纳米羟基磷灰石的合成工艺研究

羟基磷灰石是一种重要的骨引导生物材料。以四水硝酸钙和磷酸二氢铵为原料,在一定pH条件下,以三乙醇胺为分散剂,采用化学共沉淀法制备纳米羟基磷灰石,并考察了反应温度、滴加速度、煅烧温度、正丁醇处理对羟基磷灰石的影响。通过FT-IR,XRD,SEM等手段,对粉体化学组成、晶相和形貌进行表征和分析。研究结果表明,在体系反应温度为70℃、磷酸二氢铵滴加速度为3.33 mL/min、煅烧温度为800℃时,得到粒径为8~15 nm的高纯度羟基磷灰石纳米材料;用正丁醇处理后,团聚现象得到明显改善。     

纳米羟基磷灰石的合成工艺研究

羟基磷灰石是一种重要的骨引导生物材料.以四水硝酸钙和磷酸二氢铵为原料,在一定pH条件下,以三乙醇胺为分散剂,采用化学共沉淀法制备纳米羟基磷灰石,并考察了反应温度、滴加速度、煅烧温度、正丁醇处理对羟基磷灰石的影响.通过FT-IR,XRD,SEM等手段,对粉体化学组成、晶相和形貌进行表征和分析.研究结果表明,在体系反应温度为70℃、磷酸二氢铵滴加速度为3.33 mL/min、煅烧温度为800 ℃时,得到粒径为8～15 nm的高纯度羟基磷厌石纳米材料;用正丁醇处理后,团聚现象得到明显改善.     

醇-水法合成HAP/ZrO_2复合微粉及其表征

以硝酸钙、磷酸氢二铵、氨水、氯氧化锆、氧化钇为原料,采用醇-水法合成羟基磷灰石/氧化锆(HAP/Zr O2)复合粉体。研究了醇水比、热处理温度对产物的晶相和颗粒尺寸的影响,同时对所制得干燥样品在升温过程中的变化情况进行了分析。结果表明:在本实验条件下,采用醇-水法成功合成了HAP/Zr O2复合粉体,当醇水比(体积比)为3∶7时合成的HAP/Zr O2复合粉体粒径最小。     

溶胶–凝胶法制备纳米羟基磷灰石粉体

以四水合硝酸钙和五氧化二磷为原料，无水乙醇为溶剂，采用溶胶一凝胶法制备了含co}的羟基磷灰石（hydroxy印atite，HAP）粉体。采用热重-差热分析、X射线衍射、透射电子显微镜、Fourier变换红外光谱等研究了反应体系pH值、反应温度及前驱体热处理温度等因素对产物结构与性能的影响规律，结果表明：采用溶胶-凝胶工艺，调控反应体系的pH、反应温度及前驱体的热处理温度是获得纯度高、分散性较好的纳米HAP粉体的关键。pH值为8．0、反应温度为30℃，经600℃热处理可获得到粒径为40~50nm的HAP纳米粉体。     

烧结温度和pH值对HA合成的影响

采用液相沉淀法制备了纳米级的HAP粉末,并进一步对合成的材料进行DTA和RD分析,研究了温度和pH值对羟基磷灰石粉体合成的影响。制备的羟基磷灰石粉体纯度较高,随着温度的增加其晶化程度增加。     

纳米孔活化贝壳粉的制备工艺优化研究

为制备纳米孔贝壳粉并获得最优工艺条件,在单因素实验的基础上,采用三因素三水平正交设计法,研究贝壳粉煅烧活化的煅烧温度、煅烧前贝壳粉粒径、煅烧时间3个因素对贝壳粉的比表面积的影响。研究结果表明:3个因素对贝壳粉比表面积的影响大小次序为:煅烧前贝壳粉粒径、煅烧温度、煅烧时间。通过正交试验获得最优方案并进行了验证试验,确定制备纳米孔贝壳粉的优化工艺条件为:颗粒粒径600目、煅烧温度900℃,煅烧时间1.5h,在此条件下制备的纳米贝壳粉平均孔径分布在0.4～1.5nm,比表面积为10.92860m~2·g~(-1),可应用于果蔬的农药残留、重金属吸附。     

模拟体液中仿生羟基磷灰石超细粉的制备及表征

从仿生合成的思路出发,以模拟体液为反应介质,通过磷酸和硝酸钙反应合成了羟基磷灰石(hydroxyapatite,HAP)粉体.利用差热分析、X射线衍射、红外光谱和透射电镜对合成HAP的晶相转变、微观结构和形貌进行了研究,研究了硝酸钙浓度对羟基磷灰石粉体晶相纯度和高温稳定性的影响.结果表明:在模拟体液中合成的HAP粉体不需要热处理就含有较多的HAP晶相,经500℃热处理后转变为纯相HAP,硝酸钙浓度为0.2 mol/I时所合成的HAP具有很好的纯度和高温稳定性,经1 550℃烧结后只有微量α-Ca3(PO4)2析出;所合成的HAP为纳米颗粒,呈现出球状和短棒状形态,接近于人体骨磷灰石.体外生物活性表明:HAP具有较强的诱导Ca,P沉积的能力.     

鱼鳞中纳米生物羟基磷灰石的提取

采用高温煅烧法从鱼鳞中提取羟基磷灰石(hydroxyaptite,HAP),研究了煅烧温度、时间和预处理液pH值对产物相组成和结构的影响。应用X射线衍射分析、红外光谱、元素分析和扫描电子显微镜对提取物进行了表征。结果表明：直接煅烧鱼鳞只能得到HAP与β-磷酸三钙(β-tricalcium phosphate,β-TCP)的混和物。经过碱性溶液预处理后,800℃煅烧鱼鳞1h即可得到HAP。不同鱼鳞煅烧所得产物的钙与磷摩尔比有所差异。     

温和条件下超声波合成纳米羟基磷灰石

采用超声波以CaCl2和（NH4）：HPO4为原料合成纳米羟基磷灰石（HAP）,并与沉淀法和加表面活性剂超声法相比较。利用热分析（TG—DSC）,红外光谱（FTIR）,X-射线衍射（XRD）,扫描电镜（SEM）对样品进行了表征,研究了不同方法、不同煅烧温度对HAP组成和结构的影响。实验表明,超声波法合成的HAP呈不规则球形,平均粒径为42．85nm,沉淀法的HAP呈不规则球形和棒状,球形平均粒径为71．42nm,棒状为71．42×85．71nm,比较而言,超声波法的样品粒径均匀,而沉淀法粒径较大且容易团聚。温度高于750℃后,开始失去羟基,在800℃图中明显出现斜方晶系的磷酸钙的XRD峰。     

磁性羟基磷灰石制备的研究进展

羟基磷灰石(HAP)是一种典型的生物活性材料,已在骨外科、牙科临床等方面得到了广泛的应用。由于HAP比表面积大,吸附能力强,HAP在药物递送、污水处理等领域也得到了广泛应用。磁性纳米颗粒具有良好的电磁性能、可回收性和电磁制热性能,已受到越来越多的关注。近年来,为了结合以上两种材料的优点,将磁性材料与羟基磷灰石相结合是上述领域研究应用的重点方向。此前,有综述报道过关于磁性羟基磷灰石复合材料的制备研究,但重点关注于与其他材料的复合,缺乏针对磁性羟基磷灰石制备方法的系统总结。本文以掺杂和包覆两种将磁性引入羟基磷灰石的方式为出发点,系统总结了磁性羟基磷灰石的经典制备方法及其优缺点,并讨论了其相关应用,特别是论述了进一步研究拓展的关键问题以及今后的研究趋势,以期为磁性羟基磷灰石的深入拓展提供参考。     

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。