Generation of Airborne Multi-Walled Carbon Nanotubes for Inhalation Studies

Recent studies suggest that inhaled or intratracheally instilled multi-walled carbon nanotubes (MWCNTs) cause adverse health effects depending on the fiber length. In the present study a simple batch particle generation system was developed to generate airborne MWCNTs for inhalational toxicology studies. The generation rate can be controlled by the amplitude of sieve shaker. Maximum concentration of respirable airborne MWCNTs was 1.2 mg m^–3 at a nose-exposure chamber supplied with air at flow rate of 30 L min^–1. We examined the performance of airborne MWCNT generation system and characterized properties of generated fibrous particles at mass concentrations of 0.4 mg m^–3 (particle number; ca. 1700 cm^–3). Monomodal shaped size distributions with peak located at electrical mobility diameter of 300 nm (in number) and aerodynamic diameter of 1–2 μm (in mass) were measured with a scanning mobility particle sizer and with a low-pressure impactor, respectively. Two hour particle generation reproducibility tests were conducted five times, in which stability and repeatability of particle size and total number concentration were within an acceptable range. Aerodynamically classified particle morphology was studied by TEM, dissociated fiber-like and agglomerated MWCNT particles were observed. The former contributes up to 38% to counted particles, and the average width and length of fiber were 80 nm and 3.7 μm, respectively, with an aerodynamic size for particle of 260–381 nm.     

纳米粒子在润滑油中的分散稳定性研究

纳米粒子作为润滑油添加剂,具有非常好的抗磨减摩效果.纳米粒子团聚与分散机制比较复杂,形式多样.使用静电抗团聚理论分析纳米粒子在液体介质油中的分散稳定性,找出解决纳米粒子的分散问题,必须要求有足够高的能量以防止粒子间相互膨胀接触而重新团聚.最后用胶体的稳定性理论,即双电层排斥理论探讨纳米粒子在液体介质中的分散性问题,需要利用表面活性剂对其进行表面改性,使其处于良好、充分的分散状态.     

Vaporization--Condensation Generation of Ultrafine Hydrocarbon Particulate Matter for Inhalation Toxicology Studies

An evaporation/condensation particle generator produced 30-50 nm count median diameter particles from both pure hydrocarbons and from a complex mixture--used motor oil--at a concentration above 1 2 10 6 /cm 3 . The objective was to generate ultrafine aerosols for inhalation toxicology studies using specified organic components as surrogates for the particulate emissions generated by diesel internal combustion engines. This nanoparticle generation system, assembled from commercially available components, produced smaller particle size and higher particle number concentration than has been previously documented using Sinclair-La Mer condensation generator technology. The paper describes both the experiments used to design and characterize the particle generator and the operating conditions used for a specific inhalation experiment as an example of the system capability.     

片状Fe3O4纳米颗粒在润滑油中的摩擦化学性质

以片状Fe3O4纳米颗粒为润滑油添加剂,在四球摩擦试验机中考察了其在#40机油中的摩擦化学性质和对摩擦副摩擦化学的影响。结果表明:与摩擦前的片状Fe3O4纳米颗粒相比,摩擦化学作用使得摩擦后纳米颗粒的性质(如:相组成、晶粒尺寸、比表面积、氧化转变温度、磁性能、结晶度和晶面间距)有所改变。片状Fe3O4纳米颗粒由于与摩擦副持续的高速摩擦产生了机械力化学效应,其诱发片状Fe3O4纳米颗粒在摩擦副表面发生摩擦化学反应,最终生成了一层或多层富含Fe、FeO、Fe3O4、γ-FeOOH、γ-Fe2O3和α-Fe2O3等物相的稳定抗摩擦自修复保护膜,从而阻止摩擦副直接接触,起到抗磨减摩作用。     

纳米粒子作为润滑添加剂的摩擦学特性

作为润滑添加剂,纳米粒子具有独特的物理化学特性和优良的摩擦学性能。纳米添加剂可以提高基础油的润滑性能,减摩抗磨性能。综述了纳米粒子润滑添加剂的摩擦学特性和润滑机理。目前关于纳米粒子减摩抗磨机理比较一致的观点是纳米粒子在摩擦表面较易吸附且形成润滑保护膜。     

润滑油生物降解菌的筛选

以被石油基润滑油污染的土壤为出发菌源,通过增加环境选择压力的方法,驯化、筛选分离出对石油基润滑油具有一定降解能力的菌株RHY-1,该菌株的100 mL菌悬液48 h对5 mL润滑油的降解率为82.4％,可生长的pH值范围为3.0～11.0,可耐受的NaC1浓度为27 g·L-1;在30℃、pH值为8.0、NaCl浓度为...     

Generation of Radiolabeled "Soot-Like" Ultrafine Aerosols Suitable for Use in Human Inhalation Studies

We have developed a method for radiolabeling ultrafine carbon particle aggregates with technetium-99m. The carbon aggregate aerosol was chosen to mimic the physical properties of urban combustion or ''soot-like'' particulate. The radioisotope is a short lived (t_1/2 = 6.02 h) gamma emitter commonly used in human studies where scintigraphic methods are employed. Primary carbon parti cles, the aggregation of which is controlled by concentration and time, were produced by arcing between graphite electrodes under an argon atmosphere. Radiolabeling of particles was accomplished by applying a pertechnetate solution onto the tips of electrodes prior to arcing. The activity median diameter of experimental aerosols could be varied from 50 to 150 nm. The specific activity of aerosols increased with the amount of activity applied to the electrodes and decreased with time of generator operation. In-vitro leaching of the radioisotope from particles into solution was also measured. Leaching appeared to increase with the specific activity of the aerosol but was not affected by particle size.     

合成润滑油的基础油聚醚油的物性及实用性研究

本文综述了聚醚油的主要物性，评价了聚醚油的水溶性、低温特性、热稳定性、摩擦、磨损特性。由聚醚油制成的润滑油有良好的润滑和抗剪切性，在高温状态下不结焦、不沉淀。在高温齿轮传动、压缩机、内燃机和冷冻机润滑中特别有效。     

润滑油的指标检验要点解析

润滑油使用一段时间后会发生性能的降低或改变,必须适时更换,做到既不浪费,也保证设备的正常运行。就润滑油检验中的八大指标:水分、粘度、倾点、闪点、粘度指数、泡沫性、酸碱值、机械杂质进行详细论述,最后再简单阐述润滑油检验中的两点特殊指标:氧化安定性和热安定性。     

新型冷冻机油的生物降解研究

综述了聚醚及其改性物和酯类化合物作为冷冻机基础油的生物降解性，添加剂对生物降解性的影响，以及各种评价生物降解性的试验方法。     

聚乙烯润滑油桶专用料的开发

抚顺乙烯聚乙烯装置通过丁烯—1共聚，调整工艺参数，开发出符合润滑油桶要求的专用料，取代抚顺化塑厂注塑车间润滑油桶塑料原料混合料。工业化产品2810A已经面世。结果表明，在现有装置上只需添加一定量的丁烯—1，便可以提高塑料的韧性、耐环境应力开裂等综合性能，开发生产出了性能优良的专用料，其质量稳定可靠，具有较高的经济价值。     

润滑油的分类及选用

文章介绍了润滑油的分类和代号,阐述了润滑油的选用原则,目的是更好地指导润滑油的应用,加强润滑油的日常管理,保障机械设备的正常运行,避免用错油导致的事故。     

碳纳米润滑添加剂的应用研究

碳纳米材料作为一种新型材料,拥有很好的摩擦学性能。通过收集、整理大量的文献资料,详细介绍了以富勒烯、石墨烯和碳纳米管为代表的碳纳米材料在润滑领域的研究现状。     

以混合溶剂精制润滑油

以混合溶剂精制润滑油杨卓如黄洪杨晓燕兰仁华陈焕钦（华南理工大学化工学院，广州５１０６４１）关键词润滑油溶剂精制糠醛１前言目前，我国在润滑油精制过程中仍主要用糠醛作为溶剂。糠醛精制装置占溶剂精制装置的７５．８％，其精制工艺已趋于成熟。预计糠醛精制仍将...     

废润滑油再生利用控制系统研究

介绍了一种环境友好、适合中(小)规模生产的废润滑油再生处理工艺的控制系统设计.采用S7-300PLC和KingView组态软件,通过结构化编程,实现对废润滑油再生处理工艺的控制,提高了生产效率,增加了工艺参数的可控性,同时为工作人员提供了安全保证,为废润滑油再生处理工艺的大面积推广提供了可靠的技术支持.     

Lubricating Oil Additives Based on Polyalkylpolyamines

This work is confined to the preparation and characterization of additives. These additives are based on the reaction of polyisobutylene with different ethanolamine and then amination with tetraethylenepentamine. The molecular weights of the prepared compounds were determined by gel permeation chromatography (GPC). The efficiency of the prepared compounds as antioxidant and detergent/dispersantadditives for lube oil was studied. It was found that the efficiency increases with increasing the molecular weight and -NH- group of the prepared compounds.     

烷基苯制润滑油

对合成洗涤剂烷基苯和其副产重烷基苯的润滑特性 ,以及烷基苯制取五类 (电器用油、冷冻机油、液压油、汽轮机油和导热油 ) 10种润滑油的生产应用进行了综述 ,对拓展烷基苯类产品在润滑方面的应用有指导意义     

高压氨泵主电机润滑系统改造

1　概述河南省中原大化集团有限责任公司尿素装置高压氨泵电机为CT5 0 0Y2型 ,额定转速 2 979r/min ,采用对开式滑动轴承 ,甩油环润滑 ,N32抗氨汽轮机油。其结构见图 1。图 1　滑动轴承结构图自投产以来 ,电机轴承温度一直偏高 ,夏季更高达 90℃以上。长期的非正常状态导致轴承和甩油环磨损 ,大量的铜粉粘于轴径上及落入油中 ,加剧了滑动轴承和甩油环磨损 ,大大缩短了其使用周期 ,有时运行一周即需停车处理 ,严重影响了尿素装置安全、稳定、长周期运行。2　原因分析1 )结构设计甩油环的运动形式是靠与轴颈的摩擦力相对于轴滑动及滚动 ,由…     

发动机与润滑油的研究

本文主要介绍了发动机的润滑系统、润滑方式，以及润滑油的作用，发动机润滑油（车用内燃机油）的选用，来说明发动机与润滑油之间相辅相成、不可分割的重要性。通过选用合适的润滑油来提高发动机的使用寿命，节省资源、提高效益。