Catalytic Synthesis and Characterization of Biodegradable ...

More documents

Recommendations

Info

Chapter 1 diamagnetic products, hydroxypiperidines structure (NOH), and oxo-piperidinium cations (NO + ). Figure 1.6.1 shows such one-electron redox reactions of free nitric oxide derivatives. Figure 1.6.1 The one-electron redox reactions of nitroxide free radicals. 178 Based on the redox properties of the nitroxyl radicals, polymers bearing stable radicals in the side chains, also known as radical polymers, have been extensively studied as redox resins which catalyze the oxidative and/or reductive reactions of organic compounds. For example, poly(acrylate)-combined TEMPOs were synthesized and studied as a catalytic reagent for the oxidation of alcohols into aldehydes and ketones. 179 The organic radical-based or metal-free redox reagents have been recently reexamined from the perspective of green or environmentally compatible chemical reaction processes. In addition to this chemistry application, the robust electron exchange between unpaired electrons in the polymer side chains suggests these radical polymers to be used for organic electronic or magnetic materials. However, it is not until recently that the applications have been intensively investigated for use in organic secondary battery or memory devices by our group. The large population of the radical redox sites along the polymer chain allows the effective redox gradient-deriven electron transport, which leads to organic batteries with large energy density. On the other hand, polymers with nitroxyl radicals also attracts significant interest to be as biomedical materials since the stable nitroxyl radials have been discovered to have similar functions as nitric oxide (NO•) which was presence in many bioprocess such as inflammation, blood clotting, blood pressure, neurotransmission, cardiovascular disorders and antimicrobial property. 180-182 Thus, emphasis of this part of introduction would focus on the radical polymers for organic electronic devices and biomedical applications. ‐ 40 ‐
1.6.1 Radical Polymers for Organic Electronic Devices 1.6.1.1 Organic Radical Batteries - 41 - Polymerization and Applications of Biodegradable Polyesters Rechargeable secondary batteries are widely used in portable equipments. Li-ion battery represents the currently most popular usage. However, the application of metal-based electrodes has come up against some inherent disadvantages, such as limited raw-material resource and tedious waste process. Therefore, organic-based electrode-active materials have received more and more attentions. Over the past few years, we have focused on the development of polymer bearing densely populated unpaired electrons, such as nitroxides, phenoxyl and galvinoxyl, in the pendant per repeating unit and utility of them as electro-active or charge-storage material in a rechargeable device. 178, 183-190 The organic 178, 183, 188 radical battery composed of the radical polymer electrodes has several advantages: (1) a high charging and -discharging capacity (>100 mAh/g), ascribed to the stoichiometric redox of the radical moieties, (2) a high-charging and -discharging rate performance resulting from the rapid electron-transfer process of the radical species and from the amorphous state of the radical polymers, and (3) a long cycle life, often exceeding 1000 cycles, derived from the chemical stability of the radicals and from the amorphous electrode structure. A variety of polymer backbones have been employed by our group to bear the pendant radicals, such as poly(meth)arylates, polystyrene derivatives, polymer(vinyl ether)s, polyethers and poly(norbornene)s, and were depicted in Figure 1.6.2 and Figure 1.6.3. Radical polymers, most of time, were synthesized by conventional radical polymerizations, and an additional oxidation processes must be needed in this case. The unpaired electron density of the polymers was then measured by SQUID, revealing the presence of the radicals in each repeating unit. The versatile of the polymers backbones also have another advantage, i.e. the polymers allow to be conveniently placed on the surface of a current collector by a solution-based wet process such spin-coating method. When the polymer is placed on the surface of the current collector and equilibrated in electrolyte solution, charge propagation within the polymer layer is sufficiently accomplished, leading to high-density charge storage because the redox sites are so populated that electron self-exchange reactions are completed within a finite distance of the polymer layer. 189
Page 1 and 2: Catalytic Synthesis and Characteriz
Page 3 and 4: Preface Biodegradable polyesters ha
Page 5 and 6: Chapter 3 Polymerization of Lactic
Page 7 and 8: Chapter 1 Polymerization and Applic
Page 9 and 10: - 3 - Polymerization and Applicatio
Page 13 and 14: 1.2.2 Aluminum Catalysts - 7 - Poly
Page 17 and 18: 1.3 Polylactide 1.3.1 Introduction
Page 19 and 20: - 13 - Polymerization and Applicati
Page 21 and 22: 1.3.4 Application of PLA Figure 1.3
Page 27 and 28: 1.5.1.4 Polyaniline (PANi) - 21 - P
Page 45: - 39 - Polymerization and Applicati
Page 51 and 52: initialization of the device by app
Page 55 and 56: 1.6.2.4 Others - 49 - Polymerizatio
Page 63 and 64: 182. R. B. Weller, J. Invest. Derma
Page 65 and 66: Chapter 2 Synthesis and Electrochem
Page 67 and 68: Synthesis and Electrochemistry of S
Page 79: Synthesis and Electrochemistry of S
Page 84 and 85: Chapter 3 3.1 Introduction Poly(lac
Page 86 and 87: Chapter 3 polydispersity index (PDI
Page 88 and 89: Chapter 3 aluminum based complexes
Page 90 and 91: Chapter 3 3.5 Conclusions Co(III) c
Page 92 and 93: Chapter 3 22. Z. H. Tang, X. S. Che
Page 94 and 95: Chapter 4 4.1 Introduction Stimulus
Page 96 and 97:
Chapter 4 the proton of methenyl gr
Page 98 and 99:
Chapter 4 attributed to the amide g
Page 100 and 101:
Chapter 4 4.4 Thermal Properties Th
Page 102 and 103:
Chapter 4 Figure 4.8 MTT assay for
Page 104 and 105:
Chapter 4 The 1 H NMR and 13 C NMR
Page 106 and 107:
Chapter 4 Cell viability (%) = (Asa
Page 109 and 110:
Chapter 5 Synthesis of Triblock Cop
Page 111 and 112:
5.2 Synthesis of Triblock Copolymer
Page 113 and 114:
Sample Table 1. Feed and result com
Page 115 and 116:
= 25 μm. B: MTT assay for the cyto
Page 117 and 118:
‐ 109 ‐ Synthesis of Triblock C
Page 119:
‐ 111 ‐ Synthesis of Triblock C
Page 124 and 125:
Chapter 6 6.1 Introduction Since th
Page 126 and 127:
Chapter 6 6.3 Synthesis of MPEG-b-P
Page 128 and 129:
Chapter 6 used to characterize the
Page 130 and 131:
Chapter 6 Figure 6.6 Cyclic voltamm
Page 132 and 133:
Chapter 6 vivo cytotoxicity was als
Page 134 and 135:
Chapter 6 NMR. Characterization of
Page 136 and 137:
Chapter 6 CO2 for 24 h. RSC96 cells
Page 141 and 142:
Chapter 7 Conclusion and Future Pro
Page 143 and 144:
‐ 131 ‐ Conclusion and Future P
Page 145 and 146:
‐ 133 ‐ Conclusion and Future P
Page 147 and 148:
13. Xuan Pang, Xuesi Chen, Xiuli Zh
Page 149:
Acknowledgments The present thesis
show all

Catalytic Synthesis and Characterization of Biodegradable ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?