Nanopin film
Encyclopedia
Nanopin film is an experimental material in nanotechnology
developed in 2005 with unusual superhydrophobic properties . A droplet of water makes contact with the surface of this film and forms an almost perfect sphere with a contact angle
of 178°
. The film is able to do this because it is covered with nanoscale topped off pin
s or cones
perpendicular
to the surface. The surface is regarded as a composite material
with mostly air and a small fraction made up by the tops of the cones. When the contact angle
of the cone material is sufficiently large Cassie's law
predicts large contact angle values for the composite.
This particular nanopin film is produced with borosilicate glass
as the primary substrate. A solution of CoCl2•6H2O or cobalt chloride hexahydrate is heated at 60 °C for 24 hours in a chemical bath deposition
to form a brucite
type cobalt(II) hydroxide
layer with composition
The top coating is provided by lauric acid
in a separate step. A 3 square micrometer surface now contains on average 166 such cones with cone height of around 100 nm and the cone diameter at the tip of 6.5 nm. The Cassie's law
prediction for this material with the lauric acid
surface area
of 0.000612 and flat film contact angle
of 75°
is 177.8°
.
Nanotechnology
Nanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometres...
developed in 2005 with unusual superhydrophobic properties . A droplet of water makes contact with the surface of this film and forms an almost perfect sphere with a contact angle
Contact angle
The contact angle is the angle at which a liquid/vapor interface meets a solid surface. The contact angle is specific for any given system and is determined by the interactions across the three interfaces. Most often the concept is illustrated with a small liquid droplet resting on a flat...
of 178°
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
. The film is able to do this because it is covered with nanoscale topped off pin
Pin (device)
A pin is a device used for fastening objects or material together. It is usually made of steel, or on occasion copper or brass. It is formed by drawing out a thin wire, sharpening the tip, and adding a head. Nails are related, but are typically larger....
s or cones
Cone (geometry)
A cone is an n-dimensional geometric shape that tapers smoothly from a base to a point called the apex or vertex. Formally, it is the solid figure formed by the locus of all straight line segments that join the apex to the base...
perpendicular
Perpendicular
In geometry, two lines or planes are considered perpendicular to each other if they form congruent adjacent angles . The term may be used as a noun or adjective...
to the surface. The surface is regarded as a composite material
Composite material
Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...
with mostly air and a small fraction made up by the tops of the cones. When the contact angle
Contact angle
The contact angle is the angle at which a liquid/vapor interface meets a solid surface. The contact angle is specific for any given system and is determined by the interactions across the three interfaces. Most often the concept is illustrated with a small liquid droplet resting on a flat...
of the cone material is sufficiently large Cassie's law
Cassie's law
Cassie's law describes the effective contact angle θc for a liquid on a composite surface . The law explains how simply roughing up a surface increases the apparent surface angle...
predicts large contact angle values for the composite.
This particular nanopin film is produced with borosilicate glass
Borosilicate glass
Borosilicate glass is a type of glass with the main glass-forming constituents silica and boron oxide. Borosilicate glasses are known for having very low coefficients of thermal expansion , making them resistant to thermal shock, more so than any other common glass...
as the primary substrate. A solution of CoCl2•6H2O or cobalt chloride hexahydrate is heated at 60 °C for 24 hours in a chemical bath deposition
Chemical bath deposition
The chemical bath deposition method is one of the cheapest methods to deposit thin films and nanomaterials, as it does not depend on expensive equipment and is a scalable technique that can be employed for large area batch processing or continuous deposition. In 1933 Bruckman deposited PbS thin...
to form a brucite
Brucite
Brucite is the mineral form of magnesium hydroxide, with the chemical formula Mg2. It is a common alteration product of periclase in marble; a low-temperature hydrothermal vein mineral in metamorphosed limestones and chlorite schists; and formed during serpentinization of dunites...
type cobalt(II) hydroxide
Cobalt(II) hydroxide
Cobalt hydroxide or cobaltous hydroxide is the chemical compound composed of cobalt and the hydroxide ion with the formula Co2. It occurs in two forms, either as a rose-red powder, which is the more stable of the two forms, or as bluish-green powder...
layer with composition
- CoOH1.13Cl0.09(CO3)0.39.0.05H20
The top coating is provided by lauric acid
Lauric acid
Lauric acid , the saturated fatty acid with a 12-carbon atom chain, is a white, powdery solid with a faint odor of bay oil or soap.-Occurrence:...
in a separate step. A 3 square micrometer surface now contains on average 166 such cones with cone height of around 100 nm and the cone diameter at the tip of 6.5 nm. The Cassie's law
Cassie's law
Cassie's law describes the effective contact angle θc for a liquid on a composite surface . The law explains how simply roughing up a surface increases the apparent surface angle...
prediction for this material with the lauric acid
Lauric acid
Lauric acid , the saturated fatty acid with a 12-carbon atom chain, is a white, powdery solid with a faint odor of bay oil or soap.-Occurrence:...
surface area
Surface area
Surface area is the measure of how much exposed area a solid object has, expressed in square units. Mathematical description of the surface area is considerably more involved than the definition of arc length of a curve. For polyhedra the surface area is the sum of the areas of its faces...
of 0.000612 and flat film contact angle
Contact angle
The contact angle is the angle at which a liquid/vapor interface meets a solid surface. The contact angle is specific for any given system and is determined by the interactions across the three interfaces. Most often the concept is illustrated with a small liquid droplet resting on a flat...
of 75°
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
is 177.8°
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
.
