To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The content of this chapter provides a brief overview of the basic concepts of colloid science that will be used in this book. Foundational knowledge is provided by reviewing our understanding of the simplest case of suspensions of hard spheres. First, the characteristic properties of Brownian hard spheres are presented. This includes a discussion of the relevant forces on and between particles in fluids at rest or during flow. On this basis, the microstructure and the phase behavior of the suspensions under consideration are evaluated. The basic rheology of hard sphere suspensions is reviewed in some detail, covering linear and nonlinear shear behavior, oscillatory flow, and also normal stress differences and shear thickening. The rheology is discussed in relation to the effect of flow on microstructure. As a foundation for understanding more complex suspensions, some basic colloidal interaction potentials are introduced along with their resulting, rich phase behavior. A special section of this chapter is dedicated to thixotropy, as this phenomenon occurs in several of the real life systems discussed in subsequent chapters. An appendix reviews the basic rheological concepts as an aid to the reader.
Some industrial products and processes involving colloid rheology are presented within the framework of this book. Paint rheology is presented and analyzed, where effects such as coating defects are avoided by ensuring the right rheology at each stage. Coating formulation is discussed, in particular for waterborne coatings. Carbon black suspensions are also widely used. Their microstructure is considered at different length scales. The resulting rheology includes time effects such as thixotropy. Measurement problems are reviewed as well as their electrical and dielectric behavior. For bitumen and asphalts, thermorheological behavior and aging are important and are controlled by their specific microstructure. A colloidal approach can also be used here. The rheology is discussed on the basis of the Roscoe model. For cement and cement-based products the rheology during shaping and hardening is linked to the underlying physical processes and interactions in the cement. Thixotropy and yield stress are relevant factors here. In the final part large scale processes are tackled. These often involve mixtures of large and small particles. Practical measurements such as the vane and the slump test are discussed, as well as the prediction of suspension behavior in industrial equipment. The compression behavior can be relevant here, including the compressive yield stress.
An essential text on practical application, theory and simulation, written by an international coalition of experts in the field and edited by the authors of Colloidal Suspension Rheology. This up-to-date work builds upon the prior work as a valuable guide to formulation and processing, as well as fundamental rheology of colloidal suspensions. Thematically, theory and simulation are connected to industrial application by consideration of colloidal interactions, particle properties, and suspension microstructure. Important classes of model suspensions including gels, glasses and soft particles are covered so as to develop a deeper understanding of industrial systems ranging from carbon black slurries, paints and coatings, asphalt, cement, and mine tailings, to natural suspensions such as biocolloids, protein solutions, and blood. Systematically presenting the established facts in this multidisciplinary field, this book is the perfect aid for academic researchers, graduate students, and industrial practitioners alike.
When using bifunctional core@shell catalysts, the stability of both the shell and core–shell interface is crucial for catalytic applications. In the present study, we elucidate the stability of a CuO/ZnO/Al2O3@ZSM-5 core@shell material, used for one-stage synthesis of dimethyl ether from synthesis gas. The catalyst stability was studied in a hierarchical manner by complementary environmental transmission electron microscopy (ETEM), scanning electron microscopy (SEM) and in situ hard X-ray ptychography with a specially designed in situ cell. Both reductive activation and reoxidation were applied. The core–shell interface was found to be stable during reducing and oxidizing treatment at 250°C as observed by ETEM and in situ X-ray ptychography, although strong changes occurred in the core on a 10 nm scale due to the reduction of copper oxide to metallic copper particles. At 350°C, in situ X-ray ptychography indicated the occurrence of structural changes also on the µm scale, i.e. the core material and parts of the shell undergo restructuring. Nevertheless, the crucial core–shell interface required for full bifunctionality appeared to remain stable. This study demonstrates the potential of these correlative in situ microscopy techniques for hierarchically designed catalysts.
A new closed cell is presented for in situ X-ray ptychography which allows studies under gas flow and at elevated temperature. In order to gain complementary information by transmission and scanning electron microscopy, the cell makes use of a Protochips E-chipTM which contains a small, thin electron transparent window and allows heating. Two gold-based systems, 50 nm gold particles and nanoporous gold as a relevant catalyst sample, were used for studying the feasibility of the cell. Measurements showing a resolution around 40 nm have been achieved under a flow of synthetic air and during heating up to temperatures of 933 K. An elevated temperature exhibited little influence on image quality and resolution. With this study, the potential of in situ hard X-ray ptychography for investigating annealing processes of real catalyst samples is demonstrated. Furthermore, the possibility to use the same sample holder for ex situ electron microscopy before and after the in situ study underlines the unique possibilities available with this combination of electron microscopy and X-ray microscopy on the same sample.
Colloidal suspensions are encountered in a multitude of natural, biological and industrially relevant products and processes. Understanding what affects the flow behaviour, or rheology, of colloid particles, and how these suspensions can be manipulated, is important for successful formulation of products such as paint, polymers, foods and pharmaceuticals. This book is the first devoted to the study of colloidal rheology in all its aspects. With material presented in an introductory manner, and complex mathematical derivations kept to a minimum, the reader will gain a strong grasp of the basic principles of colloid science and rheology. Beginning with purely hydrodynamic effects, the contributions of Brownian motion and interparticle forces are covered, before the reader is guided through specific problem areas, such as thixotropy and shear thickening; special classes of colloid suspensions are also treated. On line resources include: questions and solutions for self-study, updates, and links to further resources.