ڪاربن نينوٽيوب

**ڪاربان نينوٽيوب** (CNT) ڪاربان مان ٺهيل هڪ ٽيوب آهي جن جو قطر نينوميٽر حدن (نانو اسڪيل) ۾ آهي. اهي ڪاربان جي ايلوٽروپ مان هڪ آهن. ڪاربان نانوٽيوب جون ٻه وڏي قسمون سڃاتل آهن:

* *سنگل ڀت واري ڪاربن نينوٽيوب* (SWCNTs) جو قطر تقريباً 0.5-2.0 نانو ميٽر هوندو آهي، جيڪو انساني وار جي ويڪر جو 1,00,000هون حصو آهي. انهن کي هڪ ٻه-طول عرض واري گرافين شيٽ مان ڪٽ آئوٽ جي طور تي جيڪو هڪ خالي سلنڈر ٺاهڻ لاءِ مٿي ڪيو ويندو آهي، لاء مثالي بڻائي سگهجي ٿو. 
* *گھڻ-ديوار واري ڪاربن نينوٽيوب* (MWCNTs) هڪ نيسٽڊ، ٽيوب-۾-ٽيوب ڍانچي ۾ نيسٽڊ سنگل-ديوار واري ڪاربن نينوٽيوب تي مشتمل آهن. ٻٽي ۽ ٽي ڀتين واري ڪاربن نانوٽيوب (MWCNT) جا خاص ڪيس آهن.

ڪاربن نينوٽيوب قابل ذڪر خاصيتون، جهڙوڪ غير معمولي ٽينسل طاقت ۽ حرارتي چالکائيڇاڪاڻ ته انهن جي نينو اسٽريچر ۽ ڪاربن ايٽمن جي وچ ۾ بانڊ جي طاقت، ڏيکاري سگهن ٿيون. ڪجھ سنگل ڀت واري ڪاربن نينوٽيوب (SWCNT) ڍانچا اعليٰ برقي چالکائي ڏيکارين ٿا جڏهن ته ٻيا نيم پسرائيندڙ (Semiconductors) آهن. ان کان سواء، ڪاربان نينوٽيوب کي ڪيميائي طور تي تبديل ڪري سگهجي ٿو. انهن خاصيتن جي ٽيڪنالاجي جو ڪيترن ئي شعبن ۾ قيمتي هجڻ جي اميد آهي، جهڙوڪ اليڪٽرانڪس، بصريات (Optics) جامع مواد (ڪاربن فائبر کي تبديل ڪرڻ يا مڪمل ڪرڻ)، نينو ٽيڪنالاجي (نينو ميڊيسن سميت) ۽ مواد جي سائنس جي ٻين ايپليڪيشنن ۾ قيمتي هجڻ جي اميد آهي.

SWCNTs لاءِ اڳڪٿي ڪيل خاصيتون دلچسپ هيون، پر انهن کي گڏ ڪرڻ جو رستي جو 1993ع تائين فقدان هو، جڏهن اين اي سي (NEC) ۾ آئيجيما ۽ ايچيهاشي ۽ بيٿون ۽ آء بي ايم (IBM) ۾ ساٿين آزاديءَ سان دريافت ڪيو ته ڪاربن جي گڏيل بخارات ۽ منتقلي ڌاتو جهڙوڪ لوهه ۽ ڪوبالٽ خاص طور تي SWCNT جي ٺهڻ کي متحرڪ ڪري سگهن ٿا. هي دريافت اهڙي تحقيق کي شروع ڪيو جيڪا ڪيٽيليٽڪ پيداوار ٽيڪنڪ جي ڪارڪردگي کي تمام گهڻو وڌائڻ ۾ ڪامياب ٿي ۽ SWCNTs جي خاصيت ۽ ايپليڪيشنن کي ڳولڻ لاءِ ڪم جي ڌماڪي جو سبب بڻي.

## ڪجهه اطلاق

Carbon nanotubes are currently used in multiple industrial and consumer applications. These include battery components, polymer composites, to improve the mechanical, thermal and electrical properties of the bulk product, and as a highly absorptive black paint. Many other applications are under development, including field effect transistors for electronics, high-strength fabrics and biosensors for biomedical and agricultural applications.

### Biomedical applications
Because of their relatively large surface area, CNTs are capable of interacting with a wide variety of therapeutic and diagnostic agents (drugs, genes, vaccines, antibodies, biosensors, etc.). This can be utilized to assist in drug delivery directly into cells. In addition, CNTs have recently been used as reinforcements in implants and scaffolds due to their suitable reaction area, high elastic modulus, and load transfer capability.

CNTs have been shown to increase the effectiveness of bioactive coatings for the attachment, proliferation, and differentiation of osteoblasts, and has been used as a bone substitution material.

CNTs may be used as reinforcing materials for chitosan-containing coatings used on implants and medical scaffolds.

### Biosensing
SWCNTs have nanoscale dimensions that fit to the size of biological species. Due to this size compatibility and their large surface-to-volume ratio, they are sensitive to changes in their chemical environment. Through covalent and non-covalent surface functionalization, SWCNTs can be precisely tailored for selective molecular interactions with a target analyte. The SWCNT represents the transduction unit that converts the interaction into a signal change (optical or electrical). Due to continuous progress in the development of detection strategies, there are numerous examples of the use of SWCNTs as highly sensitive nanosensors (even down to the single molecule level) for a variety of important biomolecules. Examples include the detection of reactive oxygen and nitrogen species, neurotransmitters, other small molecules, lipids, proteins, sugars, DNA/RNA, enzymes as well as bacteria.

The signal change manifests itself in an increase or decrease in the current (electrical) or in a change in the intensity or wavelength of the fluorescence emission (optical). Depending on the type of application, both electrical or optical signal transmission can be advantageous. For sensitive measurement of electronic changes, field-effect transistors (FET) are often used in which the flow of charges within the SWCNTs is measured. The FET structures allow easy on-chip integration and can be parallelized to detect multiple target analytes simultaneously. However, such sensors are more invasive for in vivo applications, as the entire device has to be inserted into the body. Optical detection with semiconducting SWCNTs is based on the radiative recombination of excitons in the near-infrared (NIR) by prior optical (fluorescence) or electrical excitation (electroluminescence). The emission in the NIR enables detection in the biological transparency window, where optical sensor applications benefit from reduced scattering and autofluorescence of biological samples and consequently a high signal-to-noise ratio. Compared to optical sensors in the UV or visible range, the penetration depth in biological tissue is also increased. In addition to the advantage of a contactless readout SWCNTs have excellent photostability, which enables long-term sensor applications. Furthermore, the nanoscale size of SWCNTs allows dense coating of surfaces which enables chemical imaging, e.g. of cellular release processes with high spatial and temporal resolution. Detection of several target analytes is possible by the spatial arrangement of different SWCNT sensors in arrays or by hyperspectral detection based on monochiral SWCNT sensors that emit at different emission wavelengths. For fluorescence applications, however, optical filters to distinguish between excitation and emission and a NIR-sensitive detector must be used. Standard silicon detectors can also be used if monochiral SWCNTs (extractable by special purification processes) emitting closer to the visible range (800 – 900&nbsp;nm) are used. In order to avoid susceptibility of optical sensors to fluctuating ambient light, internal references such as SWCNTs that are modified to be non-responsive or stable NIR emitters can be used. An alternative is to measure fluorescence lifetimes instead of fluorescence intensities. Overall, SWCNTs therefore have great potential as building blocks for various biosensors.
To render SWCNTs suitable for biosensing, their surface needs to be modified to ensure colloidal stability and provide a handle for biological recognition. Therefore, biosensing and surface modifications (functionalization) are closely related.

Potential future applications include biomedical and environmental applications such as monitoring plant health in agriculture, standoff process control in bioreactors, research/diagnostics of neuronal communication and numerous diseases such as coagulation disorders, diabetes, cancer, microbial and viral infections, testing the efficacy of pharmaceuticals or infection monitoring using smart implants. In industry, SWCNTs are already used as sensors in the detection of gases and odors in the form of an electronic nose or in enzyme screening.

### Other current applications

* Easton-Bell Sports, Inc. have been in partnership with Zyvex Performance Materials, using CNT technology in a number of their bicycle components – including flat and riser handlebars, cranks, forks, seatposts, stems and aero bars.
* Amroy Europe Oy manufactures Hybtonite carbon nano-epoxy resins where carbon nanotubes have been chemically activated to bond to epoxy, resulting in a composite material that is 20% to 30% stronger than other composite materials. It has been used for wind turbines, marine paints and a variety of sports gear such as skis, ice hockey sticks, baseball bats, hunting arrows, and surfboards.
* Surrey NanoSystems synthesizes carbon nanotubes to create vantablack ultra-absorptive black paint.
* "Gecko tape" (also called "nano tape") is often commercially sold as double-sided adhesive tape. It can be used to hang lightweight items such as pictures and decorative items on smooth walls without punching holes in the wall. The carbon nanotube arrays comprising the synthetic setae leave no residue after removal and can stay sticky in extreme temperatures.
* Tips for atomic force microscope probes.

### Applications under development

Applications of nanotubes in development in academia and industry include:

* Medical devices: Using single wall carbon nanotubes in medical devices results in no skin contamination, high flexibility, and softness, which are crucial for healthcare applications.
* Wearable electronics and 5G/6G communication: Electrodes with single wall carbon nanotubes (SWCNTs) exhibit excellent electrochemical properties and flexibility.
* Bitumen and asphalt: The world's first test section of road pavement with single wall carbon nanotubes (SWCNTs) showed a 67% increase in resistance to cracks and ruts, increasing the lifespan of the materials.
* Nanocomposites for aviation, automotive, and renewable energy markets: Modifying resin with just 0.02% single wall carbon nanotubes (SWCNTs) increases electrical conductivity by 276% without compromising the mechanical properties of fiber-reinforced polymers, also improving flexural properties and delaying thermal degradation.
* Additive manufacturing: single wall carbon nanotubes (SWCNTs) are mixed with a suitable printing medium or used as a filler material in the printing process, creating complex structures with enhanced mechanical and electrical properties.
* Utilizing carbon nanotubes as the channel material of carbon nanotube field-effect transistors.
* Using carbon nanotubes as a scaffold for diverse microfabrication techniques.
* Energy dissipation in self-organized nanostructures under the influence of an electric field.
* Using carbon nanotubes for environmental monitoring due to their active surface area and their ability to absorb gases.
* Jack Andraka used carbon nanotubes in his pancreatic cancer test. His method of testing won the Intel International Science and Engineering Fair Gordon E. Moore Award in the spring of 2012.
* The Boeing Company has patented the use of carbon nanotubes for structural health monitoring of composites used in aircraft structures. This technology is hoped to greatly reduce the risk of an in-flight failure caused by structural degradation of aircraft.
* Zyvex Technologies has also built a 54' maritime vessel, the Piranha Unmanned Surface Vessel, as a technology demonstrator for what is possible using CNT technology. CNTs help improve the structural performance of the vessel, resulting in a lightweight 8,000&nbsp;lb boat that can carry a payload of 15,000&nbsp;lb over a range of 2,500 miles.
* IMEC is using carbon nanotubes for pellicles in semiconductor lithography.
* In tissue engineering, carbon nanotubes have been used as scaffolding for bone growth.

Carbon nanotubes can serve as additives to various structural materials. For instance, nanotubes form a tiny portion of the material(s) in some (primarily carbon fiber) baseball bats, golf clubs, car parts, or damascus steel.

IBM expected carbon nanotube transistors to be used on Integrated Circuits by 2020.

SWCNTs have found use in long lasting, faster charged lithium ion batteries; polyamide car parts for e-painting; automotive primers for cost benefits and better aesthetics of topcoats; ESD floors; electrically conductive lining coatings for tanks and pipes; rubber parts with improved heat and oil aging stability; conductive gelcoats for ATEX requirements and tooling conductive gelcoats for increased safety and efficiency; and heating fiber coatings for infrastructure elements.

### Potential/Future applications

The strength and flexibility of carbon nanotubes makes them of potential use in controlling other nanoscale structures, which suggests they will have an important role in nanotechnology engineering. The highest tensile strength of an individual multi-walled carbon nanotube has been tested to be 63&nbsp;GPa. Carbon nanotubes were found in Damascus steel from the 17th century, possibly helping to account for the legendary strength of the swords made of it. Recently, several studies have highlighted the prospect of using carbon nanotubes as building blocks to fabricate three-dimensional macroscopic (>1mm in all three dimensions) all-carbon devices. Lalwani et al. have reported a novel radical initiated thermal crosslinking method to fabricated macroscopic, free-standing, porous, all-carbon scaffolds using single- and multi-walled carbon nanotubes as building blocks. These scaffolds possess macro-, micro-, and nano- structured pores and the porosity can be tailored for specific applications. These 3D all-carbon scaffolds/architectures may be used for the fabrication of the next generation of energy storage, supercapacitors, field emission transistors, high-performance catalysis, photovoltaics, and biomedical devices and implants.

CNTs are potential candidates for future via and wire material in nano-scale VLSI circuits. Eliminating electromigration reliability concerns that plague today's Cu interconnects, isolated (single and multi-wall) CNTs can carry current densities in excess of 1000&nbsp;MA/cm2 without electromigration damage.

Single-walled nanotubes are likely candidates for miniaturizing electronics. The most basic building block of these systems is an electric wire, and SWNTs with diameters of an order of a nanometre can be excellent conductors. One useful application of SWNTs is in the development of the first intermolecular field-effect transistors (FET). The first intermolecular logic gate using SWCNT FETs was made in 2001. A logic gate requires both a p-FET and an n-FET. Because SWNTs are p-FETs when exposed to oxygen and n-FETs otherwise, it is possible to expose half of an SWNT to oxygen and protect the other half from it. The resulting SWNT acts as a *not* logic gate with both p- and n-type FETs in the same molecule.

Large quantities of pure CNTs can be made into a freestanding sheet or film by surface-engineered tape-casting (SETC) fabrication technique which is a scalable method to fabricate flexible and foldable sheets with superior properties. Another reported form factor is CNT fiber (a.k.a. filament) by wet spinning. The fiber is either directly spun from the synthesis pot or spun from pre-made dissolved CNTs. Individual fibers can be turned into a yarn. Apart from its strength and flexibility, the main advantage is making an electrically conducting yarn. The electronic properties of individual CNT fibers (i.e. bundle of individual CNT) are governed by the two-dimensional structure of CNTs. The fibers were measured to have a resistivity only one order of magnitude higher than metallic conductors at . By further optimizing the CNTs and CNT fibers, CNT fibers with improved electrical properties could be developed.

CNT-based yarns are suitable for applications in energy and electrochemical water treatment when coated with an ion-exchange membrane. Also, CNT-based yarns could replace copper as a winding material. Pyrhönen et al. (2015) have built a motor using CNT winding.
## پڻ ڏسو
## حوالا

## ٻاهريان ڳنڍڻا

* Nanocarbon: From Graphene to Buckyballs. Interactive 3D models of cyclohexane, benzene, graphene, graphite, chiral & non-chiral nanotubes, and C60 Buckyballs – WeCanFigureThisOut.org.
* C<sub>60</sub> and Carbon Nanotubes a short video explaining how nanotubes can be made from modified graphite sheets and the three different types of nanotubes that are formed
* Learning module for Bandstructure of Carbon Nanotubes and Nanoribbons
* Selection of free-download articles on carbon nanotubes
* WOLFRAM Demonstrations Project: Electronic Band Structure of a Single-Walled Carbon Nanotube by the Zone-Folding Method
* WOLFRAM Demonstrations Project: Electronic Structure of a Single-Walled Carbon Nanotube in Tight-Binding Wannier Representation

زمرو:ڪاربن نينو ٽيوب 
زمرو:نينو مواد
زمرو:ڪاربان جا ٻهروپ 
زمرو:شفاف اليڪٽروڊ 
زمرو:ريفريڪٽري مواد  
زمرو:دريافتن ۽ ايجادن جون تڪرارون 
زمرو:سالڊ اسٽيٽ فزڪس