微乳液体系中酶促反应的研究

综述了在微乳液体系中的酶促反应。讨论了表面活性剂、溶剂和助表面活性剂的选择对微乳液中酶促反应的影响及酶在反胶束中的增溶位置。庚烷、辛烷、壬烷是较好的溶剂 ,酶分子可增溶于反胶束中的水池 ,或吸附于油—水界面层极性头微乳液膜附近。描述了微乳液中水含量和缓冲溶液 pH对酶活力的影响 ,酶活力与水含量一般呈钟形曲线 ,与 pH可呈钟形或S形曲线。     

乙草胺微乳液的研究

采用拟三元相图的方法研究了乳化剂和助乳化剂对乙草胺微乳液区域的影响,确定非离子表面活性剂采用酚醚,阴离子表面活性剂为十二烷基苯磺酸钙,助表面活性剂使用正丁醇,最佳乳化剂配方:非离子表面活性剂、阴离子表面活性剂、助表面活性剂的质量比为5:2:3.通过电导率测定,确定了乙草胺,乳化剂,水三元体系中乳液区的W/O、O/W类型.通过对液晶现象观察,绘制了在混合制剂(A)/混合制剂(T)/水拟三元相图中液晶区域范围.并讨论了微乳剂配制过程中的相行为变化.     

无机盐对十六烷基三甲基溴化铵（CTAB）微乳液相行为的影响

微乳液通常由水、油、盐、表面活性剂及助剂组成,各组分对微乳液体系的相行为及增溶情况都有影响。本文利用Winsor相图和ε-β鱼状相图来研究无机盐种类、浓度对十六烷基三甲基溴化铵（CTAB）型微乳液相行为的影响。研究发现,随着无机盐浓度或醇量增加,微乳液都会发生从WinsorⅠ→WinsorⅢ→WinsorⅡ的相转变,但具有不同阳离子或阴离子的无机盐对微乳液体系相行为的影响不同。无机盐在微乳液体系中主要与表面活性剂的反离子发生作用,对阳离子表面活性剂配成的微乳液体系,无机盐阴离子的作用比较强,且价态越高,离子半径越大,对微乳液相态的影响越大。通过对不同无机盐条件下的界面组成及增溶参数分析可知：无机盐种类的改变对鱼头、鱼尾点表面活性剂含量及醇在界面层中的分布影响较小;无机盐中阴离子改变对微乳液增溶能力影响较大,阳离子的改变对微乳液增溶能力影响较小。     

微乳液在溶剂萃取分离中的应用研究进展

综述了用微乳液法萃取分离水中的非离子有机污染物、重金属离子和在湿法冶金工业中萃取分离金属离子的研究进展。表面活性剂、助表面活性剂、油和水形成WinsorⅡ或WinsorⅢ型微乳液,非离子有机污染物和金属离子进入微乳液的双连续区域或者是W/O型的微乳液中,从而实现水和有机物或金属离子的分离。对影响微乳液萃取的因素如助表面活性剂、助表面活性剂与表面活性剂的比率(nC/nS)和盐度等进行了论述。     

微乳液相转变在分离有机污染物方面的应用

Winsor型微乳液的相转变WinsorⅢWinsorⅠWinsorⅢ在分离有机污染物方面有重要应用.WinsorⅢ型微乳液中的Na 取代高价态阳离子(Al3 和Ca2 )时被破坏,转变为WinsorⅠ型.有机污染物在WinsorⅠ型微乳液中的增溶能力比在WinsorⅢ型微乳液中的增溶能力要小得多,从而使增溶到中相微乳液中的有机污染物被释放出来.Winsor型微乳液可发生可逆转换,表面活性剂可重复使用.     

W/O型环己烷微乳液的研究

考察了不同种类醇、表面活性剂用量和配比对环己烷微乳液增溶水量和电导率的影响;探讨了电解质对环己烷微乳液相行为的影响。实验结果表明：正戊醇为最佳助剂,助剂与表面活性剂碳链比适中更易形成微乳液;随着表面活性剂质量分数的增加,体系增溶水量增大,电导率下降;电解质对环己烷微乳液有重要的影响,随着NaCl质量分数的逐渐增大,体系从下相微乳液过渡到中相微乳液,进而形成上相微乳液。     

微乳液形成及相行为研究

微乳液作为一种表面活性剂浓溶液体系,在采油过程以其超低的界面张力、高的增溶能力及热力学稳定性等优点大幅度提高原油采收率从而受到人们的重视。本文主要研究微乳液的形成方式、微观结构、相行为特点和微乳液在三次采油过程中的主要作用。     

反相微乳液法制备糊精纳米微球

以正己烷为油相,去离子水为水相,Span 60和Tween 60为表面活性剂,正戊醇为助表面活性剂配制微乳液,对影响微乳液特性的各因素做了分析。并以糊精为原料,三偏磷酸钠为交联剂,制备糊精纳米微球。结果表明,在微乳液体系中,表面活性剂的量与体系溶水能力在一定范围内正向相关,而助表面活性剂正戊醇对溶水能力则具有逆向作用。红外光谱测试证实糊精与三偏磷酸钠发生交联,经扫描电镜观察,糊精微粒纳米形态均一,粒径在500～600 nm之间。     

油水比对阴离子型微乳液相行为的影响

微乳液由水、油、盐、表面活性剂及助表面活性剂组成,其相行为及增溶情况受各组分的影响。研究发现,在SDBS（SDS、SLS）/航空煤油/水/正丁醇/氯化钠体系中,随着NaCl含量的不断增多,微乳液体系发生Winsor Ⅰ型→Winsor Ⅲ型→Winsor Ⅱ型的相态转变。固定水的用量,通过油扫实验不断改变体系中的油水比,利用相图研究油水比对微乳液相行为的影响,并通过冷冻电镜对不同相态下微乳液的微观形貌进行了表征。随着油水比的增加,在低盐度下,体系由胶团溶液转变为Winsor Ⅰ型;而在高盐度下,体系发生由胶团溶液→Winsor Ⅱ型→Winsor Ⅲ型→Winsor Ⅰ型的相态转变。盐度一定时,微乳液的中相形成及消失所需的油量会随着表面活性剂浓度的增多而增多,且三种表面活性剂中,表面活性剂的增溶能力的大小顺序为SDBS>SDS>SLS,对煤油的敏感程度顺序为SLS>SDS>SDBS。     

汽油微乳液拟三元相图及电导率研究

以阳离子表面活性剂D0821和非离子表面活性剂AEO3的复配体系为研究对象，系统研究了D0821／AEO3-汽油-正丁醇-水体系一系列拟三元相图，并采用电导率法确定了微乳液结构。结果表明，表面活性剂D0821与AEO3不同复配配比对拟三元相图影响很大，随着阳离子表面活性剂D0821比例逐渐增加，液晶的面积按小一大一小的顺序变化；在D0821比例较大时，结构由W／O型微乳液→双连续→双折射→O/W型微乳液，随着表面活性剂含量降低，有大面积的乳液区出现；电导率的变化与相变化存在一致性。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。