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1 Jurnal f the Krean Ceramic Sciety Vl. 44, N. 6, pp. 297~32, 27. Square Wave Vltammetry in Cathde Ray Tube Glass Melt Cntaining Different Plyvalent Ins Ki-Dng Kim, Hy-Kwang Kim, and Yung-H Kim Faculty f Materials Science and Nan-chemical Engineering, Kunsan Natinal University, Kunsan, Krea (Received April 24, 27; Accepted June 1, 27) ƒ w w Square Wave Vltammetry ½» Á½zŸÁ½ y w ù ywœw ( ; ) ABSTRACT With aids f square wave vltammetry (SWV) the redx behavir fr varius cmbinatin f plyvalent ins (Sb Fe, Sb Zn, Sb Ce Ti Z was investigated in alkali-alkaline earth-silica CRT (Cathde Ray Tube) glass melts. The current-ptential curve s called vltammgram was prduced at temperature range f 14 t 1 C under the scanned ptential between and 8 mv at 1 Hz. In the case f the Sb Fe and SbZn dped melts, peak fr Sb 3 /Sb shwn vltammgram was shifted t negative directin cmparing t the nly Sb dped melts. Hwever, accrding t vltammgram f SbCeTiZn dped melt, Ti and Ce except Zn had hardly any influence n the redx reactin f Sb. Based n the temperature dependence f the peak ptential, standard enthalpy ( H ) and standard entrpy ( S ) fr the reductin f Fe 3 t Fe 2, Sb 3 t Sb, Zn 2 t Zn and Ti 2 t Ti in each plyvalent in cmbinatin f CRT glass melts were calculated. Key wrds : Plyvalent in, Redx reactin, Square Wave Vltammetry, Vltammgram 1. œ ƒw Sb(antimny) y y w»s, (fining)» w, (<1 wt%) w ƒ (plyvalent i y y (reductin xidatin w w redx) mw,, üy,, Ÿ œ š w e. w ƒ ( :³ 1-3) y ), w ( :üy, mlybdenum ) (fining agents) l ù p w ( : Ÿ n ) w» w ƒ. redx k w / w ù ƒ. ƒ Crrespnding authr : Ki-Dng Kim kdkim@kunsan.ac.kr Tel : Fax : , y (xygen activity) w redx k, y CaO Y 2 - y ZrO 2» w š w w ƒ w, 4-6) redx t w ƒ w data y vltammetric», p square wave vltammetry (SWV) w ƒ w. 7-1) Display alkali-alkaline earth-silica (Cathde Ray Tube:CRT) Sb, slarizatin brwning w Ce, Fe, Zn Ti ƒ w w š ù, CRT k yy w ww., CRT sda-lime-silica CRT ƒ yy w 198 z t š, 7-12) Sb, Fe, Ti, Zn, Ce w ƒ w w CRT SWV w ww t ù13,14) 2 ƒ w w 297

2 298 ½» Á½zŸÁ½ y w. SbFe, SbZn, SbCe Ti Zn w 2 ƒ w w CRT SWV w ƒ y redx w. 2. Redx square wave vltammetry wš ƒ (M) w w ƒ w. M x M ( x n 2 --O 2 n 4 --O 2 n ƒ w kƒ y, O 2 w. w w M w ƒ ƒw ù w redx w, ƒ redx œw ù ü w w ƒ w. ù wù k w x (x M M k œ w, Redx (, y [ M y sx k w x ] ) [ M ( x ],,»( ) w. w ƒ š Redx p. (1)» Redx T sx w, sx K(T) wš (PO2) w txw. KT ( ) [ M x n 4 ] P O2 M ( x = [ ] SWV w ƒ q w» w», d cell Fig. 1 3, wrking electrde(pt), reference electrde (Y 2 y ZrO 2 ) cunter electrde(pt), ptentistat mw wrking electrde ( ü.21 bar w š œ» ) reference electrde w w wrking electrde cunter electrde ƒ. w ƒ dnatin acceptance x w w w redx» w š w, w faradaic. z wrking electrde reference electrde w w d š, w l Fig. 2 currentptential š vltammgram w, w y-y». w current-ptential š, vtammgram ƒ redx» w p peak current(i P ) peak ptential(e P ) ùkù, š xk redx w ƒ y,» wrking electrde t, wrking electrde reference electrde w (scan rate:v/sec) (2) Fig. 1. Electrchemical cell fr SWV measurements and cnnectin state f electrdes. 1 : Wrking electrde, 2 : Reference electrde, 3 : Cunter electrde Fig. 2. Typical current-ptential curve by square wave vltammetry. w wz

3 ƒ w w Square Wave Vltammetry 299 q w. (2) ùkù T s x K(T) vltammgram l E P w (3) ùký. KT ( ) [ M x n 4 ] P O2 M ( x = = exp [ ] n F E p T» F faraday š». K(T) = exp H S w (3) (4) T k. In K( T) H S n F E p = = T T (3) (4) T redx enthalpy ( H) entrpy ( S) ln K 1/T l»» r l. 3. x 3.1. CRT w ml% 73.6SiO 2, 1.4Al 2, 9NaO, 5K 2 O, 6SrO, 4BaO,.9ZrO 2 w blank w, CRT ƒ w wš ƒ š w SiO 2.7Sb 2.7Fe 2 O,.7Sb 2.4ZnO,.7Sb 2.11CeO 2.37TiO 2.4ZnO w ƒ w w. š w w ƒ y w. œ w CRT ƒ w w œ w ƒ ƒ w w. 3 g yw 14~15 C Pt/Rh ƒ k z, ³ w w 1 Pt/Rh w w. ƒ 14 C š»»š, y k z SWV d w SWV d w SWV d w d y e»» w vw» w» w. w SWVd, Ptentistat(M273A, EG & G, USA) mw w ptential ~ 8 mv, q 1 Hz, C l 1 C¾ ƒ w» vltammgram blank vltammgram vltammgram w, Fig. 3. Square wave vltammgram f CRT glass melt cntaining.7sb 2 and.7fe 2. sftware(m27, EG & G, USA) vltammgram w. 4. š 4.1. ƒ y Fig. 3.7Sb 2.7Fe 2 w wš CRT 1-14 C vltammgram ùkü. w 13,14) ƒ w w CRT vltammgram w, Fe 3 /Fe y w 2 ptential peak Sb w w 4~ 3 5 mv shulder w û. Sb 3/2O 2 Sb 3/4O 2 w Sb 3 /Sb y peak e 1~ 3 mv Sb w w w. Sb 3 /Sb y peak e w Fe w sda lime silicate w. ù 12) Sb 5 /Sb y 3 w peak 1 C yw ùkù» w. Fig. 4(a) 12 C.7Sb 2.4ZnO w wš CRT w vltammgram ùkü. Sb 3 / Sb ( Zn 2 O 2 Zn 1/2O 2 w) Zn 2 /Zn y» w ƒƒ peak ptential e ùkù. Sb Zn ƒƒ w ƒ w w Fig 4(b) 13) vltammgram ƒ w w Fig. 4(a) vltammgram w Sb Zn y. Zn 2 /Zn peak e w Sb 3 /Sb peak e w w. Zn Fe Sb redx w e. Fig. 5.7Sb 2,.11CeO 2,.37TiO 2,.4ZnO 44«6y(27)

4 3 ½» Á½zŸÁ½ y Fig. 4. Square wave vltammgram f CRT glass melt cntaining. (a).7sb 2 and.4zno tgether, (b).7sb 2 and.4zno individually at 12 C w wš CRT w vltammgram ù kü. Fig C vltammgram Sb Zn w wš Fig. 4(a) vltammgram Fig. 6. Square wave vltammgram f CRT glass melt prepared frm industrial raw materials. w e w peak wš. Zn Sb Redx w 2 e, Ti( Ti O 2 Ti 4 1/2O 2 ) Ce( Ce 1/2O 2 Ce 3 1/4O 2 ) w e w. Fig. 5 p ƒ Sb, Zn, Ti y» w peak w w š. ¾ ƒ y» w w wù ƒ w w CRT Redx w vltammetry d w w w. ù CRT ƒ Sb, Ce š Zn Ti Fe S w wš. Fig. 6.7Sb 2,.11CeO 2,.37TiO 2,.4ZnO w š w œ w w CRT vltammgram ùkü. Fig. 5 ƒ Sb 3 /Sb, Zn 2 /Zn Ti 4 /Ti y» Fig. 5. Square wave vltammgram f CRT glass melt cntaining.7sb 2,.11CeO 2,.37TiO 2 and.4zno. Fig. 7. Square wave vltammgrams f CRT glass melt at 12 C, curve 1 : Sb 2 CeO 2 TiO 2 ZnO, curve 2 : industrial raw materials, curve 3 : Sb Fe, curve 4 : Sb Zn w wz

5 ƒ w w Square Wave Vltammetry 31 w peak ùkù, p Sb 3 / Sb» w peak shulder xk û. Zn peak e Zn w w Fig. 4(b) Zn ƒ w wš Fig. 4(a) Fig. 5 w w. Sb shulder peak e š w Fig. 5 w w. Fig. 7 ¾» w 4 ƒ w CRT w 12 C vltammgram ùkü. œ w vltammgram, curve 2 Zn w peak e ƒ curve 1 curve 4 ùkù Zn peak w ew Sb e shulder ùkùš. œ CRT ùkù w peak xk y w S w ƒ. S 6, 4, š 2 ƒ k w, 15) S w w sda-lime-silica ~ 8 mv ww SWV d w ptential ü peakƒ ùkù peak S 4 /S S /S 2- w š šwš. CRT 16,17) sda-lime-silica š S redx w peak e CRT Zn Sb peak e w. œ y S w peak Zn Sb peak peak e jš s š shulder x k w. wz S w w CRT w vltammetry mw y w v ƒ Redx w w data Table 1 w ƒ w, 13,14) Table 2 ww ƒ w CRT w SWV d w Sb 3 /Sb, Fe 3 /Fe 2, Zn 2 /Zn Ti 2 /Ti» w peak ptential(e P ) enthalpy entrpy ù kü. Table 2 SbFe Sb 3 /Sb w E P w Sb ƒƒ w wš Table 1 E P w w ƒw. Sb w w y w w. w, Table 2 SbZn, SbCeTiZn w E P ƒ w w Table 1 w Zn 2 /Zn peak e w š Sb 3 /Sb peak e w w., Zn Sb redx Fe w w e. ƒ œ w sx k Sb y w, Zn w w y w Table 1. Peak Ptential (E p ) and Enthalpy ( H ), Entrpy ( S ) fr Fe 3 /Fe 2, Sb 3 /Sb and Zn 2 /Zn in CRT Glass Melts Cntaining 13, 14) Single Plyvalent In Redx pair E p (mv) 1673 K 1573 K 1473 K 1373 K 1273 K H (kj mle -1 ) S ( J mle -1 K -1) ) Fe 3 /Fe Sb 3 /Sb Zn 2 /Zn Table 2. Peak Ptential (E p ) and Enthalpy ( H ), Entrpy ( S ) fr Fe 3 /Fe 2, Sb 3 /Sb, Zn 2 /Zn and Ti 2 /Ti in CRT Glass Melts Cntaining Different Plyvalent Ins FeSb SbZn SbCeTiZn Redx pair E p (mv) H (kj mle -1 ) S ( J mle -1 K -1) ) Sb 3 /Sb Fe 3 /Fe 2 Sb 3 /Sb Zn 2 /Zn Sb 3 /Sb Zn 2 /Zn Ti 2 /Ti Sb 3 /Sb *IRM Zn 2 /Zn Ti 2 /Ti *IRM: Industrial Raw Materials 44«6y(27)

6 32 ½» Á½zŸÁ½ y w. Sƒ w IRM w E P w (4) w Table 2 enthalpy( H ) entrpy( S ) ƒ w w Table 1 w, Fe Sb yƒ ù Sb Zn SbCeTiZn Sb 3 /Sb w H S w yƒ ùküš. Sb 3 /Sb y E P H S e Zn w q w. 5. Sb, Ce, Fe, Zn, Ti ww ƒ w wš alkali-alkaline earth-silica CRT Square Wave Vltammetry d ww. Vltammgram w y Sb Zn œ w ƒ w, Ti w e w. Peak ptential w w ƒ ƒ enthalpy( H ) entrpy ( S ) w w ùkü. Acknwledgement 26 ( w» ) w w w (N. R ) REFERENCES 1. C. R. Bamfrd, Clr Generatin and Cntrl in Glass, pp , Elsevier Scientific Publishing C Annemieke Wndergem-de Best, Redx Behavir and Fining f Mlten Glass, pp. 43-7, Dissertatin f Eindhven Uni H. Bach, F. Baucke, and D. Krause, Electrchemistry f Glasses and Glass Melts, Including Glass Electrdes, pp Springer, C. Ruessel, R, Khl, and H. Schaeffer, Interactin between Oxygen Activity f Fe 2 Dped Sda-lime-silica Glass Melts and Physically Disslved Oxygen, Glastech. Ber. 61 [8] (1988). 5. O. Lafrukhi, J. Hertz, J. P. Hilger, and G. Crnier, Electrchemical Measurement f Oxygen Activity in Lead Glass by Means f a Stabilized ZrO 2 Sensr, Part 2. Determinatin f the Equilibrium Cnstants in the Redx Systems Arsenic and Antimny, Glastech. Ber. 64 [11] (1991). 6. M. Yamashita and H. Yamanaka, Oxygen Activity Change in Sda-lime-silica Glass Melts with r withut Refining Agent, Glastech. Ber. Glass Sci. Technl. 7 [12] (1997). 7. C. Ruessel and E. Freude, Vltammetric Studies f the Redx Behaviur f Varius Multivalent Ins in Sda-limesilica Glass Melts, Phys. Chem. Glasses 3 [2] 62-8 (1989). 8. C. Ruessel, The Electrchemical Behavir f Sme Plyvalent Elements in a Sda-lime-silica Glass Melts, J. Nn- Cryst. Slid (199). 9. O. Claussen, C. Ruessel, and A. Matthai, Electrchemical Studies n the Fining f Glass, pp , Prceeding f IV ESG Cnference n Glass Science and Technlgy, Vaexje, Sweden, June S. Gerlach, O. Claussen, and C. Ruessel, A Vltammetric Study n the Thermdynamics f the Fe 3 /Fe 2 -Equilibrium in Alkali-lime-alumsilicate Melts, J. f Nn-Crystalline Slids (1999). 11. G. vn der Genna and C. Ruessel, Redx Equilibria f Plyvalent Elements in Binary Na 2 OxSiO 2 Melts, Glastech. Ber, Glass Sci. Technl. 73 [4] 15-1 (2). 12. C. Ruessel, Electrchemical Study n the Redx Behavir f Selenium-cntaining Sda-lime-silica Melts, Glastech. Ber, Glass Sci. Technl. 74 [1] 1-5 (21). 13. K. D. Kim, Y. J. Kim, H. S. Jung, and Y. H. Kim, Vltammetric Apprach t Redx Behavir f Varius Elements in CRT Glass Melts, Prceeding f the XI Internatinal Cnference n the Physics f nn-crystalline Slids, Rhdes, Greece, Oct. 25 Nv. 2, H.-S. Jung, K.-D. Kim, H.-K. Kim, and Y.-H. Kim, Redx equilibrium f antimny by square wave vltammetry methd in CRT display glass melts, J. Kr. Ceram. Sc. 44 [1] 1-5 (27). 15. R. G. C. Beerkens and K. Kahl, Chemistry f Sulphur in Sda-lime silica Melts, Phys. Chem. Glasses (22). 16. T. Krdn, C. Rssel, and E. Freude, Vltammetric Investigatins in Na 2 SO 4 -Refined Sda-lime-silica Glass Melts, Glastech. Ber., 63 [8] (199). 17. C. Clauben and C. Russel, Vltammetry in a Sulfur and Irn-cntaining Sda-lime-silica Glass Melt, Glastech. Ber. Glass Sci. Techn., 7 [8] (1997). w wz