The exploration of IN SITU carbon carbon transitions to form porous fibers

THE EXPLORATION OF IN SITU CARBONCARBON TRANSITIONS TO FORM POROUS FIBERS ZHOU YI’EN (B.Eng (Chemical) (Hons.), NUS) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF CHEMICAL AND BIOMOLECULAR ENGINEERING NATIONAL UNIVERSITY OF SINGAPORE 2013 DECLARATION I hereby declare that this thesis is my original work and it has been written by me in its entirety. I have duly acknowledged all the sources of information which have been used in the thesis. This thesis has also not been submitted for any degree in any university previously. ZHOU YI’EN 31 December 2013 Declaration Page Page Acknowledgements I would firstly like to express my sincere gratitude and heartfelt appreciation to my supervisor, Associate Professor Hong Liang for his patient guidance and continual encouragement, in addition to his valuable advice and unceasing support throughout the duration of my Ph.D. project, without which the completion of this work would not have been able to proceed as smoothly and swiftly. My sincere thanks also go out to my colleagues Mr. Chen Fuxiang, Mr. Ng Yeap Hung, Ms. Xing Zheng, Dr. Chen Xinwei, Dr. Sun Ming, Dr. Liu Lei and Dr. Guo Bing for their encouragement, support and camaraderie throughout the duration of my PhD course. I would also like to recognize the contributions of Mr. Ng Kim Poi for his timely assistance and advice on fabrication and design of the various setups used in my experiments, laboratory staff Mr. Alistair Chan, Mr. Ang Wee Siong, Ms. Xu Yanfang and Ms. Sandy Khoh for their assistance on equipment usage as well as purchases. I am exceptionally grateful to my family members, especially my wife, who supported me and encouraged me during my PhD course as well as fervently prayed for me. I thank God for them and for his blessings showered upon me. Finally, I would like to acknowledge all the other staff in National University of Singapore (NUS) and NRF grants (R279-000-261-281, R279-000-388-281) for the support and funding of my research. Acknowledgements Page Contents Acknowledgements Table of Figures . Summary 11 Introduction 13 1.1 Motivation and Overview 13 1.2 Research Objectives 14 1.3 Thesis Structure . 15 1.4 Author’s Note 19 Background and Theory . 20 2.1 Porous Carbon Nanofibers 21 The Growth of Porous Carbon Fibers Through in situ Vapor Deposition24 3.1 Porous Carbon Fibers Abstract . 24 3.2 Introduction to Porous Carbon Fibers . 24 3.3 Literature Review of Porous Fibrous Activated Carbons . 26 3.3.1 Gas Adsorption Isotherms 27 3.3.2 Mesopore analysis – Barrett-Joyner-Halenda (BJH) method 27 3.3.3 Formation of Porous Carbons 29 3.4 Experimental Procedures . 30 3.4.1 Formation of Porous Carbon Fibers . 30 3.4.2 Surface Condition Analysis and Structural Characterizations . 32 Contents Page 3.4.3 3.5 Results and Discussions 33 3.5.1 Analysis of Surface Condition . 33 3.5.2 Pore Analysis of Porous Carbon Fibers . 36 3.5.3 FTIR Characterization of Porous Carbon Fibers . 42 3.5.4 H2S Adsorption Test 44 3.6 H2S Adsorption Test 33 Conclusion . 45 Growth of Dendritic Micron-sized Carbon Spines in a Vortex Field over the Pt-aided Sublimation Frontier 47 4.1 Abstract . 47 4.2 Introduction . 47 4.3 Experimental Procedure 49 4.3.1 Carbon Spinal Growth . 50 4.3.2 Dendritic Carbon Growth 50 4.4 Results and Discussion 51 4.4.1 Formation of Dendritic Structures at Solid-cogas Interface 51 4.4.2 Formation of Carbon Spinal Structures . 55 4.4.3 Analysis of Structural Characteristics of Fiber and Flake Network 57 4.4.4 4.5 Raman Spectroscopy 58 Conclusion . 60 Evolution of Carbon Micron Rods via Assembling of Curvature PAH Sheets . 61 5.1 Abstract . 61 Contents Page 5.2 Introduction . 62 5.3 Experimental Procedure 63 5.3.1 Synthesis of PAH flakes 63 5.3.2 Carbon-Carbon transition to Carbon Micron Rods (CMR) . 64 5.4 Results and Discussion 65 5.4.1 CMR observation and Nanotube growth from PAH flake . 65 5.4.2 Surface and Bulk features of MCR 72 5.4.3 Infrared finger prints to scrutinize fine carbon structures 76 5.4.4 Unique structural character of PET as precursor leading to CMRs formation . 77 5.5 Conclusion . 79 The Incorporation of Adsorptive Carbon into Zinc-doped Kaolinite Support Matrix for Phenol Removal 80 6.1 Abstract . 80 6.2 Introduction . 80 6.3 Experimental Procedure 81 6.3.1 Fabrication of High Porosity Kaolin pellet 81 6.3.2 Fabrication of High Porosity Kaolin Hollow Tube 83 6.3.3 Inclusion of carbonaceous matrix 83 6.4 Results and Discussion 83 6.4.1 Fabrication of high porosity zinc-doped kaolin matrix 84 6.4.2 Honeycomb porous activated carbon flakes and Fibrous growth 89 6.4.3 Removal of dilute phenol via adsorption . 91 6.5 Conclusion . 93 Contents Page Conclusion 94 7.1 Recommended Future Work . 96 Acknowledgements 97 References 98 Contents Page Table of Figures Figure 1: (a) Activated carbon flake; (b) Pure N2 5h incubation; (c) N2-CO2 5h incubation; (d) TEM image of fiber from sample 1(c). . 31 Figure 2: Magnified view of a single fiber grown from graphite particles attached to its surface under N2-CO2 incubation. 34 Figure 3: X-ray Diffraction results of AC under various conditions showing crystalline properties 37 Figure 4: Isotherms of BET with pore volume and surface areas for various pore structures. . 38 Figure 5: FT-IR spectra showing the various changes in organic functional groups due to activation and incubation. . 43 Figure 6: H2S gas adsorption test results (per gram of adsorbent) for breakthrough 45 Figure 7: Schematic of setup used for the formation of dendritic growth . 52 Figure 8: TEM image of dendrite produced by sputtered Pt; enlarged image of carbon spines (inset) 54 Figure 9: Tree-like growth from a main stem observed from sputtered Pt sample. . 54 Figure 10: Dense needle-like spines growing radially from flakes . 55 Figure 11: Carbon spines growing radially from a carbon flake center 56 Figure 12: XRD plot comparing the various treated activated carbon samples 57 Table of Figures Page Figure 13: Raman Spectrum of sample prepared by Pt-sputtering and incubation (Sputtered Pt) and microwave method after incubation (Microwaved Pt) 59 Figure 14: (a) Polyethylene terephthalate flake; (b) Polyethylene terephthalate fiber after co-gas treatment 66 Figure 15: Activated carbon flake obtained from carbonization of pristine PET without co-gas treatment 67 Figure 16: Carbon nanotubes growing forth directly from the carbonized PET flake 67 Figure 17: Carbon nanotube produced from PET under co-gas atmosphere . 69 Figure 18: 13C-NMR of the carbon sample obtained from carbonizing polypyrrole and calcination at 600 °C for h in Ar. . 70 Figure 19: Activated carbon flake obtained from carbonization of PPy without co-gas treatment . 71 Figure 20: Trace amount of fibers formed in PPy after co-gas treatment . 71 Figure 21: Slight ditches formed due to CO2 etching 72 Figure 22: Isotherm and pore characteristics measurement . 73 Figure 23: X-ray Diffraction plot of pre and post-treated activated carbon flakes 74 Figure 24: PET flake with presence of agglomerated fullerene along CNTs formed 76 Table of Figures Page Figure 25: FTIR characterization to verify significant changes between the carbon skeletons of the PET activated carbon flakes and the co-gas treated CMR . 77 Figure 26: Reaction mechanism inducing CMR growth . 78 Figure 27: Opening of Cn-fullerene cages by co-gas treatment . 79 Figure 28: Well-formed zinc-doped kaolin matrix 85 Figure 29: XRD diffraction pattern of the kaolinite matrix 5% doping after calcination at 1150 °C for 6h. (•) mullite; (*) ZnO2 86 Figure 30: XPS plot demonstrating peak shift after doping 87 Figure 31: Pore characteristics of sintered kaolin matrix 88 Figure 32: Fiber growth along the edges of an alpha D+ glucose honeycomb porous flake 90 Figure 33: Increase in crystalline properties after co-gas treatment corresponding to fibre growth 91 Figure 34: Phenol rejection rates for various loading of glucose (0.5M – 2M) and zinc (5wt% - 20wt%) 92 Figure 35: Variation of rejection rate with volume of permeate . 93 Table of Figures Page 10 noteworthy observation was the honeycomb porous feature of the porous AC flakes that were formed without the aid of a template, unlike what was done previously [106-111]. Figure 32: Fiber growth along the edges of an alpha D+ glucose honeycomb porous flake The growth of the fibers in the carbonized -D-glucose polymer sample is attributed to the same process outlined in 3.4.1. However, the fibers formed are not as porous but similarly exhibit an increase in crystalline properties after the fibers are formed, as shown in the XRD plot in Figure 33. This supports the theory that the fibers must have been formed via the same layerby-layer sublimation-condensation mechanism in order to increase the crystallinity of the internal lattice structure of the carbon. Once again, this fact Page 90 emphasizes the importance of the polymer precursor in the formation of porous AC. Figure 33: Increase in crystalline properties after co-gas treatment corresponding to fibre growth 6.4.3 Removal of dilute phenol via adsorption A layer of glucose is coated on the walls of the pore channels of the zincdoped kaolin support matrix and carbonized in inert argon atmosphere. The dilute phenol (100ppm, 0.5bar feed pressure) that flows through the pore channels would be adsorbed onto the surface of the hydrophobic carbonaceous phase that lines the walls of the pore channels, allowing only the water to pass Page 91 through. UV-VIS characterization of the feed and subsequent rejection rate was measured and tabulated for various concentrations of glucose introduced into the matrix and the corresponding rejection rates. Figure 34: Phenol rejection rates for various loading of glucose (0.5M – 2M) and zinc (5wt% 20wt%) Increasing the loading of glucose within the pore channels helped to improve the rejection rates over time substantially whilst increasing the loading of zinc did not seem to affect the rejection rates significantly. However, increasing the loading of zinc during the doping phase correspondingly increased the flux of the final membranes by a factor of 3. This is shown in Figure 35 with a plot of rejection rate against the volume of permeate collected over the same period of time. Page 92 Figure 35: Variation of rejection rate with volume of permeate 6.5 Conclusion A novel method for the creation of a high porosity kaolin matrix support with improved physical properties was investigated in detail in this work. The zincdoped kaolin matrix was well-formed and exhibited a modulus of rupture of 32.7MPa with 32.1% porosity, 0.1966cm3/g total intrusion volume and a total pore area of 4.465m2/g. Subsequently, glucose polymer was introduced into the pore channels of the kaolin support matrix and coated onto the walls before being carbonized to form a continuous carbonaceous media for removal of dilute phenol via adsorption. In the best results obtained to-date, the rejection rate remained at 100% after a period of 60min of continuous testing with a flux of 12L/ m2h. Page 93 Conclusion In this thesis, carbon to carbon transitions have been explored and greater indepth understanding of the ways polymer precursors will profoundly impact the eventual properties of the activated carbons produced have been documented and proven. The author has observed and described the phenomenon of AC flakes sourced from HEC undergoing a vaporizationcondensation process to transform into fibrous structures under a CO2containing binary atmosphere at 800 oC. This C-C transition leads to fibrous activated carbon with sizes between carbon nanotube and carbon fiber and a micro to meso porous structure. The co-gas of CO2 plays a vital role in shaping the evolution of the activated fiber and, in particular, its porous structure. This phenomenon is presumed to originate from the different molecular collision efficiencies and the kinetic diameters of gases. Eventually, the H2S adsorption test was undertaken to validate the surface properties obtained from BET analysis. Subsequently, platinum was used to mediate the process and it was demonstrated that dendritic carbon growth could be effectively produced from regular activated carbon flakes through the use of activated carbon flakes coated with platinum in a co-gas atmosphere. This phenomenon has never been observed anywhere else before for a solid-gaseous interface nor ever for a solid carbon substance. Once again, the atmosphere plays a vital role in this conversion but more importantly, the presence of the hydrate group in the Page 94 precursor is a key element in the production of the carbon dendrites. This is especially apparent when conducting the control experiments and polypyrrole was unresponsive to the treatment despite being incubated under similar conditions to HEC as well as -D-glucose polymer. The amount of platinum coated onto the activated carbon flakes is also pivotal in the final structure of dendritic growth obtained. Whilst treatment with lower concentrations of platinum results in bushy tree-like structures, increasing the platinum loading results in spikey cactus-like growth of carbon needle-like spines. A more intriguing finding was when PET was used as the precursor for the production of activated carbon. Whilst it can be proven that the co-gas method is pivotal in the formation of carbon fibers earlier, it also led to the production of carbon micron rods and nanotubes when PET was carbonized and treated in the co-gas atmosphere. In particular, it is noteworthy that nanotubes could be grown without the need for metal catalysts and just using the co-gas process as demonstrated in this paper. The growth of the nanotubes stemmed from the formation of macromolecular carbons that seeded the radial growth of hollow nanotubes from the carbonized PET flakes and were assembled with graphitized flakes that had vaporized and had high affinity for similar carbons when condensed. These carbons assembled around the central macromolecular carbon and continuously pushed it outward as the assembly process continued. Finally, an application was developed for the carbon to carbon transitions process that I have developed. A novel method for the creation of a high Page 95 porosity kaolin matrix support with improved physical properties was outlined in detail. The zinc-doped kaolin matrix was well-formed and exhibited a modulus of rupture of 32.7MPa with 32.1% porosity, 0.1966cm3/g total intrusion volume and a total pore area of 4.465m2/g. Subsequently, glucose polymer was introduced into the pore channels of the kaolin support matrix and coated onto the walls before being carbonized to form a continuous carbonaceous media for removal of dilute phenol via adsorption. In the best results obtained to-date, the rejection rate remained at 100% after a period of 60min of continuous testing with a flux of 12L/ m2h. 7.1 Recommended Future Work As an extension of the current work, the porous fibrous carbon powder could be further used for a gas purification application where the increase in adsorption active surface area would improve its adsorptive capacity substantially. In addition, the porous fibrous carbon can also be used as anode materials in lithium batteries applications. These viable options can also be easily scaled up as the conditions are straightforward and costs are fairly low. Further exploration of the template-free approach for the synthesis of the honeycomb-like carbon structure can be made in order to use it for various applications in the oil and gas as well as wastewater treatment industries. As the removal of phenol from oily water has been shown to be viable, scaling up the process for commercialization would prove to be highly attractive as phenol is currently a huge challenge especially to industries heavily reliant on Page 96 polymeric membranes as these will be degraded quickly with the presence of phenol. A green initiative would also be to convert waste PET plastics into intertwined micro-carbon rods generated from the C-C transition as filler for composite materials instead of metals. Acknowledgements The author would like to thank the National University of Singapore (NUS) and Singapore National Research Foundation (NRF grant no: R-279-000-261281 and R-279-000-388-281) for the financial support rendered in the course of this research work. Page 97 References [1] J.L. Figueiredo, Functionalization of porous carbons for catalytic applications, Journal of Materials Chemistry A, (2013) 9351-9364. [2] A.R. Silva, C. Freire, B. de Castro, M.M.A. Freitas, J.L. Figueiredo, Anchoring of a nickel(II) Schiff base complex onto activated carbon mediated by cyanuric chloride, Microporous and Mesoporous Materials, 46 (2001) 211-221. [3] A.R. Silva, M. Martins, M.M.A. Freitas, A. Valente, C. Freire, B. de Castro, J.L. Figueiredo, Immobilisation of amine-functionalised nickel(II) Schiff base complexes onto activated carbon treated with thionyl chloride, Microporous and Mesoporous Materials, 55 (2002) 275-284. [4] R.E. Morris, P.S. Wheatley, Gas storage in nanoporous materials, Angewandte Chemie - International Edition, 47 (2008) 4966-4981. [5] G.P. Hao, W.C. Li, A.H. Lu, Novel porous solids for carbon dioxide capture, Journal of Materials Chemistry, 21 (2011) 6447-6451. [6] G.P. Pandey, A.C. Rastogi, C.R. Westgate, All-solid-state supercapacitors with poly(3,4-ethylenedioxythiophene)- coated carbon fiber paper electrodes and ionic liquid gel polymer electrolyte, Journal of Power Sources, 245 (2014) 857-865. [7] K. Zhang, Z. Hu, J. Chen, Functional porous carbon-based composite electrode materials for lithium secondary batteries, Journal of Energy Chemistry, 22 (2013) 214-225. [8] G. Hasegawa, T. Sato, K. Kanamori, K. Nakano, T. Yajima, Y. Kobayashi, H. Kageyama, T. Abe, K. Nakanishi, Hierarchically porous monoliths based on N-doped reduced titanium oxides and their electric and electrochemical properties, Chemistry of Materials, 25 (2013) 3504-3512. [9] M. Noked, A. Soffer, D. Arubach, The electrochemistry of activated carbonaceous materials: Past, present, and future, Journal of Solid State Electrochemistry, 15 (2011) 1563-1578. [10] F. Wang, S. Xiao, Y. Hou, C. Hu, L. Liu, Y. Wu, Electrode materials for aqueous asymmetric supercapacitors, RSC Advances, (2013) 13059-13084. [11] X. Li, B. Wei, Supercapacitors based on nanostructured carbon, Nano Energy, (2013) 159-173. [12] H. Xia, Z. Luo, J. Xie, Nanostructured LiMn2O4 and their composites as highperformance cathodes for lithium-ion batteries, Progress in Natural Science: Materials International, 22 (2012) 572-584. [13] H. Zhan, J. Xiao, Z. Nie, X. Li, C. Wang, J.-G. Zhang, J. Liu, Nanostructured materials for rechargeable batteries: synthesis, fundamental understanding and limitations, Current Opinion in Chemical Engineering, (2013) 151-159. [14] X. Mao, T. Alan Hatton, G.C. Rutledge, A review of electrospun carbon fibers as electrode materials for energy storage, Current Organic Chemistry, 17 (2013) 13901401. [15] S.L. Candelaria, Y. Shao, W. Zhou, X. Li, J. Xiao, J.-G. Zhang, Y. Wang, J. Liu, J. Li, G. Cao, Nanostructured carbon for energy storage and conversion, Nano Energy, (2012) 195-220. [16] A. Chen, P. Holt-Hindle, Platinum-Based Nanostructured Materials: Synthesis, Properties, and Applications, Chemical Reviews, 110 (2010) 3767-3804. Page 98 [17] S. Dong, X. Chen, X. Zhang, G. Cui, Nanostructured transition metal nitrides for energy storage and fuel cells, Coordination Chemistry Reviews, 257 (2013) 19461956. [18] E. Frackowiak, F. Béguin, Electrochemical storage of energy in carbon nanotubes and nanostructured carbons, Carbon, 40 (2002) 1775-1787. [19] Y. Wu, X. Zhao, Y. Zhao, S. Liu, Synthesis and structure control of hierarchical ordered porous carbons via soft-templating methods, Progress in Chemistry, 25 (2013) 735-743. [20] C. Marichy, N. Pinna, Carbon-nanostructures coated/decorated by atomic layer deposition: Growth and applications, Coordination Chemistry Reviews, 257 (2013) 3232-3253. [21] E. Frank, F. Hermanutz, M.R. Buchmeiser, Carbon fibers: Precursors, manufacturing, and properties, Macromolecular Materials and Engineering, 297 (2012) 493-501. [22] Y. Liu, S. Kumar, Recent progress in fabrication, structure, and properties of carbon fibers, Polymer Reviews, 52 (2012) 234-258. [23] J.A. Newell, D.D. Edie, Factors limiting the tensile strength of PBO-based carbon fibers, Carbon, 34 (1996) 551-560. [24] Y.S. Bae, R.Q. Snurr, Development and evaluation of porous materials for carbon dioxide separation and capture, Angewandte Chemie - International Edition, 50 (2011) 11586-11596. [25] C.E. Wilmer, O.K. Farha, Y.-S. Bae, J.T. Hupp, R.Q. Snurr, Structure-property relationships of porous materials for carbon dioxide separation and capture, Energy Environ. Sci., (2012) 9849-9856. [26] Y.-N. Jan, L.Y. Jan, Branching out: mechanisms of dendritic arborization, Nat Rev Neurosci, 11 (2010) 316-328. [27] R.O.L. Wong, A. Ghosh, Activity-dependent regulation of dendritic growth and patterning, Nat Rev Neurosci, (2002) 803-812. [28] J. Nacher, R. Guirado, E. Castillo-Gómez, Structural plasticity of interneurons in the adult brain: Role of PSA-NCAM and implications for psychiatric disorders, Neurochemical Research, 38 (2013) 1122-1133. [29] T. Shirao, C. González-Billault, Actin filaments and microtubules in dendritic spines, Journal of Neurochemistry, 126 (2013) 155-164. [30] M. Eshraghi, S.D. Felicelli, B. Jelinek, Three dimensional simulation of solutal dendrite growth using lattice Boltzmann and cellular automaton methods, Journal of Crystal Growth, 354 (2012) 129-134. [31] M.E. Glicksman, A.O. Lupulescu, Dendritic crystal growth in pure materials, Journal of Crystal Growth, 264 (2004) 541-549. [32] E. Acer, H. Erol, M. Gündüz, Relationship between growth rates and dendritic microstructure parameters in Al-5wt. Zn binary alloy, in, 2013, pp. 215-219. [33] M. Chen, X.D. Hu, D.Y. Ju, H.Y. Zhao, The microstructure prediction of magnesium alloy crystal growth in directional solidification, Computational Materials Science, 79 (2013) 684-690. [34] I. Kaldre, Y. Fautrelle, J. Etay, A. Bojarevics, L. Buligins, Thermoelectric current and magnetic field interaction influence on the structure of directionally solidified Sn-10 wt.%Pb alloy, Journal of Alloys and Compounds, 571 (2013) 50-55. Page 99 [35] U. Patakham, J. Kajornchaiyakul, C. Limmaneevichitr, Modification mechanism of eutectic silicon in Al-6Si-0.3Mg alloy with scandium, Journal of Alloys and Compounds, 575 (2013) 273-284. [36] M.-w. Wu, S.-m. Xiong, Modeling of equiaxed and columnar dendritic growth of magnesium alloy, Transactions of Nonferrous Metals Society of China, 22 (2012) 2212-2219. [37] P. Zhao, M. Vénere, J.C. Heinrich, D.R. Poirier, Modeling dendritic growth of a binary alloy, Journal of Computational Physics, 188 (2003) 434-461. [38] T.R. Anthony, J.C. Bradley, P.J. Horoyski, M.L.W. Thewalt, Graphite rod precursors for isotopically pure fullerenes and diamond, Carbon, 34 (1996) 13231328. [39] Q. An, A.N. Rider, E.T. Thostenson, Hierarchical composite structures prepared by electrophoretic deposition of carbon nanotubes onto glass fibers, ACS Applied Materials and Interfaces, (2013) 2022-2032. [40] Z. Liu, H. Nie, Z. Yang, J. Zhang, Z. Jin, Y. Lu, Z. Xiao, S. Huang, Sulfur-nitrogen codoped three-dimensional carbon foams with hierarchical pore structures as efficient metal-free electrocatalysts for oxygen reduction reactions, Nanoscale, (2013) 3283-3288. [41] M.Q. Zhao, Q. Zhang, X.L. Jia, J.Q. Huang, Y.H. Zhang, F. Wei, Hierarchical composites of single/double-walled carbon nanotubes interlinked flakes from direct carbon deposition on layered double hydroxides, Advanced Functional Materials, 20 (2010) 677-685. [42] R.W. Fu, Z.H. Li, Y.R. Liang, F. Li, F. Xu, D.C. Wu, Hierarchical porous carbons: design, preparation, and performance in energy storage, Xinxing Tan Cailiao/New Carbon Materials, 26 (2011) 171-179. [43] Y. Saito, NANOPARTICLES AND FILLED NANOCAPSULES, Carbon, 33 (1995) 979988. [44] K.Y. Lee, T. Ikuno, K. Tsuji, S. Ohkura, S. Honda, M. Katayama, K. Oura, T. Hirao, Synthesis of aligned bamboo-like carbon nanotubes using radio frequency magnetron sputtering, Journal of Vacuum Science & Technology B, 21 (2003) 14371441. [45] O. Tiprigan, A.A. Koos, P. Nemes-Incze, Z.E. Horvath, Z. Sarkozi, S. Simon, A. Darabont, L.P. Biro, Obtaining bamboo-structured, multiwalled carbon nanotubes using the spray pyrolysis method, Journal of Optoelectronics and Advanced Materials, (2007) 617-620. [46] Y.M. Chen, H.Y. Zhang, Q.F. Zhu, Y.T. Chen, L.C. Chen, D.Y. Yang, SYNTHESIS OF ALIGNED CARBON NANOTUBES ARRAY BY RADIO FREQUENCY PLASMA-ENHANCED HOT FILAMENT CHEMICAL VAPOR DEPOSITION, Journal of Infrared and Millimeter Waves, 27 (2008) 470-474. [47] T.J. Zhao, W.Z. Sun, X.Y. Gu, M. Ronning, D. Chen, Y.C. Dai, W.K. Yuan, A. Holmen, Rational design of the carbon nanofiber catalysts for oxidative dehydrogenation of ethylbenzene, Applied Catalysis a-General, 323 (2007) 135-146. [48] M. Suzuki, Activated carbon fiber: Fundamentals and applications, Carbon, 32 (1994) 577-586. Page 100 [49] J. Chen, J.Z. Wang, A.I. Minett, Y. Liu, C. Lynam, H.K. Liu, G.G. Wallace, Carbon nanotube network modified carbon fibre paper for Li-ion batteries, Energy Environ. Sci., (2009) 393-396. [50] P.J.M. Carrott, J.M.V. Nabais, M.M.L. Ribeiro Carrott, J.A. Pajares, Preparation of activated carbon fibres from acrylic textile fibres, Carbon, 39 (2001) 1543-1555. [51] D. Tashima, A. Sakamoto, M. Taniguchi, T. Sakoda, M. Otsubo, Surface modification of carbon electrodes using an argon plasma, Vacuum, 83 (2008) 695698. [52] H.-C. Lin, S.-T. Shiue, Y.-H. Cheng, T.-J. Yang, T.-C. Wu, H.-Y. Lin, Characteristics of carbon coatings on optical fibers prepared by plasma enhanced chemical vapor deposition using different argon/methane ratios, Carbon, 45 (2007) 2004-2010. [53] J.T. Zhu, J.C. Jia, F.L. Kwong, D.H.L. Ng, Synthesis of bamboo-like carbon nanotubes on a copper foil by catalytic chemical vapor deposition from ethanol, Carbon, 50 (2012) 2504-2512. [54] D. Attan, M.A. Alghoul, B.B. Saha, J. Assadeq, K. Sopian, The role of activated carbon fiber in adsorption cooling cycles, Renewable and Sustainable Energy Reviews, 15 (2011) 1708-1721. [55] E.A. Dawson, G.M.B. Parkes, P.A. Barnes, M.J. Chinn, L.A. Pears, C.J. Hindmarsh, A study of evolved gas control and its effect on carbon yield during the activation of carbon fibres by controlled rate methods, Carbon, 40 (2002) 2897-2903. [56] Y.K. Zhan, C.Y. Nie, H.B. Li, L.K. Pan, Z. Sun, Enhancement of electrosorption capacity of activated carbon fibers by grafting with carbon nanofibers, Electrochimica Acta, 56 (2011) 3164-3169. [57] J.Y. Zhou, Z.W. Wang, R. Zuo, Y. Zhou, X.M. Cao, K. Cheng, The surface structure and chemical characters of activated carbon fibers modified by plasma, Asia-Pac. J. Chem. Eng., (2012) S245-S252. [58] M. Aceituno-Medina, A. Lopez-Rubio, S. Mendoza, J.M. Lagaron, Development of novel ultrathin structures based in amaranth (Amaranthus hypochondriacus) protein isolate through electrospinning, Food Hydrocolloids, 31 (2013) 289-298. [59] S. Agarwal, A. Greiner, J.H. Wendorff, Functional materials by electrospinning of polymers, Progress in Polymer Science, 38 (2013) 963-991. [60] T. Maitra, S. Sharma, A. Srivastava, Y.-K. Cho, M. Madou, A. Sharma, Improved graphitization and electrical conductivity of suspended carbon nanofibers derived from carbon nanotube/polyacrylonitrile composites by directed electrospinning, Carbon, 50 (2012) 1753-1761. [61] Y. Qiu, J. Yu, T. Shi, X. Zhou, X. Bai, J.Y. Huang, Nitrogen-doped ultrathin carbon nanofibers derived from electrospinning: Large-scale production, unique structure, and application as electrocatalysts for oxygen reduction, Journal of Power Sources, 196 (2011) 9862-9867. [62] X. Song, Z. Wang, Z. Li, C. Wang, Ultrafine porous carbon fibers for SO2 adsorption via electrospinning of polyacrylonitrile solution, Journal of Colloid and Interface Science, 327 (2008) 388-392. [63] A. Greiner, J.H. Wendorff, Electrospinning: A fascinating method for the preparation of ultrathin fibers, Angewandte Chemie - International Edition, 46 (2007) 5670-5703. Page 101 [64] M. Wang, Z.H. Huang, Y. Bai, F. Kang, M. Inagaki, Porous carbon nanofibers: Preparation and potential applications, Current Organic Chemistry, 17 (2013) 14341447. [65] J. Alcañiz-Monge, D. Cazorla-Amorós, A. Linares-Solano, S. Yoshida, A. Oya, Effect of the activating gas on tensile strength and pore structure of pitch-based carbon fibres, Carbon, 32 (1994) 1277-1283. [66] D. Gunther, J. Beckmann, M. Schoneich, P. Schmidt, O. Klepel, Porous concrete as a template for the synthesis of porous carbon materials, Carbon, 50 (2012) 30963098. [67] S. Lei, J.I. Miyamoto, T. Ohba, H. Kanoh, K. Kaneko, Novel nanostructures of porous carbon synthesized with zeolite LTA-template and methanol, J. Phys. Chem. C, 111 (2007) 2459-2464. [68] Y. Meng, D. Gu, F.Q. Zhang, Y.F. Shi, H.F. Yang, Z. Li, C.Z. Yu, B. Tu, D.Y. Zhao, Ordered mesoporous polymers and homologous carbon frameworks: Amphiphilic surfactant templating and direct transformation, Angewandte Chemie-International Edition, 44 (2005) 7053-7059. [69] C. He, L.Z. Sun, J. Zhong, Prediction of superhard carbon allotropes from the segment combination method, Journal of Superhard Materials, 34 (2012) 386-399. [70] F.P. Bundy, W.A. Bassett, M.S. Weathers, R.J. Hemley, H.K. Mao, A.F. Goncharov, The pressure-temperature phase and transformation diagram for carbon; updated through 1994, Carbon, 34 (1996) 141-153. [71] V.V. Brazhkin, A.G. Lyapin, S.V. Popova, S.C. Bayliss, T.D. Varfolomeeva, R.N. Voloshin, A.G. Gavrilyuk, M.V. Kondrin, V.V. Mukhamad'yarov, I.A. Troyan, S.V. Demishev, A.A. Pronin, N.E. Sluchanko, Interplay between the structure and properties of new metastable carbon phases obtained under high pressures from fullerite C60 and carbyne, JETP Letters, 76 (2002) 681-692. [72] K. Yamada, Y. Tanabe, A.B. Sawaoka, Allotropes of carbon shock synthesized at pressures up to 15 GPa, Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties, 80 (2000) 1811-1828. [73] E.P. Barrett, L.G. Joyner, P.P. Halenda, THE DETERMINATION OF PORE VOLUME AND AREA DISTRIBUTIONS IN POROUS SUBSTANCES .1. COMPUTATIONS FROM NITROGEN ISOTHERMS, Journal of the American Chemical Society, 73 (1951) 373380. [74] C. Vakifahmetoglu, V. Presser, S.H. Yeon, P. Colombo, Y. Gogotsi, Enhanced hydrogen and methane gas storage of silicon oxycarbide derived carbon, Microporous and Mesoporous Materials, 144 (2011) 105-112. [75] M.B. Vazquez-Santos, E. Geissler, K. Laszlo, J.N. Rouzaud, A. Martinez-Alonso, J.M.D. Tascon, Graphitization of highly porous carbons derived from poly(pphenylene benzobisoxazole), Carbon, 50 (2012) 2929-2940. [76] M. Sun, L. Hong, Impacts of the pendant functional groups of cellulose precursor on the generation of pore structures of activated carbons, Carbon, 49 (2011) 2173-2180. [77] P.W. Atkins, -, Atkins' physical chemistry, 8th ed. ed., Oxford University Press, Oxford ; New York :, 2006. [78] G. Aguilar-Armenta, G. Hernandez-Ramirez, E. Flores-Loyola, A. UgarteCastaneda, R. Silva-Gonzalez, C. Tabares-Munoz, A. Jimenez-Lopez, E. Rodriguez- Page 102 Castellon, Adsorption Kinetics of CO2, O2, N2, and CH4 in Cation-Exchanged Clinoptilolite, The Journal of Physical Chemistry B, 105 (2001) 1313-1319. [79] C.G. Zoski, Handbook of Electrochemistry, Elsevier Science, 2007. [80] R. Trivedi, W. Kurz, Dendritic growth, International Materials Reviews, 39 (1994) 49-74. [81] A. Criscio e, D. Ki tea, Ž. Tuković, S. Jakirlić, I.V. Rois a , C. Tropea, Crystallization of supercooled water: A level-set-based modeling of the dendrite tip velocity, International Journal of Heat and Mass Transfer, 66 (2013) 830-837. [82] R. Akolkar, Mathematical model of the dendritic growth during lithium electrodeposition, Journal of Power Sources, 232 (2013) 23-28. [83] D.K. Sun, M.F. Zhu, S.Y. Pan, C.R. Yang, D. Raabe, Lattice Boltzmann modeling of dendritic growth in forced and natural convection, Computers & Mathematics with Applications, 61 (2011) 3585-3592. [84] J.D. Hunt, S.-Z. Lu, Numerical modelling of cellular and dendritic array growth: spacing and structure predictions, Materials Science and Engineering: A, 173 (1993) 79-83. [85] Y. Miyata, Y. Shima, Self-consistent analytical theory of dendritic growth with convection, in: Advanced Materials '93, Elsevier, 1994, pp. 621-624. [86] T. Haxhimali, A. Karma, F. Gonzales, M. Rappaz, Orientation selection in dendritic evolution, Nat Mater, (2006) 660-664. [87] Y.e. Zhou, L. Hong, The Growth of Porous Carbon Fibres Through in-situ Vapour Deposition, RSC Advances, (2013). [88] Z. Liu, J.Y. Lee, W. Chen, M. Han, L.M. Gan, Physical and Electrochemical Characterizations of Microwave-Assisted Polyol Preparation of Carbon-Supported PtRu Nanoparticles, Langmuir, 20 (2004) 181-187. [89] O.V. Kharissova, B.I. Kharisov, Less-Common Nanostructures in the Forms of Vegetation, Ind. Eng. Chem. Res., 49 (2010) 11142-11169. [90] Y.-A. Lim, P. Babu, R. Kumar, P. Linga, Morphology of Carbon Dioxide– Hydrogen–Cyclopentane Hydrates with or without Sodium Dodecyl Sulfate, Crystal Growth & Design, 13 (2013) 2047-2059. [91] S. Costa, E. Borowiak-Palen, M. Kruszyñska, A. Bachmatiuk, R.J. Kaleńczuk, Characterization of carbon nanotubes by Raman spectroscopy, Materials SciencePoland, 26 (2008) 433-441. [92] M.S. Dresselhaus, M.A. Pimenta, P.C. Eklund, G. Dresselhaus, Raman Scattering in Fullerenes and Related Carbon-Based Materials, in: W. Weber, R. Merlin (Eds.) Raman Scattering in Materials Science, Springer Berlin Heidelberg, 2000, pp. 314364. [93] E. Zussman, X. Chen, W. Ding, L. Calabri, D.A. Dikin, J.P. Quintana, R.S. Ruoff, Mechanical and structural characterization of electrospun PAN-derived carbon nanofibers, Carbon, 43 (2005) 2175-2185. [94] M. Peng, D. Li, L. Shen, Y. Chen, Q. Zheng, H. Wang, Nanoporous structured submicrometer carbon fibers prepared via solution electrospinning of polymer blends, Langmuir, 22 (2006) 9368-9374. [95] M. Inagaki, Y. Yang, F. Kang, Carbon Nanofibers Prepared via Electrospinning, Advanced Materials, 24 (2012) 2547-2566. Page 103 [96] L.C. Chen, S.W. Chang, C.S. Chang, C.Y. Wen, J.J. Wu, Y.F. Chen, Y.S. Huang, K.H. Chen, Catalyst-free and controllable growth of SiCxNy nanorods, Journal of Physics and Chemistry of Solids, 62 (2001) 1567-1576. [97] D.C. Lee, F.V. Mikulec, B.A. Korgel, Carbon Nanotube Synthesis in Supercritical Toluene, Journal of the American Chemical Society, 126 (2004) 4951-4957. [98] V. Jourdain, C. Bichara, Current understanding of the growth of carbon nanotubes in catalytic chemical vapour deposition, Carbon, 58 (2013) 2-39. [99] L.-L. Tan, W.-J. Ong, S.-P. Chai, A.R. Mohamed, Growth of carbon nanotubes over non-metallic based catalysts: A review on the recent developments, Catalysis Today, 217 (2013) 1-12. [100] D. Takagi, H. Hibino, S. Suzuki, Y. Kobayashi, Y. Homma, Carbon Nanotube Growth from Semiconductor Nanoparticles, Nano Letters, (2007) 2272-2275. [101] B. Liu, W. Ren, L. Gao, S. Li, S. Pei, C. Liu, C. Jiang, H.-M. Cheng, Metal-CatalystFree Growth of Single-Walled Carbon Nanotubes, Journal of the American Chemical Society, 131 (2009) 2082-2083. [102] Á. Botias, C. Almécija, E.M. Guadix, A. Guadix, Recent patents on ceramic membranes applications, Recent Patents on Chemical Engineering, (2010) 38-48. [103] R.J. Ciora Jr, P.K.T. Liu, Ceramic membranes for environmental related applications, Fluid - Particle Separation Journal, 15 (2003) 51-60. [104] R. Sondhi, R. Bhave, G. Jung, Ceramic membranes: Applications & benefits From "A" to "Z", Fluid - Particle Separation Journal, 14 (2002) 130-134. [105] G. Galjaard, B. Martijn, E. Koreman, M. Bogosh, J. Malley, Performance evaluation six ® -ceramac® in comparison with conventional pre-treatment techniques for surface water treatment, Water Practice and Technology, (2011). [106] C. Wang, C. Sun, C. Yu, Y. Li, J. Zhao, D. Huang, Y. Song, Fabrication of highly ordered carbon networks as catalyst supports for aerobic oxidation of glucose, in, 2012, pp. 1186-1192. [107] R. Angelucci, I. Boscolo, A. Ciorba, M. Cuffiani, L. Malferrari, A. Montanari, F. Odorici, S. Orlanducci, R. Rizzoli, M. Rossi, V. Sessa, M.L. Terranova, G.P. Veronese, Honeycomb arrays of carbon nanotubes in alumina templates for field emission based devices and electron sources, Physica E: Low-Dimensional Systems and Nanostructures, 42 (2010) 1469-1476. [108] J. Li, H. Zhang, Y. Zhang, M. Wang, F. Zhang, H. Nie, A hierarchical porous electrode using a micron-sized honeycomb-like carbon material for high capacity lithium-oxygen batteries, Nanoscale, (2013) 4647-4651. [109] X. Liu, M.K. Ruffin, B.Y. Johnson, M.O. Owusu, High porosity in situ catalyzed carbon honeycombs for mercury capture in coal fired power plants, in, 2011, pp. 123-136. [110] T. Xue, J. Meng, Z. Jin, Study on the performance of honeycomb ceramics carrier based on the ordinary paper, Materials Science and Engineering A, 528 (2011) 8512-8516. [111] Y. Zhang, W. Liu, L. Zhang, M. Zhao, Nitrogen doped honeycomb-like carbon as a highly efficient catalyst support for Pt-Ru nanoparticles and their electrocatalytic oxidation of methanol, Indian Journal of Chemistry - Section A Inorganic, Physical, Theoretical and Analytical Chemistry, 52 (2013) 585-592. Page 104 [112] S.H. Hong, et. al, Fabrication method for porous carbon fibers, US Patent App, (2012) 385,763 [113]W. Li, F. Zhang, et. al, A self-template strategy for the synthesis of mesoporous carbon nanofibers as advanced supercapacitor electrodes, Advanced Energy Materials, (2011) 382-386 [114]S. Shin, J. Jang, S.H. Yoon, I. Mochida, A study on the effect of heat treatment on functional groups of pitch based activated carbon fiber using FTIR, Carbon, 35, No.12 (1997) 1739-1743. [115]T. Zhang, et al., Hydrogen storage on carbon adsorbents: A review, Environanotechnology, Chapter 7, pp 137-163. [116]J. Alcaniz-Monge, D. Cazorla-Amoros, A. Linares-Solano, Effect of the activating gas on tensile strength and pore structure of pitch-based carbon fibers, Carbon, 32, No.7 (1994) 1277-1283. [117]G.F. Alvarez, M. Mamlouk, K. Scott, An investigation of palladium oxygen reduction catalysts for the direct methanol fuel cell, Intl. J. of Electrochemistry, 2011 (2011) 684535. Page 105 [...]... cutting-edge technical routes and the fundamentals developed for carbon transitions and the fabrication of porous media and porous carbon fibers Whilst most carbon fibers today consist mainly of microporous structuers, the carbon fibers synthesized by the method outlined in this work subsequently has a pore size variation from microporous to mesoporous structures The review supports the novelty of the. .. was absent from the incubation atmosphere, thereby validating the role of CO2 in skinning miniature graphenes 3.5.2 Pore Analysis of Porous Carbon Fibers The porous structures of porous carbon fibers evolved under different incubation atmospheres are studied in detail in this section Their BET isotherms and the specific surface properties are ostensibly greater than that of the activated carbon flakes... and the diameter of the fibers does not change much after initial activation [116] Page 23 3 The Growth of Porous Carbon Fibers Through in situ Vapor Deposition 3.1 Porous Carbon Fibers Abstract This study investigates the carbon- to -carbon transition of activated carbon flakes from 2-hydroxyethylcellulose polymer to porous carbon fibers (PCF) through vaporization fragments of polyaromatic hydrocarbons... transition of the HEC-derived AC to a particular type of sub-micron porous carbon fibers through a calcination process under an inert gas atmosphere, activation in a CO2 atmosphere, and subsequently treatment in a co-gas flowing stream Sublimation of the carbon fragments such as planar PAHs with the aid of CO2-etching and thermal stimulation from the AC leads to the formation of porous carbon fibers The resulting... ways of synthesizing porous carbons is through template assisted routes using industrial porous concrete and the carbonization Page 29 of sucrose to form carbon replicas of the template [66] However, a trail run of this method only produced surface areas of 475m2/g 3.4 Experimental Procedures The procedures for the fabrication of the high surface area porous carbon fibers are outlined below 3.4.1 Formation... presented in the thesis work 1.3 Thesis Structure The thesis has been segmented into several chapters for the convenience of the reader Although the individual chapters can be read and understood independently, the author would encourage the individual to read the chapters in chronological order in order to best appreciate the evolution and novelty of the complete work Page 15 Chapter 3 presents the transition... respectively In short, the solid state C-C transition is a fresh area of carbon material that is significantly affected by the source of the precursor carbon and atmosphere in which the transition is incubated In summary, C-C transitions may offer a direct methodology for the production of porous carbon fibers from flakes In order to achieve this, comprehensive studies of C-C transitions from flake to fiber in. .. without the mediation by Pt atomic clusters in the typical temperature range of 700-750°C The first type of C-flake was obtained specifically from the pyrolysis of 2-hydroxyethyl cellulose (HEC) High aspect ratio fibers exhibiting both laminar and porous semi-crystalline structures are produced via the C-C transition in the N2-CO2 co-gas purge On the other hand, introducing Pt atomic clusters to mediate the. .. conditions to those used to prepare the sample in Fig 1c Unlike the thick PCF growth in sample 1c, only a scarce number of fibers in larger diameters can be incubated from the graphite specimen because of the strong association of graphene sheets in graphite The occurrence of the fibers supports the etching role of CO2 and the proposed sublimation/deposition mechanism Figure 2: Magnified view of a single... obtained through the polymerization of -D-glucose in a hydrothermal system The -GP was then converted to AC subsequently via the C -to- C treatment as described in the preceding chapters The converted AC flakes possessed a honeycomb-like carbon porous medium attached to dense carbon fibers along each flake This dual structural feature was incorporated into the pore channels of a ceramic membrane for integrating . with the aid of CO 2 -etching and thermal stimulation from the AC leads to the formation of porous carbon fibers. The resulting porous fibers exhibit a broad distribution of XRD d-spacings. fabrication of porous media and porous carbon fibers. Whilst most carbon fibers today consist mainly of microporous structuers, the carbon fibers synthesized by the method outlined in this work. THE EXPLORATION OF IN SITU CARBON- CARBON TRANSITIONS TO FORM POROUS FIBERS ZHOU YI’EN (B.Eng (Chemical) (Hons.), NUS) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY