Dispersionen sind ein heterogenes Gemisch aus zwei Stoffen, die sich nicht miteinander mischen. In der vorliegenden Arbeit werden sowohl Suspensionen bestehend aus einer festen dispersen Phase in einem flussigen Dispersionsmedium, Emulsionen bestehen aus zwei nicht mischbaren Flussigkeiten als auch Schaume, gebildet aus einer Gasphase dispergiert in einer Flussigkeit, untersucht. Als Hauptcharakterisierungsmethode dient die Fourier Transformations-Rheologie (FT-Rheologie), welches eine mechanische Charakterisierungsmethode im nichtlinearen Bereich darstellt.
This book introduces fundamentals, measurements, and applications of rheology of fresh cement-based materials. The rheology of a fresh cement-based material is one of its most important aspects, characterizing its flow and deformation, and governing the mixing, placement, and casting quality of a concrete. This is the first book to bring the field together on an increasingly important topic, as new types of cement-based materials and new concrete technologies are developed. It describes measurement equipment, procedures, and data interpretation of the rheology of cement paste and concrete, as well as applications such as self-compacting concrete, pumping, and 3D printing. A range of other cement-based materials such as fiber-reinforced concrete, cemented paste backfills, and alkali-activated cement are also examined. Rheology of Fresh Cement-Based Materials serves as a reference book for researchers and engineers, and a textbook for advanced undergraduate and graduate students.
The influence of shear fields on water-based systems was investigated within this thesis. The non-linear rheological behaviour of spherical and rod-like particles was examined with Fourier-Transform rheology under LAOS conditions. As a model system for spherical particles two different kinds of polystyrene disper- sions, with a solid content higher than 0.3 each, were synthesised within this work. Due to the differences in polydispersity and Debye-length, differences were also found in the rheology. In the FT-rheology both kinds of dispersions showed a similar rise in the intensities of the magnitudes of the odd higher harmonics, which were predicted by a model. The, in some cases additionally appearing second harmonics, were not predicted. A novel method to analyse the time domain signal was developed, that splits the time domain signal up in four characteristic functions. Those characteristic functions correspond to rheological phenomena. In some cases the intensities of the Fourier components can interfere negatively. FD-virus particles were used as a rod-like model system, which already shows a highly non-linear behaviour at concentrations below 1. % wt. Predictions for the dependence of the higher harmonics from the strain amplitude described the non-linear behaviour well at large, but no so good at small strain amplitudes. Ad- ditionally the trends of the rheological behaviour could be described by a theory for rod-like particles. An existing rheo-optical set-up was enhanced by reducing the background birefringence by a factor of 20 and by increasing the time resolution by a factor of 24. Additionally a combination of FT-rheology and rheo-optics was achieved. The influence of a constant shear field on the crystallisation process of zinc oxide in the presence of a polymer was examined. The crystallites showed a reduction in length by a factor of 2. The directed addition of polymers in combi- nation with a defined shear field can be an easy way for a defined change of the form of crystallites.
Advances in Food Rheology and Its Applications: Development in Food Rheology, Second Edition presents the latest advances in the measurement and application of food rheology, one of the most important tools for food companies when characterizing ingredients and final products, and a predictor of product performance and consumer acceptance. This second edition provides coverage of new rheological measurement techniques, including ultrasonic measurements of rheological properties of food and NMR approach, and precision in data handling, including coverage of mathematical modeling of rheological properties. As the range of food products has also broadened as a result of consumer demands and preference, this second edition includes a series of new chapters on dairy and plant-based foods. The amalgamation between food texture and sensory attributes will also be addressed. In addition, coverage of the correlation between rheological behavior and modeling of the fluid in a human stomach and food digestion will be assessed. A special focus has given on rheology of gel systems, including, food hydrogels, bigel and organogels. Written for food scientists, food technologists, sensory scientists, and others working in academia and industry, Advances in Food Rheology and Its Applications: Development in Food Rheology, Second Edition will be a welcomed and updated reference. - Considers the impact of artificial intelligence and machine vision on rheological characterization and process control - Presents ultrasonic measurements of rheological properties of food and NMR approach, and precision in data handling - Covers thermodynamic approach of rheology and interfacial rheology - Explains various gel systems rheology, including bogels and organogo gels
This book first introduces polymers and polymer composites which are widely used in different industrial and engineering applications where the proper selection of fiber, filler, and polymer can be tailored for particular application. The primary objective of this book is to broaden the knowledge of tribology of polymer composites in a new dimension for Industry 4.0. For instance, the book covers polymer composites used as self-lubricating material used in the automotive industry and other manufacturing equipment to reduce the effect of energy loss due to friction and wear. This book is of interest to researchers and industrial practitioners who work in the field of tribology of polymer composites, manufacturing equipment and production engineering.
Rheology of Polymer Blends and Nanocomposites: Theory, Modelling and Applications focuses on rheology in polymer nanocomposites. It provides readers with a solid grounding in the fundamentals of rheology, with an emphasis on recent advancements. Chapters explore potential future applications for nanocomposites and polymer blends, giving readers a thorough understanding of the specific features derived from rheology as a tool for the study of polymer blends and nanocomposites. This book is ideal for industrial and academic researchers in the field of polymer blends and nanocomposites, but is also a great resource for anyone who wants to learn about the applications of rheology. - Sets out the principles of rheology as it is applied to polymer blends and nanocomposites - Demonstrates how rheological techniques are best applied to different classes of nanocomposites - Assesses the opportunities and major challenges of rheological approaches to polymer blends and nanocomposites
This book deals with colloidal systems in technical processes and the influence of colloidal systems by technical processes. It explores how new measurement capabilities can offer the potential for a dynamic development of scientific and engineering, and examines the origin of colloidal systems and its use for new products. The future challenges to colloidal process engineering are the development of appropriate equipment and processes for the production and obtainment of multi-phase structures and energetic interactions in market-relevant quantities. The book explores the relevant processes and for controlled production and how they can be used across all scales.
