Stability of aqueous nano-ceramic coatings with two different dispersants

Abstract

The effects of sodium carboxymethyl cellulose and sodium citrate as dispersants on nano-ceramic aqueous suspension were examined by the measurements of ζ-potential and the sedimentation test. The results show that proper addition of sodium carboxymethyl cellulose or sodium citrate into nano-ceramic coating, exhibits an enhanced dispersion and stability compared with the coating without dispersants. The negative ζ-potential of the particles in the nano-coating increases with the increase of pH value of the coating, and the curve of ζ-pH moves to lower pH range when the dispersants are added into the coating. To ensure that the coating has not only good stability and dispersibility but also no corrosivity to substrate alloy, adding 1.00% sodium citrate into coating with pH value of 7–8 is preferable to adding sodium carboxymethyl cellulose.

Keywords

nano-ceramic coating / dispersion / dispersant / ζ potential

References

[1] XiaChang-qing, GuYi, TanCheng-yu. Study of the dispersion of nano-ceramic suspension[A]. Symposia proceedings of C-MRS (in Chinese)[C], 2001, Beijing, Met Technol Press

[2] NieszD E, BennettR B, SnyderM. Strength characterization of powder aggregates[J]. Am Ceram Soc Bull, 1972, 51(9): 677-80

[3] ScottC E, ReedJ S. Effect of laundering on the sintering behavior of stabilized ZrO₂ powders [J]. Am Ceram Soc Bull, 1979, 58(6): 587-90

[4] HaberkoK. Characteristics and sintering behavior of zirconia ultrafine powders[J]. Ceram Int, 1979, 5(4): 148-54

[5] NishiokaM, ChiangS S, FulrathR M, et al.. Influence of mixing medium on sintering and coupling coefficient of PZT ceramics[J]. Ceram Int, 1981, 7(3): 87-89

[6] SacksM D, PaskJ A. Sintering of mullite-containing materials II : effect of agglomeration[J]. J Am Ceram Soc, 1982, 65(2): 70-77

[7] RhodesW H. Agglomerate and particle size effects on sintering yttria-stabilized zirconia [J]. J Am Ceram Soc, 1981, 64(1): 19-22

[8] NapperD HPolymeric Stabilization of Colloidal Dispersions[M], 1983, London, Academic Press

[9] CesaranoJ, AksayI A. Stability of aqueous α-Al₂O₃ suspensions with poly (methacrylic acid) polyelectrolyte[J]. J Am Ceram Soc, 1988, 71(4): 250-55

[10] PapenhuijzenJ, Van der SheeH A, FleerG J. Polyelectrolyte adsorption I: A new lattice theory[J]. J Colloid Interface Sci, 1985, 104: 540-561

[11] TongJian-feng, ChenDa-ming, ChenYu-hang. Optimization of alumina-silicon carbide dispersions in the process of the nanocomposite ceramic materials[J]. Bulletin of the Chinese Ceramic Society, 2000, 20(3): 24-27(in Chinese)

[12] WuQi-sheng, ZhangShao-ming, MaZhen-hua. Influence of polyelectrolyte on dispersing performance of α-Al₂O₃ suspensions[J]. China Powder Science and Technology, 1999, 5(3): 33-35(in Chinese)

[13] HashibaM, Okamoto, NurishiY, et al.. Dispersion of ZrO₂ particles in aqueous suspensions by ammonium polyacrylate[J]. Journal of Materials Science, 1989, 24: 873-876

[14] AndersonP J. Zeta potentials in relation to rheological properties of oxide slips[J]. J Amer Ceram Soc, 1975, 42(2): 70-74

[15] ZhangQing-cen, LiuXiao-he, LiuJian-ping, et al.. Synthesis of hyperdispersant and its influences on dispersion and stabilization of the silica particles[J]. J Cent South Univ Technol, 2002, 33(3): 234-237(in Chinese)