The adsorption effect of adsorption resin on organic matter is closely related to the structure and properties of the resin itself, the structure of the adsorption material and the operating conditions in the adsorption process. Based on years of experience, Alfa Chemistry makes the following summary of the factors affecting the adsorption process for your reference.
Influence of structural properties of resin itself
For macroporous adsorption resin, medium polar resin is suitable for the separation of large polar compounds, non-polar resin is suitable for the separation of small polar compounds, but the polarity is a relative concept, generally need to pass a certain pre-experiment and TLC judgment.
Mechanical properties of resin
For macroporous resin, the higher the porosity, the larger the pore volume, the worse the strength. The strength directly affects the service life of the resin, thus affecting the process cost. For ion exchange resin, in the exchange process is often used under high pressure and dynamic conditions, in order to ensure the service life, generally choose good toughness, impact resistance with saturated carbon chain polymer skeleton.
Pore size, specific surface area and porosity
The pore size directly affects the free entry and exit of molecules of different sizes, thus making the resin selective. For ion exchange resins, large specific surface area and appropriate pore size are very important to improve exchange capacity and exchange speed.
For different adsorbed substances, their sensitivity to temperature is different. In general, pure adsorption resin is greatly affected by temperature, while ion exchange and coordination complex play a major role in the adsorption process is relatively less affected by temperature. In use to consider the resin limit temperature, in order to prevent decomposition, melting or chemical reaction, is irreversible changes in the resin.
Resin surrounding medium
The medium here refers to a large number of other substances around the adsorbent that should not be adsorbed in addition to the adsorbent, mainly some liquid solvents and gaseous substances. The most common are mobile phase used in separation, aqueous solution in water purification process, etc. Because there will be competitive adsorption between the medium and the adsorbed material, so the influence of the medium must be considered in the selection of adsorbent.
Other influencing factors
In addition to the above factors, there are also external dynamic factors such as flow rate of mobile phase, solution viscosity and diffusion coefficient of adsorbed substance. The adsorption process is a slow process, when the flow rate is too fast, the adsorption process may not be completed, which is not conducive to the role of the adsorbent. The viscosity of the solution mainly affects the diffusion rate of the adsorbed substance, and the surface tension affects the wettability of the adsorbent, all of which will affect the adsorption process.