Carbon nanotubes (CNTs) have shown exceptional structural, electrical, mechanical, and thermal properties.1-3 CNTs-based nanocomposites possess unique property combinations and have been extensively investigated for various technological applications such as actuators,4, 5 body armor,6 conductive tapes,7 flame retardant,8 energy storage,9 tissue engineering,10, 11 delivery devices,12, 13 biosensors,14-16 and biomedical devices.17-19 Despite interesting physical and chemical properties, the true potential of CNTs-based nanocomposites is not achieved.20-22 This is due to strong π-π stacking interactions between CNTs that limits the dispersion of CNTs within polymeric matrix and decreases its ability in improving structural, chemical and biological properties of the nanocomposites network.
To overcome this shortcoming, numerous techniques are used to augment the dispersion of CNTs within the polymeric network such as surface functionalization.23-26 The surface of CNTs are modified with different polar groups including carboxyl,27 hydroxyl,28 and amine,29 to facilitate their uniform distribution within polymeric matrix. Other strategies to enhance solubility of CNTs in aqueous and non-aqueous solutions includes use of surfactant,30 proteins,31 and single-stranded deoxyribonucleic acid (ssDNA)32.The uniform dispersion of CNTs within the polymeric network results in enhanced surface interactions and significant increases in stiffness of the nanocomposites.33
Grafting polymeric chains on nanotube surfaces can modify the surface of CNTs.34 In this approach, polymeric chains shield the surface of CNTs and the adjoining polymeric network simply recognizes the surface-grafted polymer. This shielding method improves CNTs distribution withi...
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...e erosion mechanism and can be tailored to follow the ECM biosynthesis without exhibiting any sudden change in structural, physical and chemical properties.40
Here, we developed chemically crosslinked PGS-carbon nanotubes (PGS-CNTs) nanocomposites. The presence of additional hydroxyl groups on PGS backbone esterifies with the carboxylic groups present on CNTs surfaces during the thermal curing process, which is an advantage over other polyester-based nanocomposites. The chemical conjugation of CNTs with polyester backbone significantly enhances the physical and chemical properties of the nanocomposites. By covalently conjugating PGS with CNTs, we expect to obtain mechanically stiff nanocomposites that can be used for a range of biomedical applications, including as bone scaffolds, cardiac patches, nerve conduits, as well as for a range of other biomedical devices.
Acting as the controlled group to lessen the effects of all variables except the independent variable, at 0% concentration, the height of foam produced is 0 mm. Attributions to these results is because at 0% substrate concentration, no molecules were present to occupy all the available active sites. As an outcome, the final volume of oxygen is none since there were no collisions taken place between the enzymes and substrate. Therefore, prevented the number of collisions to reach the activation energy.
Due to the varied properties and the scope of application which the CNTs possess, it is of paramount importance that CNTs are produced sufficiently at a competitive cost with the existing technology. The research over two decades, since the discovery of CNTs at Iijima’s Laboratory in 1991, has not helped in reduction of cost or production of CNTs of well-defined properties on a massive scale (Kumar, n.d.). This is mainly because of the complexity in the growth mechanism of CNTs. Extra ordinary properties and applications cannot be unleashed without the fundamental understanding of the growth mechanism of Carbon Nanotubes (Kumar, n.d.). There are several methods to produce Carbon Nanotubes in a laboratory setup. Some of widely used techniques include
The [ES] complex can then undergo two different pathways; the complex can dissociate to [E] and [S], at a rate of k or it can shift equilibrium to the left with a rate constant of k2 to form [E] and product [P]1. In this model, the breakdown of the ES complex to yield P is the overall rate-limiting step. Three assumptions of a Michaelis-Menton plot are that a specific [ES] complex in rapid equilibrium between [E] and [S] is a necessary intermediate, the amount of substrate is more than the amount of enzyme so the [S] remains constant, and that this plot follows steady state assumptions. Steady state assumptions states that the intermediate stays the same concentration even if the starting materials and products are constantly changing.2 The rapid equilibrium between enzyme and substrate, and the enzyme-substrate complex yields a mathematical description regarded as the Michaelis-Menton
In this case study, our concern goes for the chitosan nanoparticles; firstly nanoparticles are able to adsorb and/or encapsulate a drug, thus protecting it against chemical and enzymatic degradation. Furthermore the encapsulated drug may be prevented from crystallization, thus forming a solid solution. Depending on drug solubility in the carrier, a drug load varying from only a few percent up to 50%] Secondly, chitosan is ...
induce the formation of an amyloid fold, in which the protein polymerizes into an aggregate consisting
The three-dimensional contour limits the number of substrates that can possibly react to only those substrates that can specifically fit the enzyme surface. Enzymes have an active site, which is the specific indent caused by the amino acid on the surface that fold inwards. The active site only allows a substrate of the exact unique shape to fit; this is where the substance combines to form an enzyme- substrate complex. Forming an enzyme-substrate complex makes it possible for substrate molecules to combine to form a product. In this experiment, the product is maltose.
Berger, M. (n.d.). Carbon Nanotubes could make t-shirts bulletproof. Retrieved March 11, 2014, from Nano Werk: http://nanowerk.com/spotlight/spotids1054.php
They can be seen as a collection of rolled sheets of graphene. CNTs demonstrate superconductivity with very large temperature transition. Electrons transport and resistance of CNTs do not depend on the sizes of CNTs. Carbon nanotubes electrodes are constructed by combining graphite powder and multiwall carbon nanotubes in a pestle and a mortar. Then, paraffin is added to the mixture by a syringe before the mixture is packed in a glass tube. After the construction, its electrochemistry is tested to verify its electro-activity by using standard solution of Fe(CN)63-/Fe(CN)64. Care is taken on information about electrode interfaces; mass transiport needs to be minimized in order to be used in catalysis, sensing and electrodeposition (Elrouby, 2013).
We have discussed various cell-wall associated biopolymers. Select one irregular biopolymer and describe its structural arrangements in the context of molecular and supramolecular level -- draw sketches. Indicate an experimental technique that could show how the biopolymer may respond to abiotic/environmental stresses
Up to present date there are many polymer hosts [1] have been discovered and some examples are
the discovery of carbon nanotubes, the strongest material known to man, a possible solution has been found.
an enzyme is used to speed up the process in the equation above. In my
Polymers are large molecules that are formed of many smaller molecules joined together as sub units, known as monomers. They portray a huge role in society as they tend to make up most plastics used ranging from plastic shopping bags to styrofoam. Polymers can be found naturally an example being DNA the building blocks of life but most usable polymers are man made (American Chemistry Council, n.d). The polymers in plastics widely used by society today are known as homopolymers, as they are the product of two or more identical monomers that have undergone polymerisation. However, here is an alternative form of polymer that is not as widely used called copolymers. Copolymers are constructed when two or more
American Chemical Society. "Carbon nanotubes twice as strong as once thought." ScienceDaily, 16 Sep. 2010. Web. 5 Dec. 2013.
I have chosen nanotechnology as my topic area of choice from the food innovation module.