钛酸钡纳米复合材料制备与性能研究

对钛酸钡颗粒进行羟基化和巯基官能化处理,将纳米银粒子成功接枝到钛酸钡颗粒表面制备了x Ag@BT颗粒(x为银质量分数,BT为钛酸钡),并用溶液共混法制备了Ag@BT/PVDF纳米复合材料(PVDF为聚偏氟乙烯)。结果表明,x Ag@BT颗粒为具有草莓结构的纳米颗粒,尺寸为2~16 nm的银粒子成功装饰在钛酸钡颗粒表面;纳米银粒子的引入可以降低复合材料在低频下的介电损耗和电导率,且当纳米银粒子质量分数为1.0%时复合材料的特征击穿强度达到最大值;与传统BT/PVDF纳米复合材料相比,1.0%Ag@BT/PVDF纳米复合材料具有更优良的电性能。     

译海撷英

利用超声技术制备聚合物纳米粒子纳米尺寸的聚合物颗粒广泛应用于涂料、油墨、粘合剂等,还应用于医疗诊断和药物输送,并有希望在电子器件和光子器件中使用。最近,研究人员发现一种方法,利用声波爆破聚合物单体和水的混合物可制备出结构可控的纳米尺寸聚合物粒子。该方法使在不使用表面活性剂的情况下制备聚合物纳米颗粒成为可能,它     

红细胞膜封装负载姜黄素的金纳米粒子

针对姜黄素在水中溶解性差、稳定性差、难吸收、代谢快等缺点,以姜黄素、金纳米颗粒和哺乳动物红细胞膜为原料,设计开发了红细胞膜仿生纳米载药系统(Au-Cur@RBC)。抗癌药物姜黄素通过疏水作用吸附到利于封装的小尺寸金纳米颗粒表面,然后通过物理挤压的方式将载药纳米粒子包封到红细胞膜囊泡内。结果表明,制备的金纳米粒子尺寸均一度高,分散性良好,平均粒径为13.18 nm。金-姜黄素纳米颗粒中姜黄素的吸附率为86.85%,载药率为20.25%。金纳米颗粒的负载可显著提高姜黄素的稳定性,金-姜黄素纳米颗粒在水溶液中储存30 d后仍保留了52%的姜黄素。同时,暗场显微镜结果表明,红细胞膜涂覆增强了制备的Au-Cur@RBC对暗场显微镜入射光线的折射与衍射能力,从而呈现更清晰的图像。     

液相共沉淀法制备四氧化三铁纳米粉

采用液相共沉淀法制备了纳米级四氧化三铁颗粒，通过X-Ray谱图证实了该粒子的组成结构。通过能谱图(EDS)研究表明样品中含有氯元素，这是因为在纳米级四氧化三铁颗粒表面处理过程中，其表面层与盐酸反应，表面生成氢氧化铁带电颗粒，Cl^-吸附在该颗粒表面，从而有效防止纳米粒子团聚，提高其分散效果。通过HRTEM研究表明，由该法所制得的四氧化三铁粒子主要为球形，粒径分布均匀，平均粒径在10nm左右。     

高性能纳米改性氨纶

一般纳米粒子采用有机物质（如表面活性剂）对其表面加以处理。在纳米技术聚氨酯弹性体材料中有两种方法效果明显：一种方法称为原位聚合法，经表面处理的纳米粒子加入到单体中，然后引发单体聚合，从而达到纳米改性聚合物目的，再由硅胶分解成纳米SiO2，将此工艺与聚酯多元醇合成工艺结合一起，即可制得纳米聚酯多元醇。用此纳米聚酯多元醇原料可制得高性能的纳米改性氨纶（包括干法和熔纺法）。     

SiO2/聚氨酯纳米复合物的在位合成及其在环氧树脂中分散行为的研究

以水性阳离子聚氨酯纳米粒子为纳米微囊,利用原位水解法使正硅酸乙酯(TEOS)在囊内水解、聚合生成二氧化硅(SiO2)纳米粒子,从而合成出SiO2/聚氨酯纳米复合物的稳定水基乳液,实现纳米复合物中SiO2纳米粒子的均匀分散和良好的界面结合。并以此作为已表面改性的纳米粒子实现SiO2纳米粒子在环氧树脂的均匀分散。通过能谱扫描、透射电镜和乳液粒子粒径与分布等测试方式对含有环氧树脂的水性SiO2/聚氨酯纳米复合物进行测试。结果表明,SiO2/聚氨酯纳米复合物可以在环氧树脂中均匀分散且不团聚,同时也可促进环氧树脂在水中的分散。     

表面处理对原位悬浮聚合制备PVC／纳米碳酸钙复合材料的影响

对纳米碳酸钙进行表面预处理，在纳米碳酸钙粒子表面包覆上一薄层有机高分子，降低纳米粒子的高表面能，调节疏水性，改善其与有机基料之间的润湿性和结合性，从而达到与氯乙烯等有机物亲和良好的状态，防止纳米碳酸钙粒子自身的团聚，将经过表面处理和未处理的纳米碳酸钙粒子分别在5L和50L反应釜中与氯乙烯单体进行悬浮聚合，使纳米碳酸钙粒子原位复合到PVC中，将聚合完毕的PVC粒料浆液进行透射电镜，扫描电镜观察，比较纳米碳酸钙的表面处理对于原位悬浮聚合法制备PVC／纳米碳酸钙复合材料的影响。     

红细胞膜封装负载姜黄素的金纳米粒子

针对姜黄素在水中溶解性差、稳定性差、难吸收、代谢快等缺点，设计开发了红细胞膜仿生纳米载药系统（Au-Cur@RBC）。抗癌药物姜黄素通过疏水作用吸附到利于封装的小尺寸的金纳米颗粒表面，然后通过物理挤压的方式将载药纳米粒子包封到红细胞膜囊泡内。结果表明，制备的金纳米粒子尺寸均一度高，分散性良好，平均粒径为13.18 nm。金-姜黄素纳米颗粒中姜黄素的包封率为86.85%，载药率为20.25%。通过金纳米颗粒的负载，可显著提高姜黄素的稳定性，金-姜黄素纳米颗粒在水溶液中储存30天后仍保留了52%的姜黄素。同时，暗场显微镜结果表明，红细胞膜涂覆改善了制备的Au-Cur@RBC对暗场显微镜入射光线的折射与衍射能力，从而呈现更清晰的图像。上述结果表明所制备的仿生纳米颗粒展示出应用于癌症治疗与成像的潜力。     

纳米技术在聚氨酯氨纶纤维应用取得突破

一般纳米粒子采用有机物质（如表面活性剂）对其表面加以处理。在纳米技术聚氨酯弹性体材料中有两种方法效果明显：一种方法称为原位聚合法，经表面处理的纳米粒子加入到单体中，然后引发单体聚合，从而达到纳米改性聚合物目的。再由硅胶分解成纳米SiO2，将此工艺与聚酯多元醇合成工艺结合一起，即可制得纳米聚酯多元醇。用此纳米聚酯多元醇原料可制得高性能的纳米改性氨纶（包括干法和熔纺法）。[第一段]     

碳酸钙／二氧化硅纳微复合粒子的高能球磨制备

采用高能球磨法制备了碳酸钙(纳米)/二氧化硅(微米)复合粒子.用X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、能谱分析仪(EDS)和傅里叶变换红外光谱仪(FT-IR)研究了球磨过程中复合粉体的相组成和微观组织;对碳酸钙/二氧化硅复合粒子的粒径、形态、结构进行了测定与表征.结果表明随着球磨时间的延长,复合粉体在强烈的冲击、挤压作用下逐渐细化和均匀化;球磨240 min可形成结合紧密的碳酸钙/二氧化硅复合粒子,并使之球形化;纳米碳酸钙均匀复合于二氧化硅的表面及其空隙,复合过程中没有产生新物质;强烈的机械力作用,使纳米碳酸钙表面晶体结构发生畸变,颗粒表面无定形化程度增加.     

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。