What are the characteristics of the electrolytic membrane
Issuing time:2023-08-29 11:19
An electrolyte membrane, also known as an ion exchange membrane, is a semipermeable membrane that conducts certain ions while blocking other ions or substances of different charge, such as an electrolyte membrane that can selectively conduct certain ions based on their charge and size , such as cationic electrolyte membranes (CEM) are usually permeable to cations, such as sodium (Na+), potassium (K+) or hydrogen (H+), while blocking anions; while anion exchange membranes (AEM) are mainly selectively conductive anions, Including chloride (Cl-), sulfate (SO42-) or hydroxide (OH-), etc., while blocking cations.
What are the characteristics of electrolytic membrane?
1. Ionic conductivity, the ability to transport ions through the membrane, the ionic conductivity range of the electrolyte membrane can vary according to various factors, including the specific membrane material, its composition, structure and operating conditions, etc., in general, such as proton exchange Membrane (PEM) is used in applications such as fuel cells. The ion conductivity at room temperature is usually about 0.01 to 0.1 S/cm, and the PEM with improved performance can exhibit higher conductivity, reaching more than 0.1 S/cm; anion Exchange membranes (AEMs) are commonly used in applications such as water electrolysis or electrodialysis, and their ionic conductivity will vary, but typical values at room temperature range from 0.01 to 0.1 S/cm, and again, some high performance AEMs have conductivity The rate is also over 0.1 S/cm.
2. Selective, the degree to which the electrolytic membrane allows certain ions to pass and blocks others, depends on several factors such as ion exchange groups, charge density and affinity, size exclusion, operating conditions, etc.
3. Stability, the ability of the electrolytic membrane to maintain its structure and function under operating conditions, here is the chemical stability of the membrane, most common CEM can withstand a pH value of about 1 to 12; AEM can withstand about 1 pH values in the range of 14 to 14, the pH tolerance of the electrolytic membrane may vary depending on factors such as membrane material, thickness, composition, and the presence of additives or coatings, so in practical applications, it is recommended to Use electrolytic membranes in the pH range.
4. Permeability, the rate at which ions or other substances pass through the membrane, the permeability of the electrolytic membrane usually includes ion permeability, water permeability, air permeability, etc., and the same permeability is related to the selectivity introduced above.
5. Fouling resistance, the ability of a membrane to resist the accumulation on its surface of unwanted substances, including pollutants, impurities, scale, or other deposits that may impede membrane performance or efficiency. The fouling resistance of electrolytic membranes is a broad topic as it is influenced by many factors such as the surface properties of the membrane, such as its charge, hydrophilicity or hydrophobicity, roughness or specific coatings, which can affect its fouling resistance , because the smooth and hydrophilic surface can prevent the adhesion of dirt and promote easier cleaning or removal; the structure of the electrolytic membrane, including its pore size, morphology and surface area, such as a membrane with a small pore size or a dense structure may be less prone to fouling, Because they can limit the penetration or deposition of fouling; surface modification or coating can enhance the antifouling ability, because these membranes add antifouling agents in the process, apply hydrophilic coatings or change surface charge, etc. can help repel fouling and reduce its adhesion;
Other operating conditions, including temperature, pH, pressure, and flow, can affect stain resistance. Proper pretreatment and regular cleaning regimens for feed solutions used in electrolytic membranes can help prevent fouling and maintain membrane performance.
Electrolytic membranes are based on the above characteristics, making them suitable for a variety of industries and applications, including some energy fuel cells and batteries, water treatment industry using electrodialysis method, electrochemical synthesis industry, biotechnology and pharmaceuticals, chlor-alkali industry, gas separation, etc. , with advances in membrane materials, manufacturing technologies, and understanding of transport mechanisms, the application prospects of electrolytic membranes will further expand in the future.