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1.
采用溶剂-非溶剂法重结晶CL-20,研究了溶剂-非溶剂体系中表面活性剂对CL-20晶体形貌的影响。用激光粒度仪、光学显微镜、红外光谱仪对重结晶CL-20的颗粒分布、形貌、晶型进行表征。结果表明,表面活性剂的种类、含量对CL-20的晶体形貌的影响较大,在以乙酸乙酯为溶剂、三氯甲烷为非溶剂、温度20℃、非溶剂稀释速度0.2~0.25mL/min、搅拌速度100r/min的转晶体系中,添加Span60使CL-20晶体颗粒生长形状趋近球形,表面光滑,颗粒均匀。  相似文献   

2.
采用毛细显微摄像技术对反应结晶法制备多形貌萘普生药物的晶体生长进行了直观、实时的观察和研究. 实验考察了表面活性剂种类和浓度、药物浓度及反应温度对生成的萘普生结晶颗粒形貌和尺寸的影响,并对颗粒的生长机理进行了讨论. 结果表明,在表面活性剂Tween-80, PVP, Karomic-90或CMC的作用下,可分别得到针状、球状、蝴蝶状及棒状萘普生晶体,药物浓度、表面活性剂浓度及反应温度对萘普生晶体的尺寸均有显著的影响.  相似文献   

3.
郑志雯  刘小健  赵娜如  张淑花  魏坤  王迎军 《硅酸盐学报》2012,40(5):715-716,717,718,719,720,721,722
在前期利用模板剂法制备层状纳米羟基磷灰石(nano-hydroxyapatite,n-HA)的基础上,利用透射电子显微镜、X射线衍射和Fourier变换红外光谱等研究并讨论工艺参数对材料结晶性能影响以及形成机理。结果表明:反应24h后,HA晶体形成且层状结构清晰;在碱性条件下,生成的产物主要是n-HA,酸性条件下则生成CaHPO4;乙醇与水的质量比为2.0时,纳米晶体形状、大小相对均一。工艺参数的变化会影响表面活性剂的堆积参数,沿着表面活性剂模板生长的羟基磷灰石颗粒有不同的微观结构及形貌。  相似文献   

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为提高低渗油藏的采收率,本文使用聚乙二醇修饰的Si O2纳米颗粒作为添加剂来提高泡沫稳定性,采用溶胶凝胶法合成了4种不同表面修饰量的Si O2纳米颗粒(即聚乙二醇膜),并对纳米颗粒进行了表征,对零电荷点和化学组成等性质进行了测试分析。通过表面活性剂溶液和纳米颗粒的混合得到纳米流体。纳米颗粒在与表面活性剂协同作用下,对气泡的结构强化,以增加其半衰期和耐久性。当表面活性剂浓度高于CMC时,泡沫稳定性达到最大值。纳米流体中纳米颗粒浓度越低,聚合粒径越小。聚乙二醇的用量可以阻止或促进纳米颗粒的聚集,粒径越小,泡沫的稳定性越好。使用α-烯烃磺酸盐表面活性剂和修饰的纳米颗粒生成的泡沫比仅使用表面活性剂的泡沫更稳定。  相似文献   

5.
胡新星  檀柏梅 《硅酸盐通报》2018,37(10):3256-3259
硅溶胶等残留颗粒是铜CMP后清洗需要去除的沾污之一.在FA/OⅡ螯合剂的协同作用下,对比了八种表面活性剂和四种添加剂对铜表面颗粒沾污去除的影响,表面活性剂包括阴离子型ALS、LABSA、MAP-K、LPS-30和非离子型AEO6、LEP-10、LDEA、APG1214,添加剂为硝酸钾、柠檬酸、乙二醇、枧油.并对表面活性剂和添加剂的浓度进行优化.清洗方式为使用PVA刷进行刷洗,清洗后通过金相显微镜检测剩余颗粒,扫描电镜观测铜表面形貌.实验得出颗粒去除效果较好的表面活性剂为AEO6,较佳的浓度为0.02 M.聚氧乙烯类表面活性剂与FA/OⅡ螯合剂的配伍效果较好.添加0.9wt%枧油可使AEO6清洗液的颗粒去除效果略微提升,枧油做复配的非离子表面活性剂.  相似文献   

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借助聚焦光束反射测量仪(FBRM)和颗粒录影显微镜(PVM)对丁二酸冷却结晶过程中的聚结现象进行研究,通过加晶种实验和不加晶种实验初步推断大小颗粒的共存及颗粒间的相互结合力是形成聚结需要考虑的两个因素。在此基础上,将3种类型的表面活性剂十六烷基三甲基溴化铵(CTAB)、十二烷基苯磺酸钠(SDBS)和吐温80(Tween80)加入到丁二酸冷却结晶系统,考察了表面活性剂对结晶过程中颗粒聚结的抑制作用。晶体形貌变化表明,所选的表面活性剂均能吸附于晶体表面,且可大大降低聚结,可推测表面吸附产生的机械隔离能够降低晶体间的相互结合力,并促使结晶产品的粒度更为均匀。这一研究证明添加表面活性剂可降低结晶过程的聚结程度。  相似文献   

7.
研究了不同浓度硅溶胶的黏度性质.在硅溶胶中添加不同种类的表面活性剂,利用黏度法研究了表面活性剂对硅溶胶黏度性质的影响,发现加入3种不同表面活性剂后,硅溶胶的黏度都出现了不同程度的下降,其中以添加十二烷基苯磺酸钠(SDBS)的降黏作用最明显,添加乳化剂OP-10和十二烷基硫酸钠(SDS)的次之.表面活性剂的降黏作用机理推测为SDBS在硅溶胶颗粒上的包覆作用.SDBS的降黏作用与其浓度有关,表现为临界胶束浓度规律,临界浓度约为4.6×10-3mol/L.  相似文献   

8.
脉冲激光轰击法连续制备纳米铜研究   总被引:2,自引:0,他引:2  
采用脉冲激光轰击法连续制备了纳米铜及表面活性剂原位修饰的油溶性纳米铜,用UV-Vis研究了不同表面活性剂不同浓度对纳米铜/乙醇溶胶的紫外-可见光谱的影响,从而确定各表面活性剂的最佳浓度,用TEM研究了不同表面活性剂对纳米铜溶胶分散稳定性的影响,确定了最佳表面活性剂为平平加O,傅立叶红外光谱发现纳米铜/乙醇溶胶中乙醇分子基团振动波长受纳米铜颗粒的影响而出现红移现象,分散性实验表明:平平加O表面修饰纳米铜具有良好的油溶性。  相似文献   

9.
选择溶水量较大的微乳液作为反应介质、适宜浓度的盐溶液作为反应物制备硫化镍粒子,通过透射电镜(TEM)观察所得硫化镍粒子的形状及大小.结果表明,硫化镍超细粒子的大小可以通过调节盐溶液浓度、水/表面活性剂摩尔比及表面活性剂浓度来控制.硫化镍粒子的形状也因微乳液组成不同而变化.  相似文献   

10.
阐述了纳米颗粒与表面活性剂之间通过协同作用减缓液膜排液、气泡并聚与破裂、泡沫粗化的衰变过程;简述了不同表面活性剂与纳米颗粒在稳定泡沫机理上的异同;综述了纳米颗粒浓度和亲疏水性对不同表面活性剂泡沫流体性能的影响;分析发现纳米颗粒的加入使泡沫压裂液体系性能得到改善。提出对纳米颗粒稳泡机理、表面活性、改性修饰、稳定性的研究是今后的重要探索方向,最后对纳米颗粒未来在泡沫压裂液中的应用进行了展望。  相似文献   

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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.  相似文献   

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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.  相似文献   

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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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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。  相似文献   

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