As is well known, polyacrylamide is roughly divided into three major categories based on its charging characteristics: anionic, cationic and nonionic. Their appearance is all white powder or white granular. It is impossible for us to determine which type of polyacrylamide it is just by its appearance. Now, I will share how to distinguish the model of polyacrylamide through a simple way.
1. Judging from the dissolution time
The complete dissolution time of different types of polyacrylamide in water is also not the same. Anionic polyacrylamide... Nonionic polyacrylamide < Cationic polyacrylamide. The dissolution time of anions is approximately within 30 minutes, that of nonions is around 40 minutes, and that of cations is generally around 60 minutes. Therefore, the type of polyacrylamide can be roughly distinguished from the dissolution time.
2. Determine by testing the pH value
By testing the pH value of the polyacrylamide aqueous solution, as the acidity and alkalinity of different types of polyacrylamide vary, the performance of polyacrylamide can be identified through this method. However, due to the different production processes of various manufacturers, there may be slight deviations. The pH value can be determined through the production process for judgment.
3. The method of mixed addition
Those who frequently come into contact with polyacrylamide are probably well aware that the anionic and cationic ionic types cannot be mixed for use. Mixing and adding them together will cause a reaction effect. Due to the contact of positive and negative charges, a cotton-like substance will be formed, and the liquid will become cloudy and unclear. So this method can also be used for judgment. If you want to be certain, you can ask the manufacturer to provide a clear test result.
4. Judge through sewage testing
The classification of different polyacrylamides can be clearly determined by their adaptability in wastewater. Generally, anionic polyacrylamide is suitable for suspensions with high concentration and positive charge, and the PH value is neutral or alkaline. Cationic polyacrylamide is suitable for suspensions with negative charges. Nonionic polyacrylamide is suitable for suspensions in a mixed state of organic and inorganic substances, with a PH value of neutral or acidic.
