Download or read book The Effects of Particle Anisotropy on the Rheology and Microstructure of Concentrated Colloidal Suspensions Through the Shear Thickening Transition written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Though suspensions comprised of anisotropic particles are ubiquitous in industry, little has been done to elucidate the effects of particle anisotropy on concentrated suspension rheology, or the mechanism responsible for the reversible shear thickening observed in these systems. This dissertation explores the rheology and shear-induced microstructure of anisotropic particle suspensions through the shear thickening transition, and provides the first account of anisotropic particle alignment during shear thickening. For this investigation, Poly(ethylene glycol) (PEG)-based suspensions of acicular precipitated calcium carbonate (PCC) particles of varying particle aspect ratio (nominal L/D & sim; 2, 4, 7) are generated that demonstrate both continuous and discontinuous reversible shear thickening with increasing applied shear rate or stress. The critical volume fraction for the onset of discontinuous shear thickening decreases as the average particle aspect ratio is increased. However, the critical stress for shear thickening is found to be independent of particle anisotropy and volume fraction, and can be predicted based on the minor axis dimension of the particles in agreement with the critical stress scaling for hard-sphere suspensions. Small angle neutron scattering during shear flow (Rheo-SANS) demonstrates that long-axis particle alignment with the flow direction is maintained throughout the range of shear stresses investigated, including the shear thickening regimes for both continuous and discontinuous shear thickening PCC/PEG suspensions. Investigations of particle flow alignment following flow cessation provide evidence that the critical volume fraction for shear thickening may be associated with an isotropic-nematic transition within the anisotropic particle suspensions. Rheo-SANS investigations of concentrated kaolin clay suspensions demonstrate that disk-shaped particles exhibit particle alignment with the face surfaces orthogonal to the gradient direction during both continuous and discontinuous shear thickening. The critical stress at the onset of shear thickening for discontinuous shear thickening clay suspensions is observed to scale with the particle thickness dimension. The rheology and Rheo-SANS observations for both the acicular PCC and disk-like kaolin clay suspensions invalidate earlier hypothesis suggesting that shear thickening behavior in anisotropic particle dispersions results from increased particle rotations out of flow alignment potentially leading to particle jamming. Rather, the observations suggest that shear thickening in anisotropic particle suspensions is a consequence of short range hydrodynamic lubrication forces resulting in the formation of hydroclusters at higher shear rates, analogous to the behavior established for spherical particle suspensions. Lastly, anisotropic particle suspensions are used to successfully develop of shear thickening fluid (STF)/ballistic fabric composites. Shape anisotropy imparts the advantage of lower solids loading required to achieve energy dissipative improvements compared to spherical particle STFs. The observed improvements in ballistic and stab resistance response of these composites over that of ballistic fabrics alone suggests that they could potentially be used in the development of personal body armors with improved, multi-threat protective capabilities.
Download or read book Colloidal Suspension Rheology written by Jan Mewis and published by Cambridge University Press. This book was released on 2012 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented in an accessible and introductory manner, this is the first book devoted to the comprehensive study of colloidal suspensions.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theory and Applications of Colloidal Suspension Rheology written by Norman J. Wagner and published by Cambridge University Press. This book was released on 2021-04-15 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Essential text on the practical application and theory of colloidal suspension rheology, written by an international coalition of experts.
Download or read book The Effects of Concentration Interaction Size Distribution and Shape Anisotropy on Rheology of Colloidal Mixtures written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microstructure and Rheology of Concentrated Colloidal Suspensions with Varying Nanotribological Interactions written by Yu-Fan Lee and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is divided into two research aims: The first aim, presented in Chapters 3 and 4, is to test the theoretical framework of friction contact models with rheological and nanotribological measurements on model suspensions with controlled surface properties. In Chapter 3, we first present comprehensive experimental tests of a friction contact model based on correlating simulation results against rheological measurements for both model and industrial colloidal dispersions complemented by independent estimates of the particle-scale friction coefficients from literature surveys. The comparisons emphasize the sensitivity of the first normal stress difference can distinguish between states of shear thickening dominated by hydrodynamic friction or contact friction. Based on the findings in Chapter 3, a systematic exploration of nanotribological measurements using lateral force microscopy (LFM) is presented in Chapter 4. Our systematic studies qualitatively agree with the Stribeck relationship regardless of the solvent environment. It is also confirmed that the friction coefficient obtained from the bulk rheology lies in the high Sommerfeld number regime, suggesting that directly applying the friction coefficient obtained from the nanotribological measurements for predicting the rheology using the friction contact model is not quantitative.
Download or read book Product Design and Engineering written by Ulrich Bröckel and published by John Wiley & Sons. This book was released on 2013-08-02 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the whole value chain - from product requirements and properties via process technologies and equipment to real-world applications - this reference represents a comprehensive overview of the topic. The editors and majority of the authors are members of the European Federation of Chemical Engineering, with backgrounds from academia as well as industry. Therefore, this multifaceted area is highlighted from different angles: essential physico-chemical background, latest measurement and prediction techniques, and numerous applications from cosmetic up to food industry. Recommended reading for process, pharma and chemical engineers, chemists in industry, and those working in the pharmaceutical, food, cosmetics, dyes and pigments industries.
Download or read book Microstructure and Rheology of Concentrated Suspensions of Near Hard sphere Colloids written by Dennis P. Kalman and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The relationship between colloidal suspension microstructure and rheology is investigated to provide a solid understanding of the nonlinear rheology of concentrated suspensions, with a focus on shear thickening. These suspensions are also studied as a treatment to woven fabric in body-armor applications, where the insight from microstructural measurements is used to attempt to improve the application. The colloid and suspension properties are characterized via SEM, DLS, SANS, USANS, and rheometry. The rheology is mapped onto an effective hard-sphere model with the addition of a yield stress. An additional excluded volume shell, as measured by SANS and USANS structural measurements, accounts for interparticle interactions due to surface forces arising from the stabilizing layer on the particles. The microstructure of these near hard-sphere concentrated, shear-thickening colloidal dispersions are measured via SANS and USANS as a function of volume fraction, shear rate, and particle size. Special Rheo-SANS, flow-SANS, and flow-USANS instruments are developed and validated to measure microstructure in flowing systems. Structures measured via USANS show a cluster peak that arises from hydrocluster formation in concentrated, shear thickening suspensions. Structure measurements in SANS via 1-d averaged analysis and analysis of the 2-d structure corresponds to that expected from Stokesian Dynamics simulations. Micromechanics theory via a Stress-SANS law is used to calculate rheology from the microstructure for comparison. As the rheology calculated from the SANS data qualitatively agrees with that of the suspension and the structures seen correspond to those expected from simulations, strong confirmation of the hydrocluster mechanism for shear thickening is observed. This improved knowledge of the hydrocluster structure is used to develop an elastohydrodynamic theory for the limiting viscosity at high shear stresses due to particle deformations in the hydrocluster. Measurements of particle modulus give consistent application of this elastohydrodynamic model to suspensions studied in this thesis. In addition, the model is applied to widely varying suspensions, including those of hard mineral particles, polymer particles, microgels, and emulsions and consistent results are seen. The results of these fundamental studies of how particle size, concentration, and hardness affect suspension microstructure and rheology are used to engineer shear thickening fluid treated textiles, suitable for various types of protective devices.
Download or read book Rheology and Microstructure of Concentrated Near Hard Sphere Colloidal Dispersions at the Shear Thickening Transition written by Brent J. Maranzano and published by . This book was released on 2001 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wormlike Micelles written by Cecile A Dreiss and published by Royal Society of Chemistry. This book was released on 2017-03-21 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wormlike Micelles describes the latest developments in the field including new systems, characterization and applications.
Download or read book Theory and Applications of Colloidal Suspension Rheology written by Norman J. Wagner and published by Cambridge University Press. This book was released on 2021-04-15 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Granular Media written by Bruno Andreotti and published by Cambridge University Press. This book was released on 2013-06-13 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides the state-of-the-art of the physics of granular media for graduate students and researchers in physics, applied mathematics and engineering.
Download or read book Boundary Effects and Shear Thickening of Colloidal Suspensions A Study Based on Measurement of Suspension Microstructure written by M.Tharanga D. Perera and published by . This book was released on 2014 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: The confocal microscopy technique also provides us with the advantage of measuring structure in real process flows. We have investigated how the microstructure evolves upstream and downstream in a porous medium. We notice more structure in a high volume fraction suspension and notice anisotropic behavior at regions where shear from the wall of the posts dominate. In other cases, a mixed flow behavior is observed due to collisions between pore surfaces and other particles resulting in a deviation from flow streamlines.
Download or read book Rheology and Microstructure of Concentrated Suspensions of Plate Shaped Colloidal Particles written by Suzanne Michelle Jogun and published by . This book was released on 1998 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1990 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Structure and Rheology of Complex Fluids written by Ronald G. Larson and published by OUP USA. This book was released on 1999-01-28 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Structure and Rheology of Complex Fluids describes the microstructures of polymeric, colloidal, amphiphilic, and liquid crystalline liquids, and the relationship between microstructure and mechanical and flow properties. It provides illustrations, practical examples, and worked problems. This book can serve as both a textbook for a graduate course and a research monograph.
Download or read book Magnetorheology written by Norman Wereley and published by Royal Society of Chemistry. This book was released on 2014 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leading experts provide a timely overview of the key developments in the physics, chemistry and uses of magnetorheological fluids.
