There are two main types of membranes: hydrophilic and hydrophobic. But what does that mean? And what are the differences between the two? Hydrophilic membranes are attracted to water, while hydrophobic membranes repel it. This difference in wettability is key in determining how each membrane is used. Hydrophilic membranes are often used in water filtration, while hydrophobic membranes are more common in oil and gas applications. Keep reading to learn more about these important types of membranes!
Hydrophilic membrane for water filtration and more
The wettability of a membrane is determined by its chemical composition. Hydrophilic membranes are typically made of materials like hydrophilic polymers such as nylon or polyethersulfone (PES). Other possible materials are inorganic silver and ceramics. A wide selection of materials is needed as the applications for hydrophilic membranes range from different biological sample filtrations to the food industry. Hydrophilic membranes are often used in reverse osmosis (RO) systems. RO systems use pressure to force water through a membrane, leaving contaminants behind. The contaminants are then flushed away, leaving clean, filtered water on the other side.
Hydrophobic membrane for oil and gas filtration
Hydrophobic membranes are usually made of hydrophobic polymers such as polytetrafluoroethylene (PTFE), or ceramics that need to be chemically treated to achieve hydrophobicity. In addition, the membrane surface can be roughened to enhance hydrophobicity. There are many applications for hydrophobic membranes such as filtration, gas separation, membrane gas adsorption, membrane distillation, and more that cannot be done with hydrophilic membranes.
As the wettability of the membrane has a crucial role, it is often studied with contact angle measurements. To read more about contact angle measurements, download the white paper through the link below.