The influence of 3 important factors on the filtration effect of microporous filtration membrane

There are three more important factors that will affect the filtration effect when using microporous filtration membranes, namely the type of membrane material, process conditions, and material thickness.

type of material

Microporous filtration membrane is a membrane material that selectively filters substances through the size of the pores. Its main materials include polyester, polysulfone, polycarbonate, polyurethane, etc. Microporous filtration membranes of different materials have different chemical and physical properties, which affect their filtration effects.

Different chemical properties of materials: Polyester, polysulfone, polycarbonate, polyurethane and other materials have different chemical structures, resulting in different chemical properties, such as chemical resistance, heat resistance, mechanical strength, etc.

1. Different physical properties of materials: Different materials have different physical properties, such as density, hardness, elastic modulus, etc.

2. The pore size and shape of the membrane are different: the pore size and shape of the microporous filtration membrane made of different materials are also different, which leads to their different filtration effects.

3. Different preparation processes: Different materials have different processes for making microporous filtration membranes, such as hot pressing, stretching, injection molding, etc., which affect the properties of the membrane and the filtration effect.

Membrane thickness

The thickness of the microporous membrane will also affect its filtration effect. In general, thinner microporous membranes are more prone to pressure differentials, but have higher filtration efficiencies. Thicker microporous membranes offer better durability and longer life. Therefore, the filtration effect and strength of the microporous filtration membrane are two contradictory factors. In order to ensure the filtering effect, the pore size of the membrane must be small enough, but this will lead to a decrease in the strength of the membrane. In order to ensure the strength, the thickness of the membrane must be large enough, but this will cause the pore size of the membrane to become larger, which will affect the filtration effect.

Therefore, to find a balance between filtering effect and strength, it is necessary to choose the appropriate material, thickness and process conditions. Commonly used materials include polyimide, polyamide, polypropylene, and the like. The thickness is generally between 0.1-10 microns. Process conditions include membrane preparation temperature, pressure, rate, etc. In specific applications, it is necessary to optimize the design according to the actual situation. For example, the strength of the membrane can be improved by multilayer composite, or the filtration performance of the membrane can be improved by surface modification. At the same time, it is also necessary to pay attention to the use and maintenance of the membrane to avoid the influence of external force damage and pollution on the membrane.

Process conditions

Process conditions are also an important factor affecting the filtration effect of microporous filtration membranes. Including the preparation of membrane materials, the preparation process of membranes, the heat treatment conditions of membranes, etc. Different process conditions will affect the pore size, distribution, shape, etc. of the microporous filtration membrane, thereby affecting its filtration effect. The manufacture of microporous membranes mainly includes the following processes: hot pressing method, solution impregnation method, stretching method, injection molding method, electrochemical method, plasma polymerization method, etc. Different processes can affect the pore size, distribution and shape of the membrane. For example, the pore size and shape of the membrane produced by the hot pressing method are relatively uniform, while the pore size and shape of the membrane produced by the stretching method are not regular, but the distribution is relatively uniform. In addition, different materials can also affect the pore size and shape of the membrane.

In general, the material, thickness, process conditions and other factors of the microporous filtration membrane will affect its filtration effect. Therefore, when selecting a microporous filtration membrane, it is necessary to select the appropriate material, thickness and process conditions according to actual needs in order to achieve the best filtration effect.

Citation

1.Zhang, Y.,& Sun, S. (2019). Preparation and characterization of microporouspolyvinylidene fluoride membranes via thermally induced phase separation.Journal of Membrane Science, 584, 132-141. doi: 10.1016/j.memsci.2019.03.057

2.Wang, L., Li,Y., & Zhang, L. (2018). Preparation and characterization of microporouspolyethersulfone membranes via thermally induced phase separation. Journal ofMembrane Science, 563, 498-507. doi: 10.1016/j.memsci.2018.06.064

3.Higuchi, T.,& Kato, T. (2018). Preparation of microporous polyamide membranes byinterfacial polymerization using polyethylene glycol as a pore-forming agent.Journal of Membrane Science, 550, 1-8. doi: 10.1016/j.memsci.2017.11.055

4.Li, X., Wang,X., & Wang, Y. (2019). Fabrication and characterization of microporouspolyimide membranes by thermally induced phase separation. Journal of MembraneScience, 573, 238-246. doi: 10.1016/j.memsci.2018.12.008