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.

Influence of dielectric properties of a substrate upon plasmon resonance spectrum of supported Ag nanoparticles

Plasmon resonance spectra of supported Ag nanoparticles are studied by depositing the particles on different substrates. It was found that the dielectric properties of the substrates have significant effects on the spectral line shape, except the resonance frequency. Beyond the plasmon resonance band, the spectral shape is mainly governed by the dielectric function, particularly its imaginary part, of the substrate. The plasmon resonance band, on the other hand, may be severely distorted if the substrate is absorbing strongly.

聚合物负载茂金属催化剂粒子在乙烯聚合过程中的破碎行为及其应用

本论文对聚苯乙烯颗粒用作茂金属催化剂载体方面进行了研究，重点考察了载体粒子的结构设计以及聚乙烯的粒子成核模型。此外，我们基于烯烃聚合过程中的载体破碎模型提出了制备聚合物共混物的新方法。本论文的主要工作和研究成果，急结如下：1．制备了多孔性聚苯乙烯乳胶粒，并用于负载茂金属催化剂以及乙烯聚合试验。通过与对应的实心型负载催化剂对比发现，多孔型催化剂表现出更高的活性以及聚合出形态更好的聚乙烯产物，我们用催化剂粒子的破碎模型对这种现象进行了解释。最后，通过考察载体成份在聚乙烯中的分布情况给出了多孔载体在乙烯聚合过程中破碎的证据，指出这种破碎行为是提高催化剂活性和改善聚乙烯形态的根本原因。2．制备了大孔结构以及疏松结构的聚苯乙烯树脂颗粒，并用于茂金属催化剂的负载化和乙烯聚合试验。研究了载体粒子的溶胀能力以及溶胀程度对催化剂负载量和催化剂活性的影响。结果表明，随着载体溶胀度的提高，催化剂负载量和催化剂活性都得到提高。当载体粒子充分溶胀时，大孔型和疏松型催化剂显示出很高的活性，而载体溶胀程度低时则催化剂的活性很低。实验结果证明充分溶胀的载体粒子在乙烯聚合过程中已分裂成碎片，而没有溶胀的载体粒子则不能破碎，表明载体粒子是通过溶胀过程达到破碎目的的，并因此能够提高催化剂活性和改善聚乙烯产物的形态。3．我们提出了利用多孔型聚苯乙烯微球负载茂金属催化剂催化乙烯聚合过程来原位合成聚乙烯／聚苯乙烯（PE／PS）共混材料的新方法。聚苯乙烯组分首先作为载体负载催化剂，在乙烯聚合过程中破裂成碎片而均匀的分散在聚乙烯相中。我们着重考察了载体粒子的设计以及载体的破碎效果对共混物形态结构和力学性能的影响。这种方法即使没有增容剂也可以使聚苯乙烯组分以纳米级的相尺寸分散在聚乙烯基体中，得到具有细微相形态的共混物，因而能够有效的改善材料的力学性能。

Photocatalytic degradation of AZO dyes by supported TiO2+UVin aqueous solution

The photocatalytic degradation performance of photocatalysts TiO2 supported on 13-X, Na-Y, 4A zeolites with different loading content was evaluated using the photocatalytic oxidation of dyes direct fast scarlet 4BS and acid red 3B in aqueous medium. The results showed that the best reaction dosage of TiO2-zeolite catalysts is about 2 g/l and the photocatalytic kinetics follows first order for all supported catalysts. The photocatalytic activity order of the three series catalysts is 13X type >Y type >4A type. The physical state of titanium dioxide on the supports is evaluated by X-ray photoelectron spectra (XPS), powder X-ray diffraction (XRD), BET, and FTIR. (C) 2000 Elsevier Science Ltd. All rights reserved.