Nanofibers are defined as fibers with diameters less than 1000 nm nanometers. They can be produced by interfacial polymerization and electrospinning

Electrospinning

Electrospinning uses an electrical charge to draw very fine fibres from a liquid. Electrospinning shares characteristics of both electrospraying and conventional solution dry spinning of fibers. The process does not require the use of coagulation chemistry or high temperatures to produce solid...

. Carbon nanofibers are graphitized fibers produced by catalytic synthesis.
For optical nanofibers see subwavelength-diameter optical fiber.

Synthesis

Inorganic nanofibers (sometimes called ceramic

Ceramic

A ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous...

 nanofibers) can be prepared from various kinds of inorganic substance

Chemical substance

In chemistry, a chemical substance is a form of matter that has constant chemical composition and characteristic properties. It cannot be separated into components by physical separation methods, i.e. without breaking chemical bonds. They can be solids, liquids or gases.Chemical substances are...

s by electrospinning

Electrospinning

Electrospinning uses an electrical charge to draw very fine fibres from a liquid. Electrospinning shares characteristics of both electrospraying and conventional solution dry spinning of fibers. The process does not require the use of coagulation chemistry or high temperatures to produce solid...

 technique. The most frequently mentioned ceramic materials with nanofiber morphology

Morphology (biology)

In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....

 are titanium dioxide

Titanium dioxide

Titanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula . When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it comes in two different forms, rutile and anatase. It has a wide range of...

 (TiO₂), silicon dioxide

Silicon dioxide

The chemical compound silicon dioxide, also known as silica , is an oxide of silicon with the chemical formula '. It has been known for its hardness since antiquity...

 (SiO₂), zirconium dioxide (ZrO₂), aluminum oxide (Al₂O₃), lithium titanate

Lithium titanate

Lithium titanate is a compound containing lithium and titanium. It is an off-white powder at room temperature and has the chemical formula Li2TiO3....

 (Li₄Ti₅O₁₂), titanium nitride

Titanium nitride

Titanium nitride is an extremely hard ceramic material, often used as a coating on titanium alloys, steel, carbide, and aluminium components to improve the substrate's surface properties....

 (TiN) or platinum

Platinum

Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...

 (Pt). The synthesis usually consists of two main steps. In the first step, the polymer

Polymer

A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...

 (organic) nanofibers are created by conventional electrospinning technique. As prepared, polymer nanofibers made of inorganic salts or organometallic compounds are subsequently transformed to ceramics by heat treatment. Other production methods include direct drawing from a solution or melt and "island in the sea".

Potential applications

• Medical: artificial organ components, tissue engineering, implant material, drug delivery, wound dressing, medical textile materials.
• Protective materials: sound absorption materials, protective clothings against chemical and biological warfare agents, sensor applications for detecting chemical agents.
• Textile: sport apparels, sport shoes, climbing, rainwear, outerwear garments, baby diapers.
• Filtration: HVAC system filters, HEPA
  HEPA
  High-Efficiency Particulate Air or HEPA is a type of air filter. Filters that are awarded the HEPA accolade are used in various locations, whether in medical facilities, automotive vehicles, airplanes, home filters, or wherever very pure air is sought. The filter must satisfy certain standards of...
  
  , ULPA filters, air, oil, fuel filters for automotive, filters for beverage, pharmacy, medical applications.
• Napkins with nanofibers contain antibodies against numerous biohazard
  Biohazard
  Biohazard may refer to:* Biological hazard* Biohazard , a book by Ken Alibek* Biohazard , a New York hardcore punk band** Biohazard , a self-titled album from Biohazard...
  
  s and chemicals that signal by changing color (potentially useful in identifying bacteria in kitchens).
• In wound healing nanofibers assemble at the injury site and stay put, drawing the body's own growth factor
  Growth factor
  A growth factor is a naturally occurring substance capable of stimulating cellular growth, proliferation and cellular differentiation. Usually it is a protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes....
  
  s to the injury site.
• Filter media for new air and liquid filtration
  Filtration
  Filtration is commonly the mechanical or physical operation which is used for the separation of solids from fluids by interposing a medium through which only the fluid can pass...
  
   applications, such as vacuum cleaner
  Vacuum cleaner
  A vacuum cleaner, commonly referred to as a "vacuum," is a device that uses an air pump to create a partial vacuum to suck up dust and dirt, usually from floors, and optionally from other surfaces as well. The dirt is collected by either a dustbag or a cyclone for later disposal...
  
  s.
• Dye-sensitized solar cell
• Pigment
  Pigment
  A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...
  
  s for cosmetics
  Cosmetics
  Cosmetics are substances used to enhance the appearance or odor of the human body. Cosmetics include skin-care creams, lotions, powders, perfumes, lipsticks, fingernail and toe nail polish, eye and facial makeup, towelettes, permanent waves, colored contact lenses, hair colors, hair sprays and...
  
  
• Energy: Li-ion batteries, photovoltaic cells, membrane
  Artificial membrane
  An artificial membrane, or synthetic membrane, is a synthetically created membrane which is usually intended for separation purposes in laboratory or in industry. Synthetic membranes have been successfully used for small and large-scale industrial processes since the middle of twentieth century. A...
  
   fuel cells.
• Carrier materials for various catalysts
• Photocatalytic air/water purification
• Micropower
  Micropower
  Micropower describes the work that researchers at several universities are doing to develop very small electric generators and prime movers or devices to convert heat or motion to electricity, for use close to the generator...
  
   to operate personal electronic devices via piezoelectric nanofibers woven into clothing.

Self-twisting

Self-brading of nanofibers is related to a balance between flexibility, adhesion, and evaporation of solvent. Its potential applications include:

• Substances that can change optical properties on demand
• Molecule capture and release for e.g. timed drug delivery
• Energy storage
• Adhesives

See also

• Subwavelength-diameter optical fiber
• Nanofiber seeding
  Nanofiber seeding
  Nanofiber Seeding is the process to control the bulk morphology of chemically synthesized electronic organic polymers.-Description:A new synthetic approach, called nanofiber seeding, was developed to control the bulk morphology of chemically synthesized electronic organic polymers...
  
  
• Polyaniline nanofibers
  Polyaniline nanofibers
  Polyaniline nanofibers are the high aspect version of polyaniline created by several techniques including nanofiber seeding, electrochemical synthesis , electrospinning of composites and several oxidative polymerization methods. Most of these methods required templates that had to be removed,...