A promising ketone containing alternating copolymer for organic photovoltaics

An alternating copolymer containing dithienylcyclopentadienone, thiophene and benzothiadiazole was synthesized by palladium (0) catalyzed Stille coupling reaction. Structural characterization of the synthesized alternating copolymer was carried out by NMR and FTIR spectroscopy. This solution processable copolymer shows an excellent thermal stability and has a broad absorption range from 300-800 nm. High LUMO energy level and low band gap of the synthesized copolymers suggest that, this copolymer will be a better donor material for application in organic photovoltaics. Particle size analysis and molecular weight determination of the synthesized copolymer through dynamic light scattering experiment indicates that, high molecular weight copolymer was obtained by this polymerization route. Photovoltaic devices were fabricated from the blend of copolymer and phenyl-C61- butyric acid methyl ester as the active material. Fabricated photovoltaic device results show that this alternating copolymer is a promising candidate for use in organic photovoltaics.

Phthalate mediated hydrogelation of a pyrene based system: a novel scaffold for shape-persistent, self-healing luminescent soft material

Two-component super-hydrogelation triggered by the acid-base interaction of a L-histidine appended pyrenyl derivative (PyHis) and phthalic acid (PA) was reported. The use of isomeric isophthalic or terephthalic acid or other comparable acids in place of PA does not lead to salt formation and therefore hydrogelation is not observed. Excimer formation of the pyrenyl unit has not been detected although the PyHis : PA = 1: 1 system undergoes extensive self-assembly in aqueous solution. The synergistic effect of intermolecular H-bonding forces, pi-pi stacking, electrostatic interactions, etc. is found to be responsible for robust hydrogel formation. Development of chiral supramotecular assemblies has been verified through circular dichroism spectroscopy. Morphological investigations involving the PyHis : PA = 1: 1 system show vesicular nano-structures with a definite bilayer width at relatively low concentrations. The latter fuses to construct coiled-coil left-handed helical fibers upon increase in the concentrations of the gelators. The intertwining of the resultant helical fibers eventually results in hydrogel formation. The probable bilayer packing in the self-assembled structures has been probed using X-ray diffraction (XRD) studies and lanthanide sensitization, which suggests that the polar imidazolium hydrogen phthalate unit of the gelator forms the head group and faces the hydrophilic water environment while the hydrophobic pyrenyl units sit inside the hydrophobic core of the bilayer. The hydrogel exhibits multi-stimuli responsiveness including thixotropic behavior. In addition, shape-persistent as well as rapid self-healing behaviour of the hydrogel was established. Furthermore load-bearing characteristics of the hydrogel have also been demonstrated.

Strategy for Enhancing the Dielectric Constant of Organic Semiconductors Without Sacrificing Charge Carrier Mobility and Solubility

Current organic semiconductors for organic photovoltaics (OPV) have relative dielectric constants (relative permittivities, epsilon(r)) in the range of 2-4. As a consequence, Coulombically bound electron-hole pairs (excitons) are produced upon absorption of light, giving rise to limited power conversion efficiencies. We introduce a strategy to enhance epsilon(r) of well-known donors and acceptors without breaking conjugation, degrading charge carrier mobility or altering the transport gap. The ability of ethylene glycol (EG) repeating units to rapidly reorient their dipoles with the charge redistributions in the environment was proven via density functional theory (DFT) calculations. Fullerene derivatives functionalized with triethylene glycol side chains were studied for the enhancement of epsilon(r) together with poly(p-phenylene vinylene) and diketo-pyrrolopyrrole based polymers functionalized with similar side chains. The polymers showed a doubling of epsilon(r) with respect to their reference polymers in identical backbone. Fullerene derivatives presented enhancements up to 6 compared with phenyl-C-61-butyric acid methyl ester (PCBM) as the reference. Importantly, the applied modifications did not affect the mobility of electrons and holes and provided excellent solubility in common organic solvents.

Zinc oxide nanostructures and high electron mobility nanocomposite thin film transistors

This paper reports on the synthesis of zinc oxide (ZnO) nanostructures and examines the performance of nanocomposite thin-film transistors (TFTs) fabricated using ZnO dispersed in both n- and p-type polymer host matrices. The ZnO nanostructures considered here comprise nanowires and tetrapods and were synthesized using vapor phase deposition techniques involving the carbothermal reduction of solid-phase zinc-containing compounds. Measurement results of nanocomposite TFTs based on dispersion of ZnO nanorods in an n-type organic semiconductor ([6, 6]-phenyl-C61-butyric acid methyl ester) show electron field-effect mobilities in the range 0.3-0.6 cm2V-1 s-1. representing an approximate enhancement by as much as a factor of 40 from the pristine state. The on/off current ratio of the nanocomposite TFTs approach 106 at saturation with off-currents on the order of 10 pA. The results presented here, although preliminary, show a highly promising enhancement for realization of high-performance solution-processable n-type organic TFTs. © 2008 IEEE.

Avaliação da acidez de bio-óleos obtidos pela pirólise de óleos vegetais pós-consumo

O descarte irregular do óleo vegetal pós-consumo diretamente na rede de esgoto vem causando grandes problemas para o meio ambiente. Atualmente, essa problemática tem se intensificado devido ao aumento de produção e consumo destes óleos, o que por conseqüência aumenta o despejo desordenado. No presente estudo foi realizada a obtenção do bio-óleo a partir da pirólise térmica em atmosfera de nitrogênio, a 400C, por 20 minutos, do óleo vegetal pós-consumo, provenientes das seguintes oleoginosas: soja, milho, girassol e canola. As pirólises não-catalíticas apresentaram uma geração média entre 40 e 50% de um bio-óleo, de elevado índice de acidez, 81,8 mg NaOH/g. Na pirólise catalítica, a argila ácida K10 foi o catalisador que apresentou melhor eficácia para geração de um bio-óleo de menor índice de acidez. A concentração ótima do catalisador foi de 5%(m/m), gerando 482 % de um bio-óleo com índice de acidez de 43,8 mg NaOH/g. A caracterização dos líquidos pirolíticos obtidos foi realizada através da técnica de espectrofotometria na região do infravermelho (FTIR) e cromatografia em fase gasosa acoplada a espectrômetro de massas (CG/EM) que monstraram que a trioleína, o triglicerídeo do ácido oléico, foi craqueado, gerando o hexadecanoato de octadecila e o oleato de eicosila, ésteres do respectivo ácido graxo

Avaliação da aspirina e do ácido cafeico fenetil estersobre o reparo tecidual cutâneo

Numerosos modelos in vitro e in vivo foram desenvolvidos para estudar o reparo de lesões e identificar os mecanismos chave deste processo. Visando avaliar o processo de cicatrização utilizamos um modelo de lesão excisional total e um modelo de queimadura promovida por escaldamento. No estudo utilizando o modelo de lesão excisional total, abordamos o uso da aspirina (um inibidor não seletivo da COX) e seu efeito diferenciado sobre os sexos na cicatrização cutânea de camundongos. Observamos que os grupos fêmea controle e tratado apresentaram contração atrasada comparado aos grupos macho controle e tratado, respectivamente. Entre os grupos fêmea e macho controles, as fêmeas apresentaram menor atividade da mieloperoxidase e menor quantidade de células MIF-positivas do que os machos controle. Já entre os grupos fêmea e macho tratados, foi observado que nas fêmeas tratadas, a atividade da mieloperoxidase e a quantidade de macrófagos F4/80-positivos estavam maiores do que no grupo macho tratado. Ainda entre os grupos tratados, as fêmeas apresentaram menores níveis de hidroxiprolina e maior expressão proteica de vWF e VEGF comparado aos machos. No estudo das lesões causadas por queimadura, avaliamos as propriedades anti- inflamatórias e antioxidantes do ácido cafeico fenetil ester (CAPE) no reparo destas lesões e observamos que em 7, 14, 21 e 70 dias após a queimadura, o grupo queimado+CAPE apresentou menor área lesada, além de menor atividade da mieloperoxidase e dos níveis de nitrito do que o grupo queimado. Também foi observado que no grupo queimado+CAPE a expressão proteica de CD68 e de PECAM-1 estava reduzida comparada ao grupo queimado. Analisando os parâmetros de dano oxidativo foi observado que os níveis de MDA e de proteínas carboniladas estavam menores no grupo queimado+CAPE do que no grupo queimado, tanto no plasma quanto na lesão. Em suma, nosso estudo avaliou o processo de cicatrização de dois modelos de lesão, em roedores de diferentes espécies e em abordagens distintas. No modelo de lesão excisional total em camundongos observamos que a administração da aspirina prejudicou o processo de cicatrização em camundongos Balb/c fêmeas, mas não afetou esse processo nos machos da mesma linhagem, o que pode ser explicado pela redução dos níveis de estrógenos nas fêmeas. A utilização do CAPE na cicatrização de queimaduras em ratas comprovou sua eficácia anti-inflamatória e antioxidante devido ao grupo queimado+CAPE ter apresentado maior taxa de cicatrização, redução da resposta inflamatória, além da redução do dano oxidativo em lipídeos e proteínas comparado ao grupo queimado.

Effects of buffer layer properties and annealing process on bulk heterojunction morphology and organic solar cell performance

The performance of polymer-fullerene bulk heterojunction (BHJ) solar cells is strongly dependent on the vertical distribution of the donor and acceptor regions within the BHJ layer. In this work, we investigate in detail the effect of the hole transport layer (HTL) physical properties and the thermal annealing on the BHJ morphology and the solar cell performance. For this purpose, we have prepared solar cells with four distinct formulations of poly(3,4- ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) buffer layers. The samples were subjected to thermal annealing, applied either before (pre-annealing) or after (post-annealing) the cathode metal deposition. The effect of the HTL and the annealing process on the BHJ ingredient distribution - namely, poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) - has been studied by spectroscopic ellipsometry and atomic force microscopy. The results revealed P3HT segregation at the top region of the films, which had a detrimental effect on all pre-annealed devices, whereas PCBM was found to accumulate at the bottom interface. This demixing process depends on the PEDOT:PSS surface energy; the more hydrophilic the surface the more profound is the vertical phase separation within the BHJ. At the same time those samples suffer from high recombination losses as evident from the analysis of the J-V measurements obtained in the dark. Our results underline the significant effect of the HTL-active and active-ETL (electron transport layer) interfacial composition that should be taken into account during the optimization of all polymer-fullerene solar cells. © 2012 The Royal Society of Chemistry.

Non-destructive optical characterization of phase separation in bulk heterojunction organic photovoltaic cells

The dithiophene donor-acceptor copolymers that are bridged either with carbon (C-PCPDTBT) or silicon atoms (Si-PCPDTBT) belong to a promising family of materials for use in photoactive layers for organic photovoltaic cells (OPVs). In this work, we implement the non-destructive Spectroscopic Ellipsometry technique in the near infrared to the far ultraviolet spectral region in combination with advanced theoretical modeling to investigate the vertical distribution of the C-PCPDTBT and Si-PCPDTBT polymer and fullerene ([6,6]-phenyl C71-butyric acid methyl ester - PC70BM) phases in the blend, as well as the effect of the polymer-to-fullerene ratio on the distribution mechanism. It was found that the C-PCPDTBT:PC70BM blends have donor-enriched top regions and acceptor-enriched bottom regions, whereas the donor and acceptor phases are more homogeneously intermixed in the Si-PCPDTBT:PC70BM blends. We suggest that the chemical incompatibility of the two phases as expressed by the difference in their surface energy, may be a key element in promoting the segregation of the lower surface phase to the top region of the photoactive layer. We found that the increase of the photoactive layer thickness reduces the polymer enrichment at the cathode, producing a more homogeneous phase distribution of donor and acceptor in the bulk that leads to the increase of the OPV efficiency. © 2014 Elsevier B.V.

酸化油固定床酶法合成生物柴油研究

酸化油是油脂工业中以皂脚、油脚经酸化处理得到的产品。它的主要成分是游离脂肪酸及中性油，是生产脂肪酸的重要原料，但生产过程中有水解废水的产生，若将其直接排放，既污染了环境又浪费了资源。生物柴油的主要成分是脂肪酸甲酯（fatty acid methyl ester，FAME）。它具有原料丰富而且可再生、可生物降解、无毒、不含芳香烃、二氧化硫等污染物、燃烧排放低、闪点高、运输储存安全等特点。作为石化柴油的潜在替代能源，生物柴油因其独特的优越性和现实的需求越来越受到关注。利用酸化油生产生物柴油不仅可以缓解生物柴油原料不足问题，还可解决酸化油所带来的环境问题。

The convertion of acid oil to biodiesel by use of immobilized Candida lipase absorbed on textile cloth was studied in a fixed bed reactor, which can not only reduce the environmental pollution of acid oil, but also produce a substitute for petroleum diesel. The acid oil mixed with methanol was pumped into three fixed bed reactors in series, and the methanol was added with the molar flow rate same as the acid oil in each reactor. The effects of enzyme content, solvent content, water content, flow rate of reactant and temperature on the enzymatic reaction were analyzed. The result of orthogonal experiments indicates that the optimal transesterification can be performed under the following conditions： immobilized lipase content in acid oil, 20% ; hexane content in acid oil, 10% ; water content in acid oil, 10%, reaction temperature, 50 ℃ ; and flow rate of reactant, 0.08 g/rain. Under these conditions, the FAME content of 90.18% in the product is obtained. The immobilized lipase can be reused with relatively stable activity after glycerol being removed from the surface. By refining, most of the chemical and physical properties of biodiesel will meet the American and Germany biodiesel standards and exceed the Chinese standard of 0^# petroleum diesel except for carbon residue, density and kinematic viscosity.

酸化油固定床酶法合成生物柴油研究

以固定化的假丝酵母酶为催化剂，在三段式固定床反应器内，醇油摩尔比为1：1，采用分级流加甲醇的方式，将高酸值的酸化油转化为生物柴油，探讨了酶量、溶剂量、水量、温度、反应液流速等与产物中甲酯含量的关系。正交实验结果表明，反应的最适条件为酶用量、溶剂量、水量分别为油重的15％、10％、10％，反应液流速为0.8g·min^-1，温度为45℃，在此条件下，产物中甲酯含量达到了90．18％。

生物柴油转化效果测定方法的研究

生物柴油的生产原料、催化剂、工艺流程等存在多样化特点，为比较各种方法的优劣，需要建立一种适宜、通用的测定方法。通过分析国内外相关测定方法，提出以气相色谱测定反应产物，十七碳脂肪酸甲酯为标准物，内标法计算反应转化率和产率的方法。

Synthesis of biodiesel from waste cooking oil using immobilized lipase in fixed bed reactor

Waste cooking oil (WCO) is the residue from the kitchen, restaurants, food factories and even human and animal waste which not only harm people's health but also causes environmental pollution. The production of biodiesel from waste cooking oil to partially substitute petroleum diesel is one of the measures for solving the twin problems of environment pollution and energy shortage. In this project, synthesis of biodiesel was catalyzed by immobilized Candida lipase in a three-step fixed bed reactor. The reaction solution was a mixture of WCO, water, methanol and solvent (hexane). The main product was biodiesel consisted of fatty acid methyl ester (FAME), of which methyl oleate was the main component. Effects of lipase, solvent, water, and temperature and flow of the reaction mixture on the synthesis of biodiesel were analyzed. The results indicate that a 91.08% of FAME can be achieved in the end product under optimal conditions. Most of the chemical and physical characters of the biodiesel were superior to the standards for 0(#)diesel (GB/T 19147) and biodiesel (DIN V51606 and ASTM D-6751).

Production and characterization of biodiesel from tung oil

The feasibility of biodiesel production from tung oil was investigated. The esterification reaction of the free fatty acids of tung oil was performed using Amberlyst-15. Optimal molar ratio of methanol to oil was determined to be 7.5:1, and Amberlyst-15 was 20.8wt% of oil by response surface methodology. Under these reaction conditions, the acid value of tung oil was reduced to 0.72mg KOH/g. In the range of the molar equivalents of methanol to oil under 5, the esterification was strongly affected by the amount of methanol but not the catalyst. When the molar ratio of methanol to oil was 4.1:1 and Amberlyst-15 was 29.8wt% of the oil, the acid value decreased to 0.85mg KOH/g. After the transesterification reaction of pretreated tung oil, the purity of tung biodiesel was 90.2wt%. The high viscosity of crude tung oil decreased to 9.8mm(2)/s at 40 degrees C. Because of the presence of eleostearic acid, which is a main component of tung oil, the oxidation stability as determined by the Rancimat method was very low, 0.5h, but the cold filter plugging point, -11 degrees C, was good. The distillation process did not improve the fatty acid methyl ester content and the viscosity.

Production of biodiesel from soapstock using an ion-exchange resin catalyst

The feasibility of biodiesel production from soapstock containing high water content and fatty matters by a solid acid catalyst was investigated. Soapstock was converted to high-acid acid oil (HAAO) by the hydrolysis by KOH and the acidulation by sulfuric acid. The acid value of soapstock-HAAO increased to 199.1 mg KOH/g but a large amount of potassium sulfate was produced. To resolve the formation of potassium sulfate, acid oil was extracted from soapstock and was converted to HAAO by using sodium dodecyl benzene sulfonate (SDBS). The maximum acid value of acid oil-HAAO was 194.2 mg KOH/g when the mass ratio of acid oil, sulfuric acid, and water was 10:4:10 at 2% of SDBS. In the esterification of HAAO using Amberylst-15, fatty acid methyl ester (FAME) concentration was 91.7 and 81.3% for soapstock and acid oil, respectively. After the distillation, FAME concentration became 98.1% and 96.7% for soapstock and acid oil. The distillation process decreased the total glycerin and the acid value of FAME produced a little.

野桂花的化学成分研究

首次从野桂花（Osmanthus yunnanensis Fr. P. S. Green）地上部分95%乙醇提取物中通过色谱分离得到20个化合物, 其中化合物20为新化合物。基于波谱数据它们被鉴定为(E)-阿魏酸二十烷基酯(1)、β-谷甾醇(2)、羽扇豆醇(3)、齐墩果酸(4)、7-oxo-β-sitosterol(5)、乙酰齐墩果酸(6)、(6′-O-palmitoyl)-sitosterol 3-O-β-D-glucoside(7)、rotundioic acid(8)、地榆糖甙Ⅱ(9)、27-O-(E)-对羟基肉桂酰-28-齐墩果酸(10)、27-O-(Z)-对羟基肉桂酰-28-齐墩果酸(11)、hycandinic acid ester(12)、绿原酸丁酯(13)、4,5-二咖啡酰奎尼酸丁酯(14)、4,5-dihydroxyprenyl caffeate(15)、28-O-β-D-glucopyranosyl rotundioic acid (16)、4-(6-O-caffeoyl-β-D-glucopyranosyloxy)-5-hydroxyprenyl caffeate (aohada-glycoside C, 17)、 4-β-D-glucopyranosyloxy-5-hydroxy-prenyl caffeate (aohada-glycoside A, 18)、β-胡萝卜甙(19)以及3-[O-β-D-(6-O-咖啡酰吡喃葡萄糖)]-甲基-2-烯-γ-内酯 (20)。化合物13、14、15和17有较强的α-葡萄糖甙酶抑制活性。当浓度为1 mg/ml时，它们对α-葡萄糖甙酶的抑制分别为61.5%、95.5%、72.1%、62.6%，活性高于阿卡波糖。 综述了木犀属植物化学成分及1993年以来苯丙素甙类化合物活性研究进展。 Twenty compounds were isolated from the 95% ethanol extract of the aerial parts of Osmanthus yunnanensis Fr. P. S. Green by chromatography for the first time. On the basis of spectral data, they were identified as (E)-ferulic acid eicosyl ester (1), β-sitosterol (2), lupenol (3), oleanolic acid (4), 7-oxo-β-sitosterol (5), acetyloleanolic acid (6), (6′-O-palmitoyl)-sitosterol 3-O-β-D-glucoside (7), rotundioic acid (8), ziyu glycosideⅡ (9), 3β-hydroxy-27-p-(E)-coumaroyloxy-olean-12-en-28-oic acid (10), 3β-hydroxy-27-p-(Z)-coumaroyloxyolean-12-en-28-oic acid (11), hycandinic acid ester (12), chlorogenic acid butyl ester (13), 4,5-di-O-caffeoylquinic acid butyl ester (14), 4,5-dihydroxyprenyl caffeate (15), 28-O-β-D-glucopyranosyl rotundioic acid (16), 4-(6-O-caffeoyl-β-D-glucopyranosyloxy)-5-hydroxyprenyl caffeate (aohada- glycoside C, 17), 4-β-D-glucopyranosyloxy-5-hydroxyprenyl caffeate (aohada- glycoside A, 18), β-daucosterol(19) and 3-[O-β-D-(6-O-caffeoylglucopyranosyl)]- methyl-2-en-γ-lactone (20). Compound 20 is a new one. Compounds 13, 14, 15 and 17 inhibit α-glucosidase with corresponding inhibitory rate of 61.5%, 95.5%, 72.1% and 62.6% at a concentration of 1 mg/ml, higher than acarbose. The chemical studies on Osmanthus genus and bioactivities of phenylpropanoid glycosides were summarized.