Ion resin is often divided into two types: gel type and macroporous type.
The polymer skeleton of gel-type resin has no pores in dry condition. It swells when it absorbs water, forming very fine pores between macromolecular chains, commonly known as micropores or ion exchange resin.
These resins are more suitable for adsorbing inorganic ions, and their diameters are smaller. This kind of resin can not adsorb macromolecular organic substances, because the latter is larger in size.
Macroporous ion exchange resin is a porous spongy framework formed by adding pore-forming agent in the polymerization reaction. There are a large number of micro-pores in it and then introduced into the exchange group to make it. It has both micro-pore and large-mesh wetting resin pore size, which can be controlled in the manufacturing process. This not only provides a good contact condition for ion exchange, shortens the ion diffusion path, but also adds many chain active centers. Molecular adsorption can be produced by van der Waals attraction between molecules, which can adsorb various non-ionic substances like activated carbon and expand its functionality. Some macroporous resins without exchange functional groups can also adsorb and separate various substances, such as phenols in wastewater from chemical plants.
Macroporous ion exchange resin has many large pores, large surface area, many active centers, fast ion diffusion rate, and fast ion exchange rate, which is about ten times faster than that of gel-type resin. The utility model has the advantages of fast action, high efficiency and shorter processing time. Macroporous resins also have many advantages: swelling resistance, non-fragmentation resistance, oxidation resistance, wear resistance, heat resistance, and temperature resistance, as well as easy adsorption and exchange of organic macromolecule substances, so they are highly resistant to pollution and easy to regenerate.