Die Adsorptionstechnik – ein Gebiet mit Zukunft

Adsorption technology – an area with potential for the future . Adsorption offers considerable industrial potential for separation of individual components or mixtures of components from gases and liquids. Since the separation process occurs at ambient temperatures or only slightly raised temperatures it offers the advantage of energetically favourable conditions. Adsorption is also particularly good for isolation of components present in very low concentrations. It therefore plays a significant role in the development of trace technology. Future possibilities depend on both the development of high performance adsorbents and on the development of adsorption devices of high specific performance. Solution of physicochemical and of engineering problems are of comparable importance. The present article describes general fundamentals of adsorption, the principal properties of adsorbents, and some technical adsorption processes. Contemporary adsorber designs are presented and some developmental trends addressed.     

Die Integration von Chromatogrammen – Ergebnisse mit neuen elektronischen Integratoren

Integration of Chromatograms – Results Obtained with New Electronic Integrators The author gives a review about the application, the accuracy and reproducibility of modern electronic integrators as they are available now for the analytical chemist. He discusses the application of these integrators in a number of cases and the principle requirement of a user on such instruments.     

Bronidox,ein neues Konservierungsmittel für die Kosmetik Eigenschaften und toxikologisch-dermatologische Prüfergebnisse

Bronidox – A New Preserving Agent for Cosmetics: Properties, Toxicological and Dermatological Assays 5-Bromo-5-nitro-1, 3-dioxane (Bronidox) has good microbiostatic properties and it is technologically suitable for preserving cosmetic products. In the present study, the results are reported of toxicological and dermatological tests, which were carried out in order to assess the safety of this product. These studies have shown that this product can be employed in certain fields of cosmetics, especially for preserving shampoos and foam baths.     

Fettpolymere – Herstellverfahren und Eigenschaften

The radical polymerization of esters of acrylic, methacrylic or crotonic acid with fatty alcohols proved to be an efficient method for production of polymers with hydrophobic moieties. By co-polymerisation with hydrophilic co-monomers - such as maleic anhydride - copolymers with a broad spectrum of properties can be designed. As an example the copolymerisation of fatty crotonates with maleic anhydride was studied in detail. The reaction was carried out as bulk polymerisation in a semi-batch process. By this method the compatibility problems of the two monomers, which have very different hydrophilicities could be overcome. The product acts as a very effective fat liquoring agent in leather treatment: the maleic moieties cause an outstanding fixing of the agent on the leather and the fatty crotonate moieties create a very smooth leather. Terpolymers of fatty acrylates, hydrophilic monomers and terpenes could also be synthesized in a similar way. These terpolymers proved to be useful as dispersing agents for pigments in paints and varnishes.     

Spektroskopische Untersuchungen zur Struktur von Silicium-Schwefel-Verbindungen mit mindestens einer Si-S-Bindung – ein Überblick

Spectroscopic Properties of Silicon-Sulfur-Compounds with at least one Si-S-bound – A Review Bond lenghts, bond angles and ²⁹Si-NMR data are tabulated. If possible this parameters are discussed on the bases of covalent radii, electronegativities and other general properties. Qualitative estimations of ²⁹Si-NMR shifts as a function of series of compounds, as a function of ring-size and by comparison with homologous Si-O compounds are suggested. Observations of contrarotating effects of ²⁹Si-NMR shifts in organosubstituted Si-O and Si-S molecules as compared to their hydrogensubstituted counterparts are discussed briefly.     

Extraktion – ein historischer Rückblick

The extraction of plants with the aid of water is one of the oldest techniques known to humankind for obtaining aromatic principles and medicaments from these sources. Extraction vessels excavated in Mesopotamia can be dated back to around 3500 BC, and Sumerian clay tablets describing the preparation of medicaments which were found in the same region date from around 2100 BC. The Greek and Roman civilisations of antiquity inherited extraction together with other skills from their predecessors, and this knowledge was passed on to Christendom by Arabian scholars. Europe of the Middle Ages saw the development of pharmacy, medicine, and mining, as well as the sugar industry, all of which made active use of extraction with a wide range of solvents. Whereas technological applications of extraction were thus steadily increasing prior to the industrial revolution, the equipment used underwent hardly any changes up the end of the 18^th century. It was only in the 19^th century that active development of equipment, materials, and modes of operation started, while successful combination of theory and practice and treatment of extraction by the methods of engineering science had to wait until the 20^th century. This article reports about equipment, solvents, and extraction processes up to the beginning of the present century, and places then in a political and sociological context.     

Schmelzgranulierung - ein neues Verfahren zur Bildung fester Kügelchen mit definiertem Korn aus Schmelzen

Melt Granulation - A New Method for the Formation of Compact Globules with defined Bead from Melt A method by which uniform beads of a definite size can be produced from the melts is described. The construction and working of a plant already erected is explained as well as the methods of calculation for the lay out and dimensioning are given. The application is shown with the help of an example.