fog windows and let ice form on exposed parts.

Common Applications of Hydrophilic Coatings in the Aerospace Industry

• Cockpit and Cabin Windows: Hydrophilic coatings spread condensation into a clear film so windows stay see-through during rapid temperature changes.
• Sensor and Instrument Surfaces: External sensors and optical instruments need a clean, clear surface to read accurately. Coatings help keep fog and water from disturbing their readings.
• Anti-Icing and De-Icing Support: Managing how water sits and spreads on a surface can support ice control on exposed parts.
• Cabin Interior Surfaces: Interior panels and windows can fog as cabin conditions shift. Hydrophilic surfaces help control condensation and keep these areas clear.
• Fluid and Environmental Systems: Coated surfaces in fluid and air management systems help liquids spread and drain evenly.

Benefits of Hydrophilic Coatings for Aerospace

• Clear Visibility at Altitude: Condensation spreads into a thin film instead of fog.
• Support for Ice Management: Controlling how water spreads can help reduce ice formation on exposed surfaces.
• Thin and Lightweight: The coating adds almost no weight and does not change the shape of the part.
• Stable in Harsh Conditions: The coating is made to hold up through moisture, temperature swings, and repeated use.

6. Optical Components

Optical parts are one of the most natural fits for hydrophilic coatings. That is because their main job depends greatly on staying clear. When moisture forms tiny droplets on a lens or mirror, it scatters light and creates fog that blurs the view. A hydrophilic coating spreads that same moisture into a thin, even film that light passes through cleanly, so the surface stays transparent.

Common Applications of Hydrophilic Coatings in the Optical Industry

• Lenses and Eyewear
• Camera and Imaging Optics
• Mirrors
• Optical Sensors and Windows
• Microscopy and Lab Optics

Benefits of Hydrophilic Coatings for Optical Components

• Fog-Free Clarity: Moisture spreads into a clear film instead of fog droplets. This keeps the optical surface transparent and easy to see through.
• Sharper Image Quality: With no droplets to scatter light, images stay crisp and undistorted. This matters for cameras, sensors, and precision optics.
• Consistent Optical Performance: The surface stays clear across temperature and humidity changes. As such, the optics perform reliably in varied conditions.
• Cleaner Surfaces: The hydration layer helps reduce spotting and buildup on the lens. This keeps the surface cleaner and lowers the need for wiping.
• Thin and Non-Distorting: Hydrophilic coatings are extremely thin and do not affect the optical path. This preserves the original clarity and focus.

7. Consumer Electronics

Hydrophilic coatings help consumer electronics deal with moisture, fog, and smudging on the surfaces people look at and touch. For example, screens, lenses, and sensors need to stay clear and responsive even in humid conditions or during temperature changes.

Common Electronics Coated with Hydrophilic Formulations

• Smartphone and camera lenses use hydrophilic coatings to resist fog and water spots for sharp photos and video in humid or wet conditions.
• Displays and Touchscreens
• Smartwatches and fitness devices face sweat and moisture during daily use. Coatings help keep their sensors and surfaces working reliably.
• Headset lenses can fog quickly with body heat and movement. A hydrophilic layer keeps the view clear for a comfortable, uninterrupted experience.

Benefits of Hydrophilic Coatings for Consumer Electronics

• Fog and Water Resistance
• Clearer Displays and Images
• Reliable Sensor and Touch Response
• Cleaner, Smudge-Resistant Surfaces
• Thin and Unobtrusive

8. Marine

A boat moving through water creates turbulence and drag along its hull, which slows it down and burns more fuel. A hydrophilic coating binds a thin layer of water to the hull and lowers the surface interfacial energy, which reduces turbulence and lets the vessel move through the water more easily. Hydromer’s Sea-Slide is one such coating, a water-based polymer that absorbs water without dissolving and cures to a durable, drag-reducing surface.

Common Marine Parts That Can Be Coated with Hydrophilic Formulations

• Boat and Ship Hulls
• Sailing Vessels
• Propellers and Underwater Fittings
• Fouling-Prone Surfaces
• Performance and Racing Craft

Benefits of Hydrophilic Coatings for Marine

• Lower drag helps sail-powered boats move faster in lighter winds. This gives a real advantage where every bit of speed counts.
• The coating binds water to the hull and lowers interfacial energy. This cuts turbulence and lets the vessel move through the water more easily.
• Less drag means the same speed takes less power. As such, powered vessels can save fuel over time.
• The water-bound layer makes it harder for growth and deposits to stick. This supports easier maintenance and steadier performance.
• The coating cures to a tough, long-lasting surface built for constant water contact. This keeps its benefits in place through regular use.

9. Energy

The energy sector uses hydrophilic coatings to manage water and heat and to keep surfaces clean in demanding conditions. Many energy systems depend on efficient heat transfer, steady fluid flow, and clear surfaces, and all three are affected by how water behaves on a surface.

Applications of Hydrophilic Coatings in the Energy Sector

• Solar Panels: A hydrophilic coating helps rainwater sheet across the panel and rinse away dust and dirt.
• Heat Exchangers and Condensers: Even water spreading and controlled condensation improve heat transfer on these surfaces.
• Fuel Cells: Water management is critical inside a fuel cell, where flooding or drying can hurt performance. Hydrophilic surfaces help move and distribute water in a controlled way.
• Cooling Systems: Coated surfaces support even wetting and drainage in cooling equipment.
• Wind and Turbine Components: Surfaces exposed to moisture stay cleaner when deposits cannot grip easily.

Benefits of Hydrophilic Coatings for Energy

• Better Heat Transfer: Even water spreading and controlled condensation improve thermal exchange. This helps energy systems run more efficiently.
• Self-Cleaning Surfaces: Water sheets across the surface and rinses away dust and dirt. As such, panels and components stay cleaner with less manual cleaning.
• Improved Water Management: The coating helps distribute and drain water in a controlled way. This is important in systems like fuel cells where water balance matters.
• Lower Maintenance: Reduced buildup and self-cleaning behaviour mean less frequent servicing. This helps keep energy systems running with less downtime.

10. Food Processing

In this field, both hygiene and clear visibility are of utmost importance. Hydromer® makes anti-fog coatings and additives tailored for the food packaging industry, formulated with non-toxic, food-safe materials.

Common Applications of Hydrophilic Coatings in the Food Industry

• Food Packaging Films: Anti-fog coatings keep packaging clear by spreading condensation into a thin film. This keeps the product visible and appealing on the shelf.
• Food Storage Containers: Clear containers stay see-through when moisture does not form fog droplets. This helps with product visibility and freshness checks.
• Processing Equipment Surfaces: Coated surfaces resist residue and buildup during production. This supports easier cleaning and better hygiene.
• Conveyor and Handling Parts: A smoother, cleaner surface helps the product move without sticking.
• Viewing Windows and Panels: Inspection windows on equipment stay clear when condensation spreads evenly. This keeps a clear view of the process inside.

How Do You Choose the Right Hydrophilic Coating?

Picking the right hydrophilic coating is less about finding the best coating overall and more about matching the coating to the job. For instance, a formulation that works well on a guidewire may not suit a solar panel or a packaging film. 

Below are the key things to consider to ensure that the coating performs well and lasts longer.

• Substrate Compatibility: The coating has to bond well to the base material, whether it is metal, plastic, glass, or rubber.
• Intended Function: Different jobs call for different properties, such as lubricity, anti-fog clarity, drag reduction, or fouling resistance. Being clear about the main function of the coating helps narrow down the right type of coating.
• Durability Requirements: Some parts are single-use, while others must hold up through repeated contact and cleaning/sterilization.
• Operating Environment: Temperature, moisture, chemicals, and mechanical stress all affect how a coating performs.
• Regulatory Compliance: Medical, food-contact, and other regulated uses must meet specific standards for safety and biocompatibility. As such, the coating and its materials should match the rules of the target industry from the outset.
• Application and Curing Fit: The coating should suit the shape of the part and the production process, including how it is applied and cured. 
• Supplier Support: Working with an experienced coating partner helps match the formulation, application method, and testing to your specific part. It lowers risk and shortens the path from design to production.

What is the difference between hydrophilic and hydrophobic coatings?

A common question that comes up with hydrophilic coatings is how they compare to hydrophobic ones. They can both be used for lubrication, but they differ in how they lubricate and where each is most suitable. 

Both deal with water, but in opposite ways. They both give us a way to control how a surface reacts to water or liquid. 

Hydrophilic coatings attract water and spread it into a thin film. They provide excellent lubricity and low friction in wet conditions. 

On the other hand, hydrophobic ones repel water and make it bead up. They provide good dry lubrication.

Both of them serve a different purpose, so the right choice depends on what the surface needs to do. Many times, both hydrophilic and hydrophobic materials are used on the same devices, just in different locations and serving different functions.  

	Hydrophilic Coatings	Hydrophobic Coatings
Behaviour	Attracts water and spreads it into a thin film	Repels water so it beads and rolls off
Contact Angle	Low, below 90 degrees	High, above 90 degrees
Surface when Wet	Forms a smooth, slippery hydration layer	Stays dry, with water sitting as droplets
Lubricity	Becomes slippery only when wet	Often low-friction when dry, such as PTFE
Fog Control	Prevents fog by spreading moisture into a clear film	Sheds fog by causing droplets to roll off
Common Materials	PVP, PEG, PVA, polysaccharides	PTFE, silicones, fluoropolymers, waxes
Common Applications	Guidewires, catheters, anti-fog lenses, membranes, marine hulls	Waterproofing, self-cleaning surfaces, corrosion protection

Hydromer®, Inc.: Leading Hydrophilic Coating Manufacturer and Supplier

Hydromer®, Inc has been developing hydrophilic coatings since 1980. We have more than 45+ years of experience and are one of the leading names in this field.

We offer a broad portfolio of Hydrophilic coatings, along with a wide range of contract coating services, a line of automated coating equipment, and R&D and regulatory consulting services. Our facilities are FDA-registered and ISO 13485- and ISO 9001-certified.

What makes us stand out is the mix of 40+ years of coating experience, in-house materials, formulation and application know-how, and industry-leading support that covers everything from design to delivery for both startups and OEMs. 

Contact the Hydromer® coating experts to learn more about our hydrophilic coatings and request samples.