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In Anlehnung an erfolgreich kommerzialisierte Kosmetika können auch funktionalisierte Textilien, die dem biophysikalischen Konzept folgen, einen positiven Beitrag zum Hautschutz und zur Hautpflege leisten. Anwendungsfelder können sich zukünftig im Bereich der Arbeits-, Wellness- und Sportbekleidung ergeben, die insbesondere auf den Outdoor-Bereich abzielen, da für diesen Bereich die physikalische Komponente des Strahlenschutzes deutlich zum Tragen kommt.

High X-ray absorption and, therefore, excellent X-ray protection properties are related to heavy chemical elements. Therefore, a composite fiber for X-ray protection applications was developed consisting of an organic cellulose part and an inorganic part. Whereas the preceding part provides the common properties connected to fibers and the latter part ensures the X-ray protection effect. The treatment of this composite fiber along the whole textile chain is presented and the possible usage as a common textile fiber in spinning and knitting processes is impressively demonstrated. Textile properties such as air permeability and abrasion stability are successfully tested. Furthermore, the microscopic structure is characterized by means of optical and scanning electron microscopy. The X-ray protective properties are determined by transmission experiments. The realization of a textile product is shown by production of a glove, where protective properties are impressively shown by 3D X-ray tomography. A...

Common textile materials as cotton or polyester do not possess reliable X-ray absorption properties. This is due to their morphology and chemical composition in particular. Common fibers are built up from organic polymers containing mainly the elements carbon, hydrogen, oxygen and nitrogen. These “light” elements only have low X-ray absorption coefficients. In contrast, inorganic materials composed of “heavy” elements with high atomic numbers, e.g. barium or bismuth, exhibit X-ray absorption coefficients higher by up to two orders of magnitude. To obtain a flexible yarn with high X-ray absorption properties both these materials, the organic polymer and the inorganic X-ray absorber, are combined to an inorganic/organic composite fiber material. Hence, as the organic component cellulose from modified Lyocell-process is used as carrier fiber and blended with inorganic absorber particles of low toxicity and high absorption coefficients, as bariumsulphate, bariumtitanate or bismuthoxide. A content of inorganic absorber particles equally distributed in the whole fiber of up to 20% is achieved. The composite fibers are produced as staple or filament fibers and processed to multifilament or staple fiber yarns. The staple fiber yarns are rotor-spinned to increase the comfort of the subsequent textile material. Several woven fabrics, considering multilayer structure and different warp/weft density, are developed. The energy dependent X-ray shielding properties are determined in dependence on the different yarn compositions, yarn types and structural parameters of the woven fabrics. As a result, a production process of textile materials with comfortable and dedicated X-ray absorption properties is established. It offers a promising opportunity for manufacturing of specialized textiles, working clothes or uniforms applicable for medicine, air craft and security personal, mining as well as for innovative composite materials.

Reactivity and concentration of additives, especially activated charcoal, employed for the Lyocell process, enhance the complexity of reactions in cellulose/N-methylmorpholine-N-oxide monohydrate solutions. Analytical control of the starting materials is a basic requirement to know the concentration of heavy metals, which are potential initiators of autocatalytic reactions. Seven activated charcoal and two carbon black samples have been analyzed regarding their content of seven elements, Cr, Cu, Fe, Mn, Mo, Ni and V using direct solid sampling high-resolution continuum source graphite furnace AAS (SS-HR-CS GF AAS) and inductively coupled plasma optical emission spectrometry (ICP OES) after microwave-assisted acidic digestion as a reference method. The limits of detection of the former technique are 1-2 orders of magnitude lower than those of ICP OES and comparable to those of more sophisticated techniques. For iron the working range of HR-CS GF AAS has been expanded by simultaneous measurement at two secondary absorption lines (344,099nm and 344,399nm). Partial least-squares regression between measured and calculated temperatures for beginning exothermicity (T(on)) has been used to investigate the prediction capability of the investigated techniques. Whereas the ICP OES measurements for seven elements resulted in an error of prediction of 3.67%, the results obtained by SS-HR-CS GF AAS exhibited a correlation coefficient of 0.99 and an error of prediction of only 0.68%. Acceptable correlation has been obtained with the latter technique measuring only three to four elements.

One strategy to solve the problem of unwanted PET oligomer deposits in textile production is their enzymatic cleavage. In this work a selection of different enzymes (esterases, lipases) were tested for this purpose. The capacity to hydrolyse PET oligomers of some of the tested enzymes has been previously described in the literatare. In order to imitate practical conditions both dry and precipitated PET oligomers were used. The decrease in the amount of cyclic trimer, the main component of the PET oligomers, was monitored by HPLC. After treatment with the lipase from Triticum aestivum a decrease of 80 wt.-% was found. However, the effect of this lipase seems to have less to do with catalysing hydrolytic cleavages of ester groups than with the absorption of the oligomer on the enzyme protein. Cyclic PET trimer (cyclo-tris[ethyleneglycolterephthalate]).

Der Bleistatus des Bodens im Umfeld eines Emittenten von bleihaltigem Glasstaub wurde untersucht. Aus den Einzelwerten der 34 Mespunkte wurde mittels der geostatistischen Methode Kriging die Flachen-belastung interpoliert. Der Vergleich der Anfang der achtziger Jahre ermittelten Flachenbelastung mit der aktuellen Belastung zeigt die Tendenz der Abnahme von extrem hohen Bodenbleiwerten. Gleichzeitig nimmt die kontaminierte Flache zu. An einem hoch belasteten Mespunkt wurde ein Bodenprofil untersucht. Die Bodenbleigehalte nehmen mit der Tiefe stark ab. Der Bleikontamination reicht bis zu einer Tiefe von etwa 20 cm. Der Bleigehalt korreliert signifikant mit dem organischen Kohlenstoffgehalt der Tiefenschichten des Bodens. Die Abschatzung der im Untersuchungsgebiet deponierten Bleimasse auf der Basis der erhaltenen geostatistischen Ergebnisse zeigt eine deutliche Reduzierung von 2,1 t im Jahr 1985 auf 1 t im Jahr 1994. Dieser Befund ist uberwiegend auf Sekundarstaubverfrachtung aus dem Untersuchungsgebiet auf angrenzende Flachen zuruckzufuhren. Temporal development and actual assessment of a lead soil contamination in the surroundings of a glass factory in Thuringia In this study the lead content in the area around a source of emission was investigated. The lead pollution of the soil originates in lead containing dust from glass production. The overall contamination of the considered area was found out using the geostatistical method of kriging. The measurement included 34 samples taken at different spots around the source of emission. A similar study as this was made in the beginning of the eighties. In comparison to the latter the recent results show lower values of lead contamination of the soil, but at the same time the area of pollution enlarges. At a high polluted point a profile of the soil was investigated. It showed that the lead content decreases rapidly with increasing depth. A contamination by lead can be detected down to a depth of 20 cm. The lead values show a significant correlation with the carbon contents of the soil. An estimation of the amount of lead stored in the investigated area indicates an obvious reduction from 2.1 t in 1985 to 1 t in 1994. This can be explained by a secondary transfer of the dust from the considered to adjoining areas.

Die Strukturierung von Dreiphasen-Systemen, die aus einem kolloidalen Feststoff und zwei nicht mischbaren flussigen Phasen bestehen, ist eine Moglichkeit zur Formulierung innovativer Materialien. Dieser Beitrag beschaftigt sich mit der Untersuchung des Aufbruchs und der Struktursteuerung von mit Partikeln gefullten Emulsionstropfen durch Prozessund Stoffparameter wie z. B. Scherrate oder Benetzungseigenschaften der Partikel. Hierzu wurden Partikel-gefullte Oltropfen mit unterschiedlichen definierten Scherbeanspruchungen belastet. Die resultierende Tropfengrosenverteilung und -morphologie wurden mittels dynamischer Bildanalyse charakterisiert. Fur Systeme, deren Dreiphasen-Kontaktwinkel in einer Anlagerung der Partikel in der Tropfengrenzflache resultiert, konnte eine deutliche Strukturabhangigkeit der resultierenden Tropfen von der Belastung und Partikelbeladung beobachtet werden (Abb.). Die Stabilisierung dieser nicht-spharischen Tropfen wird auf die Ausbildung einer starren Partikelschicht an der Tropfengrenzflache zuruckgefuhrt [1]. Partikel, die energetisch stabil in der Tropfenphase vorliegen, behindern den Tropfenaufbruch. Die resultierenden Kapillarzahlen sind im Vergleich zu Zweiphasen-Systemen mit ahnlichem Viskositatsverhaltnis deutlich zu groseren Werten verschoben. Ein moglicher Erklarungsansatz ist die inhomogene Tropfenviskositat solcher Systeme [2].

Thermochemical reactions with halides were employed in particular applications of optical emission spectrography (OES), i.e. d.c. arc excitation, to enhance weak signals and to improve the detection limits. For trace element determinations in Al 2 O 3 with special graphite electrodes, the detection limits of Fe, Mn, Ni, Co and Cu, were improved by one or two orders of magnitude with sodium chloride as a thermochemical reagent. These results indicated good agreement with the results of chemical-thermodynamic trend analysis. The trace elements Fe, Mn, Ni, Co and Cu form chlorides in preference to Al. Part of the matrix element Al also reacts with chlorine to form AlCl 3 . Most of this chlorine is available again at higher temperatures because AlCl 3 decomposes to AlCl at about 3300 K. In this way the alumina has an effect as an additional carrier for chlorine and improves the trace element evaporation. With this procedure for trace element determinations in alumina the blank signals of the elements Fe, Mn, Cu, Ni and Co were detectable in the Al 2 O 3 calibration matrix and in the NaCl suprapur additive. These blank values were eliminated by a combination of nonlinear blank correction and a calibration using weighted nonlinear regression. From this chemometric treatment and the thermochemical reactions resulted an improvement of the limits of detection by up to two orders of magnitude.