ADMET reactions in miniemulsion

This work investigates acyclic diene metathesis (ADMET) polymerization reactions in aqueous miniemulsion. Different types of ruthenium‐based catalysts and different surfactants (anionic, cationic, and nonionic) were evaluated. A Ru‐indenylidene catalyst (Umicore M2) showed higher activity in water if compared to the Ru‐benzylidene catalysts (Hoveyda Grubbs second generation and Grubbs first generation). Moreover, the catalyst activity was affected by the type of the surfactant. In summary, the Umicore M2 catalyst and the nonionic poly(ethylene oxide) based surfactant Lutensol AT80 were found to be the most suitable combination for ADMET reactions in miniemulsion allowing the preparation of polymers with number average molecular weight (M_n) of up to 15 kDa. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1300–1305     

The Measurement of the Gibbs Energy of Transfer Between Oil and Water Using a Nano‐Carbon Paste Electrode

The use of nano‐carbon paste electrodes for the measurement of Gibbs energies of transfer between oil and aqueous phases is reported. In this method the oil of interest is used as the binder for the nano‐carbon paste electrodes and the molecule of interest is dissolved in the organic or aqueous phase. Voltammetry is performed over a period of time and used to monitor the transfer of the molecule between the two phases. The method is illustrated for the transfer of ferrocenemethanol between water and oil using the ferrocenemethanol / ferroceniummethanol (FcCH₂OH/FcCH₂OH⁺) redox couple. Three pairs of voltammetric peaks were observed in a 0.1 M KCl solution when the nano‐carbon paste electrode was modified by dissolution of FcCH₂OH in the binder oil: P1 [E=0.23 V, 0.17 V vs. Ag/AgCl (1 M KCl)], P2 [E=0.36 V, 0.32 V vs. Ag/AgCl (1 M KCl)] and P3 [E=0.55 V, 0.46 V vs. Ag/AgCl (1 M KCl)]. These are assigned to the FcCH₂OH species existing in the aqueous solution [FcCH₂OH(aq)/FcCH₂OH⁺(aq)], originating in the oil (o) [FcCH₂OH(o)/FcCH₂OH⁺(aq)] and to oxidation of adsorbed (ads) material on the nano‐carbon [FcCH₂OH(ads)] respectively. When supporting electrolyte containing the anions Cl^?, NO₃^? or SCN^? was used, an expulsion of the oxidised ferrocene occurred and the difference in midpoint potentials (E_mid) between the peaks P1 and P2 observed in these experiments allowed the calculation of the Gibbs energy (ΔG°) of transfer of ferrocenemethanol from water to oil. The average ΔG° value thus obtained was (?12.7±0.2) kJ mol^?1. For more hydrophobic anions (X^?=PF₆^?, AsF₆^?), the electron transfer is coupled to the transfer of the anion into the oil and the ΔG° for the transfer of the ion pair of FcCH₂OH⁺ and X^? ions from water to oil was found to be ?1.3 and ?3.9 kJ mol^?1 for PF₆^? and AsF₆^? respectively.     

油页岩中几种微量元素在干馏过程的形态变迁

以桦甸油页岩为研究对象,采用逐级提取实验,考察了不同升温速率及干馏终温对其内部赋存的Cr、Co、Pb、Cu、V五种微量元素的形态变迁特性的影响。结果发现,各元素均在2.5℃/min和20℃/min升温速率下表现出了较大的迁移率,且干馏终温升高更有利于元素的迁移;低升温速率和高干馏终温更能促进元素大部分形态的迁移,但硫化物结合态的迁移在高升温速率和高干馏终温则更为有利;元素不同形态的迁移总会有一部分向有机物结合态转变。     

Cyclic Alkyl Amino Carbene (CAAC) Ruthenium Complexes as Remarkably Active Catalysts for Ethenolysis

An expanded family of ruthenium‐based metathesis catalysts bearing cyclic alkyl amino carbene (CAAC) ligands was prepared. These catalysts exhibited exceptional activity in the ethenolysis of the seed‐oil derivative methyl oleate. In many cases, catalyst turnover numbers (TONs) of more than 100 000 were achieved, at a catalyst loading of only 3 ppm. Remarkably, the most active catalyst system was able to achieve a TON of 340 000, at a catalyst loading of only 1 ppm. This is the first time a series of metathesis catalysts has exhibited such high performance in cross‐metathesis reactions employing ethylene gas, with activities sufficient to render ethenolysis applicable to the industrial‐scale production of linear α‐olefins (LAOs) and other terminal‐olefin products.     

核桃楸叶挥发油化学成分分析

采用水蒸气蒸馏法提取核桃楸叶中的挥发油,从核桃楸叶挥发油中分离了57种化合物,用气相色谱/质谱联用法鉴定了51种化合物,占被分离化合物的89.46%,其中烃类(33种,48.03%)、酮类(1种,0.55%)、醇类(5种,25.94%)、酯类(6种,8.43%)、酸类(1种,0.62%)、含氧杂环类(4种,2.62%)及甲酰类(1种,0.65%)等7大类化合物,有3类(27种,51.19%)为已知药用成分,这些数据为新药开发提供了科学信息.     

第二代生物柴油技术研究进展

第二代生物柴油是指在高温高压下,利用催化加氢脱氧反应等技术将动植物油脂转化为具有石化燃料品质的碳氢燃料,是能源领域最热门和最有前途的技术之一.本文作者对动植物油原料来源,加氢脱氧反应机理,主要的加氢生产工艺以及加氢催化剂的研究进展进行了综述,并且分析了发展第二代生物柴油的难点和发展趋势.     

Volatiles of Helichrysum italicum (Roth) G. Don from Croatia

Helichrysum italicum (Roth) G. Don is a flowering plant of the family Asteraceae. It is rich in oil that is used for different medicinal purposes and in fragrance industry. Volatile profile of four populations of H. italicum, collected from natural habitat in Dalmatia (Croatia), was analysed by capillary GC–MS. Sample from Bra? Island had α-trans-bergamotene (10.2%) and β-acoradiene (10.1%) as the majors, whereas sample collected on Biokovo Mt. was rich in neryl acetate (8.1%). β-Acoradiene was also the main constituent of sample collected near Tijarica, whereas rosifoliol (8.5%) was the most abundant constituent in sample collected near Makarska. Presented results show the influence of environmental conditions on chemical differentiation of the volatiles of H. italicum from Croatia.     

Compositions of the seed oil of the Borago officinalis from Iran

In order to investigate the composition of borage (Borago officinalis L.) seed oil, this research was performed under the field conditions at Shahriyar and Garmsar zones, Iran during the 2012 planting year. The oil yield of borage was 31.46% and 33.7% at Shahriyar and Garmsar zone, respectively, and nine and eight fatty acids were identified in the seed oil of borage at Shahriyar and Garmsar, respectively – palmitic, linoleic, stearic and γ-linolenic acids were dominant in the seed oil of borage from both zones. Unsaturated fatty acid content was more than the saturated fatty acids in both zones. The ratio of linoleic acid and α-linolenic acid in the borage cultivated at Shahriyar and Garmsar zones was 2.13 and 2.29. The fatty acid profile of Garmsar borage, oleic and oleic/linoleic acid ratio, increased. Locations with different ecological conditions resulted in changes in both seed oil content and fatty acid profile of borage.     

In vitro antibiofilm activity of Murraya koenigii essential oil extracted using supercritical fluid CO2 method against Pseudomonas aeruginosa PAO1

The antibiofilm activity of Murraya koenigii essential oil (EO) against Pseudomonas aeruginosa PAO1 was investigated in this study. A decrease in the production of rhamnolipid, extracellular polymeric substance and swarming motility was observed by the EO treatment (0.3% v/v). The static microtitre plate assay revealed 80% reduction in biofilm formation by P. aeruginosa PAO1 on M. koenigii EO treatment. Fluorescence microscopy and scanning electron microscopy analyses confirmed the reduction of biofilm formation in P. aeruginosa PAO1 when treated with M. koenigii EO. Gas chromatography–mass spectrometry analysis of the EO revealed the presence of well-known antibiofilm agents such as spathulenol (5.85%), cinnamaldehyde (0.37%) and linalool (0.04%). Cinnamaldehyde has not been previously reported in M. koenigii EO. The potent antibiofilm properties of M. koenigii EO may be effectively exploited in food and pharmaceutical industries as well as in controlling Pseudomonas biofilms on indwelling medical devices.     

小波包压缩-RBF网络同时测定润滑油中铁、铜、锌

将小波包压缩-RBF网络方法用于润滑油中铁铜锌三组分分光光度同时测定该方法采用小波包函数对光谱数据进行压缩处理,用较大的小波色系数构成新的校正集和预测集代替原始的校正集和预测集,然后用RBF网络进行数据解析。研究表明,用bior2．4小波包处理原始测定数据,最佳小波基用logenerge熵标准,选择适当阈值将变量数由46个压缩成25个（压缩比为0．54）,整体预测效果最好。将此方法用于合成样预测．预测结果与实际浓度的相对误差绝对值在2．50％～9．40％之间;用于实际润滑油样品中铁、铜和锌的同时测定,解析值与原子吸收法（AAS）的测定值的相对误差绝对值作3．55％～7．86％之间。应用结果令人满意。