油酸甲酯异构体的分离检测

采用涂有非极性固定液的毛细管柱,对油酸甲酯顺、反异构体进行分离,获得良好的分离效果。     

Determination of the Organics in Trimethylolpropane Wastewater

Organic components play a pivotal role in the treatment of trimethylolpropane wastewater; therefore, research aimed at gaining a better understanding of these components can aid in developing potential treatment methods to remove these pollutants. Thus, the use of liquid–liquid extractions coupled with gas chromatography–mass spectrometry is reported to examine the semivolatile organic components present in trimethylolpropane wastewater, while purge-and-trap coupled with flame ionization detection was used to determine the volatile organic components. Several factors which could affect the precision of the analytical method in pretreatment and detection steps were optimized. These techniques exhibited good linearity (determination coefficients greater than 0.9899), good intraday precision (less than 4.26%), and good interday precision (less than 13.09%). The optimized method was used for the determination of 23 organic components in trimethylolpropane wastewater. The main components were 2-ethylacrolein, butanoic acid, 1-hexanol, 2-ethyl-, trimethylolpropane, butyraldehyde, and toluene.     

紫外光谱法对维生素E油酸酯、维生素E与油酸的同时测定

建立了混合体系中维生素E、油酸和维生素E油酸酯同时测定的方法,用光纤光谱仪获取混合体系紫外-可见透射光谱.实验按均匀设计建立校正集和预测集,在255 ～315 nm波段采用偏最小二乘法建立了同时定量测定该3组分的校正模型,并用间隔区间偏最小二乘法(iPLS)通过优选建模区间改进油酸的预测模型.采用iPLS能够显著提高模型准确度,尤其对光谱弱响应的物质,最大相对误差从PLS直接建模的54.7%降至iPLS的8.98%,建立的模型可满足动力学研究的原位分析需要.     

Initiation of Radical Chain Reactions of Thiol Compounds and Alkenes without any Added Initiator: Thiol‐Catalyzed cis/trans Isomerization of Methyl Oleate

A kinetic study of the dodecanethiol‐catalyzed cis/trans isomerization of methyl oleate (cis‐ 2 ) without added initiator was performed by focusing on the initiation of the radical chain reaction. The reaction orders of the rate of isomerization were 2 and 0.5 for 1 and cis‐ 2 , respectively, and an overall kinetic isotope effect k_H/k_D of 2.8 was found. The initiation was shown to be a complex reaction. The electron‐donor/‐acceptor (EDA) complex of dodecanethiol ( 1 ) and cis‐ 2 formed in a pre‐equilibrium reacts with thiol 1 to give a stearyl and a sulfuranyl radical through molecule‐assisted homolysis (MAH) of the sulfur–hydrogen bond. Fragmentation of the latter gives the thiyl radical, which catalyzes the cis/trans isomerization. A computational study of the EDA complex, MAH reaction, and the sulfuranyl radical calculated that the activation energy of the isomerization was in good agreement with the experimental result of E_A=82 kJ M ^?1. Overall, the results may explain that the thermal generation of thiyl radicals without any initiator is responsible for many well‐known thermally initiated addition reactions of thiol compounds to alkenes and their respective polymerizations and for the low shelf‐life stability of cis‐unsaturated thiol compounds and of mixtures of alkenes and thiol compounds.     

聚苯乙烯/油酸/氟化镧复合纳米微球的制备、表征及抗磨性能

用种子乳液聚合的方法合成了聚苯乙烯／油酸／氟化镧复合纳米微球，通过TEM、XRD、FTIR、TG－DTA等测试手段对其结构和形貌进行了表征，并在四球试验机上考察了其摩擦学行为。结果表明，复合纳米微球具有核壳结构，平均粒径约30nm，作为新型润滑油添加剂，具有良好的抗磨性能。     

Effect of preformed egg phosphatidylcholine vesicles on spontaneous vesiculation of oleate micelles

An addition of oleate micellar solution to two original sizes (180 nm and 50 nm) of preformed vesicles was studied using gel exclusion chromatography, dynamic light scattering and freeze fracture electron microscopy. The effect of molar ratios of phospholipid and oleate on size distribution of newly formed vesicles was investigated by varying molar concentrations of these two components. After adding an equiamount of oleate to 180 nm-preformed vesicles or 50 nm-preformed vesicles, a relatively monodisperse population of newly formed vesicles was detected. For the high amount of oleate addition to two original sizes of preformed vesicles, the results were quite different. New large vesicles and a number of new small vesicles were observed in samples of mixed EggPC/oleate suspension in the presence of preformed vesicles with 180 nm of size, whereas, only some new large vesicles were detected in samples of mixed EggPC/oleate suspension in the presence of preformed vesicles with 50 nm of size. We assumed that the number of new small vesicles, with size close to preformed vesicles, increased in the latter case. The transformation of mixed EggPC/oleate micelles to mixed vesicles was investigated. The results showed that transformation of mixed EggPC/oleate micelles to vesicles was remarkably faster than transformation of mere oleate micelles to vesicles. The above findings suggested that new mixed EggPC/oleate vesicles with small size were presumably formed by partial solubilization.     

油酸甘油酯体系的低场核磁共振弛豫特性研究

甘油酯体系低场核磁共振（LF-NMR）弛豫特性的研究有助于脂质重构进程的快速监测及产物分析.本文主要对不同酯化度的单一或混合油酸甘油酯体系的LF-NMR弛豫特性进行了研究.结果表明,油酸甘油酯呈现三个弛豫峰;随酯化程度增加或温度升高,单组分和多组分弛豫时间均增大,各峰面积比例有一定改变,且酯化程度越高,弛豫时间的变化幅度越大;对二元和三元油酸甘油酯体系而言,随三油酸甘油酯（GTO）比例增至40%,单组分和多组分弛豫时间均增大,S₂₂峰面积比例增加,而S₂₃减小;三元混合体系的LF-NMR弛豫特性经主成分分析（PCA）后,混合体系在得分图上随GTO比例及二油酸甘油酯/单油酸甘油酯配比（GDO/GMO）的变化而呈规律性分布.     

Seedless synthesis of gold nanorods with longitudinal surface plasmon resonance wavelength of 1200 nm

Gold nanorods with the longitudinal plasmonic resonance peak position up to 1200?nm are prepared using an improved seedless synthetic technique. In this method, dopamine is employed as the weak reducer, whereas cetyltrimethylammonium bromide and sodium oleate are used as the binary surfactant mixture. Gold nanorods produced at various amounts of silver nitrate and hydrochloric acid were characterized by visible-near-infrared spectroscopy and scanning electron microscopy. Results show that the sizes, length-to-width aspect ratios, and the corresponding longitudinal surface plasmon resonance peaks of the synthesized gold nanorods can be tuned by altering the silver nitrate and hydrochloric acid amounts. The present method provides a new procedure for fabrication of gold nanorods with a broad range of plasmonic resonance peaks, which has a great potential for applications such as photothermal therapy and sensing.     

华根霉全细胞脂肪酶催化合成油酸油醇酯

 比较了10种不同来源的脂肪酶催化油酸与油醇酯化合成油酸油醇酯的能力,其中华根霉Rhizopus chinensis CCTCC M201021全细胞脂肪酶的催化能力最强,其反应转化率可达到90%以上. 酯化反应的最佳油酸/油醇底物摩尔比为1.5, 最佳油酸浓度为0.3 mol/L, 细胞干粉含水量为3.0%～7.5%时对酯化反应最为有利. 以生物相容性指数logP值为指标选择不同的有机溶剂作为有机相进行酯化反应,发现logP值为3.5～4.5的有机溶剂促进酯化效果较好. 全细胞脂肪酶的pH适应范围很广,最佳pH在9.0左右; 最佳反应温度为30 ℃.     

Gelation of charged bio-nanocompartments induced by associative and non-associative polysaccharides

Vesicles composed of sodium oleate (NaO) and monoolein (MO) are adequate candidates for drug nanoencapsulation and controlled release due to their stability and perceived biocompatibility. The object of the present study is to design hydrogels based on those anionic vesicles and polymers of both non-associative and associative type. The selected macromolecules were k-carrageenan (KC), carboxymethyl cellulose (CMC) and hydrophobically modified carboxymethyl cellulose (HMCMC). While the polymer-vesicle association was probed by rheology, the influence of the polymer on the vesicle stability was monitored by cryo-TEM and calorimetric measurements. The effects of the polymer on the rheological properties of surfactant aggregate solutions clearly depend on the polymer type: the storage moduli of the polymer-vesicle mixtures, compared to the vesicles alone, increases around 2 orders of magnitude if the polymer is non-associative and 4 orders of magnitude if the macromolecule is of associative type. As the vesicles are added, the non-associative polymer networks tend to be disrupted, while the networks formed by associative polymer get more robust. These observations can be explained by fundamental changes in electrostatic/hydrophobic interactions: vesicles entrapped in KC networks convert the polysaccharide in a highly charged entity and favor high electrostatic repulsions between the chains; this encourages network collapse. The opposite picture is experienced in HMCMC systems, i.e., such network is stabilized by the presence of vesicles. This is ascribed to the enhanced hydrophobic association, compensating the electrostatic repulsions between vesicles and polymer chains.