戴子安Dai, Chi-An臺灣大學:高分子科學與工程學研究所陳瑞宏Chen, Jui-HungJui-HungChen2010-05-122018-06-292010-05-122018-06-292008U0001-0808200810485100http://ntur.lib.ntu.edu.tw//handle/246246/183100本論文為研究無機/高分子奈米複合材料之合成與性質。第一部分為以異質凝聚法合成TiO2/poly(AA-co-MMA)奈米複合顆粒。首先在水相中以水解-凝縮反應合成TiO2和SiO2/TiO2奈米級粒子，再與poly(AA-co-MMA) 乳膠混成形成複合顆粒，最後與PET粉末進行混煉。複合顆粒的TGA結果顯示，帶負電的乳膠顆粒和TiO2和SiO2/TiO2經由較強的電荷吸引力結合，而帶正電的乳膠顆粒以pH值差異所引起的凝聚、羰基螯合作用及氫鍵三種作用力和TiO2和SiO2/TiO2粒子結合。以無乳化劑乳化聚合所得之poly(AA-co-MMA) 乳膠顆粒，由於其粒徑較大，總表面積較少，因此TiO2的吸附量較少。若以SiO2/TiO2取代TiO2，其吸附量會大幅上升。以SEM觀察PET和複合顆粒的混煉，可發現PET與帶正電的複合顆粒所得之混煉，在型態上比PET與帶負電的複合顆粒所得之混煉較為均勻。DSC的結果顯示，PET和複合顆粒混煉後，玻璃轉移溫度(Tg)和熔點(Tm和Tm’)會上升，結晶溫度的範圍則會縮小。顯示複合顆粒的存在會影響PET結晶時分子鍊的移動和堆積，因此改變PET的熱性質。二部份為ZnO nanorod/PEDOT複合薄膜。PEDOT具有高導電度和高透明度的特性，可作為電極和可撓式電子材料。本研究將EDOT單體和具有磺酸根的TEBS單體，起始劑Fe(OTs)3和弱鹼imidazole (IM)溶於甲醇中，再旋轉塗佈於玻璃上，以高溫進行氧化聚合成共聚物薄膜後，其導電度會大幅提升。本研究改變各反應物和EDOT單體的莫耳比例(TEBS/EDOT，IM/EDOT，Fe(OTs)3/EDOT)，並探討其對光電性質，表面型態及導電度的影響。在最佳的組成下，所得共聚物薄膜的導電度可達170 S/cm，較純PEDOT薄膜的30 S/cm高出五倍以上。導電度的提昇源自於TEBS使聚合反應的速度變慢，而使所得的共聚物薄膜均勻度提升。藉由計算反應常數之比例、分子量之比例、及兩種單體在共聚物中的分佈，可更進一步研究聚合動力。計算EDOT和TEBS的反應常數之比例可推知，EDOT較容易被氧化而接到分子鍊上。當TEBS的含量增加時，所得共聚物的分子量會增加，此乃TEBS在共聚物鍊上的含量也相對增加。當IM與EDOT的莫耳數比為2，所得共聚物的分子量為最高。當Fe(OTs)3含量提高時，所得共聚的分子量會降低，共聚物的分子練長也會變短，其原因推論為所得的共聚物分子鍊數目增加。之後在PEDOT上成長ZnO nanorods，以製備ZnO nanorods/PEDOT複合薄膜。製備的步驟分為三個部份：氧化聚合PEDOT薄膜、成長ZnO晶種、以水熱法成長ZnO nanorods。醋酸鋅與氫氧化鈉在甲醇中反應，可製備奈米及ZnO粒子，而此ZnO奈米粒子可作為ZnO成長時的晶種。欲使晶種ZnO nanorods垂直成長於基材上，晶種的存在是非常重要的。HMTA比氫氧化鈉更適合使ZnO nanorods垂直成長於PEDOT薄膜上。藉由控制水熱法的反應條件，可使ZnO nanorods垂直成長在PEDOT薄膜上。此ZnO nanorods/PEDOT複合薄膜具有酸鹼緩衝的能力，且其酸鹼緩衝能力和純ZnO粉末可相比。In this research, inorganic/polymer nanocomposites were synthesized and studied. The first part was heterocoagulation of TiO2/poly(AA-co-MMA) nanoparticles. Nano-sized TiO2 or SiO2/TiO2 particles were prepared by hydrolysis and condensation reactions in aqueous media, followed by mixing with poly(AA-co-MMA) latex to form different composite particles, then blending with poly(ethylene terephthalate), PET. The TGA results of composites indicated that negative charged latexes had greater interaction with TiO2/ or SiO2/TiO2 particles through strong electrostatic forces, while cationic latexes incorporated with TiO2/ or SiO2/TiO2 particles by pH induced coagulation, carbonyl group chelation and hydrogen bonding. The soapless latex polymer particles showed lower ability of adsorption to TiO2 particles due to the decrease of total surface area of these larger particles. If SiO2/TiO2 particles were used instead of TiO2 particles, unexpected high adsorption result was observed. Morphology results observed by SEM showed that PET blended with positive charged composites was more homogeneous than PET blended with negative charged composites. DSC results also indicated that the Tg of PET was increased, melting temperatures (Tm or Tm’) were increased, and the temperature range of crystallization was narrowed after blending with the composites. The presence of composites affected the mobility and packing of PET molecular chains therefore changing the thermal properties of PET. he second part was to synthesize highly conductive PEDOT film and ZnO nanorods/PEDOT composite thin film. PEDOT represented a class of conjugated polymers that could be potentially used as an electrode material for flexible organic electronics due to their superior conductivity and transparency. We demonstrated that the conductivity of a PEDOT containing copolymer film could be further enhanced by the oxidative chemical in situ copolymerization of a liquid film spin-coated from monomer mixture 3,4-ethylenedioxythiophene (EDOT) and 3-thienyl ethoxybutanesulfonate (TEBS), oxidant (iron(III) p-toluenesulfonate (Fe(OTs)3), weak base (imidazole, IM), and solvent (methanol). We investigated the effect of the processing parameters such as the molar ratios TEBS/EDOT, IM/EDOT, and Fe(OTs)3/EDOT on the surface morphology, optical property, and the conductivity of the resulting copolymer films. These parameters were optimized to achieve conductivities for the copolymer films as high as 170 S/cm, five times higher than the PEDOT film synthesized with method. This conductivity enhancement for the copolymer films was found to be resulted from the fact that the addition of TEBS monomer reduced the copolymerization rate, leading to the formation of much more uniform film surface without defects which increased the conductivity of the copolymer film. Kinetics study of copolymerization of EDOT/TEBS was conducted by calculation of the reactivity ratio, molecular weight ratio, and monomer distribution in the copolymer. The calculation of reactivity ratio revealed that EDOT was oxidized by oligomer more easily than TEBS. As TEBS/EDOT increased, the molecular weight also increased as a consequence of higher content of TEBS in the copolymer chain. Molecular weight was highest when IM/EDOT equaled 2. Higher content of Fe(OTs)3 resulted in lower molecular weight and shorter copolymer chain due to the increasing number of copolymer chains. nO nanorods/PEDOT film was fabricated by a three-step process: PEDOT polymerization, ZnO seeds annealing, and hydrothermal growth of ZnO nanorods. ZnO nanoparticles were synthesized from reaction of zinc acetate and sodium hydroxide in methanol medium and used as seed for ZnO growth. The presence of ZnO seed layer was important for ZnO rods to grow perpendicularly on substrates. For ZnO rods to grow on PEDOT films, hexamethylenetetramine, HMTA, was preferred as the source of base. By controlling the concentration and condition of hydrothermal growth, ZnO nanorods were able to grow perpendicularly on the PEDOT film. The pH buffering ability of ZnO nanorods/PEDOT film with four hydrothermal growth cycles was comparable to pure ZnO powders.Contents謝 Ibstract II要 Vigure Legend Xhapter 1 Introduction 1art 1 Heterocoagulation of TiO2/Poly(AA-co-MMA) 5anoparticles and Blending with PET 5hapter 2 Introduction of TiO2/Poly(AA-co-MMA) nanoparticles 5-1 Titanium dioxide 5-1-1 Photocatalyst property of TiO2 5-1-2 Photo-induced hydrophilicity 8-1-3 Synthesis methods of TiO2 10-2 Heterocoagulation 11-2-1 Basic concept of heterocoagulation 11-2-2 Development of heterocoagulation 14-3 Basic concept of emulsion polymerization 18-4 Motivation of the research 24hapter 3 Preparation of TiO2/Poly(AA-co-MMA) nanoparticles 26nd blend with PET 26-1 Materials 26-3 Preparation of SiO2/TiO2 dispersion 27-4 Preparation of poly(AA-co-MMA) latex 28-5 Preparation of TiO2/latex and SiO2/TiO2/latex composite particles 29-6 Composite particles blending with PET 30-7 Characterization 30-7-1 Dynamic light scatting measurement (DLS) and zeta potential analysis 30-7-2 X-ray diffraction (XRD) analysis 31-7-4 X-ray photoelectron spectroscopy (XPS) 31-7-5 Acid-base titration experiments 31-7-6 Thermogravimetric analysis (TGA) 31-7-7 Morphology observation 32-7-8 Differential scanning calorimetry（DSC）analysis 32-7-8-1 Thermal analysis from molten state 32-7-8-2 Thermal analysis from glassy state 32hapter 4 Discussions on TiO2/Poly(AA-co-MMA) nanoparticles 36nd blend with PET 36-1 Characterization of TiO2, SiO2/TiO2 and poly(AA-co-MMA) latex 36-1-1 Particle size 36-1-2 Characterization of TiO2 and SiO2/TiO2 37-1-3 Zeta potential of TiO2, SiO2/TiO2 and poly (AA-co-MMA) latexes 39-2 TGA analysis of TiO2/latex composite and SiO2/TiO2/latex composite 40-2-1 TGA of TiO2/latex composites 40-2-2 TGA of SiO2/TiO2/latex composites 43-3 Morphology of TiO2/latex composite and SiO2/TiO2/latex composite 44-3-1 Morphology of TiO2/latex composite 44-3-2 Morphology of SiO2/TiO2/latex composite 45-4 Morphology of PET blended with SiO2/TiO2/latex composites 45-5-1 Tc, Hc, and Tm (DSC analysis from the molten state) 46-5-2 Tg, Tc’, Hc’, Tm’ (DSC analysis from glassy state) 47hapter 5 Conclusions on heterocoagulation of TiO2/poly(AA-co-MMA) nanoparticles and blend with PET 57art 2 PEDOT film with high conductivity and ZnO nanorod/PEDOT composite thin film 59hapter 6 Introduction ZnO nanorods and PEDOT 59-1 Introduction of ZnO one-dimensional nanostructure 59-1-1 Synthesis methods of ZnO 1D nanostructure 59-1-2 Application of ZnO 1D nanostructure 63-2 Introduction of PEDOT 67-2-1 Synthesis of PEDOT 67-2-2 Application of PEDOT 72-3 Motivation of the research 74hapter 7 Preparation of PEDOT copolymer films and ZnO nanorods/PEDOT composite films 76-1 Materials 76-2 Synthesis of TEBS 77-3 Synthesis of copolymer of EDOT and TEBS 78-4 Preparation of ZnO nanoparticles suspension 80-5 Preparation of ZnO nanorods/PEDOT composite film 80-6 Characterization 82-6-1 Measurement of conductivity of copolymer films 82-6-2 UV-Visible absorption of copolymer films 83-6-3 CV of copolymer films 83-6-4 Morphology observation 83-6-5 pH buffering ability 83hapter 8 Results and Discussions on PEDOT copolymer films and ZnO nanorods/PEDOT composite films 85-1 Conductivity of Copolymer films 85-1-1 Effect of TEBS (TEBS-system) 85-1-2 Effect of IM (IM-system) 89-1-3 Effect of Fe(OTs)3 (Fe(OTs)3 -system) 91-2 Kinetics study of copolymerization 102-2-1 Calculation of the ratio of rate constants 102-2-2 Calculation of molecular weight 111-2-2-1 Effect of TEBS 113-2-2-2 Effect of imidazole 113-2-2-3 Effect of Fe(OTs)3 115-2-3 Distribution of monomers in copolymer and the average sequence length 116-4 ZnO nanorods growth on glass substrate 126-5 ZnO nanorods growth on PEDOT films 132-6 ZnO/ZnO seed/PEDOT film in pH buffering application 138hapter 9 Conclusions on PEDOT copolymer films and ZnO nanorods/PEDOT composite films 145hapter 10 Suggestions for Future Works 147eference 148ppendix 154application/pdf12716787 bytesapplication/pdfen-US二氧化鈦聚丙烯酸-甲基丙烯酸甲酯乳化聚合異質凝聚法聚三四乙烯基二氧噻吩氧化鋅導電高分子水熱法TiO2poly(AA-co-MMA)emulsion polymerizationheterocoagulationPEDOTZnOconducting polymerhydrothermal processthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/183100/1/ntu-97-F92549004-1.pdf