- Email: [email protected]
“Carbonaceous mesophase: History and prospects” — a reply
Letters to the Editor Acknowledgement - The assistance of T.W. Owens in obtaining the SEM photograph and the financial support of W.P.H. by the Air Force Office of Scientific Research is greatly appreciated. Air Force Astronautics Laboratory AFALIRKBN Edwards, CA 93523-5000
REFERENCES 1
’ 2.
W.P. HOFFMAN 4.
Departments of Physics University of California Santa Barbara, CA 93110
V.B. ELINGS
Digital Instruments, Inc. I35 Nogal Rd. Santa Barbara, CA 93110
J.A. GURLEY
5. 6. 7 8.
“Carbonaceous
157
G. Binnig and H. Rohrer, Helv. Phys. Acta, 55, 726 (1982). P.J. Bryant; UMKC-Physics; 110 E. 48th St.; K.C., MO 64110 S. Park and C.F. Quate, App. Phys. Let., 48, 112 (1986). B. Reihl, J.K. Ginzewski, J.M. Nicholls, and E. Tosatti, Phys. Rev., B33, 5770 (1986). R. Wiesendanger, R. Schlogl and H.J. Guntherodt, Ext. Abs. Carbon 86,207, Baden-Baden (1986). J. Schneir, R. Sonnenfield, P.K. Hansma, and J. Tersoff, Phys. Rev., B34, 4979 (1986). H. Mamin, E. Ganz, D.W. Abraham, R.E. Thomson, and J. Clark, Phys. Rev., B34 (1986). I.P. Batra, N. Garcia, H. Roher, H. Salemink, E. Stioll and S. Ciraci, Sur. Sci., 181 (1987).
Mesophase: History and Prospects”
- A Reply
(Received 17 June 1988, accepted 1 July 1988)
Key Words - mesophase
The recent article entitled “Carbonaceous Mesophase: History and Prospects” by H. Honda which was published in Carbon, 26, 139 (1988), contains a number of serious omissions and some technical errors. The paper is concerned primarily with mesophase and mesphase fiber research in Japan and neglects to cite most of the pioneering work carried out outside of Japan. Since Carbon is an international journal, a review article published in Carbon would be expected to be international in scope. We, therefore, feel that corrections regarding the history and technology of mesophase development would be appropriate. To be specific, it is difficult to conceive of a contemporary review article on pitch mesophase and mesophase fibers without a reference to the patent or publications of Dr. Leonard Singer on mesophase pitch fibers. The only reference to Singer (No. 33) is erroneously ascribed to the structure of mesophase spheres. Dr. Singer has received the Pettinos Award of the American Carbon Society in 1977, for his basic work in the development of fibers from mesophase pitch. The Honda article makes no other reference to the extensive publications of the Union Carbide Corporation group on mesophase, except reference (29) to the short note in Carbon by Chwastiak and Lewis. The only reference to Union Carbide’s mesophase fiber development is reference (12) which is a paper by Otani in Japan. In fact, the discussion of Union Carbide work on Page 141 implies that it was unsuccessful in spinning fiber even though mesophase pitch fibers have been available commercially since 1975. Hundreds of thousands of pounds of mesophase pitch-based continuous filament carbon fibers have been sold by Union Carbide Corporation and currently by Amoco Performance Products Incorporated.
In terms of technical inconsistencies, the discussion of mesophase softening properties and solubilities is misleading and does not appear to take into account the advances made in this area. Particularly, the extensive work of Diefendorf and his group, Rand, etc., should have been considered. It is incorrect to suggest that Brooks and Taylor fist proposed the term mesophase. As stated in their review article (Reference 8). mesophase is synonymous with liquid crystal and was used to describe their pitches since the term was common in the early liquid crystal literature. the description of an infusible mesophase in the Honda review article is therefore a contradiction in terms. The discussion of mesophase solubility is inappropriate. Although it was previously believed that mesophase content was equal to the insoluble content that developed on heat-treating pitches, it has been clear for some time that this equation is not correct. Diefendorf in particular has discussed the solubility aspects of pitches and it is now recognized that solubility and mesophase formation are separate unconnected phenomena. There is also a detailed discussion of studies of mesophase pitch by hot-stage microscopy as if this was original work. There have been a large number of investigators who have utilized the technique, none of which are cited. The Honda article does present a timely summary of current mesophase pitch fiber activity in Japan and adequately reviews some of the excellent research of Honda and his group and others in Japan on the pitch mesophase. However, we do not wish the readers of Carbon to feel that the review adequately summarizes the very extensive science and technology that has been
758
Letters to the Editor
carried out on the carbonaceous mesophase throughout the world. Review articles which cover these aspects more broadly are available in a number of publications. In particular, the recent review article by B. Rand, (Handbook of Composites, Vol. 1, Edited by W. Watt and B.V. Perov, Elsevier Publishers (1988)), is recommended for the reader desiring an inclusive and current perspective on the development of mesophase and mesophase fiber technology.
Union Carbide Corporation Panna Technical Center Carbon Products Division
p,~. Box 61~6
Cleveland, OH 44101
I.C. LEWIS R.T. LEWIS
REFERENCES 1
’ 2.
W.P. HOFFMAN 4.
Departments of Physics University of California Santa Barbara, CA 93110
V.B. ELINGS
Digital Instruments, Inc. I35 Nogal Rd. Santa Barbara, CA 93110
J.A. GURLEY
5. 6. 7 8.
“Carbonaceous
157
G. Binnig and H. Rohrer, Helv. Phys. Acta, 55, 726 (1982). P.J. Bryant; UMKC-Physics; 110 E. 48th St.; K.C., MO 64110 S. Park and C.F. Quate, App. Phys. Let., 48, 112 (1986). B. Reihl, J.K. Ginzewski, J.M. Nicholls, and E. Tosatti, Phys. Rev., B33, 5770 (1986). R. Wiesendanger, R. Schlogl and H.J. Guntherodt, Ext. Abs. Carbon 86,207, Baden-Baden (1986). J. Schneir, R. Sonnenfield, P.K. Hansma, and J. Tersoff, Phys. Rev., B34, 4979 (1986). H. Mamin, E. Ganz, D.W. Abraham, R.E. Thomson, and J. Clark, Phys. Rev., B34 (1986). I.P. Batra, N. Garcia, H. Roher, H. Salemink, E. Stioll and S. Ciraci, Sur. Sci., 181 (1987).
Mesophase: History and Prospects”
- A Reply
(Received 17 June 1988, accepted 1 July 1988)
Key Words - mesophase
The recent article entitled “Carbonaceous Mesophase: History and Prospects” by H. Honda which was published in Carbon, 26, 139 (1988), contains a number of serious omissions and some technical errors. The paper is concerned primarily with mesophase and mesphase fiber research in Japan and neglects to cite most of the pioneering work carried out outside of Japan. Since Carbon is an international journal, a review article published in Carbon would be expected to be international in scope. We, therefore, feel that corrections regarding the history and technology of mesophase development would be appropriate. To be specific, it is difficult to conceive of a contemporary review article on pitch mesophase and mesophase fibers without a reference to the patent or publications of Dr. Leonard Singer on mesophase pitch fibers. The only reference to Singer (No. 33) is erroneously ascribed to the structure of mesophase spheres. Dr. Singer has received the Pettinos Award of the American Carbon Society in 1977, for his basic work in the development of fibers from mesophase pitch. The Honda article makes no other reference to the extensive publications of the Union Carbide Corporation group on mesophase, except reference (29) to the short note in Carbon by Chwastiak and Lewis. The only reference to Union Carbide’s mesophase fiber development is reference (12) which is a paper by Otani in Japan. In fact, the discussion of Union Carbide work on Page 141 implies that it was unsuccessful in spinning fiber even though mesophase pitch fibers have been available commercially since 1975. Hundreds of thousands of pounds of mesophase pitch-based continuous filament carbon fibers have been sold by Union Carbide Corporation and currently by Amoco Performance Products Incorporated.
In terms of technical inconsistencies, the discussion of mesophase softening properties and solubilities is misleading and does not appear to take into account the advances made in this area. Particularly, the extensive work of Diefendorf and his group, Rand, etc., should have been considered. It is incorrect to suggest that Brooks and Taylor fist proposed the term mesophase. As stated in their review article (Reference 8). mesophase is synonymous with liquid crystal and was used to describe their pitches since the term was common in the early liquid crystal literature. the description of an infusible mesophase in the Honda review article is therefore a contradiction in terms. The discussion of mesophase solubility is inappropriate. Although it was previously believed that mesophase content was equal to the insoluble content that developed on heat-treating pitches, it has been clear for some time that this equation is not correct. Diefendorf in particular has discussed the solubility aspects of pitches and it is now recognized that solubility and mesophase formation are separate unconnected phenomena. There is also a detailed discussion of studies of mesophase pitch by hot-stage microscopy as if this was original work. There have been a large number of investigators who have utilized the technique, none of which are cited. The Honda article does present a timely summary of current mesophase pitch fiber activity in Japan and adequately reviews some of the excellent research of Honda and his group and others in Japan on the pitch mesophase. However, we do not wish the readers of Carbon to feel that the review adequately summarizes the very extensive science and technology that has been
758
Letters to the Editor
carried out on the carbonaceous mesophase throughout the world. Review articles which cover these aspects more broadly are available in a number of publications. In particular, the recent review article by B. Rand, (Handbook of Composites, Vol. 1, Edited by W. Watt and B.V. Perov, Elsevier Publishers (1988)), is recommended for the reader desiring an inclusive and current perspective on the development of mesophase and mesophase fiber technology.
Union Carbide Corporation Panna Technical Center Carbon Products Division
p,~. Box 61~6
Cleveland, OH 44101
I.C. LEWIS R.T. LEWIS