The longitudinal and transverse nuclear magnetic resonance relaxivity dispersion (NMRD) of H in water induced by the paramagnetic relaxation enhancement (PRE) of dissolved lanthanide ions (Ln) can become very strong. Longitudinal and transverse H NMRD for Gd, Dy, Er and Ho were measured from 20 MHz/0.47 T to 1382 MHz/32.
View Article and Find Full Text PDFQuality control in a production plant shows its maximum potential in the form of inline measurements. Defects and imperfections can be detected early and directly, and waste and costs can be reduced. Nuclear Magnetic Resonance offers a wide range of applications but requires dedicated adaptation to the respective process and material conditions.
View Article and Find Full Text PDFTo reduce unwanted fat bloom in the manufacturing and storage of chocolates, detailed knowledge of the chemical composition and molecular mobility of the oils and fats contained is required. Although the formation of fat bloom on chocolate products has been studied for many decades with regard to its prevention and reduction, questions on the molecular level still remain to be answered. Chocolate products with nut-based fillings are especially prone to undesirable fat bloom.
View Article and Find Full Text PDFInline analytics in industrial processes reduce operating costs and production rejection. Dedicated sensors enable inline process monitoring and control tailored to the application of interest. Nuclear Magnetic Resonance is a well-known analytical technique but needs adapting for low-cost, reliable and robust process monitoring.
View Article and Find Full Text PDFProcess monitoring and control require dedicated and reliable measures which reflect the status of the process under investigation. Although nuclear magnetic resonance is known to be a versatile analytical technique, it is only seldomly found in process monitoring. Single-sided nuclear magnetic resonance is one well known approach for being applied in process monitoring.
View Article and Find Full Text PDFNMR methods were applied for lubricant analysis. Different factors influence the real aging of lubricants on diverse length scales and are captured by NMR. Chemical conversion of additives is addressed by NMR spectroscopy.
View Article and Find Full Text PDFA time-dependent understanding of swelling characteristics and external stimuli behavior is crucial for the development and understanding of functional hydrogels. Magnetic resonance imaging (MRI) offers the opportunity to study three-dimensional (3D) soft materials nondestructively. This technique is already widely used as an image-based medical diagnostic tool and is applied here to evaluate complex structures of a hydrogel-a double network of chemically crosslinked casein enhanced with alginate-fabricated by 3D printing.
View Article and Find Full Text PDFThe crystallization of melt emulsions is of great interest to the food, cosmetic, and pharmaceutical industries. Surfactants are used in emulsions and suspensions to stabilize the dispersed phase; thus, questions arise about the liquid-liquid and solid-liquid interfaces of the droplets or particles and the distribution of the surfactant in the different phases (continuous and dispersed phase, interface). Nuclear magnetic resonance relaxation and diffusion measurements revealed that the internal and rotational mobility of surfactant molecules at the liquid-liquid interface decreases with increasing droplet sizes.
View Article and Find Full Text PDFSelectivity and image contrast are always challenging in magnetic resonance imaging (MRI), which are - inter alia - addressed by contrast agents. These compounds still need to be improved, and their relaxation properties, i. e.
View Article and Find Full Text PDFFront Bioeng Biotechnol
June 2022
As virtual reality (VR) has drastically evolved over the past few years, the field of applications of VR flourished way beyond the gaming industry. While commercial VR solutions might be available, there is a need to develop a workflow for specific applications. Bioprinting represents such an example.
View Article and Find Full Text PDFCharge transport, diffusion properties, and glassy dynamics of blends of imidazolium-based ionic liquid (IL) and the corresponding polymer (polyIL) were examined by Pulsed-Field-Gradient Nuclear Magnetic Resonance (PFG-NMR) and rheology coupled with broadband dielectric spectroscopy (rheo-BDS). We found that the mechanical storage modulus (G') increases with an increasing amount of polyIL and G' is a factor of 10,000 higher for the polyIL compared to the monomer (GIL'= 7.5 Pa at 100 rad s and 298 K).
View Article and Find Full Text PDFBioprinting is gaining importance for the manufacturing of tailor-made hydrogel scaffolds in tissue engineering, pharmaceutical research and cell therapy. However, structure fidelity and geometric deviations of printed objects heavily influence mass transport and process reproducibility. Fast, three-dimensional and nondestructive quality control methods will be decisive for the approval in larger studies or industry.
View Article and Find Full Text PDFLubricating greases were investigated by nuclear magnetic resonance/magnetic resonance imaging (NMR/MRI) to get insight into their structure and into their response to mechanical forces, which is related to bleeding and aging. The investigated greases are based on metallic soaps of fatty acids and oils, whereby LiOH is often used. These organic soaps act as thickeners and provide a network in which oils and their additives are embedded.
View Article and Find Full Text PDFThe current trend for ultra-high-field magnetic resonance imaging (MRI) technologies opens up new routes in clinical diagnostic imaging as well as in material imaging applications. MRI selectivity is further improved by using contrast agents (CAs), which enhance the image contrast and improve specificity by the paramagnetic relaxation enhancement (PRE) mechanism. Generally, the efficacy of a CA at a given magnetic field is measured by its longitudinal and transverse relaxivities and , i.
View Article and Find Full Text PDFIncreasing the efficiency of disperse phase crystallization is of great interest for melt emulsion production as the fraction of solidified droplets determines product quality and stability. Nucleation events must appear within every single one of the μm-sized droplets for solidification. Therefore, primary crystallization requires high subcooling and is, thus, time and energy consuming.
View Article and Find Full Text PDFTranslational mobility of guest molecules such as water and glucose in gels that are based on feruloylated polysaccharides appears to be critical to understand their nutritional and functional properties. Here, the applicability of PFG-STE-NMR on feruloylated gels was proven, and relationships to rheological data were studied. Arabinoxylans and pectins were extracted from by-products using varying conditions.
View Article and Find Full Text PDFA dedicated nuclear magnetic resonance (NMR) sensor was designed for the analysis of liquids. The magnets are arranged in a V shape, creating a spatially dependent magnetic field in the gap. Measurements of samples with diverse diameters are possible underdefined magnetic field gradients at a given position.
View Article and Find Full Text PDFThe removal or degradation of particulate organic matter is a crucial part in biological wastewater treatment. This is even more valid with respect to aerobic granular sludge and the impact of particulate organic matter on the formation and stability of the entire granulation process. Before the organic part of the particulate matter can be hydrolyzed and finally degraded by the microorganism, the particles have to be transported towards and retained within the granulated biomass.
View Article and Find Full Text PDFMilk protein fractionation by microfiltration membranes is an established but still growing field in dairy technology. Even under cross-flow conditions, this filtration process is impaired by the formation of a deposit by the retained protein fraction, mainly casein micelles. Due to deposition formation and consequently increased overall filtration resistance, the mass flow of the smaller whey protein fraction declines within the first few minutes of filtration.
View Article and Find Full Text PDFParamagnetic polyoxometalates [RECoGeWO(OH)(OH)] (Rare Earth (RE): Gd, Dy, Eu, and Y) are of special interest with regard to their application as alternative contrast agents in non-human magnetic resonance imaging which is increasingly used in materials science and process engineering. This class of new paramagnetic materials promises detailed findings in the magnetic resonance images due to their rather large total electron spin on the one hand, i.e.
View Article and Find Full Text PDFIn white biotechnology research, the putative superiority of productive biofilms to conventional biotransformation processes based on planktonic cultures has been increasingly discussed in recent years. In the present study, we chose lactic acid production as a model application to evaluate biofilm potential. A pure culture of Lactobacillus bacteria was grown in a tubular biofilm reactor.
View Article and Find Full Text PDFOil is a prominent, but multifaceted material class with a wide variety of applications. Technical oils, crude oils as well as edibles are main subclasses. In this review, the question is addressed how low-field NMR can contribute in oil characterization as an analytical tool, mainly with respect to quality control.
View Article and Find Full Text PDFFiltration and separation via membranes are key processes in food processing. One major application of membrane filtration is in the dairy industry, aiming for the separation of different milk proteins. The various chemical components of milk possess different physiochemical properties and can be used most effectively in food processing if they are separately available and remain in their native state.
View Article and Find Full Text PDFMass transfer in biofilms is determined by diffusion. Different mostly invasive approaches have been used to measure diffusion coefficients in biofilms, however, data on heterogeneous biomass under realistic conditions is still missing. To non-invasively elucidate fluid-structure interactions in complex multispecies biofilms pulsed field gradient-nuclear magnetic resonance (PFG-NMR) was applied to measure the water diffusion in five different types of biomass aggregates: one type of sludge flocs, two types of biofilm, and two types of granules.
View Article and Find Full Text PDFWith the aim to synthesize soluble cluster molecules, the silver salt of (4-(-butyl)phenyl)methanethiol [AgSCHCH Bu] was applied as a suitable precursor for the formation of a nanoscale silver sulfide cluster. In the presence of 1,6-(diphenylphosphino)hexane (dpph), the 115 nuclear silver cluster [AgS(SCHCH Bu)(dpph)] was obtained. The molecular structure of this compound was elucidated by single crystal X-ray analysis and fully characterized by spectroscopic techniques.
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