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Håkansson A, Nilsson L. Emulsifier adsorption kinetics influences drop deformation and breakup in turbulent emulsification. SOFT MATTER 2023; 19:9059-9073. [PMID: 37982600 DOI: 10.1039/d3sm01213a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
Turbulent drop breakup is of large importance for applications such as food and pharmaceutical processing, as well as of substantial fundamental scientific interest. Emulsification typically takes place in the presence of surface-active emulsifiers (natural occurring and/or added). Under equilibrium conditions, these lower the interfacial tension, enabling deformation and breakup. However, turbulent deformation is fast in relation to emulsifier kinetics. Little is known about the details of how the emulsifier influences drop deformation under turbulent conditions. During the last years, significant insight in the mechanism of turbulent drop breakup has been reached using numerical experiments. However, these studies typically use a highly simplistic description of how the interface responds to turbulent stress. This study investigates how the limited exchange rate of emulsifier between the bulk and the interface influences the deformation process in turbulent drop breakup for application-relevant emulsifiers and concentrations, in the context of state-of-the-art single drop breakup simulations. In conclusion, if the Weber number is high or the emulsifier is supplied at a concentration giving an adsorption time less than 1/10th of the drop breakup time, deformation proceeds as if the emulsifier adsorbed infinitely fast. Otherwise, the limited emulsifier kinetics delays breakup and can alter the breakup mechanism.
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Affiliation(s)
- Andreas Håkansson
- Department of Food Technology, Engineering and Nutrition, Lund University, Sweden.
| | - Lars Nilsson
- Department of Food Technology, Engineering and Nutrition, Lund University, Sweden.
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Interfacial properties of milk proteins: A review. Adv Colloid Interface Sci 2021; 295:102347. [PMID: 33541692 DOI: 10.1016/j.cis.2020.102347] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 12/14/2020] [Accepted: 12/14/2020] [Indexed: 12/22/2022]
Abstract
The interfacial properties of dairy proteins are of great interest to the food industry. Food manufacturing involves various environmental conditions and multiple processes that significantly alter the structure and colloidal stability of food materials. The effects of concentration, pH, heat treatment, addition of salts etc., have considerable influence on the surface activity of proteins and the mechanical properties of the interfacial protein films. Studies to date have established some understanding of the links between environmental and processing related parameters and their impacts on interfacial behavior. Improvement in knowledge may allow better design of interfacial protein structures for different food applications. This review examines the effects of environmental and processing conditions on the interfacial properties of dairy proteins with emphasis on interfacial tension dynamics, dilatational and surface shear rheological properties. The most commonly used surface analytical techniques along with relevant methods are also addressed.
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Fang Y, Li Y, Zhou F, Gu P, Liu J, Chen D, Li N, Xu Q, Lu J. An Efficient Photocatalyst Based on Black TiO 2 Nanoparticles and Porous Carbon with High Surface Area: Degradation of Antibiotics and Organic Pollutants in Water. Chempluschem 2020; 84:474-480. [PMID: 31943905 DOI: 10.1002/cplu.201900103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/16/2019] [Indexed: 11/10/2022]
Abstract
Porous carbon (PC) materials with high surface area can separate electron-hole pairs and adsorb organic pollutants more effectively. A series of nanocomposites were prepared by anchoring black TiO2 nanoparticles (BTN) onto PC through a calcination process. Chemical and structural features of samples were examined by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, powder X-ray diffraction (P-XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The resulting adsorption-photocatalysis synergistic effect led to a dramatically improved photocurrent for BTN@PCs, thus indicating the high photocatalytic performance toward water-soluble organic species. For instance, the degradation of tetracycline under visible light reached 90 %, which is higher than that for activated carbon doped onto BTN (57 %) without any additional agents. Moreover, the degradation of other antibiotics (such as oxytetracycline and ciprofloxacin) and methylene blue were also studied, thus showing that this system has the potential to be used for water treatment.
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Affiliation(s)
- Yu Fang
- Collaborative Innovation Center of Suzhou Nano Science and Technology College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou, 215123, P.R. China
| | - Yuanyuan Li
- Collaborative Innovation Center of Suzhou Nano Science and Technology College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou, 215123, P.R. China
| | - Feng Zhou
- Collaborative Innovation Center of Suzhou Nano Science and Technology College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou, 215123, P.R. China
| | - Peiyang Gu
- Collaborative Innovation Center of Suzhou Nano Science and Technology College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou, 215123, P.R. China
| | - Jiadi Liu
- Collaborative Innovation Center of Suzhou Nano Science and Technology College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou, 215123, P.R. China
| | - Dongyun Chen
- Collaborative Innovation Center of Suzhou Nano Science and Technology College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou, 215123, P.R. China
| | - Najun Li
- Collaborative Innovation Center of Suzhou Nano Science and Technology College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou, 215123, P.R. China
| | - Qingfeng Xu
- Collaborative Innovation Center of Suzhou Nano Science and Technology College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou, 215123, P.R. China
| | - Jianmei Lu
- Collaborative Innovation Center of Suzhou Nano Science and Technology College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou, 215123, P.R. China
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Facal Marina P, Xu J, Wu X, Xu H. Thinking outside the box: placing hydrophilic particles in an oil phase for the formation and stabilization of Pickering emulsions. Chem Sci 2018; 9:4821-4829. [PMID: 29910934 PMCID: PMC5982226 DOI: 10.1039/c8sc00678d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/26/2018] [Indexed: 01/24/2023] Open
Abstract
Pickering emulsions, also known as particle stabilized emulsions, are one kind of extremely important emulsion for both fundamental research and practical applications. Many colloidal particles have been utilized as emulsifiers to stabilize Pickering emulsions. However, the most challenging issue is preparing Pickering emulsions with highly hydrophilic particles, because their adsorption onto oil-water interfaces is either thermodynamically or kinetically unfavorable. Although several strategies have been developed to overcome the poor ability of the hydrophilic particles to stabilize the emulsions, surface modification and functionalization of the hydrophilic particles or a change in solvent (i.e. water phase) conditions such as pH and ionic strength is required. Herein, we present an effective and not yet explored strategy to stabilize Pickering emulsions with unmodified highly hydrophilic particles, strikingly, without changing the solvent conditions. The innovative aspect of the strategy presented here is the unconventional dispersion of hydrophilic particles in an oil phase before emulsification, while the results experimentally demonstrate the theoretical calculations predicted more than a decade ago. This study will promote the diversity of Pickering emulsions and expand their real-world applications.
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Affiliation(s)
- Paula Facal Marina
- Future Industries Institute , University of South Australia , Mawson Lakes Campus , Adelaide , SA 5095 , Australia .
| | - Jie Xu
- Future Industries Institute , University of South Australia , Mawson Lakes Campus , Adelaide , SA 5095 , Australia .
| | - Xuan Wu
- Future Industries Institute , University of South Australia , Mawson Lakes Campus , Adelaide , SA 5095 , Australia .
| | - Haolan Xu
- Future Industries Institute , University of South Australia , Mawson Lakes Campus , Adelaide , SA 5095 , Australia .
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