RESUMO
For the decomposition of chemical warfare agents, a hybrid material concept was applied. This consists of a copper oxide-containing phase as a component with reactive functionality supported on polymer-based spherical activated carbon (PBSAC) as a component with adsorptive functionality. A corresponding hybrid material was prepared by impregnation of PBSAC with copper(II)nitrate and subsequent calcination at 673K. The copper phase exists predominantly as copper(I)oxide which is homogeneously distributed over the PBSAC particles. The hybrid material containing 16 wt.% copper on PBSAC is capable of self-detoxifying the mustard gas surrogate 2-chloroethylethylsulfide (CEES) at room temperature. The decomposition is related to the breakthrough behavior of the reactant CEES, which displaces the reaction product ethylvinylsulfide (EVS). This leads to a combined breakthrough of CEES and EVS. The decomposition of CEES is shown to occur catalytically over the copper-containing PBSAC material. Thus, the hybrid material can even be considered to be self-cleaning.
Assuntos
Substâncias para a Guerra Química/química , Cobre/química , Gás de Mostarda/química , Óxidos/química , Carbono/química , Poliestirenos/químicaRESUMO
BACKGROUND: There is much interest in the use of textiles for sun protection. In vitro test methods are frequently used to assess the degree of protection to solar ultraviolet radiation of textile materials. It is, however, of paramount importance that methods are clearly described and that the precision of these methods is determined such that comparison between laboratories can be performed. An in vitro method for the determination of the Ultraviolet Protection Factor (UPF) is described in a new European Standard and is referred to as prEN 13758. Thirty experts from 11 European member states, forming a working group of the European Standardization Commission (CEN), have developed this method in consensus. In this paper the reliability of this test method for the determination of the UPF of textiles worn in close proximity to the skin and in a relaxed and dry state is studied. METHODS: For the determination of the precision of the test method, eight laboratories, using nine different measuring devices located in five different countries, have measured 14 textile materials of various types of construction and levels of UVR protection. Statistical analysis of the results has been performed according to ISO 5725. RESULTS: The repeatability standard deviation of the described method is independent of the UPF in the range 1-70 and is 1.36. The reproducibility standard deviation, however, clearly increases with the level of UPF. CONCLUSIONS: For high UPF values, differences between laboratories, due to factors such as different operators, equipment and calibration, can become important. This makes classification of high UPF materials questionable.
Assuntos
Roupa de Proteção/normas , Lesões por Radiação/prevenção & controle , Proteção Radiológica/normas , Luz Solar/efeitos adversos , Humanos , Lesões por Radiação/etiologia , Reprodutibilidade dos Testes , Espectroscopia de Luz Próxima ao Infravermelho , TêxteisRESUMO
A rising incidence worldwide of skin cancer has been observed for years. A high cumulative exposure to UV radiation is a major factor in the development of such neoplasms. Suitable protective measures are therefore becoming increasingly important. Textiles provide simple, effective and medically safe protection against UV radiation. At present, however, in Europe--in contrast to Australia--the UV protection factor (UPF) for summer textiles is not stated. It is a largely unknown fact that by far not all textiles offer sufficient protection. Our goal was to study the factors which determine the UV transmission of fabrics and, based on these findings, to design materials which provide enhanced protection. A spectrophotometric method was used to determine the UV transmission by fabrics made of cotton, silk, polyester and viscose. The UV protection factors of the fabrics were computed on the basis of the transmission data. The UV protection factor is dependent on the type of fibre, yarn and surface design, weight per square metre, moisture content, colour, finishing method and degree of wear. To optimize the UV protection via textiles, a viscose yarn with a low UV transmission was used. This yarn makes it possible to design light-weight summer fabrics with optimized UV protection. This development will make it possible to offer clothing with high UV protection on the European marked. This clothing will not be more expensive than normal products, so that effective prevention should be more available.