单分散大粒径硅溶胶的制备

采用单质硅粉水解法,经过初级粒子制备和粒子多级生长,制备了单分散的大粒径硅溶胶,考察了反应温度、反应时间、硅粉添加量、氢氧化钠浓度等因素对粒径及PDI的影响.最优实验条件为:反应温度70℃、反应时间12h、硅粉添加量21 g、氢氧化钠浓度0.5wt％.最优条件下的硅溶胶粒径为20 nm,通过粒径的多次生长,制备出粒径为90 nm的硅溶胶,且呈单分散性.     

用金属硅粉制备硅溶胶的新工艺

本文根据硅粉在碱做催化剂的条件下能反应生成硅溶胶的原理，采用水玻璃和氨水做催化剂，对工艺中的反应温度，反应时间和硅粉用量进行了研究和讨论，得出了制备硅溶胶较好的工艺条件。     

硅溶胶的合成及其对陶瓷的防污性能研究

硅溶胶具有比表面积大、高分散性、良好的稳定性、绝缘性和粘结性以及亲水性和憎油性等优点,广泛应用在无机涂料、抛光液、耐火材料、催化剂、医学等行业。文中采用单质硅粉水解法制备了碱性硅溶胶,研究了硅粉用量、反应时间、反应温度、NaOH用量等因素对硅溶胶收率及其性能的影响。实验结果表明制备碱性硅溶胶的最佳工艺条件为:去离子水为200 mL,硅粉用量为25 g,反应温度85℃,反应时间为10 h, NaOH用量为0.7 g。用于抛光砖表面处理,能填补陶瓷表面凹凸不平的表面,具有持久的防污效果,并能提高瓷砖的光亮度。     

用金属硅粉制备硅溶胶的新工艺

本文根据硅粉和水在碱做催化剂的条件下能反应生成硅溶胶的原理，采用水玻璃和氨水做催化剂，对工艺中的反应温度，反应时间和硅粉和用量进行了研究和讨论，得出了制备硅溶胶较好的工艺条件。     

硅晶片抛光用高纯度大粒径硅溶胶的研究

本文采用硅粉水解-胶粒整理法制备硅晶片抛光所用硅溶胶,考察了单质硅粉的加入量、反应时间、反应温度、硅溶胶底液浓度、催化剂种类及用量对硅溶胶胶粒平均粒径增长的影响,得到最佳工艺条件:单质硅粉的最佳加入量为25 g、反应时间7h、反应温度80℃、硅溶胶底液的质量浓度为8％、选稀氨水为催化剂、用量为12 mL,在此条件下可制备得到平均粒径为20 nm的硅溶胶产品.经过多次粒子生长可以制备得到适用于硅晶片抛光产业的高纯度大粒径硅溶胶.     

单质硅粉溶解法制备硅溶胶正交实验研究

研究了以单质硅粉为原料、水玻璃与氨水为复配催化剂制备硅溶胶的最佳工艺。通过正交实验设计,得出了硅溶胶的最佳制备条件:反应时间为7h,反应温度为80℃,水玻璃∶水∶硅粉=1∶20∶3(质量比)。     

硅切割废砂浆制备硅溶胶及回收碳化硅的工艺研究

以硅切割废砂浆中硅粉为来源,制备较高浓度硅溶胶,并回收得到高纯度碳化硅。结果表明,制备硅溶胶的最佳实验条件为:反应温度90℃,硅粉活化时间5 min,反应时间1 h,废油砂∶蒸馏水∶碱=10∶30∶0.6(质量比)。     

改良单质硅水解法制备硅溶胶的工艺研究

采用改良单质硅水解法工艺,经胶核制备和胶粒生长步骤制备硅溶胶.通过正交试验发现,对硅溶胶胶核平均粒径和硅粉转化率的综合影响因素大小顺序为硅粉加入量＞水玻璃加入量＞反应温度＞反应时间.最优胶核制备条件为:硅粉加入量80 g;水玻璃加入量30 mL;反应温度90 ℃;反应时间6 h.此时得到的硅溶胶胶核粒径:7～9 nm,硅粉转化率:63%～66%,SiO2质量分数:16%～20%,Na2O质量分数:0.5%.经多次胶粒生长,可制得平均粒径20 nm、40 nm、60 nm、80 nm的硅溶胶产品.     

硅粉法制备硅溶胶

采取硅粉溶解法,以氢氧化钠作催化剂制备硅溶胶。通过正交实验，找出最佳的实验方案,即反应温度为65-90℃，反应时间为8h，即可制得SiO2含量在30％以上，收率在80％以上的硅溶胶。     

硅切割废砂浆制备粗孔块状硅胶的工艺研究

提出了以硅切割废砂浆中的硅粉为硅源,制备粗孔块状硅胶,同时回收硅切割废砂浆中的碳化硅磨料和聚乙二醇切削液的工艺。重点阐述了基本原理和工艺流程,并对工艺条件进行了优化。水解反应工艺条件：硅、碳化硅混合颗粒和氢氧化钠的质量比为3.38∶1,在80 ℃下反应85 min,然后将温度提高到95 ℃继续反应150 min,最终的硅粉水解率达到100%。多硅酸钠制备硅胶工艺条件：凝胶反应在pH=10、温度为40 ℃条件下进行,硅凝胶在45 ℃老化10 h,并用质量分数为0.04%的稀氨水扩容,可得到比表面积为405 m²/g、孔容为1.422 6 mL/g的粗孔块状硅胶。该工艺实现了硅切割废砂浆回收联产粗孔块状硅胶,使硅切割废砂浆的回收更加经济合理。     

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。