What are the requirements for the support material in the composite membrane, and what are the commo

The support material in a composite membrane must meet several requirements to ensure the overall performance and durability of the membrane. These requirements include:

Mechanical strength: The support material must be mechanically strong enough to withstand pressure and stress during the membrane filtration process.The range of pressure and stress that the support material in a composite membrane can withstand depends on several factors, including the material properties, the design of the membrane module, and the operating conditions of the filtration process.Typically, during the membrane filtration process, the feed solution is pumped through the membrane module at a certain flow rate and pressure. The pressure drop across the membrane creates a driving force that allows the permeate to pass through the membrane while retaining the solutes or particles in the feed solution.The support material in the composite membrane must be able to withstand the pressure and stress generated by the feed solution during the filtration process without deforming or rupturing. The maximum allowable pressure and stress will depend on the mechanical strength and stability of the support material.

Chemical resistance: The support material must be chemically resistant to the process environment, including the feed solution and cleaning solutions.Considering the chemical compatibility in the early stage of membrane selection, the chemical compatibility of the support membrane and the filter membrane in the composite membrane should be the same or similar to ensure the overall performance and durability of the membrane. If the support membrane and the filter membrane have different chemical compatibility, it will lead to degradation, swelling or other changes in the membrane structure, which will affect the filtration performance and service life of the membrane. The same or close chemical compatibility helps ensure proper adhesion and stability of the composite membrane and prevents any chemical interactions that might affect membrane performance.

The other three factors are also very important, thermal stability, low fouling tendency, and compatibility of material structure, because the support material must be the same as the temperature of the filter membrane, and can withstand the operating temperature range of the membrane filtration process; the support material The close compatibility with the structural similarity of the filter membrane material can ensure the proper adhesion and stability of the composite membrane. The low fouling tendency of the support material minimizes fouling on the membrane surface and prolongs the lifetime of the membrane.

Commonly used support materials for composite membranes include:

1.Polymer materials: Polymeric materials such as polyethylene, polypropylene, and polytetrafluoroethylene (PTFE) are commonly used as support materials due to their low cost, high chemical resistance, and flexibility.

2.Ceramic materials: Ceramic materials, including alumina, zirconia, and silicon carbide, are used in some composite membranes because of their high mechanical strength, thermal stability, and chemical resistance.

From the above comprehensive analysis, it can be seen that, the choice of support material in a composite membrane will depend on the specific requirements of the filtration process, including the chemical and physical properties of the feed solution, operating conditions, and desired membrane performance.

Citation

1.Liu, C., & Huang, X. (2017). Preparation and characterization of composite membranes for water treatment: A review. Journal of Membrane Science, 527, 18-38. https://doi.org/10.1016/j.memsci.2016.10.035

2.Soltani, M., & Madaeni, S. S. (2019). Composite membrane support materials for water and wastewater treatment: A review. Journal of Environmental Chemical Engineering, 7(4), 103197. https://doi.org/10.1016/j.jece.2019.103197

3.Zhang, Y., Li, J., & Chen, V. (2019). Recent developments in composite membrane supports for water and wastewater treatment: A review. Chemical Engineering Journal, 358, 1171-1188. https://doi.org/10.1016/j.cej.2018.10.067

4.Zhou, L., Li, W., Liu, X., & Li, J. (2019). Composite membrane support materials: Fabrication, characterization, and applications. Chemical Engineering Journal, 357, 778-792. https://doi.org/10.1016/j.cej.2018.09.052