珍珠镍电镀添加剂、工艺条件及镀层性能研究

通过赫尔槽试验和方槽试验研究了添加剂(包括柔软剂、润湿剂、沙剂和稳定剂)以及工艺条件(包括电流密度、温度和时间)对电镀珍珠镍的影响,得到较佳的镀液配方和工艺为:Ni SO4·6H2O 400~500 g/L,Ni Cl2·6H2O 45 g/L,H3BO3 40 g/L,柔软剂双苯磺酰亚胺(BBI)8~42 m L/L,润湿剂丁二酸二己酯磺酸钠(MA-80)0.8~2.0 m L/L,沙剂TB 2.4~3.2 m L/L,稳定剂NB 0.8~2.5 m L/L,温度50~60°C,p H 3.5~4.5,电流密度2~15 A/dm2。采用金相显微镜和扫描电镜分析了珍珠镍镀层的微观结构,并通过中性盐雾试验对比研究了珍珠镍镀层和光亮镍镀层的耐蚀性。结果表明,珍珠镍镀层呈珍珠般柔和的银白色,其表面均匀分布着许多直径为3~10μm、深1~2μm的圆形凹坑。相同厚度的珍珠镍镀层的耐蚀性优于光亮镍镀层。     

金色与珍珠黑色镀层在装饰上的应用

阐述了各种黄金电镀与仿金镀层电镀工艺，以及在锡镍、锡镍铜合金镀液中获得珍珠黑色镀层的方法。     

珍珠镍电镀的研究现状

珍珠镍外观典雅,色泽柔和,具有绸缎般光泽的表面,正在逐步取代具有耀眼光泽的装饰性镀层,用于汽车、摩托车、家用电器等的零部件和装饰件。介绍了珍珠镍的3种制备方法,包括机械法、复合镀法、乳化剂法,以及后2种方法的电镀工艺。探讨了添加剂在形成缎面镀层过程中的作用机制。对珍珠镍的国内外发展现状进行了综述,提出了国内珍珠镍的研究方向。     

氨基磺酸盐镀镍的微观织构与硬度

采用氨基磺酸盐镀液电沉积镍层,通过WLI,SEM,XRD和MHT对镀层的三维形貌、微观织构及硬度进行分析。结果表明:在镀液中不含添加剂的情况下,随着阴极电流密度的增加,镀层晶粒细化,但镀层致密性变差且硬度呈近似线性关系降低;镀液中加入适量添加剂后,镀层衍射谱特征和各晶面的择优取向度无明显改变,但在相同阴极电流密度下所得镀层的晶粒更加细小且硬度有所提高。     

BH-952滚镀亮镍添加剂及工艺研究

研制出一种滚镀亮镍添加剂BH—952，对镀液、镀层的各项性能进行了测试。采用电化学方法初步探讨了添加剂的作用机理，并总结了镀液的维护特性。     

装饰性锡锌镍三元合金代镍工艺研究

研究了装饰性电镀锡锌镍三元合金代镍工艺。采用赫尔槽试验探讨了主盐、添加剂、溶液温度和pH对镀层镍含量、镀层外观及镀液稳定性的影响。结果表明:该工艺操作方便,镀液分散能力和覆盖能力好,所得锡锌镍合金镀层结晶细致,光亮,类似镍层,其耐蚀性明显优于锌镀层,适用于钢铁件高耐蚀装饰性电镀。     

多层镍镀液添加剂浓度测定

近几年来国内已开展多层镍工艺的研究和应用,无论是双层镍或三层镍,镀液都是由Watts液加入不同添加剂所组成.舔加剂中有一类主要是起整平和光亮作用,还有一类目的在于提高镍镀层的电化学活性.研究结果表明,具有优良防腐性能的多层镍其镀层间的电位差必须严格控制,而选择添加剂并控制其用量对于多层镍镀层间的电位差起着决定性作用.本文根据添加剂的性能特征,提出半亮镍、高硫镍和亮镍镀液中添加剂浓度的测定方法.     

光亮镍磷合金镀液中添加剂作用的研究

研究了镍磷合金镀液中不同添加剂的作用，结果表明，含吡啶衍生物作为添加剂的镀液具有较高的阴极极化度、电流效率、分散能力和镀层光亮度，而且所有这些性能均优于用果糖作添加剂的镀液。     

简讯

中科院光电技术研究所研制成功的钯镍电镀工艺已经通过鉴定。该镀层电阻小,耐磨损,牢固,均匀,耐腐蚀,光洁平整,可代替纯金和纯钯镀层。中科院光电技术研究所研制的 BD 黑铬工艺通过鉴定。采用 BD 添加剂的镀层呈瑰丽真黑色,镀液的分散与深镀能力良好,能在室温下直接施镀于铜、钢、不锈钢、铁等基材或锌、镍、铬等镀层上。     

含硫添加剂对镀镍层活性的影响

本文用转盘电极阳极溶出法研究糖精对镀镍薄层的电化学活性的影响,并借助 X 光电子能谱检测镀层的酸含量。结果表明,镀液中糖精浓度决定沉积层的硫含量及其电化学活性。此外,我们还研究了Watts 镀液 pH、添加剂、电流密度、电极转速等对镍镀层阳极溶出特性的影响,发现镀层的阳极溶出峰电位可用来判断镍镀层的电化学活性,峰电量则可用于测定镀液中糖精或某些芳香磺化物的浓度。     

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.     

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.