聚(3-己基噻吩)的合成与表征

采用化学氧化法,用三氯化铁(FeCl3)作氧化剂合成了聚3-己基噻吩(P3HT)。研究了反应时间、氧化剂和单体摩尔比对转化率的影响,结果表明转化率随反应时间延长而增加,氧化剂和单体摩尔比为3∶1时转化率最高,达到71%。用红外光谱,紫外-可见光谱和核磁共振(1H-NMR)表征了P3HT的结构。紫外-可见光谱表明P3HT溶液禁带宽度约为1.91eV,根据1H-NMR计算P3HT结构规整度约为80%。研究了反应时间对P3HT分子量的影响,发现随聚合反应时间延长,分子量先迅速增加然后逐渐减小。     

巯基化P3HT衍生物的合成与表征

用GRIM(Grignard Metathesis Method)合成了聚(3-溴己基噻吩),并在硫代乙酸钾和氢化铝锂的作用下合成了巯基化的P3HT衍生物聚(3-(6-巯基己基)噻吩)。通过红外光谱、核磁共振波谱、凝胶渗透色谱、紫外-可见光谱、荧光光谱以及电化学分析对中间产物和最终产物的结构和光电性能进行了表征。结果表明,所合成聚合物与目标产物的结构一致,聚合物的数均相对分子质量为5621,多分散系数为1.39,在氯仿溶液中最大吸收波长为408 nm,最大发射波长为545 nm,电化学能隙为1.81 eV。     

聚乳酸立构复合物规整度对其降解性能的影响

通过开环聚合法,利用D,L-丙交酯合成不同规整度(XD)的左旋聚乳酸PLLA和右旋聚乳酸PDLA。用溶液浇铸法制得不同规整度的聚乳酸立构复合物SC-PLA,并在50℃缓冲溶液中进行降解。通过分析剩余质量、溶液pH值、热性能(DSC)、表面形貌(SEM)、电离子喷雾质谱(ESI-MS)等评价SC-PLA的降解性能。结果表明:相同规整度时,SC-PLA降解速率小于PLLA,但pH值变化大于PLLA,立构复合物SC的存在使材料比常见PLLA更耐水解;立构规整度下降会使SC-PLA的结晶度降低,材料的降解速率加快;降解使材料的结晶度上升,立构复合物晶体SC与均聚物晶体HC熔点降低;高规整度SC-PLA相对于相同规整度PLLA及低规整度SC-PLA,其降解产物分子链长度更短。     

聚3-烷基噻吩系列物的合成与表征

采用Fe(III)催化剂合成法合成聚3-丁基噻吩(P3BT)、聚3-己基噻吩(P3HT)和聚3-十二烷基噻吩(P3DDT)。用GPC和1 H-NMR对所合成的聚合物的相对分子质量和结构进行表征,用SEM对所合成的聚合物的表面形貌进行观察,并用紫外-可见吸收光谱和荧光光谱研究3种聚合物氯仿溶液的光学性能。结果表明,用该方法合成的聚合物以非晶态形式存在;具有较高的相对分子质量;在氯仿溶液中,P3BT、P3HT、P3DDT的最大吸收峰分别为:436nm、437nm和430nm,最大发射峰分别为570.0nm、581.2nm和573.8nm。综合分析发现P3HT更适于用做聚合物太阳能电池材料。     

新型聚2,4-二乙烯基3-十二烷基噻吩-1,3,4-噁二唑交替共聚物的合成、表征及性能研究

采用Heck偶合法首次合成了新型的含有空穴传输单元3-十二烷基噻吩和电子传输单元1,3,4-噁二唑的低带隙能的聚2,4-二乙烯基-3-十二烷基噻吩-1,3,4-噁二唑共轭聚合物(P3DDTV-OXD).并且通过1H-NMR、FT-IR、凝胶色谱(GPC)、UV-vis光谱、荧光光谱(PL)、循环伏安(CV)法对所合成的共聚物进行了分析表征.与规整的聚3-十二烷基噻吩均聚物(P3DDT)相比,共聚物的UV最大吸收波长和Pl最大发射波长明显蓝移,具有强烈的蓝色荧光,且电子亲和势较高,同时拥有空穴和电子传输能力,实现了电荷在分子内的双向传输.     

聚乙二醇修饰对P3HT/ZnO复合膜形貌和光学性能的影响

首先选用聚乙二醇(PEG)对水热法合成的粒径约200nm的ZnO球进行表面钝化,考察了PEG分子量、用量对ZnO薄膜形貌及光学性能的影响和PEG的能级结构;然后采用聚3-己基噻吩(P3HT)和最优参数PEG修饰前、后的ZnO纳米球共混旋涂来制备P3HT/ZnO复合膜,利用原子力显微镜、紫外-可见分光光度计、荧光光谱分析仪考察PEG钝化修饰对复合膜形貌及光学性能的影响。结果表明,采用相对分子质量为6 000、用量为5%(质量分数)的PEG修饰ZnO时,制备的ZnO薄膜均一性最好;PEG修饰的ZnO与P3HT具有良好的能级匹配性;P3HT与PEG修饰后的ZnO形成的复合膜表面规整且缺陷较少,而且在可见光区的光吸收作用增强,荧光猝灭现象加剧,表明PEG修饰增加了ZnO和P3HT的接触面积,促进了界面间的电荷转移。     

聚烷基噻吩嵌段共聚物合成及自组装的研究进展

立构规整性聚烷基噻吩具有很好的光电特性及很高的溶解度等优点,使得该材料被应用于有机场效应晶体管、化学传感器及光伏太阳能电池等领域。介绍了立构规整性聚烷基噻吩均聚物及其棒杆-线团、棒杆-棒杆型嵌段共聚物的合成及自组装行为的研究进展,并对聚烷基噻吩嵌段共聚物的发展前景进行了展望。     

以噻吩齐聚物为推电子单元的DA型共聚物的合成及性能

采用Suzuki偶合法合成了以聚合度为7的3-已基噻吩齐聚物为推电子单元、苯并噻二唑为拉电子单元的D-π-A型共轭聚合物(PF80.5-3HT7x-BT0.5-x)。通过核磁共振氢谱、紫外可见光吸收光谱、循环伏安法等对共聚物的结构与性能进行了研究与表征,并对共聚物的光电性能进行了探讨。结果表明:共聚物PF80.5-3HT70.1-BT0.4的最大紫外吸收峰相比聚合物PF80.5-3HT70.1-BT0.4的发生了红移;并且降低了共聚物的能带隙及HOMO,LUMO能级。实验表明共聚物PF80.5-3HT70.1-BT0.4显示出更强的光电性能,器件的结构ITO/PEDOT:PSS(70nm)/Copolymer(70nm)/Al(100nm)。     

TiO_2/P3HT纳米复合微粒制备及表征研究

以纳米二氧化钛(TiO_2)和聚3-己基噻吩(P3HT)为原料,氯仿为溶剂,制备了TiO_2/P3HT纳米复合微粒。采用透射电镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、紫外-可见光漫反射光谱(UV-Vis DRS)等方法对复合微粒的结构和性能进行表征和分析。结果表明,通过P3HT修饰后的TiO_2/P3HT与纯TiO_2相比,晶型、粒径和形貌基本没有发生改变,平均粒径22nm;纳米TiO_2/P3HT比纯TiO_2在可见光区的光吸收能力增强,当TiO_2∶P3HT摩尔配合比为30∶1时,在波长508nm,TiO_2/P3HT的吸光度达到1.0123,而纯TiO_2的吸光度为0.10824。     

电子受体材料功能化还原氧化石墨烯的结构和光学性能

采用Hummers法制备氧化石墨烯(GO),利用水热法对GO分别还原5 h和10 h制得两种还原氧化石墨烯(5-RGO和10-RGO),进一步用异氰酸苯酯对还原前后的氧化石墨烯材料进行改性,即得功能化氧化石墨烯和功能化还原氧化石墨烯(SPFGO、5-SPFRGO和10-SPFRGO)。以功能化还原氧化石墨烯材料为电子受体,聚3-己基噻吩(P3HT)为电子给体,制备复合膜。结果表明:GO由3-5层组成,经水热还原后样品表面仍含有—CO,—COOH等含氧官能团;功能化后石墨烯在邻二氯苯中分散性良好,与P3HT能级相匹配,满足作为聚合物太阳能电池受体材料要求;以5-SPFRGO做为受体材料与P3HT复合制备的复合膜表面规整致密,光吸收强度高,荧光光谱强度低,性能最优。     

Synthesis, characterization, and electrical properties of regioregular alkyl-substituted PEDOTt

The regioregular hexyl-substituted poly(3,4-ethylenedioxy-2-thiophenylthiophene) (PEDOTt), structurally alternating copolymer of EDOT and thiophene, was synthesized via the Grignard Metathesis (GRIM) using catalytic amounts of Ni(dppp)Cl2. The products were characterized by 1H NMR spectroscopy, UV-vis spectroscopy and XRD. The alkyl-substituted conjugated polymer showed an enhancement of solubility in common organic solvents. Based on XRD data, the regioregular hexyl-substituted poly(3,4-ethylenedioxy-2-thiophenylthiophene) (PEDOTt) shows better crystallinity than the regiorandom hexyl-substituted PEDOTt owing to self-ordering. In addition, regioregular hexyl-PEDOTt has a conductivity of 0.788 S/cm by iodine doping.     

Synthesis and characterization of regioregular alkyl-substituted poly(3,4-ethylenedioxythiophenes)

In order to increase the solubility of PEDOT, we introduced an alkyl chain into polymer backbone. Depending on the position of the alkyl bond, the steric hindrance between the alkyl chains can also leads to regioregularity in the polymer. The regioregular polymers can easily occur self-assembly, both in solution and in the solid state, resulting in highly ordered two- and three-dimensional polymer architectures. A series of soluble regioregular alkyl-substituted PEDOTs were synthesized using the Grignard Metathesis (GRIM) for the purpose of study on regiorandom and regioregular PEDOT. The ethylene proton adjacent to the oxygen atom of regioregular methoxydodecyl-PEDOT appears at 3.51 ppm, whereas the corresponding peak of regiorandom methoxydodecyl-PEDOT appears at 3.42 ppm.     

Microwave-assisted synthesis of poly(3-hexylthiophene) via direct oxidation with FeCl3

In this work, CoolMate microwave synthesis system was employed to synthesize soluble poly(3-hexylthiophene) by direct oxidation of 3-hexylthiophene monomer with FeCl₃ as oxidant. P3HT was synthesized varying reaction time by 2 h, 1 h and 0.5 h. According to the results optimal microwave radiation time for synthesis was 1 h. On the other hand, P3HT was synthesized in two different solvents: chloroform (CHCl₃) and dichloromethane (CH₂Cl₂). The obtained yields depend on the solvent and the reaction time used in the synthesis, microwave-assisted synthesis leads to outstanding increase in yield (with dichloromethane solvent). Homogeneous thin films were prepared by spin-coating technique from toluene. Physicochemical characterization of P3HT polymers was carried out: changes in weight molecular distribution and polydispersity were obtained by HPLC (high-performance liquid chromatography); dyads and triads percent were analyzed by NMR (nuclear magnetic resonance). Surface topographical changes were obtained by atomic force microscopy (AFM). AFM images revealed that the surface morphology depends on synthesis method, reaction time and solvent used. Finally the samples were characterized by thermogravimetric analysis (TGA) and ultraviolet–visible analysis (UV–vis). Compared with the traditional method (without microwave), this method provided considerable decrease in the reaction time, both lower polydispersity and molecular weight, less volume of solvents for the synthesis, as well as more alternatives for solvent choice. The results confirmed the versatility of the procedure by microwave, which yields polymeric materials in 1 h and has no adverse effects on the polymers quality.     

End-group functionalization of poly(3-hexylthiophene) as an efficient route to photosensitize nanocrystalline TiO2 films for photovoltaic applications

Bulk heterojunction (BHJ) and dye-sensitized solar cells (DSSCs) have seen increased popularity over recent years and each technology has experienced tremendous improvements in power conversion efficiencies (PCEs), reaching 8 and 12%, respectively. The two technologies have been on independent improvement pathways, and this work establishes a link between them by using the archetypical hole conductor (poly-3-hexylthiophene, P3HT) in BHJs as a sensitizer on TiO(2) for DSSC applications. Three polymers were synthesized and examined as potential TiO(2) sensitizers in DSSCs under AM1.5 solar radiation. Using Grignard metathesis, regioregular P3HT was synthesized then functionalized with either one or two cyanoacrylic acid linker moieties to bind to the TiO(2) surface. End-group modification resulted in minimal changes to the optical and electronic properties as compared to pristine P3HT. Cyclic voltammetry (CV) experiments at anodic potentials of adsorbed sensitizer quantified the amount of alkylthiophene adsorbed on the TiO(2), whereas under reductive sweeps, cyanoacrylic acid end-group binding was determined. CVs of each polymer indicated that loading was drastically different as compared to pristine P3HT with the lowest loading on TiO(2) and monofunctionalized P3HT exhibited the highest loading. The DSSCs showed power conversion efficiencies (PCEs) of 0.1%, 0.2 and 2.2% for the polymer-sensitized TiO(2) of the unfunctionalized, monofunctionalized and difunctionalized polymers, respectively. DSSCs were then subjected to electrochemical impedance spectroscopy (EIS) in the dark and under monochromatic light radiation. The large variance in performance for the functionalized-P3HT sensitizers is attributed to differences in the adsorption modes of sensitizer on the TiO(2) surface, which in the difunctionalized case limits electrolyte recombination and favors forward charge transfer reactions.     

Synthesis and properties of diblock copolymers containing poly(3-hexylthiophene) and poly(fluorooctyl methacrylate)

This study reports the synthesis of regioregular poly(3-hexylthiophene)-b-poly(1H,1H-dihydro perfluorooctyl methacrylate) (P3HT-b-PFOMA) block copolymers by atom transfer radical polymerization of FOMA using P3HT macroinitiators. The P3HT macroinitiator was previously prepared by chemical modification of hydroxy terminated P3HT The block copolymers were characterized by 1H-NMR, 13C-NMR, GPC, DSC, TGA and TEM. The block copolymers are able to self-assemble into phase separated micellar thin film morphology from chloroform.     

有序Ag_(NW)@Au_(NP)复合纳米线的制备及其对聚(3-己基噻吩)荧光效应的影响

采用三相界面法及置换反应法,以氯金酸-乙醇溶液和无序Ag纳米线为原材料,在空白Si基底上成功制备出有序Ag纳米线(Ag_(NW))@Au纳米颗粒(Au_(NP))复合纳米线。采用场发射扫描电子显微镜(FESEM)和高分辨透射电子显微镜(HRTEM)对有序Ag_(NW)@Au_(NP)复合纳米线形貌进行了表征与分析,研究了氯金酸-乙醇溶液浓度和置换反应的反应时间对制备Ag_(NW)@Au_(NP)复合纳米线的影响,并且结合荧光光谱及激光拉曼光谱进一步研究了一系列有序Ag_(NW)@Au_(NP)复合纳米线对共轭聚合物聚(3-己基噻吩)(P3HT)荧光效应的影响。实验结果表明,有序Ag_(NW)@Au_(NP)复合纳米线上Au_(NP)的粒径随着置换反应时间的延长或氯金酸-乙醇溶液浓度的增加而增大,该复合纳米线对P3HT的荧光效应有增强作用,但其增强效应会随置换反应进行而减弱。     

聚乙烯基三苯乙炔基硅烷的制备及热性能分析

为研究聚乙烯基三苯乙炔基硅烷树脂的热性能,以苯乙炔和乙烯基三氯硅烷为原料,运用格利雅反应合成了乙烯基三苯乙炔基硅烷单体,并通过红外(FT-IR)、核磁(1H-NMR,13C-NMR,29Si-NMR)证实了合成产物.以此单体为原料,通过热聚合法制备了聚乙烯基三苯乙炔基硅烷树脂,并采用TGA-DTG研究该聚合物的热分解动力学,计算了相应动力学参数.结果表明:该树脂的热分解温度(Td5%)在550℃左右,800℃时聚合物的残炭率约80%;用Kissinger法和Ozawa法求得的聚合物热分解活化能分别为266.55和236.89 k J/mol;用Crane法求得聚合物的热分解反应级数为0.93,近似为一级反应.     

The use of nanoimprint lithography to improve efficiencies of bilayer organic solar cells based on P3HT and a small molecule acceptor

Nanoimprint lithography (NIL) was carried out on bilayer organic photovoltaics (OPVs) based on regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) as electron donor and 4,7-bis(2-(1-ethylhexyl-4,5-dicyano-imidazol-2-yl)vinyl)benzo[c]1,2,5-thiadiazole (EV-BT) as electron acceptor. The power conversion efficiency of the devices after nanoimprinting increased from 0.20% to 0.30%, closer to that of the bulk heterojunction device at 0.37%. As a result, NIL proved to be a feasible method for improving the bilayer OPV performance by increasing the donor/acceptor interfacial area.