Surfactants are extensively used in many chemical products to improve their stability, appearance, texture, and rheology. Precise control of the emulsion droplet size distribution, which depends on the characteristics...Surfactants are extensively used in many chemical products to improve their stability, appearance, texture, and rheology. Precise control of the emulsion droplet size distribution, which depends on the characteristics of the surfactant used, is important for target-oriented product design. A complete understand! ng of the structures and dynamics of emulsion droplets at the reactor level requires coupling of two mesoscale physical constraints, that at the interfacial level, i.e., smaller than a single droplet (Mesoscale- 1), and that at the device level, i.e., larger than a single droplet (Mesoscale-2). In this work, the structures and adsorption kinetics of Mesoscale-1 surfactant molecules were studied via coarse-grained molecular dynamics. A non-equilibrium model that could introduce stable shear flow into the simulation box was used to investigate the interfacial structures at the droplet interface under different shear rates. The configurations of the surfactant molecules and adsorption amounts were compared with those obtained without flow. The adsorption kinetics for different shear rates were compared to determine the effects of hydrodynamic interactions. The dominant mechanisms governing the dynamic structures can thus be summarized as maximization of the adsorption density at the interface and minimization of flow resistance in the bulk phase (water and/or oil molecules). A scheme for coupling between Mesoscale-1 and Mesoscale-2 is proposed. This method is promising for the incorporation of interfacial structure effects into the hydrodynamics at the reactor device level for the manipulation of chemical products.展开更多
The inter national conference Formula IX was held on 15-18 October, 2017 in Beijing, China, organized by Institute of Process Engineering of Chinese Academy of Sciences and Chinese Society of Particuology. This specia...The inter national conference Formula IX was held on 15-18 October, 2017 in Beijing, China, organized by Institute of Process Engineering of Chinese Academy of Sciences and Chinese Society of Particuology. This special issue “Particles Meet Formulation” in Particuology integrates selected papers of this conference contributing to multiscale approaches for description of formulation processes and complex targeted properties, aiming to reflect the state of art and cutting-edge tech no logies in this field.展开更多
The history of Formula conferences was summarized with a particular focus on Formula I and Formula Ⅸ (the first and last conferences of the series).The foundation of formulation during the middle of the 1980s by peop...The history of Formula conferences was summarized with a particular focus on Formula I and Formula Ⅸ (the first and last conferences of the series).The foundation of formulation during the middle of the 1980s by people from academia and industry in the fields of chemistry and chemical engineering was briefly overviewed.The current trends in formulation as well as in product engineering were listed.展开更多
基金This work was supported by the National Natural Science Foundation of China on the Mesoscience Program (No. 91434104)the Research Center for Mesoscience at the Institute of Process Engineering, Chinese Academy of Sciences (COM2015A005)+1 种基金Chinese Academy of Sciences (XXH13506-301)the Open Research Fund of State Key Laboratory of Multiphase Complex Systems (No. MPCS-2017-D-01).
文摘Surfactants are extensively used in many chemical products to improve their stability, appearance, texture, and rheology. Precise control of the emulsion droplet size distribution, which depends on the characteristics of the surfactant used, is important for target-oriented product design. A complete understand! ng of the structures and dynamics of emulsion droplets at the reactor level requires coupling of two mesoscale physical constraints, that at the interfacial level, i.e., smaller than a single droplet (Mesoscale- 1), and that at the device level, i.e., larger than a single droplet (Mesoscale-2). In this work, the structures and adsorption kinetics of Mesoscale-1 surfactant molecules were studied via coarse-grained molecular dynamics. A non-equilibrium model that could introduce stable shear flow into the simulation box was used to investigate the interfacial structures at the droplet interface under different shear rates. The configurations of the surfactant molecules and adsorption amounts were compared with those obtained without flow. The adsorption kinetics for different shear rates were compared to determine the effects of hydrodynamic interactions. The dominant mechanisms governing the dynamic structures can thus be summarized as maximization of the adsorption density at the interface and minimization of flow resistance in the bulk phase (water and/or oil molecules). A scheme for coupling between Mesoscale-1 and Mesoscale-2 is proposed. This method is promising for the incorporation of interfacial structure effects into the hydrodynamics at the reactor device level for the manipulation of chemical products.
文摘The inter national conference Formula IX was held on 15-18 October, 2017 in Beijing, China, organized by Institute of Process Engineering of Chinese Academy of Sciences and Chinese Society of Particuology. This special issue “Particles Meet Formulation” in Particuology integrates selected papers of this conference contributing to multiscale approaches for description of formulation processes and complex targeted properties, aiming to reflect the state of art and cutting-edge tech no logies in this field.
文摘The history of Formula conferences was summarized with a particular focus on Formula I and Formula Ⅸ (the first and last conferences of the series).The foundation of formulation during the middle of the 1980s by people from academia and industry in the fields of chemistry and chemical engineering was briefly overviewed.The current trends in formulation as well as in product engineering were listed.
