原子力显微镜在聚合物研究中的应用

原子力显微镜以其分辨率高、样品无需特殊制备、实验可在大气环境中进行等优点而广泛应用于聚合物研究之中,弥补扫描隧道显微镜不能观测非导电样品的缺憾。近年来,其应用已由对聚合物表面几何形貌的观测发展到纳米级结构和表面性能的研究领域。在介绍原子力显微镜工作原理的基础上,简要回顾其在聚合物研究方面的若干新应用,并对其应用前景作展望。     

Effects of Some Metals and Chelating Agents on Patulin Degradation by Ozone

The efficiency of ozone treatment for degradation of the mycotoxin patulin in the presence of various metal ions was evaluated in model systems. An initial patulin concentration of 250 μg/L was ozonated and residual ozone concentration was about 0.17±0.01 mg/L at the end of the experiment. Patulin showed a weak resistance to ozone, because up to 98% of this toxin was oxidized in only one minute. Degradation rates in the presence of calcium, aluminum, copper and zinc were almost the same in the absence of these metals. However, degradation of patulin was reduced from 98 to 37% when the concentration of manganese increased from 0 to 3 mg/L. Patulin was almost completely degraded in the absence of iron, while the degradation was only 8.5% in the presence of 0.5 mg/L of iron. These results have revealed that manganese and iron significantly reduce the detoxification of patulin by ozone. Agents such as ethylenediaminetetraacetic acid and sodium polyphosphate effectively chelated iron and increased the degradation rate of patulin. None of the tested agents were able to chelate manganese and to enhance patulin degradation by ozone.     

Quantification of the Bactericidal,Fungicidal, and Sporicidal Efficacy of the JLA Ltd. Ozone Laundering System

The objective of this study was to demonstrate the bactericidal, fungicidal, and sporicidal efficacy of the in-use concentration of ozone in solution generated continuously by the JLA Limited OTEX validated ozone laundering system against a range of typical microorganisms associated with laundering applications. The study used the JLA HC 100 laundering machine as the containment vessel. Test microbial suspensions were introduced directly into the drum of the laundering machine containing a known level of water in the presence of soluble ozone. Using standard microbiological techniques, the numbers of surviving bacteria, mold spores or bacterial spores were determined, and reductions in viable counts were calculated. The following test organisms were employed: Pseudomonas aeruginosa, Methicillin-Resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, E. coli, Acinetobacter baumannii, Aspergillus niger (spores), and Clostridium difficile (spores). All tests used multiple contact times of 0, 1, 3, 5, 7, 11 and 15 minutes at 20 °C±2 °C. Levels of ≤0.25 mg/L of dissolved ozone had minimal effect on the bacteria. Levels of >0.45 mg/L ozone showed good biocidal activity, except against Acinetobacter baumannii, which showed strong resistance to ozone. Against fungal spores, dissolved ozone levels of >1.2 mg/L were required to obtain a 2.8 log reduction. For Clostridium difficile spores, a dissolved ozone level between 0.90 and 1.20 mg/L gave >1.6 log reduction with no discernable spore recovery. In every instance, the control tests (no ozone) recovered levels of microorganisms that proved that the action of the laundering machine has no antimicrobial activity, and that the log reductions obtained are solely due to the effects of dissolved ozone.     

Formation and characteristics of zinc phosphate coatings obtained by electrochemical treatment: Cathodic vs. anodic

Electrochemical treatment and galvanic coupling are some of the possible modes of acceleration of low temperature phosphating process. The cathodic and anodic treatments during phosphating influence the deposition mechanism, characteristic properties and the corrosion resistance of the resultant coatings in a different way. The present paper aims to compare these aspects and to identify the possible applications of phosphate coatings obtained by these treatments.     

日化香精控制释放技术及其应用

日化香精的控制释放,对于有效地发挥其功能是十分重要的。 控制释放技术有很多方法,例如：微包囊法,环糊精法,薄膜法,凝胶法,乳化法等。 本文就近期有关日化香精控制释放技术及其在芳香织物、芳香合成纤维、芳香涂料、芳香塑料、空气清新剂等方面的应用作一综述。     

Ozone in the United States of America -- State-Of-The-Art

Applications for ozone in the United States have evolved through a lengthy maturation process, which began with drinking water treatment (taste/odor/color removal) in the early 1900s, and grew slowly until acceleration began in the mid-1980s. Although deodorization became a stable market in the 1960s-1970s, these applications were small, for the most part. One of the largest uses for ozone is oxidation of process chemicals in the chemical industry, which began in the USA about the 1940s, and subsequently has spread worldwide. Today, thanks primarily to environmental regulatory pressures which began to impact ozone in the mid-1980s, ozone now is used increasingly in the USA for drinking water treatment and for some municipal and industrial wastewater applications. The U.S. Environmental Protection Agency (EPA) has recognized the growing importance of ozone (> 200 drinking water plants use ozone today), and has appointed IOA representatives to two of its regulatory development committees as stakeholders. Several U.S. cities have installed or are installing wastewater treatment processes for potable reuse purposes, which include the use of ozone. Three full-scale U.S. pulp bleaching plants use tons/day quantities of ozone. Smaller applications for ozone include water treatment for cooling tower waters (biofouling control), swimming pools and spas, marine aquaria, bottled water disinfection and maintenance of high purity waters in the pharmaceuticals and electronics industries. A new application for ozone is in commercial laundries to reduce energy costs and replace chemicals. In mid-1997, a public declaration was made by an expert panel that ozone is Generally Recognized As Safe (GRAS) for contact with foods. This declaration opens the door for ozone to be used in U.S. food processing industries. U.S. research scientists and engineers are at the forefront in studies which define the technical aspects of ozone technologies in a variety of applications employing advanced oxidation, including the treatment of hazardous wastes, groundwater remediation, and process water recovery and reuse in the semi-conductor industry.     

The ZEBRA electric vehicle battery: power and energy improvements

Vehicle trials with the first sodium/nickel chloride ZEBRA batteries indicated that the pulse power capability of the battery needed to be improved towards the end of the discharge. A research programme led to several design changes to improve the cell which, in combination, have improved the power of the battery to greater than 150 W kg⁻¹ at 80% depth of discharge. Bench and vehicle tests have established the stability of the high power battery over several years of cycling. The gravimetric energy density of the first generation of cells was less than 100 Wh kg⁻¹. Optimisation of the design has led to a cell with a specific energy of 120 Wh kg⁻¹ or 86 Wh kg⁻¹ for a 30 kWh battery. Recently, the cell chemistry has been altered to improve the useful capacity. The cell is assembled in the over-discharged state and during the first charge the following reactions occur: at 1.6 V: Al+4NaCl=NaAlCl₄+3Na; at 2.35 V: Fe+2NaCl=FeCl₂+2Na; at 2.58 V: Ni+2NaCl=NiCl₂+2 Na. The first reaction serves to prime the negative sodium electrode but occurs at too low a voltage to be of use in providing useful capacity. By minimising the aluminium content more NaCl is released for the main reactions to improve the capacity of the cell. This, and further composition optimisation, have resulted in cells with specific energies in excess of 140 Wh kg⁻¹, which equates to battery energies>100 Wh kg⁻¹. The present production battery, as installed in a Mercedes Benz A class electric vehicle, gives a driving range of 205 km (128 miles) in city and hill climbing. The cells with improved capacity will extend the practical driving range to beyond 240 km (150 miles).     

Testing of a sodium/nickel chloride (ZEBRA) battery for electric propulsion of ships and vehicles

One of the promising future batteries for electric propulsion of vehicles and ships is the sodium/nickel chloride or ZEBRA (Zero Emission Battery Research Activities) battery. Despite some disadvantages with respect to the high temperature, the advantages with respect to specific energy and energy density are such that, especially in applications where the battery is used on a more or less continuous basis (e.g., in delivery vans and taxies) it is an interesting candidate battery. Another interesting application is on board of ships, like submarines or future electrical surface ships with electric propulsion. In 1995 a 2 year feasibility study, including experimental testing of a 10 kW h battery, was completed. This investigated the naval applicability of the sodium/sulphur battery, which is also a high temperature battery. Here the limited, experimentally proven, life-time of the batteries of about 1.5 years and this made naval application almost impossible. A paper about this study was presented at the 19th International Power Sources Symposium held at Brighton, England, in April 1995 [R.A.A. Schillemans, C.E. Kluiters, Sodium/sulphur batteries for naval applications, in: A. Attewell, T. Keily (Eds.), Power Sources 15, International Power Sources Symposium Committee, Crowborough UK, 1995. p. 421.]. Because of the more or less comparable specifications on specific energy and the more promising results of the life-time and field tests with sodium/nickel chloride batteries, a ZEBRA battery from AEG Anglo Batteries has been tested for naval applications. This was done by simulating the charge and discharge as it occurs in practice for the applications investigated. With respect to the electrical ship application (investigated for the Royal Netherlands Navy) the power versus time taken from the battery was simulated as well as the charge procedures. The same can be done for the vehicle application: in this case typical drive cycles for a van or taxi are translated to power versus time taken from the battery. The results of the tests for application of the battery in naval ships are very promising.     

An environmental aircraft battery (EAB)

The Battery Branch of the U.S. Air Force Research Laboratory began the development of an environmental aircraft battery (EAB) to replace existing nickel/cadmium (Ni–Cd) and sealed lead-/acid (SLA) batteries to minimize or eliminate use of environmentally hazardous battery materials by the USAF. A three-phase development contract was awarded in 1996 to replace the cadmium in Ni–Cd batteries with a metal hydride (MH) anode. Designs, materials, space battery technology, and results on commercial and government battery programmes were evaluated in the Phase I, Feasibility Analysis. Bipolar and prismatic designs were selected for Phase II development. Materials and cell test data are presented.     

Beneficial effect of carbon–PVA colloid additives for lead–acid batteries

Based on the previous success of adding ultra-fine carbon–PVA (polyvinyl alcohol) colloid solution to restore performance of weak batteries, a large scale test programme of practical batteries including those used in forklift, golf cart, taxi cab, truck and bus applications from 150 companies was carried out. More than 95% of the tested batteries exhibited excellent recovery in performance parameters including the specific gravity (S.G.), voltage and operation time (Ah capacity). The work reported here includes basic research studies to understand better the beneficial action of the carbon–PVA colloid additive.