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Chemie : Stoffe, Reaktionen, Umwelt ; Ausgabe Mecklenburg-Vorpommern, Realschule, 10, Lehrbuch
(2000)
Experimente mit Ozon
(1996)
Mit einer ausgewogenen Stoffauswahl aus den Teilgebieten Chemische Thermodynamik, Reaktionskinetik und Elektrochemie wird der Leser an das Studium der Physikalischen Chemie herangeführt. Das Verständnis der Theorie wird durch zahlreiche Aufgabenstellungen und die Angabe ihrer Lösungswege erleichtert. Das Buch gibt dem Studenten darüber hinaus Anregungen für ausgewählte Experimente zu den behandelten Teilgebieten, mit denen sich ein Grundverständnis physikalisch-chemischer Zusammenhänge entwickeln lässt.
Mit einer ausgewogenen Stoffauswahl wird der Leser an das Studium der Physikalischen Chemie herangeführt. Das Verständnis der Theorie wird durch zahlreiche Aufgabenstellungen und die Angabe ihrer Lösungswege erleichtert. Das vorliegende Buch gibt dem Studenten darüber hinaus Anregungen für ausgewählte Experimente zu den behandelten Teilgebieten. In der Durchführung und Auswertung der Experimente kann der Student erneut überprüfen, wie gut es ihm gelungen ist, ein Grundverständnis für physikalisch-chemische Zusammenhänge zu entwickeln.
In ihrer Vorlesung zeigt Sabine Beuermann, unter welchen Bedingungen Kohlendioxid als Reaktionsmedium für die Herstellung von polymeren Materialien genutzt werden kann. Fluides Kohlendioxid ist ein attraktives Reaktionsmedium, da es ungiftig und nicht brennbar ist. Zudem leistet es einen wichtigen Beitrag zur Entwicklung nachhaltiger chemischer Prozesse, da durch den Einsatz von Kohlendioxid die Verwendung von organischen Lösungsmitteln vermieden werden kann.
Stoffströme
(1997)
Endohedral and external through-space NMR shieldings (TSNMRS) and the magnetic susceptibilities of the fullerene carbon cages of C50, C60, C60-6, C70, and C70-6 were assessed by ab initio molecular orbital calculations. Employing the nucleus-independent chemical shift (NICS) concept, these TSNMRS were visualized as isochemical shielding surfaces (ICSS) and were applied to quantitatively estimate either the aromaticity or the anti-aromaticity on the fullerene surface pertaining to the five- or six-membered ring moieties and the shielding of any nuclei enclosed within the carbon cages. Differences between the NICSs calculated at the center of the fullerene carbon cages and the experimental chemical shifts of encapsulated NMR-active nuclei as well as experimental shieldings observed for different encapsulated nuclei were able to be understood readily for the first time.
Especially sulphur containing compounds are suitable for the separation of noble metals[ , ]. 1,2-Dithioethenes are weak chelate-forming ligands [ ]and in the case of bis(methylthio)maleonitrile[ ] the donor power of both of the sulphur atoms is further decreased by the electron withdrawing effect of the cyanogroups. Crowned dithiomaleonitrile are macrocyclic chelate ligands which extract Pd(II) at sufficient rate in a very good yields. The reason for that extraction behaviour is the fact that Pd(II) favours the square planar coordination geometry in opposite to the 3d- elements. The synthesis of the immobilized ligands proceeds from the 2-allyloxy-1,2-propanediol forming the dicarbon acid which is reduced to the diole. With the help of thionylchloride the dichloro compound is synthesized forming together with a dithiolate (1,2-disodium-1,2-dicyanethene-1,2-dithiolate, 1,2-disodium-4-methylbenzene-1,2-dithiolate [ ]) at high dilution conditions the macrocycle. Than the allysubstituted crown ether is sillylated and the resulting alkoxysilane is immobilised onto activated silca gel. The substituent forms in the same time a spacer should be modified in the future. By immobilisation at an inactive matrix the selectivity of the ligand should be applied for the accumulation of palladium from diluted solutions. The extraction was performed from nitric acid solution with a yield of 93% into a ligand solution (chloroform, kerosine). The extraction equilibrium is reached after 10 min. By atomic absorption spectroscopy the metal concentration in the aqueous phase was determined to calculate the extraction rate. By modification of the cavity of the macrocyclus the extraction rate increases from the acyclic compound through maleonitrile-dithio-21-crown-7, maleonitrile-dithio-15-crown-5 and maleonitrile-18-crown-6. The best results can be observed at the maleonitrile-dithio-12-crown-4. The rise of the function lg D= f(lg L) gives the composition of the extracted compounds as 1:1. The separation is unsatisfactory in the case of Ag(I), Hg(II), Pt(II), Tl (I) and the most 3d-elements. Also Ni(II) as a representative for the 3d-elements shows only separations coefficients of 1.43?103 . Summarizing, a very good separation of palladium from the examined elements can be specified. Additional to the extraction experiments, as well as the crystal structures and by UV spectroscopy the formation constants of selected chelates were determined. The observed order corresponds to that found by the extraction of palladium in the system water/chloroform. In the case of maleonitrile-dithio-15-crown-5 Ag(I) is endocyclic coordinated with all donor atoms of the macrocyclus. Already maleonitrile-dithio-18-crown-6 can include the silver cation into its greater cavity. In these cases a 1:1 complex is formed. A 1:2 sandwich structure was noticed only in the case of the smaller ligand maleonitrile- dithio-12-crown-4. Obviously, the formation of that structure is not favoured in the system water/chloroform from which can be explained the unfavourable extraction results.
Klassischerweise haben Salze, beispielsweise Kochsalz, Schmelzpunkte von einigen hundert Grad Celsius und mehr. Ionische Flüssigkeiten sind dagegen Salze, deren Schmelzpunkt zum Teil weit unter der Raumtemperatur liegt. Sie sind daher bei Raumtemperatur flüssig. Obwohl ionische Flüssigkeiten seit 1914 bekannt sind, hatten sie bis vor 15 Jahren keinerlei Bedeutung. Heute jedoch werden ionische Flüssigkeiten aufgrund ihrer vorteilhaften Eigenschaften, wie hohe Leitfähigkeit oder hohe Temperaturstabilität, unter anderem zur Papierverarbeitung oder in flexiblen Solarzellen eingesetzt. Die Antrittsvorlesung wird sich insbesondere mit der Herstellung anorganischer Partikel befassen und zeigen, wie ionische Flüssigkeiten zur Herstellung neuer Materialien für verschiedene Anwendungen genutzt werden können.
Complete 3D potential energy surfaces for the two lowest electronic states of the system (N2H)+
(1996)
Contents: Production and Applications of Chitin and Chitosan Krill as a promising raw material for the production of chitin in Europe - Containerized plant for producing chitin - Preparation and characterization of chitosan from Mucorales - Chitosan from Absidia orchidis - Scaling up of lactic acid fermentation of prawn wastes in packed-bed column reactor for chitin recovery - Preparation of chitin by acetic acid fermentation - Inter-source reproducibility of the chitin deacetylation process - Comparative analysis of chitosans from insects and crustacea - Effect of the rate of deacetylation on the physico-chemical properties of cuttlefish chitosan - Deacetylation of chitin by fungal enzymes - Production of partially degraded chitosan with desired molecular weight - Chitin-containing materials Mycoton for wounds treatment - Biological activity of selected forms of chitosan - Application of chitosan on the preservation quality of cut flowers - Preparation and characterization of chitosan films: application in cell cultures - Transport phenomena in chitin gels - Symplex membranes of chitosan and sulphoethylcellulose - Preparation and use of chitosan-Ca pectinate pellets - Bioseparation of protein from cheese whey by using chitosan coagulation and ultrafiltration membranes - Preparation of silk fibroin/chitosan fiber - Preparation of paper sheets containing microcrystalline chitosan - Applications of chitosan in textile printing - Permanent modification of fibrous materials with biopolymers - Ion exchanger from chitosan - Chitosan in waste water treatment - The immobilization of tyrosinase on chitin and chitosan and its possible use in wastewater treatment - Utilization of modified chitosan in aqueous system treatment Biomaterials Chemical and preclinical studies on 6-oxychitin - Diverse biological effects of fungal chitin-glucan complex - Effect of concentration of neutralizing agent on chitosan membrane properties - Preliminary investigation of the compatibility of a chitosan-based peritoneal dialysis solution - Influence of chitosan on the growth of several cellular lines - A new chitosan containing phosphonic group with chelating properties - Biocompatibility of chitin materials using cell culture method Oral Administration of Chitosan Recent results in the oral administration of chitosan - Reduction of absorption of dietary lipids and cholesterol by chitosan, its derivatives and special formulations - Chitosan in weight reduction: results from a large scale consumer study - Conformation of chitosan ascorbic acid salt - Trimethylated chitosans as safe absorption enhancers for transmucosal delivery of peptide drugs - Chitosan derivates as intestinal penetration enhancers of the peptide drug buserelin in vivo and in vitro - Chitosan microparticles for oral vaccination: optimization and characterization - Effect of chitosan in enhancing drug delivery across buccal mucosa - Influence of chitosans on permeability of human intestinal epithelial (Caco-2) cells: The effect of molecular weight, degree of deacetylation and exposure time - Oral polymeric N-acetyl-D-glucosamine as potential treatment for patients with osteoarthritis - Clinicoimmunological efficiency of the chitin-containing drug Mycoton in complex treatment of a chronic hepatitis - Interactions of chitin, chitosan, N-laurylchitosan, and N-dimethylaminopropyl chitosan with olive oil - The chitin-containing preparation Mycoton in a pediatric gastroenterology case - Antifungal activity and release behaviour of cross-linked chitosan films incorporated with chlorhexidine gluconate - Release of N-acetyl-D-glucosamine from chitosan in saliva - Physical and Physicochemical Properties Recent approach of metal binding by chitosan and derivatives - As(V) sorption on molybdate-impregnated chitosan gel beads (MICB) - Influence of medium pH on the biosorption of heavy metals by chitin-containing sorbent Mycoton - Comparative studies on molecular chain parameters of polyelectrolyte chains: the stiffness parameter B and temperature coefficient of intrinsic viscosity of chitosans and poly(diallyldimethylammonium chloride) - Crystalline behavior of chitosan - The relationship between the crystallinity and degree of deacetylation of chitin from crab shell - Reversible water-swellable chitin gel: modulation of swellability - Syneresis aspects of chitosan based gel systems - In situ chitosan gelation using the enzyme tyrosinase - Preparation and characterization of controlling pore size chitosan membranes - Fabrication of porous chitin matrices - Changes of polydispersity and limited molecular weight of ultrasonic treated chitosan - A statistical evaluation of IR spectroscopic methods to determine the degree of acetylation of ?-chitin and chitosan - Products of alkaline hydrolysis of dibutyrylchitin: chemical composition and DSC investigation - Chitosan emulsification properties Chemistry of Chitin and Chitosan Chemically modified chitinous materials: preparation and properties - Progress on the modification of chitosan - The graft copolymerization of chitosan with methyl acrylate using an organohalide-manganese carbonyl coinitiator system - Grafting of 4-vinylpyridine, maleic acid and maleic anhydride onto chitin and chitosan - Peptide synthesis on chitosan/chitin - Graft copolymerization of methyl methacrylate onto mercapto-chitin - Thermal depolymerization of chitosan salts - Radiolysis and sonolysis of chitosan - two convenient techniques for a controlled reduction of molecular weight - Thermal and UV degradation of chitosan - Heat-induced physicochemical changes in highly deacetylated chitosan - Chitosan fiber and its chemical N-modification at the fiber state for use as functional materials - Preparation of a fiber reactive chitosan derivative with enhanced microbial activity - Chromatographic separation of rare earths with complexane types of chemically modified chitosan - The effects of detergents on chitosan - Chitosan-alginate PEC films prepared from chitosan of different molecular weights - Enzymology of Chitin and Chitosan Biosynthesis and Degradation Enzymes of chitin metabolism for the design of antifungals - Enzymatic degradation of chitin by microorganisms - Kinetic behaviours of chitinase isozymes - An acidic chitinase from gizzards of broiler (Gallus gallus L.) - On the contribution of conserved acidic residues to catalytic activity of chitinase B from Serratia marcescens - Detection, isolation and preliminary characterisation of a new hyperthermophilic chitinase from the anaerobic archaebacterium Thermococcus chitonophagus - Biochemical and genetic engineering studies on chitinase A from Serratia marcescens - Induction of chitinase production by Serratia marcescens, using a synthetic N-acetylglucosamine derivative - Libraries of chito-oligosaccharides of mixed acetylation patterns and their interactions with chitinases - Approaches towards the design of new chitinase inhibitors - Allosamidin inhibits the fragmentation and autolysis of Penicillium chrysogenum - cDNA encoding chitinase in the midge, Chironomus tentans - Extraction and purification of chitosanase from Bacillus cereus - Substrate binding mechanism of chitosanase from Streptomyces sp. N174 - Chitosanase-catalyzed hydrolysis of 4-methylumbelliferyl ?-chitotrioside - A rust fungus turns chitin into chitosan upon plant tissue colonization to evade recognition by the host - Antibiotic kanosamine is an inhibitor of chitin biosynthesis in fungi - PCR amplification of chitin deacetylase genes - Amplification of antifungal effect of GlcN-6-P synthase and chitin synthase inhibitors - ?-N-Acetylhexosaminidases: two enzyme families, two mechanisms - Purification and characterisation of chitin deacetylase from Absidia orchidis - Effect of aluminium ion on hydrolysis reaction of carboxymethyl- and dihydroxypropyl-chitin with lysozyme - Structure and function relatioship of human N-acetyl-D-glucosamine 2-epimerase (renin binding protein) - Identification of active site residue(s)
Chemical Physics
(1991)
Advances in chitin science
(1996)
Stoffströme und Textilien
(1997)
Chitin handbook
(1997)