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Lanthanide Complexes (Ln=La, Nd, Dy) of Octaethyl propane-1,1,3,3-tetrayltetrakis(phosphonate): Multidentate Binding Competing with Monodentate DMSO Complexes
(2022-12-09)
The preparation of lanthanide nitrate complexes [Ln(NO₃)₃{L}]ₙ (Ln³+=La, Nd, Dy) supported by the octaethyl propane-1,1,3,3-tetrayltetrakis(phosphonate) (L) chelate ligand platform is presented. Re-crystallization of these compounds from DMSO/THF led to a complete replacement of the multidentate phosphonate ester ligand and the formation of exclusively DMSO-supported lanthanide nitrate species [Ln(NO₃)₃(DMSO)₄]. The relative basicity of a model phosphonate ester vs. DMSO is explored with theoretical means, pointing ...
Aufsatz
Emission and Mechanical Properties of Glass and Cellulose Fiber Reinforced Bio-Polyamide Composites
(2023-06-07)
Climate change, access, and monopolies to raw material sources as well as politically motivated trade barriers are among the factors responsible for a shortage of raw materials. In the plastics industry, resource conservation can be achieved by substituting commercially available petrochemical-based plastics with components made from renewable raw materials. Innovation potentials are often not used due to a lack of information on the use of bio-based materials, efficient processing methods, and product technologies ...
Aufsatz
The Influence of Thermal and Mechanical Stress on the Electrical Conductivity of ITO-Coated Polycarbonate Films
(2023-05-31)
The influence of thermomechanical stress on the conductivity of indium tin oxide (ITO)-coated polycarbonate (PC) films was investigated. PC is the industry’s standard material for window panes. ITO coatings on polyethylene terephthalate (PET) films are the main commercially available option; as such, most investigations refer to this combination. The investigations in this study aim to investigate the critical crack initiation strain at different temperatures and crack initiation temperatures for two different coating ...
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Gradual Coordination and Reversible P–P Bond Activation of a P3-Unit with Transition Metal Carbony
(2024-03-20)
Coordination of a stereochemically defined P3-chain to a series of transition metal carbonyls [M(CO)x]z− (M = Mn (x = 5, z = 1), Fe (x = 4, z = 2) or Co (x = 4, z = 1)) is explored using a 3]ferrocenophane scaffold. A gradual transition from 𝜼1-, 𝜼2- to 𝜼3-coordination is observed where in the 𝜼2-mode the terminal positions of the phosphorus chain are bridged. With an excess of cobalt carbonyl successive P–P bond activation and gradual separation of the central phosphorus atoms from the phosphorus chain has been ...
Aufsatz
Influence of Chitosan and Grape Seed Extract on Thermal and Mechanical Properties of PLA Blends
(2023-03-22)
Blends based on polylactic acid (PLA), chitosan, and grape seed extract (GE) were prepared by extrusion and injection molding. The effect of chitosan (5% and 15% on PLA basis) and natural extract (1% on PLA basis) incorporated into the PLA host matrix was explored regarding the thermal and mechanical properties. GE showed antioxidant activity, as determined by the DPPH assay method. Chitosan and GE affect the degree of crystallinity up to 30% as the polysaccharide acts as a nucleating agent, while the extract reduces ...
Aufsatz
Characterization of films and film-forming solutions of chitosan/thermoplastic rice starch associations: Role of starch oxidation and plasticizer type in the molecular interactions
(2023-09-29)
Polysaccharide films are alternative sources to replace fossil-based compounds. This study aimed to use rice starch modified by gelatinization and oxidation processes. Different properties were observed after blending it with chitosan and polyols, as evaluated on the film-forming solutions by rheology. The interaction between chitosan and oxidized starch appeared higher, as the plasticizers exhibited a low effect on the rheological behavior. Polyols played an essential role in chitosan/gelatinized associations, driven ...
Aufsatz
A General Strategy for Increasing the Air Stability of Phosphines Including Primary Phosphines
(2023-08-31)
A general approach for increasing the air-stability of various primary phosphines in the absence of kinetic stabilization is presented that contrasts with previous interpretations, which were limited to specific phosphines. This contribution shows the synthesis of a series of air-stable primary phosphines Fc(CH₂)nPH₂, where n=0,1,2,3; and Fc=ferrocenyl, and their corresponding isolable primary phosphine oxides. It was demonstrated that the ferrocene moiety exerts an antioxidant effect on the primary phosphine group, ...
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Influence of Ethylene Oxide and Gamma Irradiation Sterilization Processes on the Properties of Poly-L-Lactic-Acid (PLLA) Materials
(2023-08-18)
In order to encourage the substitution of petrochemical polymers in medical technology with sustainable, bio-based materials, there is an urgent need for further investigations, especially data regarding their sterility performance. Within the scope of the investigations, selected material properties of poly-L-lactic-acid (PLLA), a specific type of poly(lactic-acid) (PLA), were analyzed before and after sterilization (using ethylene oxide or gamma irradiation) in order to investigate deviations in its chemical ...
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Spatial and Temporal Variations of Stable Isotopes in Precipitation in the Mountainous Region, North Hesse
(2022-12-01)
Patterns of stable isotopes of water (¹⁸O and ²H) in precipitation have been used as tracers for analyzing environmental processes which can be changed by factors such as the topography or meteorological variables. In this study, we investigated the isotopic data in precipitation for one year in the low mountain range of North Hesse, Germany, and analyzed mainly for altitude, rainfall amount, and air temperature effects on a regional scale. The results indicate that the isotopic composition expressed an altitude ...
Aufsatz
Small villages and their sanitary infrastructure—an unnoticed influence on water quantity and a threat to water quality in headwater catchments
(2023-11-16)
In rural catchments, villages often feature their own, separate urban water infrastructure, including combined sewer overflows (CSOs) or wastewater treatment plants (WWTPs). These point sources affect the water quantity and quality of the receiving low order streams. However, the extent of this impact is rarely monitored. We installed discharge and water quality measurements at the outlet of two small, neighbouring headwater catchments, one that includes a village, a WWTP, and two CSOs, while the other is predominantly ...