Article
Refine
Year of publication
Document Type
- Article (597) (remove)
Keywords
- Heparin (3)
- Bacillaceae (2)
- Biotechnological application (2)
- Chemometrics (2)
- IR spectroscopy (2)
- NMR spectroscopy (2)
- Principal component analysis (2)
- Standardization (2)
- Subtilases (2)
- Subtilisin (2)
- bubble column (2)
- methanation (2)
- plug flow reactor (2)
- qNMR (2)
- (Poly)saccharides (1)
- Algal Turf Scrubber (1)
- Algal–bacterial bioflm (1)
- Alginate beads (1)
- Alkalihalobacillus okhensis (1)
- Aloe vera (1)
- Authenticity (1)
- Biofuel (1)
- Biogas (1)
- Biomass (1)
- Biorefinery (1)
- Bragg peak (1)
- Broad pH spectrum (1)
- Butanol (1)
- CRISPR/Cas9 (1)
- Chondroitin sulfate (1)
- Circular bioeconomy (1)
- Clostridium acetobutylicum (1)
- Crude heparin (1)
- Cyclotron production (1)
- Dehydrogenase (1)
- Detergent protease (1)
- Deuterated solvents (1)
- Deuterium NMR (1)
- Diaphorase (1)
- Dietary supplements (1)
- Enzymatic biosensor (1)
- Extracellular enzymes (1)
- Ga-68 (1)
- Glucosamine (1)
- Halotolerant protease (1)
- High-field NMR (1)
- Hypersecretion (1)
- IR (1)
- Inorganic ions (1)
- Ions (1)
- Lignocellulose (1)
- Linear discriminant analysis (1)
- Manufacturer (1)
- Marker-free mutagenesis (1)
- Medical radionuclide production (1)
- Metal contaminants (1)
- Methane (1)
- Microfluidic solvent extraction (1)
- Molecular modelling (1)
- Molecular weight determination (1)
- NMR (1)
- Organic acids (1)
- P2G (1)
- PLS-regression (1)
- Polysaccharides (1)
- Quality control (1)
- Quantum chemistry (1)
- Simultaneous determination (1)
- Soft independent modeling of class analogy (1)
- Spectroscopy (1)
- Stenotrophomonas maltophilia (1)
- Streptomyces griseus (1)
- Streptomyces lividans (1)
- USP (1)
- Uracil-phosphoribosyltransferase (1)
- acetoin (1)
- acetoin reductase (1)
- actuator-sensor system (1)
- alcoholic beverages (1)
- aspergillus (1)
- bacterial cellulose (1)
- bi-enzyme biosensor (1)
- bio-methane (1)
- bioavailability (1)
- biodegradable polymers (1)
- biological dosimeter (1)
- biomethane (1)
- biosensors (1)
- borehole disposal (1)
- capacitive field-effect sensor (1)
- capacitive field-effect sensors (1)
- coculture (1)
- deficit irrigation (1)
- detergent protease (1)
- disposal facility (1)
- drug metabolising enzymes (1)
- drug–drug interactions (1)
- elastomers (1)
- enzyme kinetics (1)
- enzyme-logic gate (1)
- exopolysaccharides (1)
- filamentous fungi (1)
- genome engineering (1)
- geological disposal (1)
- glycine (1)
- halotolerant protease (1)
- high-alkaline subtilisin (1)
- human metabolites (1)
- hydrogel (1)
- hydrogels (1)
- light-addressable electrode (1)
- light-addressable potentiometric sensor (1)
- mechanical properties (1)
- microfluidics (1)
- micronutrients (1)
- neutrons (1)
- nuclear waste (1)
- onion (1)
- optical fibers (1)
- oxidative stable protease (1)
- penicillinase (1)
- polyaspartic acid (1)
- power-to-gas (1)
- prebiotic (1)
- proton therapy (1)
- protons (1)
- pullulan (1)
- recombinant expression (1)
- relative dosimetry (1)
- retention time (1)
- rubber (1)
- superabsorbent polymers (1)
- supramolecular structures (1)
- swelling properties (1)
- theory and modeling (1)
- tobacco mosaic virus (TMV) (1)
- transporters (1)
- urease (1)
- water economy (1)
- yield (1)
- α-aminoacylase (1)
- ε-lysine acylase (1)
Institute
- Fachbereich Chemie und Biotechnologie (597) (remove)
The Kremer-Grest (KG) bead-spring model is a near standard in Molecular Dynamic simulations of generic polymer properties. It owes its popularity to its computational efficiency, rather than its ability to represent specific polymer species and conditions. Here we investigate how to adapt the model to match the universal properties of a wide range of chemical polymers species. For this purpose we vary a single parameter originally introduced by Faller and Müller-Plathe, the chain stiffness. Examples include polystyrene, polyethylene, polypropylene, cis-polyisoprene, polydimethylsiloxane, polyethyleneoxide and styrene-butadiene rubber. We do this by matching the number of Kuhn segments per chain and the number of Kuhn segments per cubic Kuhn volume for the polymer species and for the Kremer-Grest model. We also derive mapping relations for converting KG model units back to physical units, in particular we obtain the entanglement time for the KG model as function of stiffness allowing for a time mapping. To test these relations, we generate large equilibrated well entangled polymer melts, and measure the entanglement moduli using a static primitive-path analysis of the entangled melt structure as well as by simulations of step-strain deformation of the model melts. The obtained moduli for our model polymer melts are in good agreement with the experimentally expected moduli.
The Kremer–Grest (KG) polymer model is a standard model for studying generic polymer properties in molecular dynamics simulations. It owes its popularity to its simplicity and computational efficiency, rather than its ability to represent specific polymers species and conditions. Here we show that by tuning the chain stiffness it is possible to adapt the KG model to model melts of real polymers. In particular, we provide mapping relations from KG to SI units for a wide range of commodity polymers. The connection between the experimental and the KG melts is made at the Kuhn scale, i.e., at the crossover from the chemistry-specific small scale to the universal large scale behavior. We expect Kuhn scale-mapped KG models to faithfully represent universal properties dominated by the large scale conformational statistics and dynamics of flexible polymers. In particular, we observe very good agreement between entanglement moduli of our KG models and the experimental moduli of the target polymers.
The feasibility of light-addressed detection and manipulation of pH gradients inside an electrochemical microfluidic cell was studied. Local pH changes, induced by a light-addressable electrode (LAE), were detected using a light-addressable potentiometric sensor (LAPS) with different measurement modes representing an actuator-sensor system. Biosensor functionality was examined depending on locally induced pH gradients with the help of the model enzyme penicillinase, which had been immobilized in the microfluidic channel. The surface morphology of the LAE and enzyme-functionalized LAPS was studied by scanning electron microscopy. Furthermore, the penicillin sensitivity of the LAPS inside the microfluidic channel was determined with regard to the analyte’s pH influence on the enzymatic reaction rate. In a final experiment, the LAE-controlled pH inhibition of the enzyme activity was monitored by the LAPS.
Poly(N-isopropylacrylamide) (PNIPAAm) hydrogel films with incorporated graphene oxide (GO) were developed and tested as light-stimulated actuators. GO dispersions were synthesized via Hummers method and characterized toward their optical properties and photothermal energy conversion. The hydrogels were prepared by means of photopolymerization. In addition, the influence of GO within the hydrogel network on the lower critical solution temperature (LCST) was investigated by differential scanning calorimetry (DSC). The optical absorbance and the response to illumination were determined as a function of GO concentration for thin hydrogel films. A proof of principle for the stimulation with light was performed.