Thursday, September 27, 2007

豆腐文摘特辑:Raman Spectroscopy of SWNTs

【按:这里收录的是对搞碳管化学的同志们相当有用的部分SWNT Raman文章。收录当然远非完整,但是足够大家了解SWNT Raman的概念和用途。我自己会继续更新,也欢迎大家补充。】

Discovery:

Rao, A. M.; Richter, E.; Bandow, S.; Chase, B.; Eklund, P. C.; Williams, K. A.; Fang, S.; Subbaswamy, K. R.; Menon, M.; Thess, A.; Smalley, R. E.; Dresselhaus, G.; Dresselhaus, M. S.
Diameter-Selective Raman Scattering from Vibrational Modes in Carbon Nanotubes. Science 1997, 275, 187-191.

Reviews:

Principles and Overview:

1. Dresselhaus, M. S.; Eklund, P. C. Phonons in carbon nanotubes. Adv. Phys. 2000, 49, 705-714.

2. Dresselhaus, M. S.; Dresselhaus, G.; Saito, R.; Jorio, A. Raman spectroscopy of carbon nanotubes. Phys. Rep. 2005, 409, 47-99. [Thanks to flowingsue @ mitbbs]

3. Dresselhaus, M. S.; Dresselhaus, G.; Jorio, A. Raman Spectroscopy of Carbon Nanotubes in 1997 and 2007. J. Phys. Chem. C. 2007, ASAP article published on 10/02/2007.

Single-nanotube Raman:

1. Dresselhaus, M. S.; Dresselhaus, G.; Jorio, A.; Souza Filho, A. G.; Pimenta, M. A.; Saito, R.
Single Nanotube Raman Spectroscopy. Acc. Chem. Res. 2002, 35, 1070.

2. Dresselhaus, M. S.; Dresselhaus, G.; Jorio, A.; Souza, A. G.; Samsonidze, G. G.; Saito, R. Science and Applications of Single-Nanotube Raman Spectroscopy. J. Nanosci. Nanotechnol. 2003, 3, 19-37.

Popular Topics for Carbon Nanotube Chemists:

The Original Kataura Plot (Widely Used as Raman Guidance):

Kataura, H.; Kumazawa, Y.; Maniwa, Y.; Umezu, I.; Suzuki, S.; Ohtsuka, Y.; Achiba, Y.
Optical properties of single-wall carbon nanotubes. Synth. Met. 1999, 103, 2555-2558.

Mutliple Wavelength Excitation:

1. Kukovecz, A.; Kramberger, C.; Georgakilas, V.; Prato, M.; Kuzmany, H. A detailed Raman study on thin single-wall carbon nanotubes prepared by the HiPCO process. Eur. Phys. J. B 2002, 28, 223-230.

2. Fantini, C.; Jorio, A.; Souza, M.; Strano, M. S.; Dresselhaus, M. S.; Pimenta, M. A.
Optical Transition Energies for Carbon Nanotubes from Resonant Raman Spectroscopy: Environment and Temperature Effects. Phys. Rev. Lett. 2004, 93, 147406.

Diameter Determination from Radial Breathing Mode (RBM):

Kuzmany, H.; Plank, W.; Hulman, M.; Kramberger, C.; Gruneis, A.; Pichler, T.; Peterlik, H.; Kataura, H.; Achiba, Y. Determination of SWCNT diameters from the Raman response of the radial breathing mode. Eur. Phys. J. B 2001, 22, 307-320.

Chirality (n,m) Assignment from RBM:

1. Yu, Z.; Brus, L. E. (n, m) Structural Assignments and Chirality Dependence in Single-Wall Carbon Nanotube Raman Scattering. J. Phys. Chem. B 2001, 105, 6831-6837.

2. Jorio, A.; Saito, R.; Hafner, J. H.; Lieber, C. M.; Hunter, M.; McClure, T.; Dresselhaus, G.; Dresselhaus, M. S. Structural (n,m) Determination of Isolated Single-Wall Carbon Nanotubes by Resonant Raman Scattering. Phys. Rev. Lett. 2001, 86, 1118-1121.

3. Bachilo, S. M.; Strano, M. S.; Kittrell, C.; Hauge, R. H.; Smalley, R. E.; Weiseman, R. B. Structure-Assigned Optical Spectra of Single-Walled Carbon Nanotubes. Science 2002, 298, 2361-2366.

4. Strano, M. S.; Doorn, S. K.; Haroz, E. H.; Kittrell, C.; Hauge, R. H.; Smalley, R.E. Assignment of (n, m) Raman and Optical Features of Metallic Single-Walled Carbon Nanotubes. Nano Lett. 2003, 3, 1091-1096.

Breit-Wigner-Fano shape of G-band:

1. Pimenta, M. A.; Marucci, A.; Empedocles, S. A.; Bawendi, M. G.; Hanlon, E. B.; Rao, A. M.; Eklund, P. C.; Smalley, R. E.; Dresselhaus, G.; Dresselhaus, M. S. Raman modes of metallic carbon nanotubes. Phys. Rev. B 1998, 58, R16016.

2. Brown, S. D. M.; Jorio, A.; Corio, P.; Dresselhaus, M. S.; Dresselhaus, G.; Saito, R.; Kneipp,
K. Origin of the Breit-Wigner-Fano lineshape of the tangential G-band feature of metallic carbon nanotubes. Phys. Rev. B 2001, 63, 155414.

Applications in Characterization of Chirality/Metallicity Separation:

1. Chattopadhyay, D.; Galeska, I.; Papadimitrakopoulos, F. A Route for Bulk Separation of Semiconducting from Metallic Single-Wall Carbon Nanotubes. J. Am. Chem. Soc. 2003, 125, 3370-3375.

2. Strano, M. S. Probing Chiral Selective Reactions Using a Revised Kataura Plot for the Interpretation of Single-Walled Carbon Nanotube Spectroscopy. J. Am. Chem. Soc. 2003, 125, 16148-16153.

3. Samsonidze, G. G.; Chou, S. G.; Santos, A. P.; Brar, V. W.; Dresselhaus, G.; Dresselhaus, M. S.; Selbst, A.; Swan, A. K.; Ünlü, M. S.; Goldberg, B. B.; Chattopadhyay, D.; Kim, S. N.;
Papadimitrakopoulos, F. Quantitative evaluation of the octadecylamine-assisted bulk separation of semiconducting and metallic single-wall carbon nanotubes by resonance Raman spectroscopy. Appl. Phys. Lett. 2004, 85, 1006-1008.

4. Brar, V. W.; Samsonidze, G. G.; Santos, A. P.; Chou, S. G.; Chattopadhyay, D.; Kim, S. N.; Papadimitrakopoulos, F.; Zheng, M.; Jagota, A.; Onoa, G. B.; Swan, A. K.; Ünlü, M. S.; Goldberg, B. B.; Dresselhaus, G.; Dresselhaus, M. S. Resonance Raman Spectroscopy Characterization of Single Wall Carbon Nanotube Separation by their Metallicity and Diameter. J. Nanosci. Nanotechnol. 2005, 5, 209.

Tuesday, September 25, 2007

豆腐文摘:09/25/07

Small

Volume 3, Issue 10 (October 1, 2007)

1. Formation, Structure, and Polymorphism of Novel Lowest-Dimensional AgI Nanoaggregates by Encapsulation in Carbon Nanotubes (p 1730-1734)
Matteo Baldoni, Stefano Leoni, Antonio Sgamellotti, Gotthard Seifert, Francesco Mercuri Published Online: 11 Sep 2007 DOI: 10.1002/smll.200700296
Abstract References Full Text: HTML, PDF (Size: 708K)

2. In Situ Raman Spectroelectrochemical Study of 13C-Labeled Fullerene Peapods and Carbon Nanotubes (p 1746-1752)
Martin Kalbá, Ladislav Kavan, Markéta Zukalová, Lothar Dunsch
Published Online: 13 Sep 2007 DOI: 10.1002/smll.200700157
Abstract References Full Text:HTML,PDF (Size: 198K)

3. Magnetophoretic Continuous Purification of Single-Walled Carbon Nanotubes from Catalytic Impurities in a Microfluidic Device (p 1784-1791)
Joo H. Kang, Je-Kyun Park
Published Online: 24 Sep 2007 DOI: 10.1002/smll.200700334
Abstract References Full Text:HTML,PDF (Size: 618K)

4. Hairy Single-Walled Carbon Nanotubes Prepared by Atom Transfer Radical Polymerization (p 1803-1810)
Wei Wu, Nicolay V. Tsarevsky, Jared L. Hudson, James M. Tour, Krzysztof Matyjaszewski, Tomasz Kowalewski
Published Online: 13 Sep 2007 DOI: 10.1002/smll.200600688
Abstract References Full Text:HTML,PDF (Size: 799K)

Monday, September 24, 2007

访客数1001留念 :-)

豆腐文摘:09/24/07

JACS
Photoluminescence Recovery from Single-Walled Carbon Nanotubes on Substrates
Liming Xie, Cui Liu, Jin Zhang, Yongyi Zhang, Liying Jiao, Lai Jiang,, Lun Dai, and Zhongfan Liu

Web Release Date: 22-Sep-2007; (Communication) DOI: 10.1021/ja074927b
Abstract Full: HTML / PDF (149K) Supporting Info

【简评】

量子产率本就不高的碳管的能带荧光很容易受到各种因素的干扰而被淬灭,所以通常这种荧光只能在单分散(基本上没有bundle)的“溶液”(用表面活性剂或者功能化分子)里或者是物理悬浮(吊在两个支撑点之间)被观察到。同理,直接CVD到底物(substrate)上的管子通常是看不到荧光的,而在这篇文章里,CVD到某底物上长出来的很长的单壁管用一种高分子“粘贴-转移”技术("peel and transfer")转移到用不同长度的碳链修饰的SiO2表面 - 单壁管的荧光此时显示出来(用Raman仪器):碳链越长(18C>6C>2C),荧光效率越高(或者被淬灭程度越低)。

几个问题:

  • 文章没有对所激发的管子的(n,m)做出任何讨论;究竟可能是哪有几种管子被激发这个问题有没有意义?
  • 不同碳链修饰的表面上显示的荧光峰值都有些许不同。这种不同有多少意义?
  • 对于一个半径为~1.1-1.2nm的SWNT(根据SI的Raman RBM ~195cm-1计算),它的E11发射峰应该在less than 1500nm,激发在700-800nm;而文中的激发为633 nm(He-Ne),发射在1550 nm (Figure1的mapping是用的1580-1630nm的累积),这些是不是有些偏差?

请各位指正。


JPCC

Novel Method to Evaluate the Carbon Network of Single-Walled Carbon Nanotubes by Hydrogen Physisorption
Shinya Iwata, Yoshinori Sato, Kouta Nakai, Shohei Ogura, Tatsuo Okano, Masaru Namura, Atsuo Kasuya, Kazuyuki Tohji, and Katsuyuki Fukutani

Web Release Date: 22-Sep-2007; (Letter) DOI: 10.1021/jp076275j
Abstract Full: HTML / PDF (310K) Supporting Info

【简评】

大家都知道氢分子在SWNT上的吸附位置和吸附能有密切关系。本文利用了这种不同,用测量低温下(10-40K)氢在纯化后的单壁管上的吸附量-温度变化图来试图表达其与SWNT的缺陷度的关系。这自然是个很有趣的办法来表征SWNT缺陷,但是对sp3/sp2 ratio来说用Raman肯定更简单直接些;然而,如果考虑到SWNT的bundle程度也许可以用此法表征(表面vs管间吸附),那么Raman是万万不行的。

Nano Letters
1. Strain Tuning of the Photocurrent Spectrum in Single-Wall Carbon Nanotubes
Prasanth Gopinath, Aditya Mohite, Hemant Shah, Ji-Tzuoh Lin, and Bruce W. Alphenaar

Web Release Date: 21-Sep-2007; (Letter) DOI: 10.1021/nl071582m
Abstract Full: HTML / PDF (1040K)


2. Three-Dimensional Morphology of GaP-GaAs Nanowires Revealed by Transmission Electron Microscopy Tomography
Marcel A. Verheijen, Rienk E. Algra, Magnus T. Borgström, George Immink, Erwan Sourty, Willem J. P. van Enckevort, Elias Vlieg, and Erik P. A. M. Bakkers
Web Release Date: 21-Sep-2007; (Letter) DOI: 10.1021/nl071541q
Abstract Full: HTML / PDF (244K) Supporting Info

Thursday, September 20, 2007

豆腐文摘:09/20/07

Small

Direct Enrichment of Metallic Single-Walled Carbon Nanotubes Induced by the Different Molecular Composition of Monohydroxy Alcohol Homologues

Volume 3, Issue 9 (September 3, 2007) (p 1486-1490)

Yu Wang, Yunqi Liu, Xianglong Li, Lingchao Cao, Dacheng Wei, Hongliang Zhang, Dachuan Shi, Gui Yu, Hisashi Kajiura, Yongming Li

Published Online: 13 Aug 2007 DOI: 10.1002/smll.200700241

Abstract References Full Text:HTML,PDF (Size: 680K)

【简评】此文在《豆腐文摘:08/28/07》已收录,但是彼时没有时间八。今天看到黄兄的简述,决定细读一下。

文章要点:

(1) 用低碳单羟基醇(乙醇 - 正戊醇)作为碳源做CVD制造SWNTs。

(2) 用Raman (1.96eV,RBM & G)、吸收光谱、电计数(electrical breakdown)三种方法来定性(前两者)乃至半定量(电计数)地说明metallic SWNTs和醇碳源碳原子数目的关系:

  • (i) 醇碳原子数越多,得到的metallic SWNTs的百分比越高(e.g. 乙醇:42%;正戊醇:65%)。
  • (ii) 醇的同分异构体(三种丁醇的同分异构体:57%)不影响结果。
  • (iii) 此法制造的metallic SWNT似乎普遍高于1/3的理论含量。
(3) 文章解释:


  • (i) CVD条件下产生的OH自由基选择性地etch metallic SWNTs;
  • (ii) 高碳原子数的醇在CVD中容易形成更多的无定形碳对管子具有更好的保护作用;此过程和碳原子数有关,和碳链构造无关。
  • (iii) 因为(i)和(ii),高碳原子数的醇产生的metallic SWNTs受到更好的保护,所以百分比更高。醇的同分异构体对结果没有影响。

意见:

首先向文章对碳管金属性差异的完整表征致敬:现在类似的文章通常就用其中的一种或两种(Raman/absorption),而很少用Hongjie Dai组的电计数方法(Li, et al., Nano Lett, 2004, 4, 317-321)。这样的表征尽职尽责,无论结果是否让人100%信服,至少诚意是让人没有话说的。

Raman RBM:做成3-D的模样看起来是sexy(做TOC可以),但是在文章里还是不如直接叠在一起来得直观。另外,请注意340cm-1的那个峰(Figure 3a & 6) - 大约对应于是产品里直径最小的semiconducting SWNT - 的行为有些奇怪:强度随着醇的碳原子数增加而增加,在以两个支链的丁醇做碳源的产品里比正丁醇要弱得多。

Optical Absorption:其实不完全符合 - 正戊醇的产品的M11峰并非最高,S11/S22峰也非最低。还有,这几条谱的normalization过程没有介绍。

Counting based on electrical breakdown:这个方法由于中间牵扯的其他无关过程(比如用DMF分散,再做成device)太多,所以统计准确性还值得考虑。但无论如何,这大概是目前最好的统计方法了。

上述意见只是想法,应该完全不影响文章的结论。

文章的机理讨论部分听起来似乎很有道理,当然要等待更多的实验验证:

  • (1) 用直接产生OH自由基的试剂etch一下?
  • (2) 戊醇的几种同分异构体的结果是不是类似?
  • (3) 用碳链更多的醇是不是得到的metallic SWNTs百分比更高?Amorphous carbon的百分比如何?