Norepinephrine modified thin film composite membranes for forward osmosis

Surface modification has been demonstrated as a valuable method for improving hydrophilicity of surfaces. A number of approaches have been used for facile modification of support layer chemistry including the use of polydopamine. In this work, norepinephrine is used as an alternative monomer to dopamine for surface modification. The chemistry of norepinephrine allows for a wider array of coating conditions and tighter control of deposition. This study compares surface modification through the application of polydopamine and polynorepinephrine on thin film composite membrane support layers for use in forward osmosis. It was found that polynorepinephrine under ambient conditions performs equally well as a polydopamine modified membrane. Controlling the rate of polynorepinephrine formation by using ammonium persulfate, an oxidizing agent, provided an additional lever for tuning the modification process speed.