title: Superhydrophobic Cones for Continuous Collection and Directional Transportation of CO2Microbubbles in CO2Supersaturated Solutions.
abstract: Microbubbles are tiny bubbles with diameters below 50 μm. Because of their minute buoyant force, the microbubbles stagnate in aqueous media for a long time, and they sometimes cause serious damage. Most traditional methods chosen for elimination of gas bubbles utilize buoyancy forces including chemical methods and physical methods, and they only have a minor effect on microbubbles. Several approaches have been developed to collect and transport microbubbles in aqueous media. However, the realization of innovative strategies to directly collect and transport microbubbles in aqueous media remains a big challenge. In nature, both spider silk and cactus spines take advantage of their conical-shaped surface to yield the gradient of Laplace pressure and surface free energy for collecting fog droplets from the environment. Inspired by this, we introduce here the gradient of Laplace pressure and surface free energy to the interface of superhydrophobic copper cones (SCCs), which can continuously collect and directionally transport CO2microbubbles (from tip side to base side) in CO2-supersaturated solution. A gas layer was formed when the microbubbles encounter the SCCs. This offers a channel for microbubble directional transportation. The efficiency of microbubble transport is significantly affected by the apex angle of SCCs and the carbon dioxide concentration. The former provides different gradients of Laplace pressure as the driving force. The latter represents the capacity, which offers the quantity of CO2microbubbles for collection and transportation. We believe that this approach provides a simple and valid way to remove microbubbles.
authors.affiliation: Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry and Environment, Beihang University , Beijing 100191, China.
authors.forename: Xiuzhan
authors.initials: X
authors.lastname: Xue
authors.forename: Cunming
authors.initials: C
authors.lastname: Yu
authors.affiliation: Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry and Environment, Beihang University , Beijing 100191, China.
authors.forename: Jingming
authors.identifier: 0000-0003-1309-7211
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry and Environment, Beihang University , Beijing 100191, China.
authors.forename: Lei
authors.identifier: 0000-0003-4579-728X
authors.initials: L
authors.lastname: Jiang
keywords: continuous collection; directional transportation; gradient of Laplace pressure; microbubble; superhydrophobic cone