ZnO·Al2O3修饰Al2O3微滤膜的研究

以硝酸锌、硝酸铝、尿素为主要原料,采用均相沉淀法对Al2O3微滤膜进行了ZnO*Al2O3涂覆改性研究.实验结果表明,在适宜的涂覆液浓度、涂覆次数条件下,ZnO*Al2O3改性后可使微滤膜的水通量提高15～20%,且具有较高耐酸碱性能.     

均相沉淀法涂覆ZnO工艺对微孔Al2O3分离膜改性作用的研究[I]-反应温度与涂覆次数的影响

以硝酸锌、尿素为主要原料,采用均相沉淀法对微孔Al2O3分离膜进行了ZnO的涂覆改性研究,着重考察了反应温度与涂覆次数对改性作用的影响.实验结果表明,制备的ZnO改性膜光滑致密,晶粒为5～10nm,使改性后的微孔Al2O3分离膜水通量提高了35%.文中还对改性机理进行了分析探讨.     

TiO2改性Al2O3微滤膜荷电性及其对膜水通量的影响

以硫酸钛、尿素为主要原料，采用均相沉淀法在Al2O3，微滤膜孔表面成功制备了一层纳米TiO2改性涂层。采用显微电泳法通过测定Al2O3，微滤膜颗粒表面TiO2涂层的zeta电位表征了TiO2涂层改性Al2O3微滤膜表面的荷电性，并探讨了微滤膜荷电性其对其水通量的影响。宏观电泳测试和Zeta电位分析表明，经TiO2改性后，Al2O3微滤膜表面荷电性能发生了明显改变，未改性膜Zeta电位等电点为pH=6．3，而改性后膜在pH=2-12时均荷负电。经TiO3改性Al2O3微滤膜的纯净水渗透通量较未改性时明显提高；当pH=6．6时，经TiO2改性后Al2O3微滤膜表面zeta电位绝对值的变化规律与相应的改性Al2O3微滤膜的纯净永渗透通量的变化趋势完全一致， 表明微滤膜水过滤通量的提高与改性涂层改变了膜孔表面的电动性质密切相关。     

TiO2对微滤陶瓷复合膜改性的研究--反应物种类的影响

分别以硫酸钛，硫酸氧钛作为起始反应物，采用均相沉淀法对微滤陶瓷复合膜进行了TiO2的涂覆改性研究。实验结果表明；采用硫酸钛制备的TiO2改性膜致密光滑，晶粒尺寸在20nm以下，使改性后的微滤膜水通量提高了19.2%;而采用硫酸氧钛制备的TiO2改性膜表面粗糙，晶粒尺寸超过40nm，反而使改性后的微滤膜水通量降低了56.9%。     

α-Al2O3微滤膜的改性研究

采用共沉淀法,对α-Al2O3微滤膜进行纳米ZnO和TiO2改性.结果表明:改性后微滤膜的过滤效率与未改性膜相比得到了显著地提高.在死端过滤的条件下,改性膜水通量增幅为19.4～49.6%.同时,还对纳米ZnO改性α-Al2O3微滤膜应用进行了初步研究,结果表明:在错流过滤的条件下,改性膜稳定的过滤通量为0.708 m3·m-2·h-1·bar-1,与未改性膜稳定的过滤通量相比,膜过滤通量提高180.95%.     

平均孔径与改性氧化物对α-Al_2O_3微滤膜油水分离效率的影响

在膜法处理含油废水的过程中,考察了不同平均孔径和氧化物改性的α-Al2O3微滤膜分离效率。结果表明:采用平均孔径为0.2μm的α-Al2O3微滤膜进行油水分离时,膜渗透通量达166.7L/(m2·h)且膜渗透液中的油含量为8.27mg/L。相对于ZnO改性,TiO2改性的孔径为0.2μm的α-Al2O3微滤膜渗透通量达192.6L/(m2·h),较未改性膜提高15.5%,且表现出较好的抗污染性和耐酸碱腐蚀能力。同时,实验还从改性膜表面亲疏水性能和zeta电位角度,对改性膜渗透通量提高的机理进行了初步研究。     

SnO2纳米晶粒对α-Al2O3微滤膜的改性作用

采用原位生成法,对α-Al2O3微滤膜进行SnO2改性,考察了SnCl4浓度和浸渍次数对膜水通量及膜孔结构的影响规律.结果表明:当SnCl4溶液的浓度为0.05 mol/L、浸渍次数为二次时,SnO2的改性作用最佳,改性后的α-Al2O3微滤膜纯净水通量达到6.52 m3/(m2·h).同时发现,经SnO2改性后的α-Al2O3微滤膜,其孔径分布窄,具有良好的孔结构.     

均相沉淀法涂覆ZnO工艺对微孔Al_2O_3分离膜改性作用的研究〔I〕──反应温度与涂覆次数的影响

以硝酸锌、尿素为主要原料,采用均相沉淀法对微孔Ａｌ２ Ｏ３分离膜进行了ＺｎＯ的涂覆改性研究,着重考察了反应温度与涂覆次数对改性作用的影响。实验结果表明,制备的ＺｎＯ改性膜光滑致密,晶粒为５～１０ｍｍ,使改性后的微孔Ａｌ２Ｏ３分离膜水通量提高了３５％。文中还对改性机理进行了分析探讨。     

ZnO引发剂对铝合金直接熔融氧化生长的影响

通过热重分析实验，研究了在高温空气气氛中覆盖在Al—Zn—Si合金表面的ZnO引发剂对铝合金直接氧化生长过程的作用。实验结果表明：ZnO能显著缩短A1—Zn—Si合金熔体直接氧化所需的孕育期及Al2O3／Al复合材料的生长时间。同时发现：ZnO有助于Al2O3／Al复合材料以光滑的方式进行氧化生长，形成细化胞状晶团，提高组织结构的均匀度和材料的致密度。促进Al2O3／Al复合材料生长的ZnO覆盖最佳量为7mg／cm^2。     

纳米ZrO2修饰Al2O3微滤膜处理废冷却液的实验研究

膜分离技术处理含油废水表现出明显的技术优势,其应用还应解决膜表面易被污染,分离效果逐渐下降的问题,主要原因是由于油滴的易变形性引起的膜堵塞。为解决膜渗透通量与膜选择性的矛盾,本文在市售Al2O3微滤膜孔道表面制备纳米ZrO2涂层,利用纳米涂层改变微滤膜的表面亲水憎油性,阻止油滴的变形。研究了陶瓷膜修饰条件和膜过滤操作参数对膜渗透通量的影响,结果表明:纳米涂层能有效提高微滤膜的渗透通量。膜面流速的增加在一定程度上能提高膜渗透通量,但超过一定程度后,增加不明显。当膜面流速为7m/s,修饰陶瓷膜的最大渗透通量为280 L.m-2.h-1,油截留率为96.4%。纳米涂层修饰微滤膜具有良好的抗油滴污染性能,能有效实现稳定含油废水的油水分离。     

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。