纳米纤维素/聚3,4-乙撑二氧噻吩复合薄膜的制备及电致变色性能

以棉浆粕为原料,采用硫酸溶胀结合超声波处理的方法制备了纳米纤维素(NC).在纳米纤维素的水分散液中加入3,4-乙撑二氧噻吩单体,以过硫酸铵为氧化剂,采用原位化学氧化法制得了纳米纤维素/聚3,4-乙撑二氧噻吩(NC/PEDOT)纳米复合物.对NC和NC/PEDOT复合物进行扫描电镜、透射电镜和红外光谱分析.将纳米复合物的水分散液滴涂在氧化铟锡(ITO)玻璃表面形成复合薄膜,考察不同纳米纤维素含量对NC/PEDOT复合薄膜电致变色性能的影响.结果表明,NC呈棒状,平均直径为20 nm,长度为100~300nm;NC/PEDOT复合物中PEDOT均匀包覆在NC表面形成核壳结构,平均直径为30 nm;复合薄膜中当NC含量为60%时,其电致变色性能最好,具有最高的对比度(24.4%),最短的响应时间(1 s),最高的着色效率(51.8 cm~2/C).     

石墨烯/聚3，4-乙烯二氧噻吩复合物的电化学制备及其在超级电容器中的应用

首次提出了一种在离子液体中在石墨烯表面用恒电流法聚合3,4-乙烯二氧噻吩(EDOT)单体制备石墨烯/聚3,4-乙烯二氧噻吩(石墨烯/PEDOT)复合物的方法。用原子力显微镜、扫描电镜等技术表征证明石墨烯/PEDOT复合物是由PEDOT纳米谷粒状颗粒分散在石墨烯片表面而组成的。将该复合物用作超级电容器电极材料时,在1.0 A.g-1的充放电比电流下得到的比电容值为181 F.g-1。同时,该材料还显现出较好的充放电可逆性和稳定性。     

修饰Langmuir-Blodget膜法制备聚(3,4-亚乙基二氧噻吩)薄膜结构和导电性能的研究

采用修饰Langmuir-Blodget(LB)膜法以二十烷酸(AA)LB膜为模板,通过3,4-亚乙基二氧噻吩(EDOT)单体在LB膜亲水基团间聚合,制备了二十烷酸/聚(3,4-亚乙基二氧噻吩)(AA/PEDOT)复合LB膜.UV-Vis、FTIR和XPS分析表明EDOT在多层膜中有效聚合,生成了PEDOT导电聚合物;X射线衍射(XRD)和二次离子质谱(SIMS)分析表明薄膜具有较好的层状有序结构,进一步研究发现EDOT在AA多层膜中的聚合破坏了原有LB膜的有序性,这可能与聚合过程对层状结构产生的破坏作用有关;采用四探针仪及半导体测试仪研究了薄膜导电性能,发现AA/PEDOT多层膜的电导率随处理时间的变化产生突变,这与多层膜中导电通道的"逾渗"有关,在有效导电网络连通后电导率发生了突变.测试结果还表明AA层和PEDOT层之间具有较为明显的界面,PEDOT显示出较好的定域性,薄膜具有很好的层状有序结构.     

修饰LB膜法制备聚3,4-乙烯二氧噻吩薄膜

采用修饰Langmuir-Blodget(LB)膜法以二十烷酸(AA) LB膜为模板, 通过3,4-乙烯二氧噻吩(EDOT)单体在LB膜亲水基团间聚合, 制备了AA/PEDOT复合LB膜. 实验分析表明薄膜具有较好的层状有序结构, 并进一步研究发现EDOT在AA多层膜中的聚合破坏了原有LB膜的有序性, 这与聚合过程对层状结构产生的破坏作用有关; 研究了薄膜导电性能, 发现AA/PEDOT多层膜的电导率随处理时间的变化产生突变, 这与多层膜中导电通道的“渝渗”有关, 在有效导电网络连通后电导率发生了突变. 测试结果还表明AA/PEDOT膜导电性明显优于PEDOT旋涂膜和十八胺-硬脂酸/聚(3,4)乙烯二氧噻吩-聚苯乙烯磺(ODA-SA/PEDOT-PSS)复合膜.     

聚(3,4-乙撑二氧噻吩)导电织物的制备、结构及其电致变色性能

本文采用原位聚合法, 以耐酸性好的涤纶为基底, 制得了聚(3,4-乙撑二氧噻吩)/涤纶复合导电织物[Poly(3,4-ethylenedioxythiophene)/conducting terylene textile, PEDOT/CTT], 分析了该导电织物的形貌、导电性能及结构, 并对其电致变色性能进行了初步测试. 实验结果表明, 所得到的PEDOT/CTT具有良好的导电性和一定的电致变色性能, 有望在全固态电致变色织物的制备中获得应用.     

导电高分子PEDOT/PSS保护银纳米颗粒的制备与表征

利用导电高分子聚(3,4-二氧乙基噻吩)/聚(对苯乙烯磺酸)(PEDOT/PSS)作保护剂,制备了银纳米颗粒,用UV-Vis和TEM对其进行了表征.结果表明,选择合适量的PEDOT/PSS保护剂可以得到大小分布较窄银纳米颗粒.     

PEDOT的固相聚合法制备及其在紫外光探测器中的应用

首先以2,5-二溴-3,4-乙撑二氧噻吩（DBEDOT）为单体，通过固相聚合法在掺杂氟的二氧化锡导电玻璃（FTO）基底表面制备聚（3,4-乙撑二氧噻吩）（PEDOT）膜，然后将其与氧化锌纳米阵列（ZnO NRs）修饰的FTO组装成有机-无机异质结紫外光探测器，并研究其紫外光探测性能。采用紫外-可见分光光谱（UV-Vis）、傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）、X射线衍射光谱（XRD）等测试方法对材料进行表征。结果表明，固相聚合法制备的PEDOT能有效提升ZnO NRs基紫外光探测器的性能。器件在紫外光照射下（365 nm,0.32 mW/cm2）表现出较高响应度（15.34 mA/W）、较短响应时间（上升时间为0.159 s，下降时间为0.162 s）和较好的稳定性。     

基于3,4-乙烯二氧噻吩和吡咯-3-甲酸的共聚物薄膜的制备、表征及电致变色性能

以3,4-乙烯二氧噻吩(EDOT)和吡咯-3-甲酸(P3C)为共聚单体,EDOT和P3C分别按物质的量比1∶1,3∶1,5∶1,10∶1配比,通过电化学聚合制得了4种聚(3,4-乙烯二氧噻吩-吡咯-3-甲酸)薄膜,并依次命名为P(EDOT∶P3C)-1,P(EDOT∶P3C)-3,P(EDOT∶P3C)-5和P(EDOT∶P3C)-10.光谱电化学测试结果表明,4种共聚物薄膜都具有优良的电致变色性能,同时具有较好的电化学活性和较高的光学对比度.与聚3,4-乙烯二氧噻吩(PEDOT)相比,P(EDOT∶P3C)能展示更丰富的颜色变化,如P(EDOT∶P3C)-1薄膜随着电压的变化,可呈现从暗红色、浅褐色、灰蓝色到蓝色的变化.此外,基于EDOT和P3C以及钛氧簇[Ti_7(OEt)_(19)O_5(CoBr)],我们还设计合成了含钛共聚物薄膜P(EDOT∶P3C)-1-Ti,该薄膜不仅具有电致变色性能,而且还具有电催化氧化水的活性.     

原位聚合聚(3,4-乙烯二氧噻吩):π共轭聚电解质应用于聚合物太阳能电池空穴传输层

以带磺酸基团的π共轭聚电解质为模板,采用化学氧化还原方法制备了在水相中稳定分散的聚(3,4-乙烯二氧噻吩)(PEDOT)与聚电解质的复合物,并用作聚合物太阳能电池的空穴传输层.通过傅里叶变换红外光谱(FTIR)、紫外可见光谱(UV-Vis)、紫外光电子能谱(UPS)、原子力显微镜(AFM)、透射电子显微镜(TEM)和接触角等对聚(3,4-乙烯二氧噻吩):聚苯乙烯磺酸(PEDOT:PSS)和复合物薄膜的形貌和光电性能进行测试与表征.结果表明,相比于PEDOT:PSS,PEDOT:聚电解质复合物作为空穴传输层,具有合适的能级结构、高达95%的透光率(30 nm)、更疏水的表面形貌以及更高的空穴迁移率,有利于与活性层形成欧姆接触并提高空穴的注入和收集效率,进而提高器件的光伏性能.     

聚乙烯醇导电水凝胶制备的综合实验设计

设计了聚乙烯醇(PVA)导电水凝胶制备的综合实验。实验设计包括:前期文献调研、聚3,4-乙撑二氧噻吩/聚苯乙烯磺酸盐(PEDOT∶PSS)掺杂PVA水凝胶(PEDOT∶PSS/PVA)的制备、水凝胶结构表征与性能测试等部分。采用傅里叶变换红外光谱、扫描电子显微镜分别表征了PEDOT∶PSS/PVA的组成与形貌;采用数字万用表表征了PEDOT∶PSS/PVA的电导率;采用电子万能试验机表征了PEDOT∶PSS/PVA的机械性能及力敏性能。数据表明:PEDOT∶PSS/PVA具有良好的机械性能、导电性及力敏性能,且随着PEDOT∶PSS掺杂量的增加,PEDOT∶PSS/PVA的导电性、机械性能及力敏性能有所增加。教学实践表明,综合实验的开展有利于提高学生综合运用材料、化学专业知识的能力,在锻炼学生动手能力的同时,培养其分析问题、解决问题的能力。     

Synthetic Cu0.507(5)Pb8.73(9)Sb8.15(8)I1.6S20.0(2) nanowires

Nanowires of an iodine containing Pb-Sb-sulfosalt have been synthesized by chemical vapor transport. Their structure was studied using high-resolution transmission electron microscopy and X-ray powder diffraction. The lattice parameters show values equal to a=4.9801(4) nm, b=0.41132(8) nm (with two-fold superstructure), c=2.1989(1) nm and β=99.918(6)°. These parameters and the results of a multislice simulation are in good agreement with the mineral pillaite, Cu_0.10Pb_9.16Sb_9.84S_22.94Cl_1.06O_0.5 (space group C2/m, a=4.949(1) nm, b=0.41259(8) nm, c=2.1828(4) nm, and β=99.62(3)°). Microprobe and EDX analyses yielded a chemical composition of Cu_0.507(5)Pb_8.73(9)Sb_8.15(8)I_1.6S_20.0(2) which is close to natural pillaite but contains no oxygen and iodine instead of chlorine. The structure of the investigated material is based on chains of M-S polyhedra (M=Pb or Sb) typical for the architecture of sulfosalts implying iodine atoms in trigonal prismatic coordination with Pb atoms from the M-S polyhedra of neighboring chains. The [010] superstructure of the specimen was found to be unstable under electron beam irradiation with a rapid decrease of the b lattice parameter from 0.8 to 0.4 nm within 5 min.     

The magnesium-rich intermetallics Ir3.30(1)Mg17.96(4)In0.74(4) and Ir3Mg17.1(1)In1.9(1)

Phase analytical investigations in the system magnesium-iridium-indium revealed the magnesium-rich intermetallics Ir_3.30(1)Mg_17.96(4)In_0.74(4) and Ir₃Mg_17.1(1)In_1.9(1). The samples were prepared from the elements via induction melting in glassy carbon crucibles in a water-cooled sample chamber and subsequent annealing. Both intermetallics were investigated by X-ray powder and single-crystal diffraction: C2/c, Z=4, a=979.1(1), b=2197.4(2), , β=105.79(1)°, wR₂=0.0434, 3076 F² values, 108 variables for Ir_3.30(1)Mg_17.96(4)In_0.74(4), and a=983.39(8), b=2211.4(2), , β=105.757(6)°, wR₂=0.0487, 3893 F² values, and 115 variables for Ir₃Mg_17.1(1)In_1.9(1). Both compounds show solid solutions. In Ir_3.30(1)Mg_17.96(4)In_0.74(4), the indium site shows an occupancy by 69.9(4)% In+30.1(4)% Ir, and one magnesium site has a small mixed occupancy with indium, while nine atomic sites in Ir₃Mg_17.1(1)In_1.9(1) show Mg/In mixing with indium occupancies between 1.2(3)% and 14.8(3)%. The relatively complex crystal structure is of a new type. It can be explained by a packing of coordination number 10 and 12 polyhedra around the iridium atoms. The crystal chemical peculiarities and chemical bonding in both intermetallics is briefly discussed.     

C(膜)/Si(SiO2)(纳米微粒)/C(膜) 的光致发光性质研究

用直流辉光溅射法结合真空镀膜法制备出了一种"多层三明治结构"的光致发光材料-C(膜)/Si(SiO2)(纳米微粒)/C(膜)夹层膜,然后分别在400、650和750℃退火1 h.在波长为250 nm的紫外光激发下,刚制备出来未经退火处理的样品具有一个在398nm(3.12 eV)处的紫光宽带PL1峰.在650℃退火后,又出现了一个在360nm(3.44eV)附近的PL2峰.PL1和PL2峰形状和峰位与退火温度和激发波长无关,但强度却与退火温度和激发波长密切相关.结合形态结构分析可知,紫光PL1峰可用量子限制-发光中心(QC-LCs)模型进行解释:即光激发发生在8iO2微粒内部,而光发射源于SiO2与Si界面上的缺陷中心.紫外荧光PL2峰则源自SiC内部的电子-空穴复合发光.     

Chemiluminescence from poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS) block copolymers

A detailed analysis of the chemiluminescence emission (CL) from poly(styrene-b-ethylene-co-butylene-b-styrene), SEBS, was carried out. A phenol-phosphite stabilization system based on Irgafos 168 and Irganox 1330, was studied. The kinetic analysis of the CL profile under nitrogen shows a first-order reaction for the decay of chemiluminescence. The activation energy shows different values as a function of temperature, showing that different reactions are involved in the thermal degradation of the SEBS. The CL decay rate correlates well with the amount of the phosphite, Irgafos 168, and confirms the activity of this stabilizer as radical chain-breaking antioxidant in these copolymers.The isothermal analysis of CL under oxygen allows evaluation of the oxidation state, as well as the efficiency of the antioxidants. Good correlations are found between the CL parameters and concentration of Irgafos 168. Several factors suggest that oxidation begins in the interfacial region. Spectral analysis of the chemiluminescence shows the presence of different types of hydroperoxides.Finally, the characterization of the SEBS copolymers by differential scanning calorimetry reveals an order-disorder transition, assigned to aggregates that behave as paracrystalline regions.     

Sublimation enthalpies of the complexes W(CO)6-x(NCCH3)x (x=1,2,3) and Mo(CO)6-x(NCCH3x(x=1,3)

Vapour pressure measurements have been carried out on the complexes W(CO)_it6-x (NCCH₃x(x=1,2,3) and Mo(CO)_it6-x(NCCH₃x(x=1,3) employing the Knudsen effusion technique. The following enthalpies of sublimation, ΔH²⁹⁸_sub(kJ mole^?1), have been determined from vapour pressure data: W(CO)₅(NCCH₃)=98.1±2.0; W(CO) ₄ (NCCH₃)₂=131.0±6.0; W(CO)₃(NCCH₃₃=103.4±6.0; Mo(CO)₅(NCCH₃)=105.8± 5.6; and Mo(CO)₃(NCCH₃)₃=111.3±3.0.     

Novel (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles from (E)- and (Z)-3-styrylchromones: the unexpected case of (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles

An efficient synthetic method for the preparation of (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles has been developed. The reaction of (E)- and (Z)-3-styrylchromones with hydrazine hydrate afforded the corresponding (E)- and (Z)-4-styrylpyrazoles, respectively, saved 4′-nitro-derivatives where both (E)- and (Z)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles. The reaction mechanism for these transformations was discussed and the stereochemistry of all products was assigned by NMR experiments.     

Asymmetric dihydroxylation route to (R)-isoprenaline, (R)-norfluoxetine and (R)-fluoxetine

An efficient asymmetric synthesis of enantiomerically pure (R)-isoprenaline, (R)-norfluoxetine and (R)-fluoxetine is described using Sharpless asymmetric dihydroxylation as the key step.     

Stereoelective radical copolymerization of (RS)-α-methylbenzyl vinyl ether with (S)-(-)- or (R)-(+)-N-(α-methylbenzyl)maleimide

Racemic α-methylbenzyl vinyl ether was copolymerized with optically active (S)-(-)- or (R)-(+)-N-(α-methylbenzyl)maleimide using 2,2′-azobisisobutyronitrile in order to examine the possibility of stereoelective radical polymerization of vinyl-type racemic monomers. The resulting copolymers were found to have almost alternating sequences of the two kinds of monomeric units. The non-polymerized α-methylbenzyl vinyl ether, recovered from the copolymerization system, showed an optical activity of opposite sign to the optically active comonomer used, indicating clearly that the co-polymerization process is stereoelective. It was confirmed that α-methylbenzyl vinyl ether preferentially incorporated in the copolymer has the same absolute configuration as the optically active N-substituted maleimide.     

Synthesis of conjugated (1E,3E)- and (1Z,3Z)-1,4-di(n-pyridyl) (or n-quinolyl)-1,3-butadienes from n-(2′-chloroethenyl)pyridine (or quinoline)

The homocoupling reaction between the conjugated n-(2-chloroethenyl)pyridine; n, 2-, 3- and 4- (or quinoline; n, 2- and 4-) mediated by zero-valent nickel complexes at room temperature affords to the corresponding 1,4-diaryl-1,3-butadiene, always as the 1E,3E stereoisomer. The yield in 1,4-diaryl-1,3-butadiene increases with the nickel catalyst and hence, the active zero-valent nickel catalyst is not regenerated during the homocoupling reaction.The stereospecific synthesis of (1Z,3Z)-1,4-di(4′-pyridyl)-1,3-butadiene stereoisomer was efficiently carried out by partial hydrogenation of the appropriate 1,4-di(4′-pyridyl)-1,3-butadiyne.     

Syntheses of (E)- and (Z)-volkendousin

The first syntheses of the antitumor agents (E)-volkendousin (1) and acetonide 3 have been accomplished by efficient routes from readily available dehydroisoandrosterone (7) using allylic oxidation with SeO₂ to introduce the 4/gb-hydroxy group and 16-ketone. This sequence should make these compounds readily available for further biological evaluation.