半导体制造中清洗技术的新动向

多年来习惯采用多槽浸渍式RCA清洗的半导体清洗领域里,正在兴起的是从多槽浸渍式向单片式处理转移。并出现了取代RCA法的新型清洗液与新的生产方法。正在开始对超临界流体清洗等下一代清洗技术的开发。概述这些半导体清洗技术的最新动向。     

光辅助原位清洁制备Ag/AgCl纳米颗粒

以Ag NO3和反渗透水(RO)中的Cl–为原料,在波长为395 nm的紫外光源(20 W)下原位合成Ag/Ag Cl纳米颗粒。通过透射电子显微镜(TEM)、高分辨率的透射电镜(HRTEM)和动态光散射(DLS)表征了样品的形貌和尺寸分布,用X射线粉末衍射(XRD)、X射线光电子能谱(XPS)、紫外-可见吸收光谱(UV-Vis)和荧光光谱分别对复合材料的晶体结构和元素价态以及光催化性能进行了测试。结果表明:Ag/AgCl复合材料是球形颗粒,平均粒径为100 nm。AgNO₃溶液形成复合纳米颗粒的过程能有效降解罗丹明6G,银离子溶液在光照3 min时罗丹明6G的降解率和猝灭率分别可达96.5%和95%。     

油罐清洗作业防火安全措施

目前大型原油储罐逐步应用自动机械清洗系统进行清罐作业,而对于容量小、沉积物较少的油罐国内仍采用人工清洗方式进行。分析了油罐人工清洗作业过程时容易引发火灾的原因,并提出相应的预防火灾措施。     

装备表面微磨料喷砂快速清洗及预处理研究

战场条件下装备战损零部件表面清洗与预处理是装备战场应急维修或再制造过程中的重要工序,本文通过喷砂实验,采用单纯CaCO2、棕刚玉及石英砂磨料,对45钢及7A52型装甲铝合金进行喷砂处理,借助X射线应力测定仪、扫描电子显微镜（SEM）、划痕测试仪等检测设备对一定喷砂条件下喷砂后试件表面形貌、粗糙度变化及应力状态等进行测试分析。研究结果表明采用纯CaCO2磨料在试样表面喷砂后的粗糙度值较低,纯棕刚玉磨料的粗糙度值较高,采用经过混合后的磨料喷射后的表面粗糙度介于两者之间,并且经过喷砂后被喷射表面应力为压应力,对喷砂后应力状态影响的重要性次序依次是：粒径、流量、压强和距离。     

Polymeric compounds in activated sludge supernatant -- Characterisation and retention mechanisms at a full-scale municipal membrane bioreactor

In this study, for the first time a full-scale membrane bioreactor (MBR) was investigated with focus on organic compounds in activated sludge over a period of approximately 2 years. Soluble extracellular polymeric substances (EPS) in the sludge supernatant and permeate as well as bound EPS extracted from fouled membranes were determined photospectrometrically and revealed a typical composition of three main components in the order metals>humic acids>carbohydrates>proteins. Results showed an important influence on membrane fouling by soluble humic substances and carbohydrates in complexes with metal cations. It was found that Fe(2+) and Fe(3+) play a decisive role in natural organic matter (NOM) complexation and subsequent membrane blockage. The determination of molar mass distribution in supernatant and permeate by size exclusion chromatography (SEC) revealed a significant retention of macromolecular compounds by the porous membranes in the range of 10-50%.     

膜生物反应器长期运行条件下膜的清洗方法及机理研究

对实际工程中运行2年以上的MBR的膜使用能谱分析、傅立叶红外光谱和接触角测定等方法对膜表面的污染物特性进行了分析,对膜清洗过程中不同清洗剂的作用效果进行了探讨,并进一步对膜污染过程进行了推测.结果表明,酸性清洗剂对膜的清洗效果较好,膜表面无机污染基本被去除,但不能完全有效去除膜表面有机酸、蛋白质、多糖和多糖类物质等有机污染物;NaOH和NaClO对污染后的膜的清洗效果不佳,原因可能是由于MBR进水为混凝沉淀池出水,长期运行条件下膜污染以无机污染为主,有机污染可能起到了螯合的作用,使无机污染物和有机污染物络合,增加了碱和氧化剂去除有机污染的难度.     

一次清洗剂 HEDP 的试验研究

主要探讨ＨＥＤＰ对热力设备的清洗性能,一次清洗钝化效果,为提高化学清洗效率,改善劳动强度,降低清洗成本、缩短清洗周期、减少环境污染开辟新途径。     

An analytical method for selecting the optimal nozzle external geometry for fluid dynamic gauging

Fluid dynamic gauging (FDG) was developed to measure, in situ and in real time, the thickness of a soft deposit layer immersed in a liquid without contacting the surface of the layer. An analysis based on the lubrication assumption for the flow patterns in the space between the nozzle and the surface being gauged yielded analytical expressions for the relationships between the main flow variables and system parameters. Nozzle shapes for particular pressure, pressure gradient and shear stress profiles could then be identified. The effect of flow rate, nozzle geometry and nozzle position on the pressure beneath the nozzle and shear stress on the gauged surface showed very good agreement with computational fluid dynamics (CFD) simulations. Case studies presented include nozzle shapes for uniform pressure and shear stress profiles, which are useful for measuring the strength of soft deposit layers.     

Development of a qualitative test method for the cleanability of polymer woven filter media

In this paper a new method for cleaning of filter media is presented, and the cleanability with different textures and surface finishes is compared. With the method described, it is possible to evaluate the quality of the cleaning process. According to the German VDMA standard cleaning test, riboflavin and malt extract are applied as model contaminants for evaluation of the cleaning results. To compare the cleanability of filter media with different properties and geometries the results are adapted to the law of mass transfer and to the Sherwood number, a dimensionless parameter describing the quality of a cleaning process.