History of thought on molecular origins of surface phenomena offers a critical and detailed examination and assessment of modern theories, focusing on statistical mechanics and application of results in mean-field approximation to model systems. Emphasis on liquid-gas surface, with a focus on liquid-liquid surfaces in the final chapters. 1989 edition.

History of surface phenomena offers critical and detailed examination and assessment of modern theories, focusing on statistical mechanics and application of results in mean-field approximation to model systems. 1989 edition.

135 We first describe the thermodynamic theory of surface tension and adsorption, by the method of the dividing surface of GIBBS. The use of a dividing surface or its equivalent is indispensable for the treatment of a curved interface, as otherwise the concepts of the area and curvature of the interface, cannot be pre cisely defined. In the case of a plane interface, however, the concept of the dividing surface is not necessary and a valid alternative exposition has been proposed by GUGGEN HEIM [3J, [4J in treating the interface zone as a separate entity of some definite thickness bounded by two mathematical planes. We make, however, little mention of this method, since it seems to be of only minor importance in connec tion with the statistical treatment of an interface. To avoid any ambiguity, the treatment of a spherical interface given in this article is based not on the original method of GIBBS but on the method modified by HILL [8J and KONDO [9]. This method, however, is not applicable to non spherical interfaces, which will not be dealt with in this article. Although all the relations for a plane interface can be deduced from the cor responding ones for a spherical interface by putting the curvature equal to zero, the planar and the spherical cases are considered separately because of the prac tical importance and easy physical visualization of a plane interface.

An essential cross-disciplinary reference for molecular interactions Molecular Theory of Gases and Liquids offers a rigorous, comprehensive treatment of molecular characteristics and behaviors in the gaseous and fluid states. A unique cross-disciplinary approach provides useful insight for students of chemistry, chemical engineering, fluid dynamics, and a variety of related fields, with thorough derivations and in-depth explanations throughout. Appropriate for graduate students and working scientists alike, this book details advanced concepts without sacrificing depth of coverage or technical detail.

Open microfluidics, the study of microflows having a boundary with surrounding air, encompasses different aspects such as paper or thread-based microfluidics, droplet microfluidics and open-channel microfluidics. Open-channel microflow is a flow at the micro-scale, guided by solid structures, and having at least a free boundary (with air or vapor) other than the advancing meniscus. This book is devoted to the study of open-channel microfluidics which (contrary to paper or thread or droplet microfluidics) is still very sparsely documented, but bears many new applications in biology, biotechnology, medicine, material and space sciences. Capillarity being the principal force triggering an open microflow, the principles of capillarity are first recalled. The onset of open-channel microflow is next analyzed and the fundamental notion of generalized Cassie angle (the apparent contact angle which accounts for the presence of air) is presented. The theory of the dynamics of open-channel microflows is then developed, using the notion of averaged friction length which accounts for the presence of air along the boundaries of the flow domain. Different channel morphologies are studied and geometrical features such as valves and capillary pumps are examined. An introduction to two-phase open-channel microflows is also presented showing that immiscible plugs can be transported by an open-channel flow. Finally, a selection of interesting applications in the domains of space, materials, medicine and biology is presented, showing the potentialities of open-channel microfluidics.