Experimental and theoretical investigations on the effects of pH and topology of poly[2-(dimethylamino)ethyl methacrylate] to the absorption capacity of the polymer
Date of Issue2016
School of Materials Science and Engineering
The ability to absorb heavy metals, especially copper ions were studied at different pH values in both linear and 8-arm star-shaped topologies of poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA). The results have shown that 8-arm star-shaped PDMAEMA possesses about 3-4 times higher capacity than linear PDMAEMA does. This phenomenon can be explained by the fact that 8-arm topology provides stronger and tighter coordination bonds with copper ions compared to linear shape as the result of higher segment density in 8-arm polymer. The results also imply that the highest absorption of copper ions occurs at pH of 5.5 as observed in both shapes. The underlying reason is because increasing pH causes the copper to undergo precipitation thus being unable to exist in its free ions while too low pH gives rise to protonation of polymers which deactivates the amine functional groups of the polymers. The theoretical relationship between the percentage of absorption and polymer unit-to-copper ratio has been derived too and it shows a very close similarity to the experimental data.
Final Year Project (FYP)
Nanyang Technological University