用于回收酰胺类溶液的TS-1渗透汽化膜的制备和性能测定

采用晶种法制备了不同Ti含量的TS-1/α-Al_2O_3分子筛膜,并用于渗透汽化回收酰胺类溶液。通过X-射线衍射(XRD)、傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)等对合成的分子筛膜进行表征,结果表明钛原子进入到分子筛骨架。渗透汽化实验结果显示,TS-1分子筛膜具有较好的分离性能且优先透过有机物,可用于酰胺类有机物的回收利用。n(Ti)/n(Si)为0.015合成的TS-1分子筛膜,在进料温度为65℃,操作压力为300 Pa的条件下,分离质量分数为5%的DMF/H_2O和DMAc/H_2O溶液,渗透通量分别为1.34 kg/(m~2·h)和1.13 kg/(m~2·h),回收后溶液的质量分数提高到19.4%和16.2%。     

Silicalite-2分子筛膜的制备及其渗透汽化性能研究

利用二次晶种法在多孔α-Al2O3支撑体表面制备了全硅Silicalite-2分子筛膜。通过XRD和SEM等分析方法对分子筛膜进行表征,并考察了晶化时间、晶化温度以及水含量对分子筛成膜的影响。结果表明,在n(TBAOH)∶n(TEOS)∶n(H2O)=1∶3∶100,晶化时间为48 h,晶化温度为130℃下所制备的膜完整致密。将制备的分子筛膜用于渗透汽化分离有机物/水溶液,实验显示其具有有机物优先选择透过性。随着进料质量分数的降低和料液温度的升高,渗透通量和分离因子均增大。70℃分离5%的乙醇/水溶液、乙酸/水溶液和DMF(二甲基甲酰胺)/水溶液时,渗透通量分别为1.12、1.14 kg/(m2·h)和0.87 kg/(m2·h),分离因子分别为5.1、1.6和2.4。     

高炉渣合成NaA沸石及影响因素

从高炉渣中提取二氧化硅作为合成沸石的硅源,用水热合成法合成了高炉渣沸石。采用X射线衍射、扫描电子显微镜、能谱等手段研究了温度、水热时间、原料配比等合成参数对沸石合成的影响。研究Na含量和碱度对沸石合成的影响。结果表明:随原料中n(Si O2)/n(Al2O3)摩尔比提高,合成的沸石晶型由A型向X型转变。温度、水热时间和碱度对于结晶形貌有显著影响,特别是随碱度的提高产生晶粒细化,而Na含量对沸石合成的影响微弱。最适宜的高炉渣沸石合成条件为:原料摩尔比n(Si O2):n(Al2O3):n(Na2O):n(H2O)=2:1:6:240,合成温度为100℃左右,合成时间大于5 h。     

含甲基纤维素的NaA沸石膜的制备和表征

NaA沸石膜具有规则的孔道结构,利于分子传输,在有机物脱水领域有一定的应用。为使沸石膜生长更连续均匀,提高渗透汽化性能,本文以甲基纤维素作为空间限制剂加入合成液,探究碱度、晶化温度以及晶化时间对膜的影响,按最优条件制备合成液,并依据质量比m(MC)∶m(H₂O)=1∶100添加甲基纤维素,制备NaA沸石膜。表征方法采用XRD、SEM和渗透汽化3种方式,结果表明添加甲基纤维素的沸石膜表面结构完整,生长致密且性能优良,在75℃下对0.6mol/L的NaCl水溶液做渗透汽化测试时,通量达8.33kg/(m²·h),盐离子截留率为99.95%。在0.6mol/L的NaCl的水溶液中测试72h,结果表明添加甲基纤维素的NaA沸石膜时间依存性更好,通量保持在8.30kg/(m²·h)左右,离子截留率稳定在99.90%。渗透汽化分离ω(C₂H₆O)=90%乙醇的水溶液,随着温度从60℃升高到75℃,沸石膜的通量由1.55kg/(m²·h)升高到2.56kg/(m²·h),渗透侧水含量保持在99.90%左右。     

渗透汽化异丙醇脱水ZSM-5沸石膜的制备与表征

采用二次生长法在无有机模板剂条件下水热晶化制备高质量纯相ZSM-5沸石膜。考察了Na2O/SiO_2摩尔比和Na F/SiO_2摩尔比对制备ZSM-5沸石膜及其结构、形貌与渗透汽化异丙醇脱水分离性能的影响。结果表明,在较低Na2O/SiO_2摩尔比或Na F/SiO_2摩尔比下制备的沸石膜膜层结晶度低;而在较高Na2O/SiO_2摩尔比或Na F/SiO_2摩尔比时,易转晶生成mordenite沸石晶体;仅在Na2O/SiO_2摩尔比为0.17、Na F/SiO_2摩尔比为0.9时,制备出高质量纯相ZSM-5沸石膜,其膜层平整、连续、致密且结晶度高,该膜在渗透汽化异丙醇脱水中具有最佳的分离性能,其渗透通量为3.88 kg/(m2·h),水对异丙醇的分离系数达10 000以上。     

蒸汽相体系下低硅沸石DFT和GIS的合成

采用蒸汽相合成法,在F-作为矿化剂以及乙二胺作为液相的条件下,合成出低硅沸石DFT和GIS。重点考察了氢氟酸(HF)用量和硅铝比(n(Si O2)/n(Al2O3))对低硅沸石DFT和GIS合成的影响,其较佳固相凝胶组成分别为:n(HF)∶n(Si O2)∶n(Al2O3)∶n(H2O)=0.5∶1.0∶0.5∶5.0,n(HF)∶n(Si O2)∶n(Al2O3)∶n(H2O)=2.5∶1.0∶0.5∶5.0。元素分析和热重结果表明,双质子化的乙二胺起到平衡骨架负电荷的作用,结构导向合成出低硅沸石DFT和GIS。HF的用量对合成产物物相有明显影响,少量的HF有利于合成低硅沸石DFT,增加HF的用量则导致低硅沸石GIS的生成。     

采用复合晶种法在大孔载体上制备高性能ZSM-5沸石膜

采用复合晶种法在α-Al2O3载体上制备ZSM-5沸石膜.首先采用热浸渍-擦涂法在大孔α-Al2O3载体上预涂一层由纳米ZSM-5分子筛团聚而成的大晶种颗粒,对载体表面的大孔进行初步修饰;然后在此基础上利用提拉法涂覆小晶种,从而形成一层薄而连续的晶种层;最后在175℃下利用二次生长法制备ZSM-5沸石膜.采用SEM和XRD等方法,对制备的ZSM-5沸石膜进行表征,并对其进行渗透汽化性能测试.结果表明:制备的ZSM-5膜连续、致密且厚度为8μm;在温度353 K下,分离质量分数为90％的乙酸/水体系,其渗透通量可达0.89 kg/(m2·h),分离系数接近于无穷大.     

T型沸石膜的制备及其脱盐性能研究

以2μm和600 nm的T型沸石为晶种,采用二次生长法制备T型沸石膜,利用XRD和SEM对T型沸石膜的晶相结构、膜层形貌进行表征,并在348 K下将其用于渗透蒸发分离35 g/L氯化钠溶液。结果表明,在423 K下晶化反应4 h, T型沸石晶体交互生长形成致密的T型沸石膜,膜层厚度约4μm,渗透蒸发脱盐测试渗透通量可以稳定在7.5 kg/（m²·h）,离子截留率大于99.9%;制备的T型沸石膜渗透蒸发脱盐性能优异,有重要的海水脱盐工业应用价值。     

多步组装合成介孔二氧化硅担载膜

采用浸渍法和表面改性多步组装合成技术在商业用多孔氧化铝管上制备介孔二氧化硅担载膜。所制备的介孔二氧化硅膜层的厚度平均为2μm,平均孔径为1.59nm。单一气体的渗透实验表明:气体通过介孔二氧化硅膜层符合Knudsen扩散模型,在298K和100kPa的恒定条件下,氦气和氮气的渗透量分别为15.6×10-6mol/(s·m2·Pa)和2.5×10-6mol/(s·m2·Pa)。渗透蒸发实验表明:经六甲基二硅氮烷表面改性的二氧化硅膜层在303K和313K下分别对含3%(质量分数,下同)和5%乙醇的水溶液进行乙醇组分的提浓,乙醇的分离系数和渗透通量分别为15.2～18.7和1.09～1.25kg/(m2·h)。     

ZSM-5/MOR共生分子筛的合成机理I——合成工艺对共生物相的影响

以偏硅酸钠和硫酸铝为原料,采用直接合成法合成了ZSM-5/丝光沸石(mordenite,MOR)共生分子筛。通过X射线衍射和扫描电镜分析了合成样品的物相、形貌以及合成溶液中钠、铝含量和干基硅氧摩尔比的变化对ZSM-5/MOR共生分子筛样品结晶度的影响。结果表明:合成的样品是ZSM-5含量为90.3%,MOR含量为9.7%组成的ZSM-5/MOR共生分子筛,其大部分颗粒呈椭圆形和梭形。当合成溶液中n(Na):n(Al)=6,n(SiO2):n(Al2O3)≥20和n(O):n(Si)≥2.536时,合成的共生分子筛结晶度最好。在此基础上,提出了钠离子作为结构导向剂的合成机理。     

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。