节点文献
酞菁功能聚合物的合成与性能研究
Preparation of Phthalocyanine-containing Polymers and Investigation on Their Properties
【作者】 张键;
【作者基本信息】 苏州大学 , 高分子化学与物理, 2014, 博士
【摘要】 酞菁(Phthalocyanines, Pcs)由于其独特的光电性质,在场效应晶体管、光信息存储、有机太阳能电池、光动力治疗以及非线性光学材料等多个领域具有广泛的应用,引起了科研工作者极大的关注。酞菁聚合物即可保留酞菁本身优异的物理化学特性,又能具备高分子材料优异的溶解和加工性能,日益成为研究的热点之一。同时,将酞菁单元通过自组装形成超分子结构能够进一步提高酞菁材料的物理化学性质,是制备酞菁类分子器件的关键步骤之一。因此,设计并合成结构新颖、性能优异的酞菁聚合物及酞菁单元的可控自组装是酞菁材料领域的重要研究课题之一。本论文从酞菁聚合物材料的合成以及可控自组装的角度出发,制备了具有特殊结构的酞菁聚合物,研究了酞菁单元的自组装行为以及光、电性质。研究内容具体包括:(1)运用可逆加成-断裂链转移(ReversibleAddition-Fragmentation Chain Transfer,RAFT)方法成功进行了邻苯二腈功能化的甲基丙烯酸甲酯类单体(2-methyl-acrylicacid6-(3,4-dicyano-phenoxy)-hexyl ester, MADCE)的聚合。聚合行为呈现“活性”/可控自由基聚合的特征:反应动力学呈一级线性关系,聚合物的数均分子量随单体转化率的增加而呈线性增长,较窄的分子量分布指数和成功的扩链实验。得到的侧链含邻苯二腈的聚合物通过后修饰方法进一步转变为侧链带有锌酞菁(ZincPhthalocyanine, ZnPc)的聚合物(PMADCE-ZnPc)。运用红外光谱、紫外-可见光谱、荧光光谱、原子吸收光谱和热分析测试对PMADCE-ZnPc进行了表征。探索了PMADCE-ZnPc作为给体材料在体异质结太阳能电池中的潜在应用。结构为ITO/PEDOT:PSS/PMADCE-ZnPc:PC61BM/LiF/Al的太阳能电池的能量转换效率(PCE)为0.014%,开路电压(Voc)为0.21V,短路电流(Jsc)为0.28mA/cm2,填充因子(FF)为0.24。(2)成功合成了两个可溶性金属酞菁,四叔丁基镓氟酞菁(Fluorogalliumtetra-tert-butylphthalocyanine, ttbPcGaF)和它的前驱体四叔丁基镓羟基酞菁(Hydroxygallium tetra-tert-butylphthalocyanine, ttbPcGaOH)。通过电喷雾-行波离子迁移质谱(ESI-TWIM MS)、紫外-可见光谱(UV-vis)、广角X射线散射(WAXS)和透射电镜(TEM)研究了ttbPcGaF和ttbPcGaOH的自组装性质。结果发现,在固态下,ttbPcGaF比ttbPcGaOH拥有更强的自组装能力来形成有序的一维超分子聚合物。此外,分别研究了以ttbPcGaF和ttbPcGaOH为给体材料,以PC61BM为受体材料的体异质结太阳能电池(Heterojunction (BHJ) Organic Solar Cell, BHJ OSC)的光伏性能。由于在ttbPcGaF:PC61BM共混膜中,ttbPcGaF依然能够自组装形成有序聚集体,所以基于ttbPcGaF:PC61BM的BHJ OSC的光电转换效率(PCE)能达到0.41%。反之,ttbPcGaOH在ttbPcGaOH:PC61BM共混膜中自组装能力较差,由ttbPcGaOH:PC61BM组成的BHJ OSC只能产生非常低的PCE(0.03%)值。(3)合成了新型的偶氮苯连接的双邻苯二腈单体(Azobenzene-containingbis(ether dinitrile)s, AzoBEDN),该单体进一步在加热条件下进行四缩合成环反应,得到了含偶氮苯单元的超支化锌酞菁(Azobenzene-containing hyperbranched ZnPc,AzoHBZnPc)。通过红外光谱、紫外-可见光谱、荧光光谱和热重分析测试证实了偶氮苯超支化锌酞菁的形成,并研究了AzoHBZnPc的光物理和热稳定性能。使用紫外-可见光谱法和原子吸收光谱法分别测定并计算了不同反应时间的AzoHBZnPc中锌酞菁的含量。结果表明,随着反应时间的延长,得到的AzoHBZnPc中锌酞菁的含量逐渐增加。在不同波长的光照射下,AzoHBZnPc在四氢呋喃溶液中能够发生可逆的光致异构化反应。此外,考察了AzoHBZnPc的介电性能,其介电常数在2.87-3.12之间,介电损耗低于0.014。(4)成功合成了一个新型的偶氮苯类小分子化合物,4,4’-二硼酸偶氮苯,并首次将该偶氮苯衍生物作为构建单元,和2,3,6,7,10,11-六羟基苯并菲在溶剂热条件下通过缩合反应合成了由偶氮苯连接的共价有机框架(Azo-linked covalent organicframework, Azo-COF)二维高分子。通过X射线粉末衍射、扫描电镜、透射电镜、热重分析和氮气吸附等温线测试发现Azo-COF具有高结晶、热稳定和永久多孔等特点。Azo-COF中的偶氮苯单元在365nm波长的紫外光照射下能够发生从反式到顺式结构的光异构化反应。虽然偶氮苯的光异构化行为能够降低Azo-COF的结晶度,但是不能改变Azo-COF的孔尺寸。该体系的成功构建为以后的含偶氮苯酞菁类有机共价框架提供了研究基础。
【Abstract】 Phthalocyanines (Pcs) have received considerable attentions due to their uniqueoptical and electronic properties which give rise to the application of Pcs in variousdomains, such as organic filed effect transistors, optical information storage, organic solarcells, photodynamic therapy, nonlinear optical materials and so on.Phthalocyanine-containing polymers combine the excellent physical and chemicalproperties of Pcs and the good solubility and processability of polymers, which arebecoming one of research hotspots. In addition, the physical and chemical properties ofPcs-based materials can be further improved by self-assembly of Pcs to supramolecularstructures, which is a key issue for incorporating Pcs into molecular devices. Therefore,design and synthesis of phthalocyanine-containing polymers with novel structures andsuperior properites, and controlled organization of Pcs is one of the important researchsubjects in Pcs-based materials field.In this thesis, we designed and synthesized several phthalocyanine-containingpolymers with special structures. And the self-assembly, optical and electronic propertiesof Pcs-based materials were also investigated. The detailed researches were summarized asfollowing:(1) A benzenedinitrile functionalized monomer,2-methyl-acrylic acid6-(3,4-dicyano-phenoxy)-hexyl ester (MADCE), was successfully polymerized via thereversible addition-fragmentation chain transfer (RAFT) method. The polymerizationbehaviour conveyed the characteristics of “living”/controlled radical polymerization: thefirst-order kinetics, linear increase of number-average molecular weight with monomerconversion, narrow molecular weight distribution and successful chain-extensionexperiment. The soluble Zn(II) phthalocyanine (Pc)-containing (ZnPc) polymers wereachieved by post-polymerization modification of the obtained polymers. The Zn(II)phthalocyanine-functionalized polymer was characterized by FT-IR, UV-vis, fluorescence,atomic absorption spectroscopy and TGA analysis. The potential application of above ZnPc-functionalized polymer as an electron donor material in bulk heterojunction organicsolar cell was studied. The device with ITO/PEDOT:PSS/ZnPc-Polymer:PC61BM/LiF/Alstructure provided a power convergent efficiency (PCE) of0.014%, fill factor (FF) of0.24,open circuit voltage (Voc) of0.21V, and short circuit current (Jsc) of0.28mA/cm2.(2) Two soluble phthalocyanine compounds, fluorogalliumtetra-tert-butylphthalocyanine (ttbPcGaF) and its precursor hydroxygalliumtetra-tert-butylphthalocyanine (ttbPcGaOH) were successfully synthesized. ttbPcGaF had amuch stronger ability than that of ttbPcGaOH to self-organize into well-orderedone-dimensional (1D) supramolecular polymers in solid state as revealed by ESI-TWIMMS, UV-vis, WAXS and TEM measurements. The photovoltaic properties of ttbPcGaF andttbPcGaOH as electron donor materials in solution-processed Bulk Heterojunction (BHJ)organic solar cells (OSCs) were investigated, respectively. Due to the retention of theself-assembly property of ttbPcGaF in the ttbPcGaF:PC61BM blend film, thettbPcGaF-based BHJ OSC provided a profoundly improved power conversion efficiency(PCE) of0.41%. In contrast, ttbPcGaOH-based BHJ OSC only exhibited a low PCE of0.03%, because PC61BM prohibited the self-assembly of ttbPcGaOH into orderedsupramolecular structures in ttbPcGaOH:PC61BM blend film.(3) A new azobenzene-linked bisphthalontrile monomer (AzoBEDN) was synthesizedfor the first time. And the azobenzene-containing hyperbranched zinc phthalocyanine(AzoHBZnPc) were prepared by tetracyclomerization of AzoBEDN in high boiling pointsolvent. The formation of ZnPc in AzoHBZnPc and the photophysical and thermalproperties of AzoHBZnPc were investigated by FT-IR, UV-vis, PL and TGA measurements.The content of ZnPc in AzoHBZnPc was calculated by UV-vis spectroscopy and confirmedby atom absorption spectroscopy, respectively. The results indicated that the contents ofZnPc in AzoHBZnPc increased with the reaction time. The reversible trans-cis-transphotoisomerization of azobenzene units in AzoHBZnPc could take place under theirradiation of light with different wavelengths. Besides, the dielectric responses ofAzoHBZnPc were also studied. The dielectric constants of AzoHBZnPc were in the rangeof2.87and3.12, and the dielectric losses were below0.014.(4) A novel azobenzene (Azo) monomer (azobenzene-4,4’-diboronic acid) wassynthesized and employed as building block to produce Azo-containing covalent organicframeworks (Azo-COF) through the borate ester formation reaction with 2,3,6,7,10,11-hexahydroxytriphenylene under solvothermal condition. The obtainedAzo-COF exhibited high crystallinity, thermal stability and permanent porosity as revealedby PXRD, SEM, TEM, TGA and nitrogen sorption isotherm measurements. Thetrans-to-cis photoisomerization of Azo units in Azo-COF occurred under the radiation with365nm UV light. Most interestingly, the phoisomerization of Azo units only coulddecrease the crystallinity of Azo-COF, while could not change the pore size of Azo-COF.The successful construction of Azo-COF will provide the foundation of research for thesubsequent azobenzene-containing Pc COF.