6 research outputs found
Reliable Manipulation of Gas Bubble Size on Superaerophilic Cones in Aqueous Media
Gas bubbles in aqueous
media are ubiquitous in a broad range of
applications. In most cases, the size of the bubbles must be manipulated
precisely. However, it is very difficult to control the size of gas
bubbles. The size of gas bubbles is affected by many factors both
during and after the generation process. Thus, precise manipulation
of gas bubble size still remains a great challenge. The ratchet and
conical hairs of the Chinese brush enable it to realize a significant
capacity for holding ink and transferring them onto paper continuously
and controllably. Inspired by this, a superhydrophobic/superaerophilic
cone interface is developed to manipulate gas bubble size in aqueous
media. When the resultant force between the Laplace force and the
axial component of the buoyancy force approaches zero, the gas bubble
is held steadily by the superhydrophobic/superaerophilic copper cones
in a unique position (balance position). A new kind of pressure sensor
is also designed based on this principle
Reliable Manipulation of Gas Bubble Size on Superaerophilic Cones in Aqueous Media
Gas bubbles in aqueous
media are ubiquitous in a broad range of
applications. In most cases, the size of the bubbles must be manipulated
precisely. However, it is very difficult to control the size of gas
bubbles. The size of gas bubbles is affected by many factors both
during and after the generation process. Thus, precise manipulation
of gas bubble size still remains a great challenge. The ratchet and
conical hairs of the Chinese brush enable it to realize a significant
capacity for holding ink and transferring them onto paper continuously
and controllably. Inspired by this, a superhydrophobic/superaerophilic
cone interface is developed to manipulate gas bubble size in aqueous
media. When the resultant force between the Laplace force and the
axial component of the buoyancy force approaches zero, the gas bubble
is held steadily by the superhydrophobic/superaerophilic copper cones
in a unique position (balance position). A new kind of pressure sensor
is also designed based on this principle
Spontaneous and Directional Bubble Transport on Porous Copper Wires with Complex Shapes in Aqueous Media
Manipulation
of gas bubble behaviors is crucial for gas bubble-related applications.
Generally, the manipulation of gas bubble behaviors generally takes
advantage of their buoyancy force. It is very difficult to control
the transportation of gas bubbles in a specific direction. Several
approaches have been developed to collect and transport bubbles in
aqueous media; however, most reliable and effective manipulation of
gas bubbles in aqueous media occurs on the interfaces with simple
shapes (i.e., cylinder and cone shapes). Reliable strategies for spontaneous
and directional transport of gas bubbles on interfaces with complex
shapes remain enormously challenging. Herein, a type of 3D gradient
porous network was constructed on copper wire interfaces, with rectangle,
wave, and helix shapes. The superhydrophobic copper wires were immersed
in water, and continuous and stable gas films then formed on the interfaces.
With the assistance of the Laplace pressure gradient between two bubbles,
gas bubbles (including microscopic gas bubbles) in the aqueous media
were subsequently transported, continuously and directionally, on
the copper wires with complex shapes. The small gas bubbles always
moved to the larger ones
Reliable Manipulation of Gas Bubble Size on Superaerophilic Cones in Aqueous Media
Gas bubbles in aqueous
media are ubiquitous in a broad range of
applications. In most cases, the size of the bubbles must be manipulated
precisely. However, it is very difficult to control the size of gas
bubbles. The size of gas bubbles is affected by many factors both
during and after the generation process. Thus, precise manipulation
of gas bubble size still remains a great challenge. The ratchet and
conical hairs of the Chinese brush enable it to realize a significant
capacity for holding ink and transferring them onto paper continuously
and controllably. Inspired by this, a superhydrophobic/superaerophilic
cone interface is developed to manipulate gas bubble size in aqueous
media. When the resultant force between the Laplace force and the
axial component of the buoyancy force approaches zero, the gas bubble
is held steadily by the superhydrophobic/superaerophilic copper cones
in a unique position (balance position). A new kind of pressure sensor
is also designed based on this principle
Mussel-Inspired Chemistry and Michael Addition Reaction for Efficient Oil/Water Separation
An
oil/water separation mesh with high separation efficiency and intrusion
pressure of water has been successfully developed by combining mussel-inspired
chemistry and Michael addition reaction. The substrate of the stainless
steel mesh was first coated with the adhesive polydopamine (PDA) film
by simple immersion in an aqueous solution of dopamine at pH of 8.5.
Then n-dodecyl mercaptan (NDM) was conjugated with PDA film through
Michael addition reaction at ambient temperature. The as-prepared
mesh showed highly hydrophobicity with the water contact angle of
144° and superoleophilicity with the oil contact angle of 0°.
It can be used to separate a series of oil/water mixtures like gasoline,
diesel, etc. The separation efficiency remains high after 30 times
use (99.95% for hexane/water mixture). More importantly, the relatively
high intrusion pressure (2.2 kPa) gives the opportunity to separation
of large amount of oil and water mixtures. This study provides a new
prospect to simply introduce multiple molecules on the adhesive PDA-based
mesh to achieve various functional oil/water separation materials
Bioinspired Oil Strider Floating at the Oil/Water Interface Supported by Huge Superoleophobic Force
Oil pollution to aquatic devices, especially to those oil-cleaning devices and equipment-repairing robots during oil spill accidents, has drawn great attention and remains an urgent problem to be resolved. Developing devices that can move freely in an oil/water system without contamination from oil has both scientific and practical importance. In nature, the insect water strider can float on water by utilizing the superhydrophobic supporting force received by its legs. Inspired by this unique floating phenomenon, in this article, we designed a model device named “oil strider” that could float stably at the oil/water interface without contamination by oil. The floating capability of the oil strider originated from the huge underwater superoleophobic supporting force its “legs” received. We prepared the micro/nanohierarchical structured copper-oxide-coated copper wires, acting as the artificial legs of oil strider, by a simple base-corrosion process. The surface structures and hydrophilic chemical components of the coatings on copper wires induced the huge superoleophobic force at the oil/water interface, to support the oil strider from sinking into the oil. Experimental results and theoretical analysis demonstrate that this supporting force is mainly composed of three parts: the buoyancy force, the curvature force, and the deformation force. We anticipate that this artificial oil strider will provide a guide for the design of smart aquatic devices that can move freely in an oil/water system with excellent oil repellent capability, and be helpful in practical situations such as oil handling and oil spill cleanup