Thin Liquid Films

Thin Liquid Films PDF Author: Ralf Blossey
Publisher: Springer Science & Business Media
ISBN: 9400744552
Category : Science
Languages : en
Pages : 158

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Book Description
This book is a treatise on the thermodynamic and dynamic properties of thin liquid films at solid surfaces and, in particular, their rupture instabilities. For the quantitative study of these phenomena, polymer thin films (sometimes referred to as “ultrathin”) have proven to be an invaluable experimental model system. What is it that makes thin film instabilities special and interesting? First, thin polymeric films have an important range of applications. An understanding of their instabilities is therefore of practical relevance for the design of such films. The first chapter of the book intends to give a snapshot of current applications, and an outlook on promising future ones. Second, thin liquid films are an interdisciplinary research topic, which leads to a fairly heterogeneous community working on the topic. It justifies attempting to write a text which gives a coherent presentation of the field which researchers across their specialized communities might be interested in. Finally, thin liquid films are an interesting laboratory for a theorist to confront a well-established theory, hydrodynamics, with its limits. Thin films are therefore a field in which a highly fruitful exchange and collaboration exists between experimentalists and theorists. The book stretches from the more concrete to more abstract levels of study: we roughly progress from applications via theory and experiment to rigorous mathematical theory. For an experimental scientist, the book should serve as a reference and guide to what is the current consensus of the theoretical underpinnings of the field of thin film dynamics. Controversial problems on which such a consensus has not yet been reached are clearly indicated in the text, as well as discussed in a final chapter. From a theoretical point of view, the field of dewetting has mainly been treated in a mathematically ‘light’ yet elegant fashion, often making use of scaling arguments. For the untrained researcher, this approach is not always easy to follow. The present book attempts to bridge between the ‘light’ and the ‘rigorous’, always with the ambition to enhance insight and understanding - and to not let go the elegance of the theory.

Thin Liquid Films

Thin Liquid Films PDF Author: Ralf Blossey
Publisher: Springer Science & Business Media
ISBN: 9400744552
Category : Science
Languages : en
Pages : 158

Get Book Here

Book Description
This book is a treatise on the thermodynamic and dynamic properties of thin liquid films at solid surfaces and, in particular, their rupture instabilities. For the quantitative study of these phenomena, polymer thin films (sometimes referred to as “ultrathin”) have proven to be an invaluable experimental model system. What is it that makes thin film instabilities special and interesting? First, thin polymeric films have an important range of applications. An understanding of their instabilities is therefore of practical relevance for the design of such films. The first chapter of the book intends to give a snapshot of current applications, and an outlook on promising future ones. Second, thin liquid films are an interdisciplinary research topic, which leads to a fairly heterogeneous community working on the topic. It justifies attempting to write a text which gives a coherent presentation of the field which researchers across their specialized communities might be interested in. Finally, thin liquid films are an interesting laboratory for a theorist to confront a well-established theory, hydrodynamics, with its limits. Thin films are therefore a field in which a highly fruitful exchange and collaboration exists between experimentalists and theorists. The book stretches from the more concrete to more abstract levels of study: we roughly progress from applications via theory and experiment to rigorous mathematical theory. For an experimental scientist, the book should serve as a reference and guide to what is the current consensus of the theoretical underpinnings of the field of thin film dynamics. Controversial problems on which such a consensus has not yet been reached are clearly indicated in the text, as well as discussed in a final chapter. From a theoretical point of view, the field of dewetting has mainly been treated in a mathematically ‘light’ yet elegant fashion, often making use of scaling arguments. For the untrained researcher, this approach is not always easy to follow. The present book attempts to bridge between the ‘light’ and the ‘rigorous’, always with the ambition to enhance insight and understanding - and to not let go the elegance of the theory.

An Experimental Study of the Stability of Thin Liquid Films Flowing Down a Plane

An Experimental Study of the Stability of Thin Liquid Films Flowing Down a Plane PDF Author: William Bernard Krantz
Publisher:
ISBN:
Category :
Languages : en
Pages : 458

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Book Description


Experimental study of thin liquid films falling down a vertical surface

Experimental study of thin liquid films falling down a vertical surface PDF Author: Alexander Knaani
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Thin Liquid Films

Thin Liquid Films PDF Author: Ivan Ivanov
Publisher: Taylor & Francis
ISBN: 1351408194
Category : Science
Languages : en
Pages : 1152

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Book Description
This comprehensive reference provided a systematic examination of both the theory and applications of thin liquid films - giving a critical review of major concepts and unresolved or controversial problems, as well as revealing experimental methods. It includes results previously unpublished. Combining the work of 20 leading researchers, Thin Liquid Films furnishes a fundamental overview of thermodynamics of thin liquid films. Generously illustrated with equations, tables and drawling and containing more than 2,200 citations to pertinent literature, this is an authoritative reference for physical, surface, and colloid chemists, biophysicists and physicists; chemical engineers and advanced graduate students in chemistry, chemical engineering, biophysics and physics.

Studies on Thin Liquid Films

Studies on Thin Liquid Films PDF Author: Wilhelmus Aloisius Barbara Donners
Publisher:
ISBN:
Category :
Languages : en
Pages : 94

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Falling Liquid Films

Falling Liquid Films PDF Author: S. Kalliadasis
Publisher: Springer Science & Business Media
ISBN: 1848823673
Category : Mathematics
Languages : en
Pages : 446

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Book Description
Falling Liquid Films gives a detailed review of state-of-the-art theoretical, analytical and numerical methodologies, for the analysis of dissipative wave dynamics and pattern formation on the surface of a film falling down a planar inclined substrate. This prototype is an open-flow hydrodynamic instability, that represents an excellent paradigm for the study of complexity in active nonlinear media with energy supply, dissipation and dispersion. It will also be of use for a more general understanding of specific events characterizing the transition to spatio-temporal chaos and weak/dissipative turbulence. Particular emphasis is given to low-dimensional approximations for such flows through a hierarchy of modeling approaches, including equations of the boundary-layer type, averaged formulations based on weighted residuals approaches and long-wave expansions. Whenever possible the link between theory and experiment is illustrated, and, as a further bridge between the two, the development of order-of-magnitude estimates and scaling arguments is used to facilitate the understanding of basic, underlying physics. This monograph will appeal to advanced graduate students in applied mathematics, science or engineering undertaking research on interfacial fluid mechanics or studying fluid mechanics as part of their program. It will also be of use to researchers working on both applied, fundamental theoretical and experimental aspects of thin film flows, as well as engineers and technologists dealing with processes involving isothermal or heated films. This monograph is largely self-contained and no background on interfacial fluid mechanics is assumed.

Instabilities and Breakup in Thin Liquid Films

Instabilities and Breakup in Thin Liquid Films PDF Author: Vineeth Chandran Suja
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Liquid films having dimensions that are relatively small in the direction normal to their surface are commonly referred to as thin liquid films. Due to their prevalence in nature and due to their unique geometrical characteristics, a comprehensive understanding of thin film dynamics including instabilities and break-up within thin liquid films is of fundamental and practical interest. Practically this understanding is crucial to tuning the stability thin films in a number of important applications such as for stabilizing foams in foods and beverages, destabilizing foams in lubricants, avoiding surface irregularities in liquid coatings and treating ophthalmic disorders originating from the unnatural breakup of the tear film. Fundamentally, the microscopic thickness of these liquid films along with their large surface to volume ratio presents a convenient framework to investigate characteristics of two dimensional flows, and probe the effects of surface phenomenon such as evaporation and surfactant dynamics on fluid flows. Motivated by the importance of thin liquid films, in this thesis, we experimentally investigate the instabilities and break-up within thin liquid films. In the first part of the thesis (Chapters 2 - 4), we develop and optimize experimental tools and protocols for systematically studying thin liquid films. Notably, we show that single bubble/drop experiments are a convenient and complementary technique to study the dynamics of thin liquid films. Subsequently, we detail a new technique for automatically and robustly measuring the spatiotemporal thickness of thin liquid films - hyperspectral interferometry coupled with machine learning. Finally, we will also establish the operating regimes within which the size of bubbles formed on capillaries for single bubble experiments can be precisely controlled to avoid an air compressibility driven shape instabilities. In the subsequent parts of the thesis we utilize the developed tools to study four different problems - Bubble stability in worm like micellar (WLM) polymer solutions (Chapter 5), Lubricant foaming (Chapters 6 - 8), Drying of thin polymer films (Chapter 9) and Dewetting of the tear film (Chapter 10). In Chapter 5, we explore a problem relevant for the cosmetic industry, and characterize the drainage characteristics of thin films between bubbles and flat wormlike micellar solution - air interfaces. The supramolecular structure and elasticity of the wormlike micelles alters the dynamics of film drainage in WLM as compared to those in thin films containing pure surfactants. The unique features of film drainage include film elasticity driven 'dimple recoil' and a single step transition to a Newton black film beyond a critical film thickness. In Chapters 6 - 8, we explore a problem relevant for the lubricant industry, and study the stability of thin liquid films in lubricants with and without antifoams. Utilizing single bubble experiments, we reveal that the stability of thin films between bubbles in lubricant base oils are enhanced by Marangoni flows driven by the differential evaporation of the various components in the oil. Fundamentally, we also show that the spatiotemporal characteristics of these Marangoni flows are regulated by the concentration and volatility of the volatile species in the oil. Interestingly when the concentration of the volatile species approaches 50%, evaporation driven Marangoni flows become chaotic, with disordered spatial structure, chaotic fluctuations, spatially invariant mean film thickness statistics, high sensitivity to initial conditions, rapidly decaying spatial correlation and a power spectrum for thickness fluctuation that obeys a power law scaling that closely resembles the Kolmogorov's -5/3rd scaling. In the presence of filtered lubricants with antifoams, we reveal that the stability of thin films are positively correlated to the number of filtration cycles, and inversely correlated to the nominal filter pore size and the initial antifoam concentration. In Chapter 9 we explore a problem relevant for film coating, and study the drying of aqueous polymer solutions. Depending on the polymer concentration and the polymer diffusivities, we show that a classical Rayleigh-Taylor instability can develop within the drying solution. We also present the scaling laws describing the onset time of the instability as a function of the physical properties and initial polymer concentrations of the solutions. In Chapter 10 we report a platform to characterize the thickness of the tear film in vivo. By qualitatively comparing the dewetting characteristics observed in vivo with in vitro experiments, we will show that the mechanisms of dewetting is influenced by the presence of interfacial rheology. Further we also reveal that the spatial locations that are prone to dewetting are determined by the presence of interfacial rheology and the spatiotemporal drainage characteristics of the tear film. In Chapter 11 we summarize the findings in this thesis and discuss a number of interesting venues for future research.

Light Scattering Studies on Thin Liquid Films

Light Scattering Studies on Thin Liquid Films PDF Author: J. G. H. Joosten
Publisher:
ISBN:
Category :
Languages : en
Pages : 208

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The Characteristics of a Thin Liquid Film on a Spinning Disk

The Characteristics of a Thin Liquid Film on a Spinning Disk PDF Author: Carl Gazley
Publisher:
ISBN:
Category : Liquid films
Languages : en
Pages : 374

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Book Description
An experimental study of thin liquid films on a spinning disk is described. Such films are characterized by large values of the ratio of interfacial area to liquid volume, can be formed in very small equipment compared to falling films, and their development is independent of surface orientation to the gravitational field. This makes them interesting for a number of energy and mass transfer processes. The paper summarizes the available numerical and analytical studies of the fluid-mechanical characteristics of spinning films and presents measurements of average film thickness as a function of radial position, liquid flow rate, and rotational speed. In spite of surface-tension phenomena (waves, dry spots, etc.) not accounted for in the theoretical study, the data indicate that the theory predicts the proper relative effects of the several variables. (Author).

A Kinematic Study of the Splitting of Thin Liquid Films

A Kinematic Study of the Splitting of Thin Liquid Films PDF Author: John Clark Miller
Publisher:
ISBN:
Category : Fluids
Languages : en
Pages : 107

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Book Description