Nanofabrics are textiles engineered with small particles that give ordinary materials advantageous properties such as

superhydrophobicity Ultrahydrophobic (or superhydrophobic) surfaces are highly hydrophobic, i.e., extremely difficult to wet. The contact angles of a water droplet on an ultrahydrophobic material exceed 150°. This is also referred to as the lotus effect, after the ...

(extreme water resistance, also see " Lotus effect"), odor and moisture elimination, increased elasticity and strength, and bacterial resistance. Depending on the desired property, a nanofabric is either constructed from

nanoscopic The nanoscopic scale (or nanoscale) usually refers to structures with a length scale applicable to nanotechnology, usually cited as 1–100 nanometers (nm). A nanometer is a billionth of a meter. The nanoscopic scale is (roughly speaking) a lo ...

fibers called

nanofibers Nanofibers are fibers with diameters in the nanometer range (typically, between 1 nm and 1 μm). Nanofibers can be generated from different polymers and hence have different physical properties and application potentials. Examples of natural polyme ...

, or is formed by applying a

solution Solution may refer to: * Solution (chemistry), a mixture where one substance is dissolved in another * Solution (equation), in mathematics ** Numerical solution, in numerical analysis, approximate solutions within specified error bounds * Soluti ...

containing

nanoparticles A nanoparticle or ultrafine particle is usually defined as a particle of matter that is between 1 and 100 nanometres (nm) in diameter. The term is sometimes used for larger particles, up to 500 nm, or fibers and tubes that are less than 1 ...

to a regular fabric. Nanofabrics research is an interdisciplinary effort involving

bioengineering Biological engineering or bioengineering is the application of principles of biology and the tools of engineering to create usable, tangible, economically-viable products. Biological engineering employs knowledge and expertise from a number o ...

, molecular chemistry,

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

computer science Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...

, and

systems engineering Systems engineering is an interdisciplinary field of engineering and engineering management that focuses on how to design, integrate, and manage complex systems over their enterprise life cycle, life cycles. At its core, systems engineering util ...

. Applications of nanofabrics have the potential to revolutionize

textile manufacturing Textile Manufacturing or Textile Engineering is a major industry. It is largely based on the conversion of fibre into yarn, then yarn into fabric. These are then dyed or printed, fabricated into cloth which is then converted into useful goods ...

and areas of

medicine Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pract ...

such as drug delivery and

tissue engineering Tissue engineering is a biomedical engineering discipline that uses a combination of Cell (biology), cells, engineering, Materials science, materials methods, and suitable biochemistry, biochemical and physicochemical factors to restore, maintai ...

Nanoscale

A fiber that has a width of less than 1000

nanometers 330px, Different lengths as in respect to the molecular scale. The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American and British English spelling differences#-re ...

(1000 nm or 1 μm) is generally defined as a nanofiber. A nanoparticle is defined as a small group of

atoms Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, an ...

molecules A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...

with a

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

of less than 100

(100 nm). Particles on the nanoscale have a very high

surface area The surface area of a solid object is a measure of the total area that the surface of the object occupies. The mathematical definition of surface area in the presence of curved surfaces is considerably more involved than the definition of arc ...

volume Volume is a measure of occupied three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch). The de ...

ratio In mathematics, a ratio shows how many times one number contains another. For example, if there are eight oranges and six lemons in a bowl of fruit, then the ratio of oranges to lemons is eight to six (that is, 8:6, which is equivalent to the ...

, whereas this

is much lower for objects on the macroscopic scale. A high relative

means that a large proportion of a particle's mass exists on its surface, so

and

show a greater level of interaction with other materials. The high

observed in very small particles is what makes it possible to create many special properties exhibited by nanofabrics.

Manufacture

The use of

and

to produce specialized nanofabrics became a subject of interest after the sol-gel and

electrospinning Electrospinning is a fiber production method that uses electric force to draw charged threads of polymer solutions or polymer melts up to fiber diameters in the order of some hundred nanometers. Electrospinning shares characteristics of both elec ...

techniques were fully developed in the 1980s. Since 2000, dramatic increases in global funding have accelerated research efforts in

nanotechnology Nanotechnology, also shortened to nanotech, is the use of matter on an atomic, molecular, and supramolecular scale for industrial purposes. The earliest, widespread description of nanotechnology referred to the particular technological goal o ...

, including nanofabrics research.

Sol-gel

The sol-gel process is used to create gel-like

s which can be applied to textiles as a liquid finish to create nanofabrics with novel properties. The process begins with dissolving

in a liquid

solvent A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...

(often an

alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

). Once dissolved, several

chemical reactions A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking ...

take place that cause the

to grow and establish a network throughout the liquid. The network transforms the

into a

colloid A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others extend ...

(a suspension of solid particles in a liquid) with a gelatinous texture. Finally, the

must go through a drying process to remove excess

from the mixture before it can be used to treat fabrics. The sol-gel process is used in a similar fashion to make

polymer A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...

, which are long, ultra-thin chains of

proteins Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

bonded together.

Electrospinning

Electrospinning Electrospinning is a fiber production method that uses electric force to draw charged threads of polymer solutions or polymer melts up to fiber diameters in the order of some hundred nanometers. Electrospinning shares characteristics of both elec ...

extracts

from

s (synthesized by the sol-gel process) and collects them to form nonwoven nanofabrics. A strong

electric field An electric field (sometimes E-field) is the physical field that surrounds electrically charged particles and exerts force on all other charged particles in the field, either attracting or repelling them. It also refers to the physical field fo ...

is applied to the

to charge the

strands. The

is put into a syringe and aimed at an oppositely charged collector plate. When the

force In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity (e.g. moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a p ...

of attraction between the

and the collector plate exceed the

surface tension Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to f ...

of the

, the

are released from the

and deposit onto the collector plate. The deposited fibers form a porous nanofabric that can aid in drug delivery and

depending on the type of

used.

Applications

Textile Manufacturing

When nanoengineered coatings are applied to fabrics, the

readily form bonds with the fibers of the material. The high

relative to the

of particles increases their chemical reactivity, allowing them to stick to materials more permanently. Fabrics treated with nanoparticle coatings during manufacturing produce materials that kill bacteria, eliminate moisture and odor, and prevent

static electricity Static electricity is an imbalance of electric charges within or on the surface of a material or between materials. The charge remains until it is able to move away by means of an electric current or electrical discharge. Static electricity is na ...

Polymer A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...

nanofiber coatings applied to textiles

bond Bond or bonds may refer to: Common meanings * Bond (finance), a type of debt security * Bail bond, a commercial third-party guarantor of surety bonds in the United States * Chemical bond, the attraction of atoms, ions or molecules to form chemical ...

to the material at one end of the

, forming a surface of tiny, hair-like structures. The

"hairs" create a thin layer that prevents liquids from making contact with the actual fabric. Nanofabrics with dirt-proof, stain-proof, and superhydrophobic properties are possible as a result of the layer formed by

. Development of nanofabrics for use in the clothing and textiles industry is still in its early stages. Some applications such as bacteria-resistant clothing are not yet practical from an economic standpoint. For example, a

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach an ...

student's prototype for a bactericidal jacket cost $10,000 alone, so it may be a long time before nanofabric clothing is on the market.

Drug Delivery

Nanofabrics used in

can deliver

antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention o ...

, anticancer drugs,

, and DNA in precise quantities.

creates porous nanofabrics that can be loaded with the desired drug which are then applied to the tissue of the targeted area. The drug passes through the tissue by

diffusion Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...

, a process in which substances move through a membrane from high to low

concentration In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: '' mass concentration'', ''molar concentration'', ''number concentration'', an ...

. The rate at which the drug is administered can be changed by altering the composition of the nanofabric.

Tissue Engineering

Nonwoven fabrics made by

have the potential to assist in the growth of organ tissue,

bone A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provid ...

neurons A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. N ...

tendons A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...

, and

ligaments A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the: * Peritoneal li ...

nanofabrics can act either as a scaffold to support damaged tissue or as a synthetic substitute for actual tissue. Depending on the function, the nanofabric can be made of natural or synthetic

polymers A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic an ...

, or a combination of both.

Environmental Implications

advances, many studies have been conducted to determine the effects nanoengineered materials can have on the

environment Environment most often refers to: __NOTOC__ * Natural environment, all living and non-living things occurring naturally * Biophysical environment, the physical and biological factors along with their chemical interactions that affect an organism or ...

. Most

textiles Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the ...

can lose up to 20% of their

mass Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementar ...

during their lifetime, so

used in production of nanofabrics are at risk of being released into the air and waterways. Nano-silver is expected to have as much as 49.5% of its global production taken by the nanotextiles industry due to its

antibacterial An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...

properties. It is predicted that 20% of the nano-silver used in the nanofabrics industry will be released into waterways which could cause harm to microorganisms. However, more than 90% of nano-silver is removed during treatment at wastewater facilities, so it is likely that the environmental impact will be minimal. A study on aluminum oxide

showed that inhalation caused

inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

in rat lungs. Aluminum oxide

are not used in large quantity, so its health risks are negligible. Other studies conducted for

suggest that their environmental impact should be low as the nanotextiles industry continues to grow.

References

{{Reflist

External links

Using liquid finishes to create nanofabrics

Wyss Institute's protein matrix technology for designing nanofabrics

Bactericidal clothing

Nanotechnology textiles

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Technical fabrics