Graphene, planar sheet of sp2-bonded carbon atoms, is the fundamental component of graphite and carbon nanotubes. The discovery of Geim and Novoselov in 2004  has generated intense activity on graphene research. Sophisticated low-dimensional features and exceptional mechanical properties have given rise to many technological applications of pristine graphene in various fields. Its usage in electronic and optical devices, energy storage systems and composite materials, chemical sensors and drug delivery was suggested [9-16]. Soon after, the chemical functionalization of graphene became a center of interest in modern physics and chemistry . The main motivations of these experimental and theoretical studies were modification of electronic properties via changing the band gap, potential use of functionalized graphene for hydrogen storage, search for techniques to massively produce ‘cheap’ graphene by chemical reduction of graphene oxide, oxidation and subsequent unzipping of graphene as a method to create graphene nanostructures of a given size [17-20] . However, the reactivity of graphene as a planar sheet is much worse than those of CNTs and fullerenes. Therefore, only a few functionalization techniques have been transferred from fullerene to graphene chemistry, such as azo, aryne and nitrene additions [21-23], Claisen rearrangement , 1,3-dipolar and Diels–Alder cycloadditions [25, 26].
Carbenes (CR2, R = H, ...
... middle of paper ...
...rest to consider the structural changes in graphene affected by dichlorocarbene. The influence of position of attached carbene species on graphene framework is also an important issue. Besides, to the best of our knowledge, no attempts have been made by researchers to ascertain what influence solvents offer on the binding energy of carbenes as well as on the band gap of functionalized graphene.
As described in the previous paragraphs, the functionalization of nanotubes and fullerenes with carbenes has been of importance. Taking into consideration the significance that graphene reveals nowadays, herein, we report comprehensive density functional theory study on the CCl2 functionalization of finite-size graphene sheets, focusing on equilibrium structures of the CCl2-attached graphene and the effects of attached dichlorocarbene on the electronic properties of graphene.
Need Writing Help?
Get feedback on grammar, clarity, concision and logic instantly.Check your paper »
- To study the influence of graphene sheets ionization on their structures we, firstly, should define some useful parameters. There are two types of bonds in graphene sheets, one ‘horozontal’ (b1) and one ‘vertical’ (b2) (Fig. 2). Fig. 2. The model used herein to define structural parameters of graphene sheets: ‘horizontal’ (b1) and ‘vertical’ (b2) bond lengths. Terminate carbon atoms, between which the length of the sheet is measured, are colored in black. Hydrogen atoms omitted for clarity. It should be noted, that we use such notations to emphasize the basic difference of these bonds.... [tags: atom, carbon, bonds]
641 words (1.8 pages)
- 21,000 years ago, the Last Glacial Maximum, or LGM, occurred. It was the most recent period in climate history where ice sheets were at their peak size. This era “represents the nearest of a series of past climatic extremes characterizing the waxing and waning of Quaternary ice ages and as such serves as an excellent testing ground for assessment of sensitivity of the Earth’s climatic system,” (814, MAROGT). Due to this sensitivity of the climatic system, when data modeling global climates it is easier to see the individual effects of various external forcings (factors that alter the climate) when they are manipulated.... [tags: Climate, Climate change, Earth]
713 words (2 pages)
- Patria snuggled into Corbin’s sheets and smiled. They weren’t really his sheets. He’d put clean ones on the bed after he carried her meager belongings up and set them by the door. But, he had slept in this bed before. She drew her fingers over the mattress and wondered how he slept. On his back, or on his side. Had he stayed and slept with her last night after she’d fallen asleep, or had he quietly left to sleep in his own bed. She sighed and put thoughts of Corbin away. He was protective of her because that was in his nature, just like flirting was in Pinks.... [tags: Thought, Mind, Psychology, Sleep]
1523 words (4.4 pages)
- Google has achieved record results to the point of announcing a massive share buyback to satisfy its shareholders, the stock blazing and the company 's market capitalization exceeds $ 500 billion. The balance sheets of Alphabet and Google (in millions) As of December 31, 2013 2014 2015 Consolidated Balance Sheet Data: Cash, cash equivalents, and marketable securities $58717 $64395 $73066 Total assets 109050 129187 147461 Total long... [tags: Balance sheet, Asset, Google Chrome, Google]
774 words (2.2 pages)
- Though climate change today is subjected to many denialist interpretations, the evidence provided by understanding sea level rise and the retreat of ice sheets presents a direct link with global warming and speaks to the legitimacy of climate change. As one of the main compelling arguments to support climate change, along with extreme weather events and global temperature rise, the past and present evidence for sea level rise is tied to natural and human caused global warming. While the immediate issue at hand may be settling the dispute about accepting human causes and effects of and solutions for climate change, many also deny that the evidence for sea level rise does not provide a connect... [tags: Climate change, Global warming, Sea level, Ocean]
1518 words (4.3 pages)
- For as long as people have had the means, metal has been beaten into sheets and used for architectural purposes, from roof coverings to sewer pipes. In the late seventeenth century, this hand-hammering process was later replaced by large “rotating iron cylinders” which pressed metal into flattened sheets (Simpson 31). These water-powered rolling mills allowed for more uniform sheets as well as a less laborious and time-consuming process. The sheets were allowed to be thinner, which was advantageous when creating smaller details, such as gutters and roofing.... [tags: Installation, Metal Types, Architecture]
1622 words (4.6 pages)
- Case Study: An Information System for Use in Surveillance Rounds The equipment located in a facility at the Los Alamos National Laboratories (LANL) is monitored in order to ensure its safe operation. While critical components are continuously monitored and controlled by an automated system most of the non-vital support equipment is checked daily without the use of information technology (IT). Instead, technicians conduct surveillance rounds to check that equipment is operating properly within specified parameters.... [tags: Case Study]
1316 words (3.8 pages)
- Click chemistry was created by taking cues from how nature naturally reacts. 1 The goal of Sharpless and colleagues was to create a number of selective blocks that could be connected in many different ways with the ability to work in many various applications. 1 For a reaction to be defined as click chemistry: “the reaction must be modular, wide in scope, give very high yields, and generate only inoffensive by products that can be easily removed” and it must have undemanding reaction conditions.... [tags: nucleophilic opening of rings, cycloaddition]
951 words (2.7 pages)
- ... Archaeology continues to help researchers understand not only where and when people lived in various parts of the world, but also the logistics involving their time on earth including when and how they lived. For example, if weather patterns change this leads to the scarcity of plants or wildlife essential for larger species which may in turn lead to the migration or death of humans and other animals. We are actually seeing this domino effect now in our current environment as global warming escalates.... [tags: evidence, study, time, behavior, society]
1055 words (3 pages)
- Embezzlement has become more common in the last few years. No one knows for sure whether the problem has increased due to the bad economy, less ethical behavior among employees or other attitudes toward the government or businesses in general. Charleston, South Carolina is no exception to the rising number of fraud cases. Every year more cases are being discovered and exposed to the public. One such case is the embezzlement of cash from a county owned garage. The embezzlement case of Martina Moultrie Richardson will be discussed as well as types of evidence desired in this case, methods/procedures for gathering the evidence and procedures for cataloging and maintaining the evidence.... [tags: Case Study ]
2087 words (6 pages)