China
Africa
Explore chapters and articles related to this topic
Powdered Pressure-Sensitive Adhesives Developed Based on Biomimetics
Published in Akihiro Miyauchi, Masatsugu Shimomura, Biomimetics, 2023
Syuji Fujii, Shin-ichi Akimoto
Liquid droplets stabilized by solid particles adsorbed at the gas-liquid interface are called liquid marbles (liquid-in-gas type dispersion system), and have diameters in sub-millimeter to centimeter range [9–14]. The driving force for adsorption of particles at the gas-liquid interface is surface free energy. This is because the state in which the particles are adsorbed at the interface is energetically more stable than that in which the particles are not adsorbed at the interface (particles are in gas phase). To fabricate liquid marbles, no electrical power and magnetic field are required; therefore, autonomous energy-saving manufacturing is possible based on the liquid marble technology. Fabrication technology of liquid marbles gives us a chance to re-examine current heteronomous methods of energy-consuming manufacturing under a gravitational force. Thanks to the solid particles adsorbed on the surface of the liquid marbles, the inner liquid does not spread with wetting of the substrate but rolls on it, and the liquid can be taken out by applying external stress.
Sticking and Non-sticking Drops
Published in Andrew Terhemen Tyowua, Liquid Marbles, 2018
It has been shown (Aussillous and Quéré 2001, 2006, Quéré and Aussillous 2002), experimentally, that hydrophobic powdered particles can spread over water creating a surface film, in contrast to the long-held knowledge that liquids spread on solids (but not the other way round). Their pioneering work has intrigued and formed the basis of liquid marble research. Liquid marbles (Figure 3.7) are nonstick millimetre-sized liquid-in-air drops, encapsulated by microparticles or nanoparticles, which demonstrate very low friction when rolling on solid substrates (Aussillous and Quéré 2001, 2006, Quéré and Aussillous 2002, Vella et al. 2004). The particles, which are either hydrophobic, oleophobic, superhydrophobic, superoleophobic, or omniphobic depending on the liquid, poorly wet the liquid drop and protrude largely into the air phase. Liquid marbles are separated from a solid or liquid support by air pockets, similar to Leidenfrost drops, and this accounts for their inherent non-Amontonian friction.
Foaming honey: particle or molecular foaming agent?
Published in Journal of Dispersion Science and Technology, 2022
Andrew T. Tyowua, Adebukola M. Echendu, Stephen G. Yiase, Sylvester O. Adejo, Luter Leke, Emmanuel M. Mbawuaga, Bernard P. Binks
The particle immersion test (placing particles on a liquid surface) gives a qualitative measure of the degree to which a given liquid wets powdered particles. For example, hydrophilic particles immerse easily in water while the hydrophobic ones do not and remain on the surface of water. This is also the case with oleophilic and oleophobic particles on oil surfaces, where the oleophilic ones immerse easily in oil while the oleophobic ones do not and remain on their surface.[28,29] When aerated, foams are obtained in liquids containing hydrophobic or oleophobic particles of suitable wettability, while particle dispersions result in those with hydrophilic or oleophilic particles.[28,29] Placing a liquid drop on a particle bed is the opposite of the particle immersion test and also gives a qualitative measure of the degree to which a liquid wets a given powdered particle. In this case, so-called liquid marbles are formed when the particles are poorly wetted (hydrophobic or oleophobic) by the liquid drop, but the liquid drop simply sinks into the particle bed if the liquid wets the particles (hydrophilic or oleophilic).[28,29]