Project #6 Surface Modification of Carbon Nanotubes for Property Improvement Cuong Diep – pre-junior, Chemical Engineering Milena Fernandez – pre-junior, Computer Engineering College of Engineering and Applied Science; University of Cincinnati; Cincinnati, Ohio Dr. Vesselin Shanov- Chemical and Materials Engineering, CEAS Dr. Noe Alvarez- Chemical and Materials Engineering, CEAS Sponsored ByThe National Science Foundation Grant ID No.: DUE

Outline 1.Goals and Objectives 2.Carbon Nanotubes (CNTs) 3.The processes of improving CNTs thread –Densification –Doping –Coating 4.Integration of the transformer 5.CNT future applications 6.Summary 7.Conclusion 2

Goals To design a transformer using CNTs thread 3 Objectives 1.To design transformer 2.To modify CNTs thread by the processes of densification, doping and coating. 3.To wind CNTs thread on transformer. 4.To induce voltage to transformer and power up a light source. CNTs- Carbon nanotubes Transformer- electrical device

Carbon Nanotubes Carbon nanotubes (CNTs) are an interesting type of material due to its superior strength, and electrical conductivity. 4 Shi, Z., Wang, Z., Gu, Z., Pristine and Filled Double-Walled Carbon Nanotubes (image) Guardian.co.uk

Carbon Nanotubes Founded in 1991 by Sumio Lijima Hollow cylinders made out of carbon atoms 10,000 times smaller than a human hair 5

Comparison 6 My HairCNTs Thread 10,000 times larger

Chemical Vapor Deposition (CVD) An irreversible deposition of a solid from a mixture of gases through a heterogeneous chemical reaction 7

CNTs Thread CNTs thread gets spun up from a silicon wafer This process is like spinning cotton 8

Densification The soaking of CNTs thread in solution containing water and acetone. This procedure helps improve the CNT thread by increasing the diameter of the thread and slightly increasing its strength. 9

Chemical Doping A process of bonding electrons to the surface of the thread by disassociating an acidic solution. –Nitric Acid –Sulfuric Acid 10

SEM Pictures 11 UC Nanoworld Doped ThreadUn-doped Thread The doped thread is 6.5x small in diameter than the undoped

Resistivity- Measurement of how a material opposes the flow of electrons. Lowers through doping Resistivity is inversely proportional to the diameter of the thread 12

Doping Results MaterialAverage Resistivity (Ω  m) CNT (Nitric Acid)1.12*10 -5 CNT (Sulfuric Acid)1.20*10 -5 Copper1.68*

Coating A process of covering the thread with a thin layer of insulated polymer –Nylon –PVA –Nitrile 14

Transformer What is it? How are we using it? Why are we using it? 15 Source: eHow

Transformer Works on Faraday’s Law of induction Changes voltage and current levels Remains the same power Induced voltage vs. N(number of turns) 16 N-North S-South Source: WorldPress

What is it used for? Assists as voltage/current regulator Within the project… Will prove properties of CNTs 17

Final Product 18 Source: Energy Efficiency Power supply connected to primary coil Light source connected to secondary coil CNTs threads will replace insulated coils Transformer

Transformer with the LED Bulb 19

Transformer with CNTs 20

Transformer with the LED 21

Data 22

CNT applications CNTs Cable Wire –Light weight –High temperature resistance –Durable 23 Windsun.com

Conclusion Chemical Vapor Deposition is one way to make CNTs Lighter, and durable cables will incorporate CNTs 24

Recommendations for Additional Research Add more windings Find the right inverter Try different type of doping solution Improve coating - PVA 25

Acknowledgements Dr. Vesselin Shanov Dr. Noe Alvarez Nicholas Kienzle Brad Ruff Doug Hurd UC Nanoworld NSF - Grant ID No.: DUE

Questions ? 27