Method for testing hydrophilia of panel reverse osmosis membrane

Abstract

The invention discloses a method for testing the hydrophilia of a panel reverse osmosis membrane. According to the method, pretreatment comprises the steps of immersing the reverse osmosis membrane in pure water at the indoor temperature, washing the reverse osmosis membrane with the pure water, and carrying out vacuum drying on the reverse osmosis membrane to be prepared for use; regulating and controlling the relative humidity of the environment, test temperature and the salinity of a test solution; laying the membrane flat and sticking the membrane to a sample table of a contact angle analysis meter with a separation layer facing upwards and a supporting layer in contact with the sample table. The test is conducted with the static contact angle method, a small pure water or salt water drop is dripped onto the membrane after parameter setting of the contact angle analysis meter is regulated, a static diagram of the liquid drop can be obtained after the liquid drop is balanced on the membrane, and analysis and contact angle calculation are carried out on the static diagram of the liquid drop by means of liquid drop shape analysis software; the operation is repeated multiple times on different positions of the membrane, and an average value is obtained as the final contact angle result. According to the method for testing the hydrophilia of the panel reverse osmosis membrane, the pretreatment method of the testing process is defined, the concept that three testing conditions need to be controlled and defined is proposed, the reliability of the hydrophilia detecting method and the comparability of the detecting result are improved, and repeatability is high.

Description

technical field [0001] The invention relates to a method for testing the surface properties of a separation layer of a reverse osmosis membrane, in particular to a method for testing the surface hydrophilicity of a flat plate reverse osmosis membrane. Background technique [0002] Reverse osmosis membranes are widely used in seawater and brackish water desalination, biopharmaceuticals, chemicals, water purification and other fields. Most of the current commercial reverse osmosis membranes are aromatic polyamide flat membranes, which usually consist of a non-woven support layer, an ultrafiltration bottom membrane and a separation layer. The main component of the separation layer is aromatic polyamide material, which is formed by interfacial polymerization and is the main functional layer of the reverse osmosis membrane. [0003] The hydrophilicity of the separation layer of reverse osmosis membranes has an important impact on its performance, especially water flux and foulin...

AI Technical Summary

Problems solved by technology

However, so far, although researchers understand the testing methods for the hydrophilicity of reverse osmosis membranes, they pay less attention to the influence of test conditions on the test results.

There are only few reports on the correlation between the hydrophilicity of reverse osmosis membranes and the test conditions, and there are currently no systematic studies and reports on the influence of test conditions on the hydrophilicity of reverse osmosis membranes

This results in the lack of certain reliability and scientificity and comparability between different test results in the current test method for the hydrophilic performance of reverse osmosis membranes.