1. School of Chemistry, College of Science, University of Tehran, Iran
Michael addition grafting technique for modification of thin film composite membrane by hyperbranched poly(amine ester)
Hossein Mahdavi, Taieb Shahalizade*, Mohammad Taghi Hosseinzade, Aliasghar Kamyabi
School of Chemistry, College of Science, University of Tehran, Iran

2. Abstract
Polyamide thin-film composite membrane surface modified by Michael addition grafting of hydrophilic hyperbranched poly(amine ester)
The membrane surface was characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), water contact angle technique and field emission scanning electron microscopy (FE-SEM). Filtration performance and fouling resistance of membrane samples studied.
Surface chemical composition and contact angle indicated the successful grafting process, also, improved rejection percent and fouling resistance observed.

3. Introduction
Thin-film composite (TFC) membrane is the most important membrane that has been used in the field of reverse osmosis (RO) technology for water desalination.
The successful utilization of TFC membrane in RO technology is greatly limited by fouling, and chlorine attack
Jeong, Byeong-Heon, et al. "Antifouling Thin Film Nanocomposite (Tfnc) Membranes for Desalination and Water Reclamation." 2005 AIChE Annual Meeting and Fall Showcase

4. Introduction
Surface modification is a potential route to prepare fouling-resistant membrane by improving the surface hydrophilicity or barrier properties of membrane;
PEG-based hydrophilic coatings
Polydopamine coatings
Zwitterionic-based coatings
Layer-by-layer (LBL) assembly coatings
Rana, D., et al., Development of antifouling thin-film-composite membranes for seawater desalination. Journal of Membrane Science, (1-2): p
B.D.McCloskey, H.B.P., H. Ju, B.W. Rowe, D.J. Miller, B.D. Freeman, A bioinspired fouling-resistant surface modification for water purification membranes. J.Membr. Science in China, Series B: Chemistry, : p
Azari, S. and L. Zou, Using zwitterionic amino acid l-DOPA to modify the surface of thin film composite polyamide reverse osmosis membranes to increase their fouling resistance. Journal of Membrane Science, : p
Xu, J., C. Gao, and X. Feng, Thin-film-composite membranes comprising of self-assembled polyelectrolytes for separation of water from ethylene glycol by pervaporation. Journal of Membrane Science, (1-2): p

5. Introduction Hyperbranched polymers; no molecular entanglement
very low viscosity
high solubility
plenty of functional groups at the terminal units.
Yan, Deyue, Chao Gao, and Holger Frey, eds. Hyperbranched polymers: synthesis, properties, and applications. Vol. 8. John Wiley & Sons, 2011.

6. Experimental
1H NMR (DMSO–d6): d=7.21, 8.2 (Ar–H), 3.7 (CH2OH), 4.3 (CH2OOC), 3.1 (CH2NH), 5.81, 6.12, 6.41 (CH=CH2).

7. Result and discussion
FTIR spectrum of a) hyprbranched poly(amine ester), b) acrylated hyperbranched poymer, c) TFC membrane and d) acrylated hyperbranched poly(amin ester) modified membrane

8. Result and discussion

9. Conclusions
In this work polyamide TFC membranes modified using acrylated hyperbranched poly(amine ester).
All membrane samples represented efficient salt rejection percent and high FRR. Also there was accordance between contact angle data and bio-fouling resistance rates.
Membrane sample modified with 5% acrylated HBP, showed a uniform thin layer on top surface and lowest contact angle value.
Micheal addition approach could be used for wide range of polyamide TFCs, which suffer from lack of hydrophilicity and consequent bio-fouling.

10. Thanks for your attention

11. Refrences
1. Jeong, Byeong-Heon, et al. "Antifouling Thin Film Nanocomposite (Tfnc) Membranes for Desalination and Water Reclamation." 2005 AIChE Annual Meeting and Fall Showcase
2. Rana, D., et al., Development of antifouling thin-film-composite membranes for seawater desalination. Journal of Membrane Science, (1-2): p
3. B.D.McCloskey, H.B.P., H. Ju, B.W. Rowe, D.J. Miller, B.D. Freeman, A bioinspired fouling- resistant surface modification for water purification membranes. J.Membr. Science in China, Series B: Chemistry, : p
4. Azari, S. and L. Zou, Using zwitterionic amino acid l-DOPA to modify the surface of thin film composite polyamide reverse osmosis membranes to increase their fouling resistance. Journal of Membrane Science, : p
5. Xu, J., C. Gao, and X. Feng, Thin-film-composite membranes comprising of self-assembled polyelectrolytes for separation of water from ethylene glycol by pervaporation. Journal of Membrane Science, (1-2): p
6. Yan, Deyue, Chao Gao, and Holger Frey, eds. Hyperbranched polymers: synthesis, properties, and applications. Vol. 8. John Wiley & Sons, 2011.