水处理絮凝剂的应用及研究进展

介绍了水处理絮凝剂的种类．叙述了无机絮凝剂、合成有机高分子絮凝剂、微生物絮凝剂以及复合型絮凝剂在水处理中的应用及研究现状,特别指出了复合型絮凝剂在水处理中的应用前景。认为从低分子到高分子、由无机到有机及由单一型到复合型是絮凝剂的发展走向,应追求高效、廉价、环保的絮凝剂。     

絮凝剂在水处理中的应用与展望

主要探讨了无机絮凝剂中铝盐、铁盐的絮凝机理与应用效果,天然有机高分子絮凝剂中的改性淀粉、改性纤维素、改性木质素及壳聚糖和人造有机高分子絮凝剂在水处理中的应用机理与效果,无机与有机复合絮凝剂的种类、絮凝机理、应用效果。并对无机、有机、无机与有机复合三种类型絮凝剂在水处理中的优缺点与应用现状进行比较,指出复合絮凝剂与天然有机絮凝剂在饮用水处理方面具有良好应用前景。     

有机高分子絮凝剂的研究现状（一）

絮凝沉淀法是使用最广泛的水处理技术 ,而絮凝剂是絮凝法水处理技术的核心。与无机絮凝剂相比 ,有机高分子絮凝剂具有用量少、成本低、毒性小等优点 ,因此它的开发应用越来越受关注。本文介绍了合成有机高分子絮凝剂、天然有机高分子改性絮凝剂和微生物絮凝剂的研究现状 ,并对其发展趋势作了简单的展望。     

天然高分子改性阳离子絮凝剂

介绍了高分子絮凝剂在水处理中的发展概况 ;根据物质的组分及来源对高分子絮凝剂进行了分类 ,并对天然有机高分子絮凝剂的性能及应用进行了论述 ;综述了近十多年来我国在改性淀粉絮凝剂方面的研究进展 ,并对今后的研究工作提出了一些建议     

有机高分子絮凝剂的研究进展

简单总结了有机高分子絮凝剂的发展概况,介绍了人工合成有机高分子絮凝剂和天然改性有机高分子絮凝剂的合成方法和在水处理领域的应用,并对其发展前景进行了展望。     

有机絮凝剂的现状和未来

从絮凝剂在水处理的作用入手,简单介绍了有机絮凝剂的三大类别：即合成有机高分子絮凝剂、天然有机高分子改性絮凝剂和微生物絮凝剂,同时指出了有机絮凝剂的发展方向。     

高分子絮凝剂的研究进展

絮凝沉降法是一种很有效的净化污染水体的方法,根据复合高分子絮凝剂化学组成的不同可分为无机高分子絮凝剂、有机-无机复合高分子絮凝剂、有机高分子絮凝剂和微生物絮凝剂,其各有不同特性和应用优势。作者综述了各类絮凝剂在国内外的研究现状以及对其优缺点、制备方法和在水处理领域的应用进展,通过比较几种絮凝剂的特点,对其存在问题和发展趋势进行了展望。     

有机高分子絮凝剂在印染废水处理中的应用

简要介绍了印染废水的水质特点和处理现状，着重综述了各类人工合成有机高分子絮凝剂的合成途径、化学改性方法及其在印染废水处理中的应用进展，并对其絮凝机理进行了归纳。文章还综述了木质素、壳聚糖、改性淀粉等天然高分子絮凝剂的研制及应用进展。指出有机高分子絮凝剂是一类有效的絮凝脱色剂，对有机高分子絮凝剂的研究和应用趋势作了展望。     

絮凝剂絮凝效果浅析

絮凝法是水处理技术中最重要的方法之一。本文介绍了近年来无机、有机、天然、无机／有机复合高分子絮凝剂征印染废水处理中的应用，并对各种絮凝剂的絮凝效果进行了简要评述。     

水处理有机絮凝剂的研究进展

水的净化处理方法中,絮凝沉淀法使用的絮凝剂,根据其化学成分的不同,可以分为无机、有机和微生物絮凝剂.有机絮凝剂由于其用量小、絮凝速度快和受外界因素影响小,得到广泛的应用.它主要包括合成有机高分子絮凝剂和天然有机高分子絮凝剂.详细介绍了水处理有机絮凝剂的种类、使用性能及其研究进展.     

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.