Columnar Structures of Spheres: Fundamentals and Applications

Columnar structures, many of which are helical, refer to dense cylindrical packings of particles. They are ubiquitous, that is, they exist in the contexts of botany, foams, and nanoscience. There have been in-depth investigations of columnar structures of both hard spheres, such as ball bearings, and soft spheres, such as wet foams, through computer simulations, analytic calculations, and simple experiments. This book serves as a comprehensive guide for scientists, engineers, and artists who would like to have a good grasp of the fundamentals and applications of such aesthetically appealing structures for their own professional interests. The book begins with an introduction to the field of packing problems, where such problems are closely related not only to the columnar structures presented in the book but also to the structures of condensed matter systems in general. It then discusses about columnar structures of spheres and overviews their classifications and applications. It reviews the models and concepts employed in the authors’ studies on columnar structures of spheres. It also details the method of sequential deposition for generating columnar structures of hard spheres computationally or experimentally. Lastly, it presents some latest findings on the columnar structures of soft spheres and on the structures obtained from the longitudinal compression of a hard-sphere chain in a cylindrical harmonic potential.

Table of Contents:
1. An Introduction to Packing Problems 2. An Introduction to Columnar Structures 3. Models and Concepts for Columnar Structures 4. Packing by Sequential Deposition 5. Soft-Sphere Packings in Cylinders 6. Rotational Columnar Structures of Soft Spheres 7. Hard-Sphere Chains in a Cylindrical Harmonic Potential 8. Summary and Outlook Appendix A: Tabulated Hard-Sphere Results Appendix B: Minimization Routines Appendix C: Energies of (l,l,0) Structures

About the Author :
Jens Winkelmann is associated with the digitalization-in-mining industry and currently working as a data scientist at talpasolutions GmbH, Essen, Germany. He completed his BSc and MSc, both in physics, from Technische Universität Dortmund, Germany, in 2013 and 2015, respectively. In 2019, he earned his PhD in physics on the topic "Structures of columnar packings with soft and hard spheres" under the supervision of Prof. Stefan Hutzler at the Foams and Complex Systems Research Group of Trinity College Dublin, Ireland. Dr. Winkelmann has authored a good number of peer-reviewed scientific papers on the subjects of packing problems and, more generally, soft matter physics. Ho-Kei Chan is an associate professor of physics at the School of Science of the Harbin Institute of Technology, Shenzhen, China. He completed his BSc in engineering physics in 2002 from the Hong Kong Polytechnic University and his PhD in nonlinear and liquid crystal physics in 2007 from the University of Manchester, UK, followed by research appointments at the Hong Kong Baptist University, China; Trinity College Dublin, Ireland; and the University of Nottingham, UK. He has published peer-reviewed scientific papers in various fields such as statistical, nonlinear, and soft matter physics, including packing problems, conduction and diffusion, crystal growth, and electrostatics.