Al - Cu柱撑蒙脱土的超声制备与表征

以钠基蒙脱土为原料,在超声波作用下制备Al-Cu柱撑蒙脱土。柱撑溶液中的n(OH-)∶n(Al3 )为2.4,n(Cu)∶n(Al3 )为1∶9,可得到层间距d(001)值为1.9553 nm,比表面积为183.6m2.g-1的产物。采用X射线衍射分析(XRD)、红外光谱(FTIR)、透射电镜(TEM)、扫描电镜(SEM)和差示扫描量热(TG-DSC)等手段对制备的柱撑蒙脱土进行了表征,结果表明:钠基蒙脱土经反应后,柱撑剂进入到蒙脱土层间,与蒙脱石骨架发生成键反应形成Si-O-Cu或Si-O-Al键,使得蒙脱土的层间距和比表面积都显著的增大,热稳定性也显著地提高了。     

聚合羟基Al-柱撑蒙脱石的制备与机理研究

作者以辽宁某地的钙基膨润土经钠化改型后为原料,考察了聚合羟基Al离子(柱化剂)的制备工艺(温度和老化时间)对柱撑蒙脱石晶层间跨d001的影响,运用X-射线衍射(XRD)分析、化学分析、热重(TG)和差热(DTA)分析等手段探索了柱撑蒙脱石的微结构变化和形成机理。     

Al-Mn柱撑蒙脱石的制备和微结构变化研究

以辽宁某地的钙基膨润土为原料，首先对其钠化改型得到适合制备柱撑蒙脱石的基质，然后采用取代法合成Al-Mn柱化剂，依此制备了Al-Mn柱撑蒙脱石，并运用X射线衍射分析，化学分析，红外光谱分析及煅烧试验等手段研究了Al-Mn柱撑蒙脱石的微结构变化和热稳定性，结果表明：n(Mn^2 ):n(Al^3 )为0．5时，可得到层间距d(001)值为1．8987nm的产物，300℃煅烧后其层间距稳定在1．7859nmm,具有较好的热稳定性，钠基膨润土经柱撑反应后，柱化剂进入了蒙脱石层间，同时蒙脱石骨架[Si4O10]n与层间柱化剂离子之间发生了成键反应，形成了Si-O-Al或Si-O-Mn键。     

锆基柱撑膨润土的水热法制备及其MTO催化性能

以钠基膨润土为原料,ZrOCl2.8H2O为柱化剂的锆源,采用水热合成法制备了锆基柱撑膨润土（Zr-PILM）,结合XRD对产物进行表征,探讨了锆/土比和焙烧温度对甲醇制备低碳烯烃（Methane-to-Olefin,简称MTO）的影响。结果表明：Zr-PILM的d001值随着锆/土比的增加而增大,锆/土比从15mmol/g增加为30mmol/g时,d001值仅增大了0.03nm,说明膨润土可交换容积已基本达到饱和;经过300℃焙烧其d001可达2.16nm;对比同样经过500℃焙烧的柱撑前后膨润土,Zr-PILM的d001值由柱撑前的0.96nm变为2.01nm,说明其保留了层间结构,热稳定性提高;Zr-PILM催化MTO反应可使甲醇转化率达到95.01%,低碳烯烃的选择性达到68.24%。     

铁铝柱撑酸化蒙脱土催化剂的表征及催化性能

为改善柱撑蒙脱土的催化活性,对蒙脱土进行酸预处理,并采用离子交换法制备铁铝柱撑酸化蒙脱土(Fe-Al-酸化土)催化剂,通过XRD、BET、ICP和FI-IR对其进行表征。结果表明,蒙脱土经酸化预处理制备Fe-Al酸化土催化剂比表面积为157.3 m~2·g~(-1),层间距d001为1.787 nm,铁铝柱撑剂进入酸化蒙脱土层间域形成均一稳定的Si—O—Fe结构,在2 930 cm-1处出现尖锐的吸收峰,在协同过氧化氢降解废水实验中表现出较高的活性和稳定性。     

Al柱撑蒙脱石的制备及表征

以山西某地钙基膨润土为原料,经提纯、钠化、柱撑制备了铝柱撑蒙脱石,运用X射线衍射（XRD）、傅里叶红外光谱（FTIR）、差热．热重（DSC-TG）、扫描电镜（SEM）等分析手段对产物进行系统表征。结果表明：Al柱化剂进入蒙脱石层间,柱撑产物层间距从1．280nm增大至2．007nm,经500℃煅烧1h后（001）晶面衍射峰仍清晰可见,产物经升温至900℃脱水过程中失熏明显平缓,产物的微观孔洞结构明显增多。     

Fe/Cr柱撑蒙脱石的水热法制备与表征

以钙基蒙脱石为原料,经超声波预处理后,利用水热法合成了Fe/Cr柱撑蒙脱石。水热法与传统方法相比,可以省去钠化改型和老化等步骤,大大缩短制备周期。在水热法制备柱化剂的过程中,首次提出二次水解法。实验结果表明,经过预处理后,蒙脱石的分散度大大提高,平均粒度达0964 μm;二次水解法可以制备出更好的柱化剂。XRD和XRF分析结果表明,水热法可以制备出结晶较好、热稳定性较高和具有良好孔结构的柱撑蒙脱石,经过二次水解法制备的Fe/Cr柱撑蒙脱石的d₍₀₀₁₎达1962 nm。     

蒙脱石预处理对制备柱撑蒙脱石的促进作用研究

在制备柱撑蒙脱石的过程中，首次提出了蒙脱石的预处理工艺，并以莱西钙基膨润土为原料，研究了预处理方法、预处理时间、料浆浓度、分散剂种类及用量对蒙脱石分散程度的影响，将钙基蒙脱石颗粒分散达到0.964 μm。经过预处理后，用钙基蒙脱石直接制备柱撑蒙脱石，并用SEM、XRD、DTA-TG和SRF等进行了表征。经300 ℃焙烧2 h后，其层间距为1.262 nm，热稳定性达588 ℃，此法省去了蒙脱石的钠化改性，简化了制备工艺。     

负载型层柱黏土对模拟柴油中二苯并噻吩选择吸附性能的研究

用钠基蒙脱土合成了钛层柱黏土(Ti-PILCs),以合成的Ti-PILCs为载体负载过渡金属制备了层柱黏土吸附剂,研究了对二苯并噻吩/正己烷模拟柴油体系的选择吸附性能.Ti-PILCs对_二苯并嚷吩具有一定的选择吸附能力;Ti-PIlCs负载Ag、Zn、Cu或Ni等过渡金属后显著提高了选择吸附性能.采用浸渍法负载Zn、Zn负载量为0.5%(质量分数)、400℃焙烧的Zn/Ti-PILCs可达到最佳的吸附效果,DBT去除达90.6%.Za/Ti-PILCs吸附后经加热可多次再生,其再生吸附性能良好.     

钛交联蒙脱石纳米复合材料的合成与表征

利用经过精制的钠基蒙脱石作为基质材料,以钛酸正丁酯为钛源．制备了钛交联蒙脱石（Ti—pillared clays,TiPILCs）纳米复合材料。利用X射线衍射、热重／差热分析、红外光谱分析、N2吸附－脱附等分析手段对材料进行结构性能表征。X射线衍射分析表明：Ti—PILCs的层间距具有多分散性,d（001）值从钠基蒙脱石的1．28nm最高可上升为3．59nm。热重／差热曲线显示：Ti-PILCs的加热质量损失比钠基蒙脱石大．且脱层间水过程与脱羟基过程的界限变得不清晰。比表面测定显示：比表面积从钠基蒙脱石的31．6m^2／g增大到Ti—PILCs的400m^2／g,且随温度的变化不大。孔径分布的测定表明：钠基蒙脱石和Ti—PILCs均具有物理堆砌形成的“卡房状”孔．而Ti-PILCs中还存在大量交联柱化形成的2～4nm二维孔。红外光谱进一步证实Ti-PILCs具有Ti-O键和Ti-O-Si键的振动峰,说明该物质是钛交联多孔纳米复合材料。     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.     

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.