铁改性膨润土类Fenton法降解罗丹明B的研究

以FeSO4和膨润土为原料制备了铁改性膨润土,研究其利用类Fenton法对罗丹明B的降解性能,并考查了铁改性膨润土用量、温度和初始溶液pH、H2O2用量等因素对降解效果的影响.当pH为7.0,1 mL浓度30％的H2O2,改性膨润土的量为0.3 g,搅拌时间为1 h的条件下,对200 mg/L的罗丹明B溶液的降解率能达到94.79％.     

微波辅助Fe_3O_4/H_2O_2类Fenton法处理罗丹明B废水

采用纳米Fe3O4作为催化剂,H2O2为氧化剂,组成多相类Fenton试剂,与微波联合处理罗丹明B(Rh B)染料废水。反应在300W微波反应器中进行,系统研究了H2O2浓度,Fe3O4用量,反应时间,反应温度及催化剂循环使用等条件对罗丹明B脱色率的影响。结果表明,在pH值为4,罗丹明B浓度为100 mg/L,反应温度为80℃,反应时间为5min,H2O2用量为5.0 mL/L,Fe3O4用量为1.25 g/L时,微波辅助条件下罗丹明B脱色率达到100%。此外,催化剂六次循环实验表明,磁性催化剂非常稳定,可重复使用,且易回收。实验表明微波加热与Fe3O4/H2O2类Fenton反应的联合产生了良好的协同效果,该联合工艺可大大提高废水中有机物的处理效果。     

UV/TiO2/Fenton体系催化氧化降解罗丹明B的研究

研究在紫外光照射下,Fenton试剂在纳米级TiO2催化作用下氧化降解罗丹明B的处理效果及机理,分别研究初始反应溶液的pH值、反应时间、FeSO4投加量、H2O2溶液投加量、反应温度、TiO2投加量对处理效果的影响,确定了最优反应条件。对于100 mg/L,500 mL的罗丹明B溶液,当TiO2的投加量为0.03g,18mol/L FeSO4的加入量为5 mL,30%H2O2溶液的加入量为1.7 mL,反应溶液pH值为3时,罗丹明B的去除率随着反应温度的升高而升高,最高去除率达100%。     

Fenton试剂氧化处理甲基橙模拟废水的条件研究

Fenton试剂是H2O2和Fe^2＋混合得到的一种强氧化剂,近十几年来在废水处理中的应用得到广泛的关注。现采用Fenton试剂降解含甲基橙染料的模拟废水,探讨H2O2和Fe^2＋的用量、溶液pH值和甲基橙初始浓度、反应时间等对甲基橙去除率的影响。研究表明：当溶液pH为3,H2O2和1%FeSO4·7H2O的用量分别为1mL和3mL,甲基橙的浓度为20mg/L时,反应2分钟后,甲基橙的去除率可达90％以上,证明了Fenton试剂可以有效地处理甲基橙模拟废水．     

UV/Fenton试剂降解RDX废水的研究

研究了Fenton试剂的用量、pH值、光照时间对UV/Fenton试剂降解黑索今(RDX)废水效果的影响。结果表明,UV/Fenton试剂对RDX废水有较好的降解作用,在60 W紫外灯照射下,RDX废水初始质量浓度为180 mg/L、pH值为3、10%双氧水用量为1.20 mL、10%FeSO4溶液[(n(Fe-SO4)∶n(H2O2)=1∶10)]用量为0.12 mL、光照时间为60 m in时,RDX去除率达到95%,CODC r去除率为82%。     

Fenton试剂预处理青霉素废水的实验研究

青霉素废水是典型的难降解抗生素废水。本研究利用Fenton试剂预处理青霉素废水,探讨了pH值、H2O2用量、Fe2+用量、搅拌时间、静置时间对废水COD去除效果的影响。正交实验结果表明,Fenton试剂氧化法对青霉素废水具有良好的处理效果,在最佳实验条件下(pH=3.5;Fe2SO4·7H2O=0.9g/L;H2O2=1.2mL/L;T=40min),COD去除率为94.2%,各实验因素中Fe2+用量对实验的影响最大。     

O3/Fenton试剂复合氧化多菌灵废水实验

研究了O3/Fenton试剂联合处理农药多菌灵废水的方法,并且考察pH值、臭氧用量、Fenton试剂投加量对处理效果的影响.实验结果表明:最优条件为废水pH值调节为9左右、臭氧用量为2.0 g/L、H2O2投加量为5 mL/L时,废水COD去除率达68%,BOD/COD提高到0.36.如果用接触氧化进行二级处理,可使最终出水指标达到国家一级排放标准.     

微波强化类Fenton降解罗丹明B溶液的研究

以负载型CuO/石油焦-H2O2构成类Fenton试剂,在微波辐射条件下催化氧化罗丹明B溶液。结果表明,微波具有非常明显的强化作用,反应体系内罗丹明B得以迅速充分地降解。对于200 mL质量浓度为100 mg/L的罗丹明B溶液,微波强化类Fenton催化氧化的最优条件为：溶液的初始pH值为3.0～3.5、质量分数为30%的H2O2的投加量为0.4 mL、负载型CuO/石油焦催化剂的投加量为180 g、功率为750 W的微波辐照4 min,此时罗丹明B的去除率达到96%。对于难处理的有机染料废水,微波强化类Fenton工艺是一种较为有效的处理技术。     

超声波协同Fenton试剂降解糖蜜酒精废水的工艺

采用超声波为辅助条件,以废水的COD去除率、脱色率为评价指标,考察了Fenton试剂对糖蜜酒精废水催化降解特性.实验结果表明,Fenton试剂对糖蜜酒精废水具有良好的处理效果,超声波与Fenton试剂之间存在着协同作用.通过正交实验得出的最佳降解工艺条件为:H2O2用量10 mL/L,硫酸亚铁0.50 g/L,废水稀释倍数40倍,超声波功率200 W,反应时间30 min,废水的COD去除率达到69%,色度降解率达到74%.     

Fe/羟基磷灰石多相类Fenton体系有效降解结晶紫染料废水

以结晶紫溶液为模拟染料废水,Fe/HAP为催化剂,对该多相类Fenton体系的催化活性进行了研究,探讨了H2O2投加量、催化剂投加量、pH值、反应温度、溶液初始浓度对结晶紫去除效果的影响.结果表明在H2O2用量为1 mL,催化剂投加量为1g/L,pH值为9,降解温度为30℃,浓度为40 mg/L的结晶紫溶液脱色率在96％以上.     

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.     

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.     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.