Membrane Modification via Grafting-From Method Without the Use of a Photoinitiator

3 Membrane Modification via Grafting-From Method Without the Use of a Photoinitiator 

This approach involves the direct generation of free radicals from the base membrane polymers under UV irradiation and requires a photosensitive base polymer, a 

FIGURE 3.1 The mechanism for the photochemical modification of the PES membrane with vinyl monomers without a photoinitiator. (Reprinted from Journal of Membrane Science, 105, Yamagishi, H., et al., 237-248, Copyright (1995), with permission from Elsevier.) 

As a rule, two methods are used for membrane modification via the grafting-from approach without a photoinitiator an immersion method when the membranes are irradiated while immersed in a monomer solution, and a dip method when the membranes are dipped in a monomer solution and then irradiated in nitrogen or another inert gas (Pieracci et al. 2000). 

UV-initiated graft polymerization of AA on the surface of a PES manbrane via the immersion method using a 365 nm wavelength UV lamp was studied (Abu Seman et al. 2010). It was shown that irreversible manbrane fouling with humic acids (HA) was reduced after modification due to the increase in the hydrophilicity and the negative surface charge of the modified manbranes. 

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