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Statistical Mechanics
Published in Marc J. Assael, Geoffrey C. Maitland, Thomas Maskow, Urs von Stockar, William A. Wakeham, Stefan Will, Commonly Asked Questions in Thermodynamics, 2022
Marc J. Assael, Geoffrey C. Maitland, Thomas Maskow, Urs von Stockar, William A. Wakeham, Stefan Will
Capillary action or wicking is the ability of a porous substance to draw another liquid substance into it. A common example is the tubes in the stems of plants, but this can also be seen readily with porous paper. Capillary action occurs when the attractive intermolecular forces between the liquid at a surface and (usually) a solid substance are stronger than the cohesive intermolecular forces in the bulk of the liquid. If the solid surface is vertical, the liquid “climbs” the wall made by the solid and a concave meniscus forms on the liquid surface.
The Basic Concept for Microfluidics-Based Devices
Published in Raju Khan, Chetna Dhand, S. K. Sanghi, Shabi Thankaraj Salammal, A. B. P. Mishra, Advanced Microfluidics-Based Point-of-Care Diagnostics, 2022
At the liquid–air interface, the process of surface tension comes into play in order to minimize the surface energy, thus forming a droplet. There is an occurrence of capillary action when the surface adhesive forces of capillary and liquid are greater than the forces of cohesion between liquid molecules. Thus, the height attained by the capillary action is strongly influenced by factors such as gravity and surface tension.
Flexible Microfluidics Biosensor Technology
Published in Suman Lata Tripathi, Parvej Ahmad Alvi, Umashankar Subramaniam, Electrical and Electronic Devices, Circuits and Materials, 2021
Supriya Yadav, Mahesh Kumar, Kulwant Singh, Niti Nipun Sharma, Jamil Akhtar
Transport of fluid flow plays a vital role in microfluidic system and affects the results as well. Fluid flows in paper or any other porous materials through capillary force [26]. Capillary action is the ability of flow of liquid in a fine area from a micro-meter scale without using any external force like gravitational force, for example, water between hairs of paint brush, in paper napkin, and in biological cell. It occurs between the intermolecular forces of liquid molecule and the surrounding solid and vapor surfaces. It means it occurs on the liquid–solid–vapor interface.
Optimization and surface modification of silk fabric using DBD air plasma for improving wicking properties
Published in The Journal of The Textile Institute, 2018
K. Vinisha Rani, Nisha Chandwani, Purvi Kikani, S. K. Nema, Arun Kumar Sarma, Bornali Sarma
Silk is a textile fiber suitably known as the ‘Queen of Textiles’ for its grandeur, luxury appeal, comfort, and elegance. Silk is a filament fiber from the cocoon of silkworm (Arindam Basu, 2015). Silk is natural polymer consisting of repetitive hydrophobic and hydrophilic peptide sequences (Saranga, Bijit, Rupjyoti, Rangam, & Dipali, 2013). Silk has poor wetting properties (Pimanpang, Wang, Senkevich, Wang, & Lu, 2006). Wettability is important for characterizing liquid transport, fiber surfaces and adhesion with a polymer (Wong, Tao, Yuen, & Yeung, 2001). Wicking is the capillary action of fluids that allows a liquid to flow through tight spaces, even against gravity. Wetting is a prerequisite for wicking (Patnaik, Rengasamy, Kothari, & Ghosh, 2006). If a liquid does not wet fibers, it cannot wick into a fabric. Wicking and wetting are two interrelated processes. The ability of the fabric to wick depends on the surface properties of the constituent fibers, thickness, and their total surface area. Wetting and wicking are significant properties of textile and have a great industrial importance for many operations viz., scouring, dyeing, and finishing. By changing the chemical composition of the fibrous material, it can modify its overall surface wetting properties. It has been reported that the hydrophilicity of the silk fabric is drastically improved by being pre-treated with amine solutions, such as serine, glycine, and aspartic acid (Phattanarudee, Chakvattanatham, & Kiatkamjornwong, 2009).
Application of machine learning-based approach in food drying: opportunities and challenges
Published in Drying Technology, 2022
Md. Imran H. Khan, Shyam S. Sablani, M. U. H. Joardder, M. A. Karim
Diffusivity is one of the most important required transport properties of food materials to address the moisture transport phenomena for mathematical modeling of food drying. There are two types of diffusion: binary diffusion and capillary diffusion that occurs during food drying. Binary diffusion is defined as the movement of gas (vapor or air) concentrations from higher concentration region to lower concentration region in multiphase porous media like food materials.[39] Capillary diffusion is defined as the process of diffusion that happens due to the capillary action of the liquid. Capillary action is a result of surface tension that occurs when the liquid and the other surface come in contact with each other. The binary diffusion phenomenon is used for liquid transport in case of multiphase transport modeling. Many researchers attempted to use artificial neural network-based predictive approach to determine the diffusivity of various materials including plant-based food materials[62–64] and building materials such as concrete,[65] foamed polystyrene insulating material,[66] hydrocarbons and aromatics,[67] and other building materials.[68,69] Limited study has been conducted for food materials during drying. Mariani et al.[63] developed a new approach for the estimation of apparent diffusivity of banana at different drying temperatures using ANN-based inverse method. They found that the diffusivity of banana can change from 1.88 × 10−7 (m2/s) to 2.49 × 10−10 (m2/s). A small change in the drying temperature and moisture content of banana cause a significant change in this diffusivity value.[63]