冷等离子体处理芳纶帘线的表面结构形态及其与橡胶粘合性能的研究

本文研究了芳纶帘线的冷等离子体处理对其表面结构形态和粘合性能的影响。芳纶纤维经空气等离子体处理后,SEM分析显示纤维表面粗糙度增加,可在一定程度上提高其与橡胶的粘合性能;但结合浸胶处理后,其与橡胶的粘合性能显著提高,较未处理提高227%以上,较空气等离子体处理与胶料直接粘合提高95%以上,较工业二浴法制备的浸胶芳纶帘线提高48%以上。该法工艺简单,对环境友好,有良好的工业化应用前景。     

氮气等离子体处理对芳纶与橡胶粘合性能的影响

研究氮气等离子体处理对芳纶帘线表面形态及其与橡胶粘合性能的影响。结果表明,氮气等离子体处理可在一定程度上提高芳纶帘线与橡胶的粘合性能;芳纶经氮气等离子体处理后再结合浸胶,粘合强度显著提高;高功率、长时间处理有利于芳纶帘线与橡胶粘合性能的提高,但会使芳纶帘线的强度下降。适宜处理条件为：功率100～125W,时间5～7min。     

芳纶帘线表面处理及环境温度对芳纶帘线/橡胶界面破坏的影响

研究芳纶帘线表面处理及环境温度对芳纶帘线/橡胶界面破坏的影响.结果表明,与未处理及150 W氮等离子体处理8 min并结合浸胶工艺的试样相比,50 W空气等离子体处理5 min并结合浸胶工艺的芳纶帘线/橡胶粘合体系的最大H抽出力、最大H抽出力时的位移、抽出模量、初始裂纹形成功及裂纹扩展功较大,界面结合作用较理想.环境温度升高,粘合体系的最大H抽出力和抽出模量等呈下降趋势.     

芳纶复合帘线的加工、粘合与应用

概述芳纶复合帘线的加工、粘合机理以及在轮胎中的应用。直捻机经过改进可用于芳纶复合帘线加工;芳纶表面改性、超声波处理、γ射线辐射和二次浸渍工艺等均可提高芳纶帘线的粘合性能;将芳纶复合帘线用于子午线轮胎带束层和冠带层、工程机械轮胎缓冲层等,可减小轮胎质量,提高抗刺扎性能,延长使用寿命。     

芳纶与橡胶界面粘合技术的研究进展

综述提高芳纶/橡胶界面粘合性能主要技术方法的基本原理和研究进展.芳纶表面活化处理包括物理改性和化学改性.物理改性是通过物理技术对芳纶表面进行刻蚀和清洗,引入活性基团;化学改性是利用化学试剂与芳纶表面发生化学反应,通过化学键合或极性作用提高芳纶与基体之间的粘合强度.间苯二酚-甲醛-胶乳体系浸渍处理通过分别与芳纶表面和橡胶大分子作用,改善两者的界面粘合状态.橡胶的增粘改性处理是通过粘合剂与纤维和橡胶的反应促进两者的粘合,通常与表面活化和浸渍处理配合使用.     

阿克苏公司开发出新型粘合活化的芳纶纤维

荷兰阿克苏公司称,该公司的合成纤维部现已并入阿科迪斯公司,成为其成员公司。据报道,该公司已开发出新型的具有粘合活性的Ｔｗａｒｏｎ１０１４型芳纶纤维。芳纶纤维具有强度大、模量高、耐化学侵蚀性优异等优点,但同时又有不易与橡胶粘合的弱点,因此提高芳纶与橡胶的粘合性能成为芳纶开发中的一大问题。解决此问题的方法之一是对芳纶纤维表面进行活化处理,即在芳纶纺丝过程中,采用专用的粘合活化剂对芳纶纤维表面进行二次处理,这种方法通常被称为双浴处理法。由于采用这种方法需要使用较大的处理装置,因此处理成本较高。在８０年…     

几种胶带用聚酯和芳纶线绳浸胶技术的研究

探讨几种新浸渍材料及新浸渍方法在胶带用聚酯和芳纶长丝线绳浸胶工艺中的应用。结果表明，粘合剂IL-6减量替代一浴法浸渍液中的粘合剂RP，粘合活化聚酯长丝线绳粘合性能提高，浸渍成本降低；二浴法(第一浴浸渍液为水基环氧树脂溶液)浸渍的粘合活化芳纶长丝线绳粘合性能比一浴法好；IONOTHANE硬化剂处理的芳纶长丝硬线绳断裂强力高，耐疲劳性好，但硬度较低，浸渍成本较高；氯丁胶乳部分或全部替代RFL浸渍液中的丁吡胶乳可提高线绳的粘合性能。     

热空气老化对芳纶/橡胶复合体系粘合性的影响研究

研究了热空气老化对芳纶／橡胶复合体系粘合性的影响，通过对H抽出力一位移曲线特征值分析考察，发现芳纶经一定条件的空气等离子体处理再结合浸胶处理，与橡胶形成的粘合体系有较好的耐热空气老化能力和抵抗粘合破坏的能力，综合性能良好。     

纳米填料对芳纶纤维与天然橡胶粘合性能的影响

研究纳米填料对芳纶纤维与天然橡胶(NR)粘合性能的影响。结果表明:向间苯二酚-甲醛-胶乳(RFL)浸渍液中加入纳米填料(多壁碳纳米管和白炭黑)可以有效地提高芳纶纤维与NR之间的粘合性能;采用加入气相法白炭黑或沉淀法白炭黑的RFL浸渍液处理后,芳纶纤维与NR的粘合性能大幅提高,其中气相法白炭黑对粘合性能提高效果更好;芳纶纤维与NR的粘合性能随着气相法白炭黑用量的增大而提高。     

表面处理对芳纶纤维粘合性能的影响

研究活化液组成、间苯二酚-甲醛-胶乳(RFL)改性剂品种及浸渍工艺对芳纶纤维粘合性能的影响.结果表明,以环氧树脂-己内酰胺封闭异氰酸酯(简称封闭异氰酸酯)混合溶液作为一浴活化液的二次浸渍工艺和以封闭异氰酸酯改性RFL为浸渍液的一次浸渍工艺更适合芳纶纤维表面处理;在浸渍液成分一定的条件下,一次浸渍工艺处理效果优于二次浸渍工艺,操作更简便.     

全氟聚醚聚合物及其功能复合材料的研究进展

全氟聚醚（PFPE）聚合物具有极低的表面张力、低摩擦系数、优异的润滑性能和良好的疏水疏油性能，被广泛用作航空航天、核工业、真空、电子等领域的润滑材料以及合成功能复合材料的反应中间体。近年来，基于PFPE聚合物的含氟功能复合材料在一些新兴领域受到广泛关注。本文首先介绍了PFPE聚合物在润滑材料领域最新的研究进展，重点阐述了目前PFPE润滑剂在抗磨、防锈和PFPE基础油抗爬移方面存在的不足，并分析了其原因；其次概述了PFPE聚合物在功能涂层、含氟聚氨酯材料、氟橡胶以及类玻璃（Vitrimers）材料方面的研究进展和应用前景，并介绍了一些含氟功能复合材料的制备工艺；最后展望了PFPE聚合物未来的研究重点和发展趋势，旨在为拓宽PFPE聚合物的应用领域，开发高附加值的PFPE衍生产品提供思路。     

Electrospinning jets and polymer nanofibers

In electrospinning, polymer nanofibers are formed by the creation and elongation of an electrified fluid jet. The path of the jet is from a fluid surface that is often, but not necessarily constrained by an orifice, through a straight segment of a tapering cone, then through a series of successively smaller electrically driven bending coils, with each bending coil having turns of increasing radius, and finally solidifying into a continuous thin fiber. Control of the process produces fibers with nanometer scale diameters, along with various cross-sectional shapes, beads, branches and buckling coils or zigzags. Additions to the fluid being spun, such as chemical reagents, other polymers, dispersed particles, proteins, and viable cells, resulted in the inclusion of the added material along the nanofibers. Post-treatments of nanofibers, by conglutination, by vapor coating, by chemical treatment of the surfaces, and by thermal processing, broaden the usefulness of nanofibers.     

Possible allelopathic constituents ofCoffea arabica

The aqueous extracts of leaves, stems, and roots ofCoffea arabica significantly inhibited the seed germination and radicle growth of rye grass, lettuce, and fescue. When the extracts were diluted to 1% solution, significant suppression of lettuce growth was still found and was particularly pronounced in the extract of young seedlings. The paper chromato-gram of the ether fraction of an aqueous extract of coffee leaves was bioassayed with lettuce seeds and revealed a remarkable inhibition throughout the chromatogram except for the segment ofR _f 0.00–0.12. Paper without spotting extract was used as a standard. The phytotoxins present in coffee tissue were identified by paper and thin-layer chro-matography and mass spectrometry. The compounds include caffeine, theobromine, theophylline, paraxanthine, scopoletin, and chlorogenic, ferulic,p-coumaric,p-hydroxybenzoic, caffeic, and vanillic acids. All compounds except caffeic acid exhibited significant phytotoxicity to lettuce growth at a concentration of 100 ppm.Paper no. 222 of the Scientific Journal Series, Institute of Botany, Academia Sinica, Taiwan, and Journal Article 3582 of the Agricultural Experiment Station, Oklahoma State University, Stillwater, Oklahoma. The abstract was published in the Proceedings of 63rd Annual Meeting of American Societies for Experimental Biology, held on April 1–10, 1979, Dallas, Texas.     

Graphene-Based Sensors for the Detection of Bioactive Compounds: A Review

Over the last years, different nanomaterials have been investigated to design highly selective and sensitive sensors, reaching nano/picomolar concentrations of biomolecules, which is crucial for medical sciences and the healthcare industry in order to assess physiological and metabolic parameters. The discovery of graphene (G) has unexpectedly impulsed research on developing cost-effective electrode materials owed to its unique physical and chemical properties, including high specific surface area, elevated carrier mobility, exceptional electrical and thermal conductivity, strong stiffness and strength combined with flexibility and optical transparency. G and its derivatives, including graphene oxide (GO) and reduced graphene oxide (rGO), are becoming an important class of nanomaterials in the area of optical and electrochemical sensors. The presence of oxygenated functional groups makes GO nanosheets amphiphilic, facilitating chemical functionalization. G-based nanomaterials can be easily combined with different types of inorganic nanoparticles, including metals and metal oxides, quantum dots, organic polymers, and biomolecules, to yield a wide range of nanocomposites with enhanced sensitivity for sensor applications. This review provides an overview of recent research on G-based nanocomposites for the detection of bioactive compounds, providing insights on the unique advantages offered by G and its derivatives. Their synthesis process, functionalization routes, and main properties are summarized, and the main challenges are also discussed. The antioxidants selected for this review are melatonin, gallic acid, tannic acid, resveratrol, oleuropein, hydroxytyrosol, tocopherol, ascorbic acid, and curcumin. They were chosen owed to their beneficial properties for human health, including antibiotic, antiviral, cardiovascular protector, anticancer, anti-inflammatory, cytoprotective, neuroprotective, antiageing, antidegenerative, and antiallergic capacity. The sensitivity and selectivity of G-based electrochemical and fluorescent sensors are also examined. Finally, the future outlook for the development of G-based sensors for this type of biocompounds is outlined.     

生物质热解制备高品质生物油研究进展

生物质热解制备生物油是能源富集的有效途径,是实现碳闭路循环的重要方式,作为一种环境友好型技术受到广泛关注和研究。然而,生物质热解反应过程复杂,生成的生物油热值低、含氧量高及强酸性等特点,制约了生物油的分离提纯、制备合成气以及燃烧等方面的应用,生物油品质的提升迫在眉睫。本文从生物质三组分、原料预处理、反应参数、催化剂、反应器等方面综述了影响生物油品质的主要因素,分析了生物油的特点,不同预处理下生物质特性的变化与生物油的关系,催化剂参与的热解行为对提升生物油品质的导向作用以及常用生物质热解反应器的特点,并对影响生物油品质的主要因素进行了总结。最后,针对影响制备高品质生物油的诸多因素提出建议,以期为制备高品质生物油提供参考和借鉴。     

The Role of Supplementation with Natural Compounds in Post-Stroke Patients

Malnutrition is a serious problem in post-stroke patients. Importantly, it intensifies with hospitalization, and is related to both somatic and psychological reasons, as well as is associated with the insufficient knowledge of people who accompany the patient. Malnutrition is a negative prognostic factor, leading to a reduction in the quality of life. Moreover, this condition significantly extends hospitalization time, increases the frequency of treatment in intensive care units, and negatively affects the effectiveness of rehabilitation. Obtaining growing data on the therapeutic effectiveness of new compounds of natural origin is possible through the use of pharmacodynamic and analytical methods to assess their therapeutic properties. The proper supply of nutrients, as well as compounds of natural origin, is an important element of post-stroke therapy, due to their strong antioxidant, anti-inflammatory, neuroprotective and neuroplasticity enhancing properties. Taking the above into account, in this review we present the current state of knowledge on the benefits of using selected substances of natural origin in patients after cerebral stroke.     

Controlling particle dispersion in latex paints containing associative thickeners

Latex paints contain several types of particles including polymer binder, primary pigment, extenders, and colorants. When the paints contain associative thickeners, control of particle dispersion can be very complicated due to the interaction of the particles with dispersants, surfactants, and the associative thickener itself. In particular, dispersion of the pigments can act independently of dispersion of the binder particles. The consequences of this situation are manifested in the physical properties of the paint and of the films it forms. This paper describes these interactions in terms of their colloid chemistry and shows the consequences of additive choices on the particle dispersion and also the optical properties of model paint films. Presented at the 2006 FutureCoat! conference, sponsored by the Federation of Societies for Coatings Technology, in New Orleans, LA, on November 1–3, 2006.     

Investigations on some aspects of chemical ecology of cogongrass,Imperata cylindrica (L.) Beauv.

To understand the interference mechanism of the weed, cogongrass,Imperata cylindrica (L.) Beauv., its effect on nutrient availability and mycoflora of its soil rhizosphere as well as nodule characteristics, root length, and root/shoot ratio of Melilotus parviflora Desf. were investigated. Additionally, the effect of the leachates of leaves and root/rhizome of cogongrass on seed germination and seedling characteristics of radish, mustard, fenugreek, and tomato were examined. Furthermore, to assess the qualitative and quantitative differences in phytochemical components, the leachates and the soils from three sampling sites (with cogongrass and 1.5 m and 3 m away from cogongrass) were analyzed with high-performance liquid chromatography (HPLC) on a C18 column. No significant difference in nutrient availability was found, but qualitative and quantitative differences in phenolic fractions were recorded in the three sampling sites. Furthermore, of the 19 fungi recorded in the soils, decreases in the number of colonies (per gram of soil) ofAspergillus fumigatus, A. niger, A. candidus, and an increase of A. flavus was recorded in the soils with cogongrass. The inhibition in nodule number, weight, nitrogen fixation (acetylene reduction activity), root length, and root/shoot ratio of Melilotus parviflora were noted. Percent seed germination, root and shoot length, fresh and dry weight of seedlings of different seeds were affected by the leachates of leaves and root/rhizome. It was found that root/rhizome leachate was more inhibitory than leaf leachate. However, the inhibition was higher in soil+leaves leachate than soil+root/rhizome leachate. HPLC analysis established that four compounds were contributed by the weed to the soil system even though their relative concentration varies in various leachates. It is surmised that these compounds cause allelopathic inhibition of growth characteristics of seeds tested. Significance of the data vis-a-vis the interference potential of the cogongrass is discussed.     

油气集输过程中含油污泥减量化

集输过程中的含油污泥具有成分复杂、含液率高、乳化胶结稳定等特性，占油田危险废物新增量的约60%，是污染防治的重点。近年来，学者们开展了大量“调质-固液分离”减量化技术降低其环境风险和处置成本，但仍存在需要针对含油污泥不同来源优选相匹配的减量化调质方法和装置的难题。为此，本文回顾了氧化、破乳、絮凝、干化/半干、超声波、微波等化学与物理调质方法，离心机、叠螺机、压滤机3种固液分离装置研究进展，通过分别对各种调质方法及装置的对比分析，重点阐述了其作用机理、优缺点、适用对象。其中化学调质方法中破乳氧化、加酸更适用于高含聚油泥；表面活性剂破乳需加热，可与超声波相结合；有机和无机絮凝剂配合可提高罐底泥中油回收效果；干化/半干化法受经济效益制约。在文献基础上，认为未来应加强生物表面活性剂、生物电化学系统、椭圆叠螺机、基于固液分离装置数值模型基础上的设计与优化软件、多学科相结合的减量化耦合技术研究。