Nanotechnology Project

1

EE-451: Introduction to Nanotechnology, Spring 2018, Project 1

Project #1: Carbon Nanostructure Simulation with Nanotube Modeler Software In this project, we are going to simulate the structure of carbon nanotube, buckyball, etc. using Nanotube Modeler software. Please refer to our hint file for the details about the Nanotube Modeler software. In the project, you may need to use your student ID for the chirality of the nanotube. If the first or last two digits of your student ID happens to be very small (e.g. 00, 01, etc.), you can add each bit by 6. For example, “01” can be replaced with “67”. In this way, you can still get a reasonable chirality so that the structure of the carbon nanotube can be constructed properly. 1. Simulate the structure of single-wall carbon nanotube with chirality of (n, m), where (n, m) are the last 2 digits of your student ID. For example, if the last 2 digits of your student ID are “48”, then (n, m)=(4, 8). Keep other parameters as defaults. For example: Tube length: 25Å. Bond length: 1.41Å, MWNT: “Number of Walls”: 1, “(n,...) Increament per Wall”: 2, “(..,m) Increment per Wall”: 0. Rotate the SWNT to side view, capture the screen shot and paste it into a MS Word file. Print it out and submit it with your report. 2. Simulate the structure of an (8,8) single-wall carbon nanotube. Capture the screen shot and attach it with your report. Observe its structure. If this (8,8) SWNT is unrolled into a graphene sheet along its axis, sketch the shape of the obtained graphene sheet. Highlight the shape of its top edge. Is it zig-zag or arm-chair shape? (Hint: An example hand-sketch of graphene sheet is shown as below.)

3. Simulate the structure of an (8,0) single-wall carbon nanotube. Capture the screen shot and attach it with your report. Observe its structure. If this (8,0) SWNT is unrolled into a graphene sheet along its axis, sketch the shape of the obtained graphene sheet. Highlight the shape of its top edge. Is it zig-zag or arm-chair shape? 4. Simulate the structure of multi-wall carbon nanotube. Keep all other parameter (including (n, m) values) the same as in question #1, just change “MWNT: Number of Walls” from “1” to “3”. Rotate the 3-Wall carbon nanotube to side view, capture the screen shot and print it out. 5. Simulate the structure of a buckyball (C60). Just click the down arrow below the “Select Type” line, and change “Nano-tube” to “Bucky-Ball”. Capture the screen shot and print it out. Observe its structure, how many hexagons is each pentagon surrounded by? Do you see any two pentagons directly neighboring to each other? Count the C60 structure, how many vertices are there in it? How many edges? How many faces? How many of them are pentagons? How many of them are hexagons? Does it satisfy Euler's polyhedron formula? Please list Euler's polyhedron formula, and verify it for the C60 structure. 6. Simulate a carbon nanotube hetero-junction structure. Select type as “Nano-tube”, and click menu “Special – Hetero-junction”. The chirality of the first nanotube is still the last two digits of your student ID, and the chirality of next nanotube is the first two digits

2

of your student ID. For example, if your student ID is “123456”, then the first nanotube is (5, 6), and next nanotube is (1, 2). The length of both nanotubes is 15Å. Rotate to the side view, capture the screen shot and print it out. 7. Simulate the structure of a capped (6, 6) single-wall carbon nanotube with both ends capped. Just click on menu "Special - Capped tube - Capped (6,6) tube", select "Both Ends". Observe the structure of end caps. Rotate it to the side view, capture the screen shot and print it out. Count how many pentagons are there in each end cap? Are they directly neighboring to each other? 8. Simulate the structure of a graphene sheet. Just select type as “Graphene Sheet”. Observe the structure. Capture the screen shot and print it out. Graphene sheet can be wrapped up into carbon nanotubes, which have extremely large surface-to-volume ratio. Let’s try to estimate the total surface area of 1kg of graphene sheet. 1). Consider one hexagon unit in a graphene sheet. Given the carbon-carbon bond length as acc=1.42Å (1Å=10-10m), calculate the total surface area (both top and bottom surfaces)

of one hexagon unit. (Hint: the area of a hexagon with edge of r is: 2)2/33( rA  ).

2). How many carbon atoms are there in one hexagon unit? (Hint: Each carbon atom is shared by 3 hexagons). 3). Calculate the mass/area density of graphene sheet. (e.g. the mass of carbon atoms per unit graphene surface area). (Hint: The mass of 1 mole (1mole=6.02×1023) carbon atoms is 12g). 4). Based on above calculation, if we have 1kg of graphene sheet, what is the total surface area (both top and bottom surfaces)? 5). The total area of University of Bridgeport is 86 acres (350,000m2). How many times is the total surface area of 1kg graphene sheet compared to the area of University of Bridgeport? What conclusion can you draw from this estimation? Due on 02/26/2018, Monday in class.