动态表面张力的测定及应用研究综述

表面张力是表征溶液性质的重要物理参数,添加不同类型的表面活性剂,降低表面张力的状态也会不同,其中,动态表面张力的测定能表征表面活性剂分子在溶液内部及表面的运动特性,通过测定动态表面张力,既能表征溶液表面张力降低速率的快慢,也能体现表面活性剂分子在气-液两相吸附的差异。介绍动态表面张力的常用测定方法,归纳各种测定方法的适用范围,综述国内外动态表面张力测定在各领域的应用研究成果及价值。     

水质稳定剂性能与其表面张力的关系初探

在室温下,用滴重法测定不同浓度的表面活性剂-ATMP、IDPA、Q-IDPA及PAA溶液的表面张力,发现表面活性剂的阻垢、缓蚀、协同效应的性能与其表面张力之间存在着一定的关系。根据表面活性剂的表面张力的大小,能预示表面活性剂在工业水处理方面应用的前景。     

Research progress of physical properties of surfactant solutions

认知表面活性剂溶液物理特性是揭示表面活性剂强化沸腾换热机理的基础。本文以表面活性剂强化沸腾换热为背景,阐述了与沸腾换热密切相关的表面活性剂溶液相关物理特性的研究进展,包括表面活性剂溶液的静态表面张力、动态表面张力、黏度、润湿性能和溶解度等物理特性。最后,指出了目前表面活性剂溶液物理特性的研究不足,并对表面活性剂溶液物理特性的研究方法和研究内容进行了展望。     

部颁标准测定润湿速率方法的机理研究

本工作采用化工部部颁标准HG2-380-80(下称部颁法)测定了Aerosol OT、BX、Tergitol等阴离子表面活性剂对天然纤维的润湿速度,同时测定了它们的表面张力及其在石蜡表面的接触角。研究表明,部颁法测定的润湿时间与溶液的表面张力、石蜡表面的接触角和溶液浓度之间的关系,符合Fowkes提出的润湿模型,为部颁法测定阴离子表面活性剂溶液的润湿速率找到理论依据。     

常用临界胶束浓度的测定方法

1)表面张力法:表面张力测定法适合于离子表面活性剂和非离子表面活性剂cmc的测定,无机离子的存在也不影响测定结果。在表面活性剂浓度较低时,随着浓度的增加,溶液的表面张力急剧下降,当达到cmc后,表面张力的下降则很缓慢或停止。     

白金板法和白金环法测定橡胶胶乳表面张力的对比

对白金板法测定橡胶胶乳表面张力的原理和优势进行了分析,考察了影响白金环法和白金板法测定橡胶胶乳表面张力的影响因素,建立了与白金环法数据具有可比性的白金板法。结果表明,在测定包括天然胶乳(NRL)和合成胶乳的6种橡胶胶乳表面张力时,建立的白金板法与白金环法测定结果相当;白金板法测定的表面张力重复性为0.31～0.57 mN/m。     

ATMP、IDPA等水质稳定剂的性能与其表面张力的关系

在室温下,用滴重法测定不同浓度的表面活性剂——ATMP(氨基三甲叉膦酸)、IDPA(亚氨基二甲叉膦酸)及PAA(聚丙烯酸)水溶液的表面张力,发现表面活性剂的阻垢性能、缓蚀性能、协同效应与其表面张力之间存在着一定的关系。测定添加表面活性剂后水的表面张力的变化,将有助于预测表面活性剂在工业水处理方面的应用。     

改性纤维素类高分子表面活性剂的制备及性能

以月桂酸甲酯为反应试剂,N,N-二甲基甲酰胺为溶剂,K2CO3为催化剂,对羧甲基纤维素钠(CMC)进行疏水改性,反应得到疏水改性羧甲基纤维素高分子表面活性剂(HM-CMC)。采用红外光谱和核磁共振氢谱对产物的结构进行了表征,并计算得出产物的取代度(DS)为0.028。采用悬滴法测定表面张力、芘荧光探针测定临界缔合浓度(cac)、动态激光光散射法测定胶束的流体动力学半径分布以及流变仪测定黏度来研究产物的性能。实验结果表明,产物水溶液的质量浓度达10 g·L-1时,表面张力降至40.0 mN·m-1;cac为0.09 g·L-1;胶束的流体动力学半径随着质量浓度上升而增大;产物溶液黏度随质量分数上升而增大,临界缠结浓度为0.8%。     

FC/CH表面活性剂复配在电子布化学处理中的应用

论述了电子布化学处理采用氟碳表面活性剂（FC）、碳氢表面活性剂（CH）与硅烷偶联剂水解液复配的原因。并通过实例比较了采用不同的FC/CH表面活性剂进行复配对动态表面张力的影响。同时,作者研究了如何选择FC以及如何将FC/CH复配以达到动静态表面张力俱佳的效果。因此使用FC/CH表面活性剂复配能达到降低动态和静态表面张力的目的,提升电子布的处理品质。     

表面活性剂协同效应的研究(英文)

新型表面活性剂的开发研究及现有品种的复配是表面活性剂研究领域中的两个主要方向。对洗涤剂中常用的表面活性剂 :烷基聚氧乙烯醚硫酸钠 (AES)、椰子油酰胺丙基甜菜碱 (KBT)和椰子油二乙醇酰胺 (CDEA)的复配进行了研究。采用滴体积法测定了混合溶液AES/KBT和AES/CDEA的表面张力σ ,再根据σ与溶液浓度C曲线 ,求得溶液的临界胶团浓度cmc、C =cmc时溶液的表面张力σcmc及σ =35mN·m-1时溶液的浓度C35。溶液的起泡性和泡沫稳定性则利用根据Ross -Mile原理自制的装置来测定。实验结果显示 ,在一定混合比时 ,混合溶液的cmc值比相应的任一纯组分的cmc0i 都要低 ,C35也低于纯组分的C035,说明两复配体系均有形成胶团和降低表面张力效率的协同效应。最小cmc值所对应的复配比例 (摩尔比 )为AES/KBT =0 46∶0 5 4,AES/CDEA =0 42∶0 5 8。实验结果还显示 ,混合溶液的起泡性和泡沫稳定性均有改善 ,特别是泡沫稳定性     

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。