镁合金表面羟基磷灰石/介孔SiO_2自修复耐蚀涂层的研究

通过旋涂法,在AZ31镁合金表面制备了聚多巴胺/羟基磷灰石复合涂层,并将负载有缓蚀剂2-巯基苯并咪唑(MBI)的介孔SiO_2纳米颗粒掺杂到复合涂层中,以改善镁合金的耐腐蚀性能。使用SEM、TEM、XRD和BET等手段表征介孔SiO_2纳米颗粒的形貌、结构及缓蚀剂的负载情况;通过傅里叶红外光谱(FTIR)和扫描电子显微镜(SEM)对涂层的成分和形貌进行表征;使用电化学阻抗谱(EIS)研究了不同涂层的耐蚀性能和自修复性能。结果表明,制备的二氧化硅为介孔纳米颗粒,可负载缓蚀剂。将负载有缓蚀剂MBI的介孔SiO_2纳米颗粒掺杂到聚多巴胺/羟基磷灰石复合涂层中,能够改善涂层的耐蚀性能,使涂层具有自修复性能。     

镁合金表面羟基磷灰石/介孔SiO_2自修复耐蚀涂层的研究

通过旋涂法,在AZ31镁合金表面制备了聚多巴胺/羟基磷灰石复合涂层,并将负载有缓蚀剂2-巯基苯并咪唑(MBI)的介孔SiO_2纳米颗粒掺杂到复合涂层中,以改善镁合金的耐腐蚀性能。使用SEM、TEM、XRD和BET等手段表征介孔SiO_2纳米颗粒的形貌、结构及缓蚀剂的负载情况;通过傅里叶红外光谱(FTIR)和扫描电子显微镜(SEM)对涂层的成分和形貌进行表征;使用电化学阻抗谱(EIS)研究了不同涂层的耐蚀性能和自修复性能。结果表明,制备的二氧化硅为介孔纳米颗粒,可负载缓蚀剂。将负载有缓蚀剂MBI的介孔SiO_2纳米颗粒掺杂到聚多巴胺/羟基磷灰石复合涂层中,能够改善涂层的耐蚀性能,使涂层具有自修复性能。     

微波辅助合成羟基磷灰石研究

羟基磷灰石由于具有良好的生物相容性和生物活性而应用广泛.本文分别以Ca(NO3)2·4H2O、(NH4)2 HPO4·3H2O为Ca源和P源,采用微波辅助加热的方式合成羟基磷灰石.使用傅里叶红外光谱(FT-IR)、X-射线衍射(XRD)和扫描电镜(SEM)对获得的产物进行了表征.分别研究了微波反应时间、反应功率和原料Ca/P比对合成羟基磷灰石形貌和结晶度的影响.结果表明,不同条件下,产物的形貌与结晶度均有不同.当合成时间为5 min,微波功率为400W,Ca/P比为2.0时,产物为具有结晶良好的羟基磷灰石.     

微波辅助一步合成介孔CeO_2-SBA-1

以三嵌段共聚物F127为模板剂,Na_2SiO_3·9H_2O作为硅源,Ce(NO_3)_3·6H_2O为铈源,在酸性条件下,微波辅助一步合成了三维有序介孔CeO_2-SBA-16。利用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、N2吸附脱附等手段对样品进行表征。研究了硅源与铈源投加量、搅拌时间及微波加热时间对介孔CeO_2-SBA-16结构的影响。结果表明,当硅源与铈源的投加量均为4.71 g,搅拌时间为3 h,微波加热120 min,可得到具有有序介孔孔道的CeO_2-SBA-16,BET方法得到该Ce O2-SBA-16的比表面积为322.8 m~2/g,孔容为0.342 cm~3/g,平均孔径为8.821 nm。     

微波辅助一步合成介孔CeO_2-SBA-1

以三嵌段共聚物F127为模板剂,Na_2SiO_3·9H_2O作为硅源,Ce(NO_3)_3·6H_2O为铈源,在酸性条件下,微波辅助一步合成了三维有序介孔CeO_2-SBA-16。利用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、N2吸附脱附等手段对样品进行表征。研究了硅源与铈源投加量、搅拌时间及微波加热时间对介孔CeO_2-SBA-16结构的影响。结果表明,当硅源与铈源的投加量均为4.71 g,搅拌时间为3 h,微波加热120 min,可得到具有有序介孔孔道的CeO_2-SBA-16,BET方法得到该Ce O2-SBA-16的比表面积为322.8 m²/g,孔容为0.342 cm2/g,孔容为0.342 cm³/g,平均孔径为8.821 nm。     

硅源对Cu/SiO_2催化剂催化对羟基苯乙酸乙酯加氢性能的影响

以正硅酸乙酯(TEOS)、硅酸钠(Na_2SiO_3·9H_2O)及硅溶胶(Si-sol)为硅源,采用共沉淀法制备了负载型Cu/SiO_2催化剂,并将其用于对羟基苯乙酸乙酯的加氢。通过XRD、N2物理吸附-脱附、H_2-TPR等手段研究了硅源对催化剂结构及反应性能的影响。结果表明,不同硅源制备的Cu/SiO_2催化剂中Cu物种存在形态及还原行为不同,进而使催化剂表现出不同的催化活性。以硅酸钠为硅源制备的Cu/SiO_2催化剂中CuO分散度高,且易被氢气还原为活性金属Cu,催化剂加氢活性最高,在反应原料25g、催化剂用量1.5g、氢气压力4MPa、反应温度170℃、反应时间15h的条件下,对羟基苯乙酸乙酯转化率达到99.5%,目标产物对羟基苯乙醇收率为99.3%。     

镁源种类对熔盐法合成镁橄榄石的影响

为了研究镁源种类对熔盐法合成镁橄榄石的影响,以化学试剂Si O2为硅源,分别以化学试剂Mg O、Mg(OH)_2、MgCl_2·6H_2O为镁源,按镁橄榄石(Mg_2SiO_4)的理论化学计量比配制镁、硅混合料,按1 1的质量比配制NaCl、NaF混合盐,再将镁、硅混合料与NaCl、NaF混合盐按1 2的质量比混合均匀,于110℃干燥24 h后,放入带盖刚玉坩埚中,分别在1 200、1 250和1 300℃保温3 h合成镁橄榄石材料,最后采用XRD、SEM和TEM等手段分析合成试样的物相组成和显微结构。结果表明:1)在NaCl-NaF熔盐环境下,以MgO和Mg(OH)_2为镁源有利于Mg_2SiO_4的合成,在1 300℃保温3 h可以合成出纯相Mg_2SiO_4;以MgCl_2·6H2O为镁源则没有Mg_2SiO_4生成。2)以Mg(OH)2为镁源合成的Mg_2SiO_4晶体发育良好,晶体表面光滑,并以单晶形式择优生长;晶粒呈柱状和小颗粒状,尺寸为5~15μm。     

水热法制备羟基磷灰石涂层包覆镁合金的耐腐蚀性能和快速矿化能力EI北大核心CSCD

生物镁合金在骨组织修复中具有良好的应用潜力,但生理条件下极易受到腐蚀,失去原有的力学性能,导致植入体在服役过程中失效。为了提高其耐蚀性能和快速诱导磷灰石的能力,采用一步水热法在镁合金上制备了微纳结构的羟基磷灰石涂层,涂层极化阻抗值达到138.680 k?·cm^2,具有优异的电化学性能。在模拟体液中测试试样30 d内的体外降解性能,溶液的pH值稳定在7.10~7.60之间,腐蚀速率始终低于0.400 mm/y。在浸泡3 d时,涂层表面由羟基磷灰石形成,微纳结构能快速诱导Ca–P产物的沉积,具有良好的矿化能力。     

水热法制备羟基磷灰石涂层包覆镁合金的耐腐蚀性能和快速矿化能力

生物镁合金在骨组织修复中具有良好的应用潜力,但生理条件下极易受到腐蚀,失去原有的力学性能,导致植入体在服役过程中失效。为了提高其耐蚀性能和快速诱导磷灰石的能力,采用一步水热法在镁合金上制备了微纳结构的羟基磷灰石涂层,涂层极化阻抗值达到138.680 k?·cm²,具有优异的电化学性能。在模拟体液中测试试样30 d内的体外降解性能,溶液的pH值稳定在7.10～7.60之间,腐蚀速率始终低于0.400 mm/y。在浸泡3 d时,涂层表面由羟基磷灰石形成,微纳结构能快速诱导Ca–P产物的沉积,具有良好的矿化能力。     

Na_2SO_4掺杂含MgO铝酸钙熟料的结构表征及浸出性能

使用分析纯MgO、CaCO_3、SiO_2、Al_2O_3与Na_2SO_4在1350℃保温1 h合成了掺杂Na_2SO_4的含MgO铝酸钙熟料,在Na_2CO_3溶液体系下研究了其氧化铝浸出性能,通过XRD等分析手段对其晶体结构和自粉化性能进行了研究。结果表明,Na_2SO_4可以显著提升铝酸钙熟料的浸出性能,Na_2SO_4掺杂量由0%提高到4%,熟料的氧化铝浸出率由61.89%提高到92.01%,继续添加Na_2SO_4,浸出性能趋于稳定。由XRD结果可知,Na_2SO_4促使20CaO·13Al_2O_3·3MgO·3SiO_2(Q相)发生分解并使其转变为12CaO·7Al_2O_3(C_(12)A_7)。Na+进入C_(12)A_7晶格引起晶格畸变,从而提高C_(12)A_7的氧化铝浸出性能。Na_2SO_4的加入降低了熟料的自粉化性能,Na_2SO_4掺杂量由0%提高到6%,熟料的自粉率由97.46%下降到85.34%,当Na_2SO_4掺杂量达到10%后,熟料自粉率仅为36.3%。     

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。