Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2007 A Study of Nanostructure and Properties of Mixed Nanotube Buckypaper Materials: Fabrication, Process Modeling Characterization, and Property Modeling Cherng-Shii Yeh Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] THE FLORIDA STATE UNIVERSITY COLLEGE OF ENGINEERING A STUDY OF NANOSTRUCTURE AND PROPERTIES OF MIXED NANOTUBE BUCKYPAPER MATERIALS: FABRICATION, PROCESS MODELING CHARACTERIZATION, AND PROPERTY MODELING By CHERNG-SHII YEH A Dissertation submitted to the Department of Industrial and Manufacturing Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy Degree Awarded: Fall Semester, 2007 The members of the Committee approve the dissertation of Cherng-Shii Yeh defended on November 14. ______________________________ Zhiyong Liang Professor Directing Dissertation ______________________________ Jim P. Zheng Outside Committee Member __________________________________ Ben Wang Committee Member ______________________________ Chuck Zhang Committee Member ______________________________ David Jack Committee Member Approved: _____________________________________________ Chuck Zhang, Chair, Department of Industrial & Manufacturing Engineering _____________________________________________ Ching-Jen Chen, Dean, FAMU-FSU College of Engineering The Office of Graduate Studies has verified and approved the above named committee members. ii TABLE OF CONTENTS LIST OF FIGURES......................................................................................................................................vi LIST OF TABLES........................................................................................................................................ix ABSTRACT ...................................................................................................................................................x CHAPTER 1 INTRODUCTION..................................................................................................................1 1.1 MOTIVATION .........................................................................................................................................1 1.2 TECHNICAL CHALLENGES......................................................................................................................2 1.3 RESEARCH OBJECTIVES .........................................................................................................................3 1.4 STRUCTURE OF THE DISSERTATION .......................................................................................................4 CHAPTER 2 LITERATURE REVIEW......................................................................................................5 2.1 STRUCTURE OF NANOTUBES..................................................................................................................5 2.2 PROPERTIES OF NANOTUBES..................................................................................................................9 2.1.1 Single-walled Nanotubes (SWNTs) ...............................................................................................9 2.1.2 Multi-walled Nanotubes (MWNTs) .............................................................................................10 2.1.3 Carbon Nanofiber (CNF)............................................................................................................11 2.3 DISPERSING NANOTUBES.....................................................................................................................12 2.3.1 Mechanical Methods...................................................................................................................12 2.3.2 Chemical Methods.......................................................................................................................14 2.4 CARBON NANOTUBE BUCKYPAPER .....................................................................................................16 2.5 CHARACTERIZATION OF NANOSTRUCTURE..........................................................................................21 2.5.1 Rope Size Distribution ................................................................................................................21 2.5.2 Length Distribution.....................................................................................................................24 2.6 SURFACE AREA OF BUCKYPAPER ........................................................................................................25 2.7 ELECTRICAL CONDUCTIVITY OF BUCKYPAPERS ..................................................................................27 2.8 SUMMARY ...........................................................................................................................................29 CHAPTER 3 OPTIMIZATION OF A SWNT BUCKYPAPER FABRICATION PROCESS.............30 3.1 INTRODUCTION....................................................................................................................................30 3.2 METHODOLOGY...................................................................................................................................32 3.2.1 Characterization of Nanostructure and SWNT Rope Size Distribution ......................................32 3.2.2 Statistical Analysis of the Manufacturing Process of SWNT Buckypaper...................................34 3.3 OPTIMIZATION OF THE MANUFACTURING PROCESS OF SWNT BUCKYPAPER .....................................38 3.4 EXPERIMENTAL VALIDATIONS ............................................................................................................41 3.5 OPTIMUM DESIGN OF SONICATION USING FLOCELL.........................................................................42 3.6 SUMMARY ...........................................................................................................................................44 CHAPTER 4 MANUFACTURING PROCESS AND EXPERIMENTAL DESIGN OF MIXED BUCKYPAPERS .........................................................................................................................................46 4.1 INTRODUCTION....................................................................................................................................46 4.2 EXPERIMENTS......................................................................................................................................47 4.3 EXPERIMENTAL DESIGN OF MIXED BUCKYPAPER MANUFACTURING PROCESS...................................49 4.4.1 Factor Selections.........................................................................................................................51 4.4.2 Responses of Interest...................................................................................................................52 4.5 EXPERIMENTAL DESIGN AND STATISTICAL ANALYSIS OF MBPS ........................................................53 4.5.1 Uniformity...................................................................................................................................53 4.5.2 Purity ..........................................................................................................................................55 4.5.3 BET Surface Area........................................................................................................................56 4.5.4 Electrical Conductivity ...............................................................................................................56 4.5.5 Nanostructure and Properties of MBP........................................................................................57 4.6 SUMMARY ...........................................................................................................................................59 iii CHAPTER 5 STATISTICAL CHARACTERIZATION OF NANOSTRUCTURE OF MIXED BUCKYPAPERS .........................................................................................................................................60 5.1 INTRODUCTION....................................................................................................................................60 5.2 METHODOLOGY...................................................................................................................................60 5.2.1 Rope Size Measurement ..............................................................................................................61 5.2.2 Length Measurement...................................................................................................................62 5.2.3 Pore Size Measurement...............................................................................................................64 5.2.4 Expectation-Maximization Algorithm .........................................................................................66 5.2.5 Goodness of Fit...........................................................................................................................70 5.3 ROPE SIZE DISTRIBUTION OF MIXED BUCKYPAPERS ...........................................................................71 5.3.1 Mixed Rope Size Distributions of Mixed Buckypapers................................................................71 5.3.2 Rope Size Distribution of SWNTs................................................................................................75