What is a Cermic Membrane made of?

The material silicon carbide is a synthetically produced crystalline compound containing pure silicon and pure carbon. Silicon carbide is the second hardest material globally, exclusively exceeded by diamonds, and the hardest man-made material ever made. On Mohs Scale, which measures mineral hardness based on an ordinal scale ranging from 1-10, silicon carbide scores 9.5, while diamonds score 10. Due to silicon carbide's strength and durability, this chemical technology has been employed for various industrial applications since the late 19th century, when the material was first produced while attempting to make artificial diamonds. More recently, this element found its way to ceramic membranes for liquid filtration, where it provides a porous support structure, which filtered water can permeate. SiC ensures thermal and mechanical stability, vital for many industrial applications, especially if frequent cleaning or sterilization processes are required. Employing such a solid and long-lasting material secures a high-quality product with a long lifetime and some unique advantages.

To produce high-endurance ceramic membranes, silicon carbide grains are sintered together into a membrane with one or several parallel flow channels. Sintering silicon carbide involves a high sintering temperature of approximately 2100 °C, whereas oxide-based membranes are sintered at merely 1200-1600 °C. Producing ceramic membranes of silicon carbide thereby demands the correct manufacturing equipment, expertise, caution, and clearly defined precautionary measures. 

A special coating is placed in the ceramic membrane's flow channels to achieve all the desired effects of a ceramic membrane made of SiC. This unique coating material also contains the material silicon carbide and is first dried and then sintered at a high temperature in an inert atmosphere. This unique coating layer equips the membranes with their ruggedness and durability, but it also determines the membranes' flow channel pore sizes and water flux. Read more about how a ceramic membrane is manufactured here and more about the unique ceramic membrane coating here. 

The unique advantages of silicon carbide in ceramic membranes are many. This material provides a porous support structure, which filtered liquid can permeate while impurities are rejected. SiC also provides the highest water flux for any membrane material, making silicon carbide ceramic membranes capable of handling even the most complex and strenuous liquid filtration tasks. Add to this; silicon carbide enables reduced fouling, which reduces downtime caused by backwash and chemical cleaning-in-place (CIP). This is supported by the material's hydrophilic attributes, meaning that silicon carbide is water-loving as the material's surface absorbs liquids and repels oils. Silicon carbide is also chemically inert in all pH values from 0-14 and thermally resistant up to 800 °C. Lastly, silicon carbide contributes to low power usage and low pressure. All these unique advantages and features ensure that silicon carbide ceramic membranes can operate efficiently for a long time. This has made SiC a key player in manufacturing ceramic membranes for water filtration systems.

• Hydrophilic material
• Chemically inert pH 0-14
• Thermally resistant up to 800 °C
• Low power usage and low pressure
• Long lifetime