本實驗主要利用聚偏二氟乙烯(PVDF)膜經由臭氧表面處理的方式，使得聚偏二氟乙烯膜表面產生過氧化氫等官能基，再藉由升溫使過氧化官能基斷鍵形成自由基，並引發丙烯酸(AA)單體上的C=C官能基進行聚合反應，接枝至聚偏二氟乙烯膜上。再以末端帶有胺基之N-異丙基丙烯醯胺(PNIPAAm)與部分AA上之COOH官能基反應鍵結。最後以四氧化三鐵(Fe3O4)與COOH官能基反應鍵結，得到具有溫敏性和磁敏性的聚偏二氟乙烯薄膜。實驗結果利用磁鐵、紅外線光譜儀(FTIR)、化學分析電子儀(ESCA)、掃描式電子顯微鏡(SEM)確認此改質聚偏二氟乙烯改質膜的結構。
利用聚N-異丙基丙烯醯胺之溫敏性質，使得表面改質聚氟化二乙烯膜在不同溫度環境下進行過濾實驗，其水流通透量突然有顯著的改變。由實驗結果發現，當溫度提高時，水流通透量會增加，並利用水流通透量(Flux)與溫度關係作圖，找出LCST(lower critical solution temperature)介於40~41.5℃。在不同PH值環境下，LCST隨著PH值下降而降低，並且當PH值高於8.93時無LCST性質。將改質聚氟化二乙烯膜置於交變磁場下(Alternative magnetic field)，使得磁性奈米粒子產生熱能，進而達到溫度變化而使得N-異丙基丙烯醯胺型態改變。
以水流通透實驗裝置進行蛋白質吸附實驗，利用已改質之PVDF膜進行水洗。於外高溫去離子水並加入一固定磁場條件下，可獲得較高的水流通透恢復率(flux recovery ratio)。

In this study, thermo-responsive and magnetic poly(vinyldiene fluoride) (PVDF) membranes grafted with branched poly(N-isopropylacrylamide) (PNIPAAm) chains and magnetic Fe3O4 particles have been prepared.
The preparation method includes three reactions. The first step is grafts of poly(acrylic acid) (PAA) chains to PVDF membrane surfaces. The PVDF membrane has been treated by ozone to generate peroxide and hydroperoxide groups on the PVDF membrane surface. Surface-initiated radical polymerization of acrylic acid (AA) is then carried out to introduce PAA chains to PVDF membrane surface. The second step is incorporation of PNIPAAm chains using amino-terminated PNIPAAm as areagent through the addition reaction between the carboxylic acid groups of PAA and the amine groups of PNIPAAm. Then Fe3O4 nanoparticles are then attached onto the surface of PVDF-AA-NIPAAm through the condensation reaction between the hydroxyl groups of Fe3O4 nanoparticles and the carboxylic acid groups of PAA. The chemical structures of the surface-modified PVDF membranes have been characterized with FTIR, ESCA and SEM.
In water flux experiment, the water flux of the membrane increases with the increasing the temperatures because of the conformational change of the thermo-responsive PNIPAAm chains. The fluxes show a dramatically increase between 40 and 41.5 oC, which is corresponding to the the lower critical solution temperature (LCST) of the PNIPAAm chains. With solution under different pH values, the measured LCST’s increase with temperature increasing. Moreover, the PVDF-PAA-PNIPAAm-Fe3O4 membrane could be heated with an alternative magnetic field, as the presence of the magnetic Fe3O4 nanoparticles on the membrane surface. The magnmetothermal effect of the membrane is demonstrated.
In the membrane cleaning tests, the membrane is fouled with BSA and then cleaned under different condition. A high flux recovery ratio has been obtained with the PVDF-PAA-PNIPAAm-Fe3O4 membrane to demonstrate its ease cleaning property. The thermally and magnetically-induced structure changes of the grafted layer of PVDF-PAA-PNIPAAm-Fe3O4 membrane contribute to the release of BSA from the membrane surface and the cleaning performance of the membrane.

1. 莊清榮、游勝背，流體中的最佳守門員—微過濾與超過濾，科學發展, 2008, 429期

2. 童國倫、阮若屈，最小心眼的薄膜—逆滲透膜與奈米濾膜，科學發展, 2008, 429期

3. http://www.lasers.com.tw/?f=Water-Filtration-Membrane

4. Wei J., Helm G.S., Corner-Walker N., Hou X.L., Characterization of A Non-fouling Ultrafiltration Membrane. Desalination, 2006, 192, 252-261.

5. 金重勳.磁性技術手冊，磁性技術協會，竹東，2002

6. Pyun J. Nanocomposite Materials from Functional Polymers and Magnetic Colloids. Polymer Rev. 2007, 47, 231-263

7. http://highscope.ch.ntu.edu.tw/wordpress/?p=1629

8. http://www.doitpoms.ac.uk/tlplib/polymerbasics/co_polymers.php

9. Gromadzki D. Engineering soft nanostructured functional materials
via orthogonal chemistry. Rev Environ Sci Biotechnol 2010, 9, 301-306

10. Kulawardana E. U. Stimuli-Responsive Polymers Graduate College of Bowling Green State University 2010

11. Meng H., Hu J. A Brief Review of Stimulus-active Polymers Responsive to Thermal, Light, Magnetic, Electric, and Water/Solvent Stimuli. J. Intel. Mat. Syst. Str. 2010, 21, 859-885

12. Marten G. U., Gelbrich T., Schmidt A. M. Hybrid biofunctional nanostructures as stimuli-responsive catalytic systems. Beilstein J. Org. Chem. 2010, 6, 922-931.

13. Alarco´n C. de las H., Pennadam S., Alexander C. Stimuli Responsive Polymers for Biomedical Applications. Chem. Soc. Rev. 2005, 34, 276-285

14. Frenkel, J., Dorfman J. Spontaneous and Induced Magnetisation in Ferromagnetic Bodies. Nature 1930, 126, 274-275.

15. Kim D. K., Dobson J. Nanomedicine for Targeted Drug Delivery. J. Mater. Chem. 2009, 19, 6294-6307

16. Bulte J. W. M., Kraitchman D. L. Iron Oxide MR Contrast Agents for Molecular
and Cellular Imaging. NMR Biomed. 2004, 17, 484-499

17. Shi D., Cho H. S., Chen Y., Xu H., Gu H., Lian J., Wang W., Liu G., Huth C., Wang L., Ewing R. C., Budko S., Pauletti G.M., Dong Z. Fluorescent Polystyrene–Fe3O4 Composite Nanospheres for In Vivo Imaging and Hyperthermia. Adv. Mater. 2009, 21, 2170-2173

18. Kim, D. H., Nikles, D. E., Brazel C. S. Synthesis and Characterization of Multifunctional Chitosan-MnFe2O4 Nanoparticles for Magnetic Hyperthermia and Drug Delivery. Materials 2010, 3, 4051-4065

19. Louguet S., Rousseau B., Epherre R., Guidolin N., Goglio G., Mornet S., Duguet E., Lecommandoux S., Schatz C. Thermoresponsive Polymer Brush-Functionalized Magnetic Manganitenanoparticles for Remotely Triggered Drug Release. Polym. Chem. 2012,3, 1408-1417

20. Frimpong R. A., Hilt J. Z. Poly(n-isopropylacrylamide)-basedhydrogel Coatings on Magnetite Nanoparticles via Atom Transfer Radical Polymerization. Nanotechnology 2008, 19, 175101

21. Yang W. C., Xie R., Pang X. Q., Ju X. J., Chu L. Y. Preparation and Characterization of Dual Stimuli-responsive Microcapsules with a Superparamagnetic Porous Membrane and Thermo-responsive Gates. J. Membr. Sci. 2008, 321, 324-330

22. Ninjbadgar T., Brougham D. F. Epoxy Ring Opening Phase Transfer as a General Route to Water Dispersible Superparamagnetic Fe3O4 Nanoparticles and Their Application as Positive MRI Contrast Agents. Adv. Funct. Mater. 2011, 21, 4769-4775

23. Balasubramaniam S., Pothayee N., Lin Y., House M., Woodward R. C., Pierre T. G. St., Davis R. M., Riffle J. S. Poly(N-isopropylacrylamide)-Coated Superparamagnetic Iron Oxide Nanoparticles: Relaxometric and Fluorescence Behavior Correlate to Temperature-Dependent Aggregation. Chem. Mater. 2011, 23, 3348-3356

24. Shi D., Cho H. S., Chen Y., Xu H., Gu H., Lian J., Wang W., Liu G., Huth C., Wang L., Ewing R. C., Budko S., Pauletti G.M., Dong Z. Fluorescent Polystyrene–Fe3O4 Composite Nanospheres for In Vivo Imaging and Hyperthermia. Adv. Mater. 2009, 21, 2170-2173

25. Regmi R., Bhattarai S. R., Sudakar C., Wani A. S., Cunningham R., Vaishnava P. P., Naik R., Oupicky D., Lawes G. Hyperthermia Controlled Rapid Drug Release from Thermosensitive Magnetic Microgels. J. Mater. Chem. 2010, 20, 6158-6163

26. Ru L., Jie-rong C. Studies on Wettability of Medical Poly(vinyl chloride) by Remote Argon Plasma. Appl. Surf. Sci. 2006, 252, 5076-5082

27. Madaeni S.S., Zinadini S., Vatanpour V. A New Approach to Improve Antifouling Property of PVDF Membrane Using in Situ Polymerization of PAA Functionalized TiO2 Nanoparticles. J. Membr. Sci. 2011, 380, 155-162

28. Oh S. J., Kim N., Lee Y. T., Preparation and Characterization of PVDF/TiO2 Organic–inorganic Composite Membrane for Fouling Resistance Improvement. J. Membr. Sci. 2009, 345, 13-20.

29. Lang W. Z., Xu Z. L., Yang H., Tong W., Preparation and Characterization of PVDF–PFSA Blend Hollow Fiber UF Membrane, J. Membr. Sci. 2007, 288, 123-131.

30. Chiang Y.C., Chang Y., Higuchi A., Chen W.Y., Ruaan R.C., Sulfobetaine-grafted Poly(vinylidene fluoride) Ultrafiltration Membranes Exhibit Excellent Antifouling Property. J. Membr. Sci. 2009, 339, 151-159.

31. Chen Y., Deng Q., Xiao J., Nie H., Wu L., Zhou W., Huang B. Controlled Grafting from Poly(vinylidene fluoride) Microfiltration Membranes via Reverse Atom Transfer Radical Polymerization and Antifouling Properties. Polymer 2007, 48, 7604-7613

32. Ying L., Kang E. T., Neoh K. G., Kato K., Iwata H. Novel Poly(N-isopropylacrylamide)-graftpoly(vinylidene fluoride) Copolymers for Temperature-Sensitive Microfiltration Membranes. Macromol. Mater. Eng. 2003, 288, 11-16

33. Li Y., Chu L.Y., Zhu J. H., Wang H. D., Xia S. L., Chen W. M. Thermoresponsive Gating Characteristics of Poly(N-isopropylacrylamide)-grafted Porous Poly(vinylidene fluoride) Membranes. Ind. Eng. Chem. Res. 2004, 43, 2643-2649

34. Han C. C., Wei T. C., Wu C. S., Liu Y. L. Temperature-responsive Poly(tetrafluoroethylene) Membranes Grafted with Branched Poly(N-isopropylacrylamide) Chains. J. Membr. Sci. 2010, 358, 60-66

35. Lin D. S., Wu C.S., Hsu K.Y., Liu Y. L. Preparation and properties of amphiphilic AB2 Y-shaped poly(styrene)-poly(N-isopropylacrylamide)2 copolymers through selective amidation and Michael additions reactions. React. Funct. Polym.2010, 70, 596-601

36. Valenzuela R., Fuentes M.C., Parra C., Baeza J., Duran N., Sharma S.K., Knobel M., Freer J. Influence of stirring velocity on the synthesis of magnetite nanoparticles (Fe3O4) by the co-precipitation method. J. Alloys Compd 2009, 488, 227-231.

37. Smuleac V., Bachas L., Bhattacharyya D., Aqueous-phase synthesis of PAA in PVDF Membrane Pores for Nanoparticle Synthesis and Dichlorobiphenyl Degradation. J. Membr. Sci. 2010, 346, 310-317

38. Ying L., Kang E.T., Neoh K.G. Characterization of membranes prepared from blends of poly(acrylic acid)-graft-poly(vinylidene fluoride) with poly(N-isopropylacrylamide) and their temperature and pH-sensitive microfiltration. J. Membr. Sci.2003, 224, 93-106

39. Li Y., Chu L.Y., Zhu J. H., Wang H. D., Xia S. L., Chen W. M. Thermoresponsive Gating Characteristics of Poly(N-isopropylacrylamide)-Grafted Porous Poly(vinylidene fluoride) Membranes. Ind. Eng. Chem. Res. 2004, 43, 2643-2649

40. Chu L. Y., Niitsuma T., Yamaguchi T., Nakao S. I. Thermoresponsive Transport through Porous Membranes with Grafted PNIPAM Gates. AIChE Journal 2003, 49, 896-909

41. Cai T., Neoh K.G., Kang E.T. Surface-Functionalized and Surface-Functionalizable Poly(vinylidene fluoride) Graft Copolymer Membranes via Click Chemistry and Atom Transfer Radical Polymerization. Langmuir 2011, 27, 2936-2945

42. Echeverria C., Mijangos C. UCST-Like Hybrid PAAm-AA/Fe3O4 Microgels. Effect of Fe3O4 Nanoparticles on Morphology, Thermosensitivity and Elasticity. Langmuir 2011, 27, 8027-8035

43. Fu J., Wang M., Zhang C., Wang X., Wang H., Xu Q.Template-induced covalent assembly of hybrid particles for the facile fabrication of magnetic Fe3O4–polymer hybrid hollow microspheres. J. Membr. Sci.2013,48,3557-3565

44. Dong L.C., Hoffman A. S. A novel approach for preparation of pH-sensitive hydrogels for enteric drug delivery. J. Controlled Release 1991,15,141-152

45. Chen G., Hoffman A.S. Graft copolymers that exhibit temperature-induced phase transitions over a wide range of PH. Nature 1995, 373, 49

46. Yoo M.K., Sung Y.K., Lee Y.M., Cho C.S. Effect of polyelectrolyte on the lower critical solution temperature of poly(N-isopropyl acrylamide) in the poly(NIPAAm-co-acrylic acid) hydrogel. Polymer 2000, 41, 5713–5719

47. Liu Y.L., Chang Y., Chang Y.H., Shih Y.J. Preparation of Amphiphilic PolymerFunctionalized Carbon Nanotubes for Low-Protein-Adsorption Surfaces and
Protein-Resistant Membranes. ACS Appl. Mater. Inter. 2010, 2, 3642-3647

48. Yu H.Y., He X.C., Liu L.Q., Gu J.S. , Wei X.W. Surface modification of polypropylene microporous membrane to improve its antifouling characteristics in an SMBR: N2 plasma treatment. WATER R ESEARCH, 2007, 41, 4703- 4709