纳滤和反渗透膜形貌结构与膜性能关系探索

纳滤和反渗透膜表面形貌结构、亲疏水性的性质与膜脱盐率、水通量等性能存在一定关系。对几款商用纳滤、反渗透膜进行表面形貌结构、表面粗糙度、亲水性表征。结果表明,纳滤膜表面平整粗糙度低、亲水性强、脱盐率较低,但水通量高。反渗透膜表面存在大量疏松的峰谷结构,比纳滤膜粗糙度更大、亲水性强。对比两款海水反渗透膜,推测调整反渗透膜"叶片"大小和数量可调节反渗透膜的脱盐率和水通量性能。     

纳米级Al2O3陶瓷膜通量衰变实验研究

实验研究了纳米级氧化铝陶瓷膜处理高浊度水时膜通量衰减变化规律,比较了几种酸碱清洗剂(HCl、NaClO、 HNO3、NaOH)的作用及效果。发现在周期性反冲洗条件下,膜通量衰减明显减缓,而HNO3虽然清洗效果好,但由于具有很 强的腐蚀性,不宜作清洗剂。     

净水设备用新型反渗透功能膜制备及应用研究

反渗透膜在使用过程中,常出现易结垢、寿命短、脱盐率低、水通量小等问题。主要针对净水设备用反渗透膜出现的问题进行改性实验研究,通过工艺设计并对其性能影响因素进行分析。通过含浸界面接枝法改性的新型反渗透功能膜通量和脱盐率达到了最佳的平衡状态,亲水性可控。据此方法进行中试后生产的新型反渗透功能膜脱盐率99.52%,水通量大于31.5 L/m²·h,净水产水量3000 L;节水率(净水产水率)57.5%。     

超薄复合反渗透膜的研制

在聚砜薄膜表面通过胺化物与异氰酸脂的界面缩聚反应,复合一层具有反渗透性能的薄膜,可得到有良好脱盐率和透水能力的超薄复合反渗透膜。本文研究了基膜和复合膜的制备条件。着重讨论了复合膜的形态结构,复合液浓度和成孔剂分子量对膜脱盐率、水通量的影响。基本上掌握了制备复合反渗透膜的条件。所研制膜的脱盐率为85-95％,水通量为0.85-2.55ml/cm~2·h,具有一定的应用价值。     

反渗透技术在尾矿废水处理中的应用

针对高含盐量、高硬度的尾矿废水,采用锰砂过滤、在线絮凝过滤、活性炭过滤和投加针对性的阻垢剂作预处理,主体工艺采用反渗透技术对其进行处理.分别考察了反渗透系统在50%和70%回收率的条件下,预处理工艺的处理效果、反渗透膜的污染情况以及反渗透膜脱盐率的影响因素.试验结果表明,顸处理效果良好,其产水SDI基本保持在3.5左右;反渗透系统运行稳定,反渗透膜没有出现明显污染倾向;在进水水质、水温、膜通量和操作压力一定的条件下,反渗透膜进水流量与脱盐率成正比.     

反渗透膜的制备与性能优化

在介绍反渗透膜材料的发展史的基础上,首先介绍了反渗透膜制备单体多元胺、多元酰氯的发展状况。其次介绍了反渗透膜性能优化的几种方法包括界面添加反应剂、提升支撑层厚度,优化孔型结构、表面改性、溶液表面涂敷和化学表面接枝法。通过上述方法与界面聚合相结合可改善膜的性能,提高反渗透膜水通量、脱盐率以及抗氯性、抗污染性能。最后介绍了纳米材料在反渗透膜中的应用及其发展现状。     

有机污染海水对硅藻土预涂动态超滤膜通量及清洗的影响

膜的有机污染严重制约着超滤在海水预处理中的应用。通过硅藻土预涂覆强化超滤去除海水中有机物的试验,对比分析了硅藻土预涂覆和直接超滤海水后的膜通量变化。结果表明,硅藻土在膜面形成的滤饼层能够有效避免有机物与膜的直接接触,降低膜的有机物污染程度。利用三维荧光光谱(3D-EEM)及原子力显微镜(AFM)考察了受污染动态膜经HCl、NaOH、NaClO、超声及纯水这5种清洗处理后清洗液组成及膜面形貌变化。清洗效果由高到低依次为NaOH、NaClO、超声、HCl及纯水,膜通量恢复率分别为96.3%、89.2%、72.4%、50.8%和44.1%,NaOH及NaClO可有效去除膜面集聚的类蛋白及腐植酸类有机物。     

反渗透膜的制备与性能优化

在介绍反渗透膜材料的发展史的基础上,首先介绍了反渗透膜制备单体多元胺、多元酰氯的发展状况。其次介绍了反渗透膜性能优化的几种方法包括界面添加反应剂、提升支撑层厚度,优化孔型结构、表面改性、溶液表面涂敷和化学表面接枝法。通过上述方法与界面聚合相结合可改善膜的性能,提高反渗透膜水通量、脱盐率以及抗氯性、抗污染性能。最后介绍了纳米材料在反渗透膜中的应用及其发展现状。     

反渗透处理尾矿废水脱盐率的影响因素研究

针对高含盐量、高硬度的尾矿废水,采用锰砂过滤、在线絮凝过滤、活性炭过滤和投加针对性的阻垢剂作预处理,主体工艺采用反渗透技术对其进行处理.考察了反渗透膜进水流量、膜通量、水温、水质、操作压力和回收率对膜脱盐率的影响.试验结果表明,在进水水质、水温、膜通量、操作压力和回收率一定的条件下,反渗透膜进水流量与脱盐率成正比.     

聚砜酰胺(PSA)反渗透膜研究的进展添加剂及蒸发过程的影响

研究了添加剂及蒸发过程对PSA反渗透膜性能的影响。结果指出,通过采用合适的多组份添加剂及选择适宜的蒸发条件,在其它操作条件与脱盐率不变的情况下,可将膜的水通量比早期研究的PSA膜提高一倍以上。促进了PSA反渗透膜在工业生产上的应用。     

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。