45(3)-15(유승곤).fm

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1 Korean Chem. Eng. Res., Vol. 45, No. 3, June, 2007, pp l lm n go o i kçmy Ç Çl re o 220 ( o 10p r, o 19p }ˆ) The Optimum Stabilization Conditions of -containing Pitch Fiber Sang Yong Eom, Chang Ho Lee, Kwan Ho Park and Seung Kon Ryu Department of Chemical Engineering, Chungnam National University, 220, Gung-dong, Yuseong-gu, Daejeon , Korea (Received 10 November 2006; accepted 19 March 2007) k o op r kr s p o l p o p l o rs, l v kr s l op m pqp p m. l p op kr e kr m, o p rp l p v. kr o ˆ pp 71~82 wt.% tp, l p l p o p p ˆ pp k. kr rl l p o p pp (C=O)m e (-COOH) p el p p p p ˆ e l o r l. ˆ op o p v l rr ƒ rp, t rq Œ rq p l op l pqm k r, ˆ r t p p k pl. srp 0.5 wt.% o o o 280 o Cl 3 hr r kr s p re pl. h Abstract -containing pitch fibers were prepared and various stabilization variables were investigated by characterizations of the fibers and behaviors of particles in the optimum stabilization conditions. When pitch fiber was stabilized by air at the optimum condition, the fiber weight increased as an increase of the stabilization temperature and a decrease of concentration. The carbonization yield was 71~82 wt.%, showing a decrease of the yield with the increase caused by the catalytic activity of to combustion. During the stabilization, newly developed carbonyl and carboxyl groups were introduced on the fiber surface and cross-linking reactions were progressed resulting the thermosetting property, which was verified by the replacement of hydrogen with oxygen. Pore size of the activated carbon fiber was increased by an increase in concentration. In the considerations of the aggregation behaviors of the particles, the optimum stabilization conditions of 0.5 wt.% containing petroleum-based pitch fiber were suggested as 280 o C, 3 hr. Key words: Pitch Fiber, Stabilization, Carbonization, -containing CF, Catalytic Activator 1. vp p yp qn p l rqm r p, p rqm r p ns p pl p OH radical eˆ. ml OH radicalp qnl p o o p pp tl kp s t vp tp k eˆ p. ˆk p pn n, m rp lp p np } pp l To whom correspondence should be addressed. skryu@cnu.ac.kr ep p. o vp pn o m p m p vl ~ eˆ l v tp, o ˆp rs o l p p ˆ (supercritical carbon dioxide)m o v (metal organic chemical vapor deposition)p n m [1-3]. o ˆ o(activated carbon fiber, ACF) rsl l kv n rp, Ryu [4]p o ƒ p np e m l o ˆ o rs mp rs ~rp l n., ˆ op rs rp v,, kr, 269

2 270 l nëp} Ë Ëod ˆ p p. v o l p ˆ r k op ˆ ov o l k 300 o Cl kr ( p, ) rp p p. p kr rp srp llv ˆ o p v rs nl q m p n tn r p k r p. ˆ rl kr rp ~ l p r kr o s m ˆ p e ˆ pr ˆ t pp o e ˆ p l o l [5]. kr rl k l l Fitzer [6] Mochida [7] p kr e dm, m ove p rr eˆ pl ˆ op s mp, Jung [8]p s pd op kr o p Œ ˆ ˆ qp svp o p te yp skin-core s v v m., kr re r (viscous flow)p v o l Park [9]p m p n ol Œeˆ q mp op r s Ž s ˆ lpl p m l p kr pp n p lv m. pm p p p p k r l pl p m m qe p n p m l e l rp kr p r np n p l. l Donnet [5]p r pn l, ms, p v, m p n mp kr rp eˆv m. Lee [10]p v v l p o op kr l p m mp e p 1/ o C r m lpl ˆ pp 5~9 wt.% v mpp p. ˆ rl kr rl p s p l v l m l, p t pp ˆ p ˆ pp. ˆ pp 600 o C p l p lv CO, CO 2 H 2 O, p m p l pl ˆ pl H 2 m CH 4 p p k r [11]., Lee [12]p v v o op ˆ p kk nm Š e p p s m p p l v ˆ v, r vl p l p m. v vp l p op kr ˆ rl p, r rp o p oeˆ ˆ o rs[13-15] l pl p p o op k r ˆ rl p l p l erp. p p m l qnp ˆ eˆ pp, Table 1. Properties of naphtha cracking bottom (NCB) oil and reformed isotropic pitch Softening point ( o C) o45 o k Elemental analysis (wt.%) Molar ratio Solubility (wt.%) a C H N Diff. (C/H) BI QI k m p rp o ˆ o rse r kr s l l n., l o v l ƒ l l ~ p l o o rs, l s l kr eˆ p ˆ l rs ˆ op pqp p p f o ˆ o rse r kr s p rp p. s o ˆ op p p ˆ om, q m e l n o o o Kim [16]p re l q o(naphtha cracking bottom oil) v l lp ƒ l, p ~ o l Ryu [4]p rk p titanium dioxide(, 99.5%, M.P 200 o C, Degussa) wt.% np l ll. q om v p p Table 1l nk m. l r(softening point)p Mettler FP 800(USA)l p r mp, JIS K2425l p benzene insoluble(bi) ASTM D l p quinoline insoluble(qi)p r m op kr 10 cm p r pr (k 3 g)p o r l 2 o C/minp kr m (250 o C, 280 o C, 310 o C) v dm ql o l ~ e (0, 0.5, 1, 2, 3 e )p l m. kr op ˆ v o l 10 o C/min 1,000 o C v dm p m l 30 ove mp, 900 o Cl 60 v s ˆ o rs m. kr, ˆ r r p r l p p mp, TG (TGA 2050, TA instruments)p ee m. o kr o l l o k k o o (EA 1110, CE instrument, Italia)p ee m, FT-IR (Travel IR, SensIR technologies)p kr e p m. t rq (SM-500, TOPCON)p op ˆ mp, o p Žˆ p r s o l Œ rq (JEM-2010, JEOL) XRD (D/MAX-2200, Japan)p ee m. s o ˆ op p ASAP 2010 (Micromeritics, USA)p pn l 77 Kl v m p r m. Density (g/cm 3 ) Aromaticity (Fa) NCB Pitch a BI, benzene insoluble; QI, quinoline insoluble

3 3. y 3-1. l m Table 2l np o op p re m. l m p p ƒ p r m k l [17, 18]p m v ƒ p l r k 40 o C r p m p, oel p 5~10 o C p m rpl. p ƒ p np m e p ~, p p v q n l o, r m, p l m p e l p o p v o m r m v r kvp k p. l l r m e lv lp 1,000 m p p m rp m. o op r kr s 271 l op m p(weight loss ratio)p Fig. 1l ˆ l. p op l,. v v op p p kv 800 m/min p l r p e l p p 40 wt.% p m. o op n, p op nm l op l p lp ƒvp k p. p np l p o ˆ o rs l [19, 20]l ˆ p p p v qn l r p v p go oq lm kr rt op v p pp p q n p v p rrp k t. Fig. 2 k r e l kr m m o Table 2. Characteristics of -containing pitch fibers content (wt.%) Elementary analysis (wt.%) C H O Atomic ratio (C/H) Average diameter (µm) Spinning temp. ( o C) Spinning speed (m/min) ~ ~1, ~ ~ ~ ~650 Fig. 1. The thickness and weight loss ratio of circular shaped pitch fiber with respect to winding speed: (a) pure pitch, (b) 0.5 wt.% -containing pitch. Fig. 2. Weight increase of pitch fibers as a function of stabilization time at different (a) temperature without and (b) content, 280 o C. Korean Chem. Eng. Res., Vol. 45, No. 3, June, 2007

4 272 l nëp} Ë Ëod l ˆ p. l kr m p v, p p lvp k pp e p l l v rr v p l. p tp ol n l pl l l, }} p p. Jung [8]p kr e p v o p pl v kk p ˆ k m p t ˆ o llv l p p. kr ol p m l. o kr op kr e p l v m, o p p v p p m. p p prl [8] m p o p k ˆ ˆ qp svp o p te yp skincore s v v p p Ž. v, kr e o l rp p, p p, p p. rp o p p p o p r p p. Fig. 3p kr rp o ˆ eˆ r l ˆ r pp e p. ˆ pp kr r p v m kr e p l, k r m p k. v, kr e p l p v ˆ pp kvp k p p p ˆ rp ˆ pp CO, CO 2, H 2 O p p. ˆ pp n, Lee [12]p e p 77~82 wt.%p l l 71~82 wt.% p p p. p kr m m e l p pv l p p p lv. o ˆ p kr e p l m. k m v p n, v p p n p r l ˆ pp p p m ˆ. p p p ˆ p, o l p k l [18, 21]p v l l p q qn m ˆ p pp ve k p Ž., o p p ˆ pp p p pp, kr e p ˆ pp p p v l p l p p Ž. o om kr op lkr p p s o l p p TG Fig. 4l ˆ l. p o 300 o C t e q, p l k p vp kr op n pl p qn p lkr p v p. kr o p k v m p m v l qn ˆ -ˆ pl t pp ppp k p go i n o op kr e l p kr m m o p Fig. 5l ˆ l. o v kp op n Table 2l re m p Fig. 3. Carbonization yields of stabilized fibers as a function of stabilization time at different (a) temperature without and (b) content, 280 o C. o45 o k Fig. 4. TGA curves of 0.5 wt.% -containning (a) pitch fiber and (b) stabilized fiber.

5 o op r kr s 273 Fig. 6. FT-IR spectra of (a) pitch fiber, (b) stabilized fiber, and (c) 0.5 wt.% -containing stabilized fiber. Fig. 5. Oxygen and hydrogen contents as a function of stabilization time at different (a) temperature without and (b) content, 280 o C. 0.6 wt.%, 5.1 wt.%mp, kr r l m p kr s l p pp 22.3 wt.% v v, 2.4 wt.% v m. p kr l p p p ˆ p el, qn p v pp p. p v p k kr e v m o p p. v, kr m p p p kp kp, o p r p p p kp k. v, ˆ p k kr m o p rp p p k. Lee [10]p l l p v m l v p v, p r e v v p n p. p f kr e v rp pp o ppp k p. rp tp l ˆp p l v kk o Fig. 6l om kr op FT-IR ˆ l. op n 3,030 cm -1 l s C-H e v 2,920 cm -1 l v s C-H e v l p p, kr o 1,700 cm -1, 1,600 cm -1, 1,260 cm -1 l C=O, C=C, C-O e v l p l. 0.5 wt.% o op kr l p mll p l. p kr rp k o (C=O), e (-COOH) qn l p ˆ pp pl l kr o, p pp veˆ l p ppp k pl l lm Š Fig. 7p t rq p ˆ op p p. o v kp op p kt o op l p p vp l. p p vp Ryu [4]p m v, l lv. l particle size(21 nm)l n ƒrpp k p, p kr ˆ rt p p ~ l p Ž. p vp pv p o l SEM-EDS(electron dispersive spectra) p m Fig. 7(d)l ˆ, o Žˆ p sq p pl. l Au el p e r vp o l Žp m p. l m p r op n kl llp e (burn-off) 60 wt.% p p op n l p k o ˆ o r~l p p lpp m p. Fig. 8l ˆ op v m p ˆ l. m p r rp Type-Ip p p p 20 Å p pp k p. m p p Table 3l r m. l m p p o p v v, r p p k p. p e p p t ˆ p v p p ~ l t p m p. Hisashi [20] 0.3 wt.% ~ lp np 23.3 Å p l, Shigeyuki [1]p 2.5 wt.% ~ 47.3 Åpp mp p o p v eˆ ˆ op j v eˆ p Ž., op rp l p n o o, ˆ, p, Hisashi Shigeyuki p ~ Korean Chem. Eng. Res., Vol. 45, No. 3, June, 2007

6 274 l nëp} Ë Ëod Fig. 7. SEM photos of (a) non-containing CF, (b) 0.5 wt.% -containing CF, (c) 0.5 wt.% -containing ACF and (d) EDS of 0.5 wt.% -containing ACF. Fig. 8. Adsorption isotherms of N 2 on several content -containing ACFs. vrrp l. Fig. 9 XRD p l o p sq e p p. XRD l k p m p o o45 o k kr o, ˆ o ˆ ol (anatase) m p 2θ=25 o l p sq p p p., r r~rp rp p r p ˆ p p p Lu [22]p, o ˆ p XRD m n o. Ryu [4]p l l o ˆ o l k v kkpp m. Fig. 10p 0.5 wt.% o ˆ op Œ rq (TEM) vp op l pq v kpp k p. p o op k r rt p pq ~ l p Ž. o ˆ o s rp o vp o ˆ op rsl p. p r l sr l n. k l l Jung [23]p v p vl Ž m, Shigeyuki [1]p o o / ˆ ~ t p p o ˆ mv p l kv eq p pl l n.

7 o op r kr s 275 Table 3. Pore characteristics of ACFs activated at 900 o C for 1 h content (wt.%) S BET (m 2 /g) V T (cc/g) V micro (cc/g) V meso (cc/g) D p (Å) Burn-off (wt.%) , , , p p p l o op n o p p p l n r p r p m s o ˆ op n l kr s p sr n p. e p, o p 0.5 wt.% p n 280 o C, 3 hrp r kr s p re. p l q vl ep lp lp pl. y Fig. 9. XRD curves of 0.5 wt.% -containing (a) pitch fiber, (b) ACF and (c) (anatase). Fig. 10. TEM photos of 0.5 wt.% -containing ACF. 4. o p o kr, ˆ rp ~ o ˆ o rs mp, k m p p pl. (1) o p r m p ƒ p n k 5~10 o C kp, r k 300~400 m/min k r~rp p lvp k p. (2) kr m o p rp l p v, o op n l p kr r m o p p ˆ p pp. (3) o ˆ ol 20 Å p p p o p v l ˆ op v, op l pl p p p l. 1. Shigeyuki, K., Hisashi, T., Hajime, Y., Yoshio, Y., Noriko, Y. and Minoru, S., Synthesis of Activated Carbon from Organometallics/coal Composites, The 23th Conference on Carbon Materials, Chiba, Japan, Dec.(1996). 2. Narihito, T., Hiroshi, I., Norihiko, S. and Yoshiaki, F., Preparation of Titanium Dioxide/activated Carbon Composites Using Supercritical Carbon Dioxide, Carbon, 43(11), (2005). 3. Zhang, X., Zhou, M. and Lei, L., photocatalyst Deposition by MOCVD on Activated Carbon, Carbon, 44(2), (2006). 4. Ryu, S. K., Eom, S. Y., Yim, K. S. and Edie, D. D., Pore Characteristics of -Containing Activated Carbon Fibers, Korean Chem. Eng. Res., 42(3), (2004). 5. Donnet, J. B., Wang, T. K., Peng, J. C. M. and Rebouillat, S., Carbon Fibers, 3rd ed., Marcel Dekker Inc., New York, 1-83(1998). 6. Fitzer, E., Frohs, W. and Heine, M., Optimization of Stabilization and Carbonization Treatment of PAN Fibres and Structural Characterization of the Resulting Carbon Fibres, Carbon, 24(4), (1986). 7. Matsumoto, T. and Mochida, I., Oxygen Distribution in Oxidatively Stabilized Mesophase Pitch Fibre, Carbon, 31(1), (1993). 8. Jung, D. H., Lee, Y. S. and Rhee, B. S., The Stabilization of Mesophase Pitch Based Carbon Fiber, HWAHAK KONGHAK, 29(1), 89-96(1991). 9. Park, Y. D., Mochida, I. and Matsumoto, T., Extractive Stabilization of Mesophase Pitch Fiber, Carbon, 26(3), (1988). 10. Lee, J. K., In, S. J., Lee, D. W., Rhee, B. S. and Ryu, S. K., Stabilization of the Isotropic Pitch Fibers Drived from Petroleum with Nitric Acid Vapor, HWAHAK KONGHAK, 28(6), (1990). 11. Suzuki, T. and Hamaguchi, M., Proceedings, the 19th Biennial Conf. on Carbon, Penn. State University, USA, 166(1989). 12. Lee, J. K., In, S. J., Rhee, B. S. and Ryu, S. K., Carbonization of Isotropic Pitch Fiber Oxidized with Nitric Acid Vapor or Hot Air, HWAHAK KONGHAK, 29(4), (1991). Korean Chem. Eng. Res., Vol. 45, No. 3, June, 2007

8 276 l nëp} Ë Ëod 13. Ryu, S. K., Kim, S. Y., Gallego, N. and Edie, D. D., Physical Properties of Silver-containing Pitch-based Activated Carbon Fibers, Carbon, 37(10), (1999). 14. Eom, S. Y., Cho, T. H., Cho, K. H. and Ryu, S. K., Pore Size Distribution of Metal(Ag, Cu, Co)-containing Activated Carbon Fibers, HWAHAK KONGHAK, 38(5), (2000). 15. Oya, A., Wakahara, T. and Yoshida, S., Preparation of Pitch-based Antibacterial Activated Carbon Fiber, Carbon, 31(8), (1993). 16. Kim, M. C., Eom, S. Y., Ryu, S. K. and Edie, D. D., Reformation of Naphtha Cracking Bottom Oil for Preparation of Carbon Fiber Precursor Pitch, Korean Chem. Eng. Res., 43(6), (2005). 17. Cho, T. H., Kim, S. Y., Cho, K. H. and Ryu, S. K., Melt-spinning of Silver-containing Precursor Pitches, HWAHAK KONGHAK, 38(3), (2000). 18. Yim, K. S., Eom, S. Y., Ryu, S. K. and Edie, D. D., Microporosity and Behaviors of Metal(Ag,Cu,Co)-Containing Activated Carbon Fibers, HWAHAK KONGHAK, 41(4), (2003). 19. Lee, Y. S., Basova, Y. V., Edie, D. D., Reid, L. K., Newcombe, S. R. and Ryu, S. K., Preparation and Characterization of Trilobal Activated Carbon Fibers, Carbon, 41(13), (2003). 20. Hisashi, T., Shigeyuki, K., Hisashi, T., Makiko, I., Hajime, Y., Takayoshi, K. and Juji, M., Synthesis of Mesoporous ACF and Their Adsorption, The 23th Conference on Carbon Materials, Chiba, Japan, Dec.(1996). 21. Oya, A., Yoshida, S., Alcaniz-Monge, J. and Linares-Solano, A., Formation of Mesopores in Phenolic Resin-Derived Carbon Fiber by Catalytic Activation using Cobalt, Carbon, 33(8), (1995). 22. Lu, Y., Zhu, Z. P. and Liu, Z. Y., Effect of Catalyst on the Growth of Carbon Nanotubes Using a Detonation Approach, New carbon materials (China), 19(1), 1-6(2004). 23. Jung, S. C., Kim, S. C. and Seo, S. G., Photocatalytic Activity of the Film Grown by Chemical Vapor Deposition, HWAHAK KONGHAK, 39(4), (2001). o45 o k