Sains Malaysiana 47(7)(2018): 1591–1597

http://dx.doi.org/10.17576/jsm-2018-4707-30

 

Improvement of Colloidal Stability in Colloidal Processing for Highly Translucent, Nanosized Zirconia

(Peningkatan Kestabilan Koloid dalam Pemprosesan Koloid bagi Zirkonia Berkelutcahayaan Tinggi, Bersaiz Nano)

 

CHUIN HAO CHIN1, ANDANASTUTI MUCHTAR1*, CHE HUSNA AZHARI1, MASFUEH RAZALI2 & MOHAMED ABORAS1

 

1Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

 

2Periodontology Department, Faculty of Dentistry, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Federal Territory, Malaysia

 

Received: 14 December 2017/Accepted: 23 February 2018

 

ABSTRACT

This study aimed to improve the colloidal stability of yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) suspension through colloidal processing to obtain highly translucent Y-TZP. Agglomeration is often the main complication in the processing of nanosized Y-TZP as it deteriorates mechanical and optical properties. Thus, colloidal processing is necessary to mitigate the agglomeration in Y-TZP. The colloidal stability of Y-TZP suspension plays a key role for the success of colloidal processing. In this study, colloidal processing was conducted at several stages, namely, dispersant addition, pH adjustment and sedimentation. Changes in particle size and zeta potential at various stages were recorded. The suspensions were then slip-casted to form green bodies. Green bodies were sintered and characterized for density and translucency. The results showed that dispersant addition followed by pH adjustment effectively dispersed soft agglomerates by introducing electrosteric stabilization, whereas sedimentation successfully segregated hard agglomerates and contributed excellent colloidal stability. With high colloidal stability, the translucency of Y-TZP was improved by approximately 30%. This study demonstrated different colloidal processing stages and proved that high colloidal stability and fine particle size are vital to produce highly translucent Y-TZP.

 

Keywords: Colloidal stability; slip casting; translucency; zirconia

 

ABSTRAK

Kajian ini bertujuan meningkatkan kestabilan koloid polihablur zirkonia tetragonal separa stabil oleh yttria (Y-TZP) melalui pemprosesan berkoloid untuk menghasilkan Y-TZP berkelutcahayaan tinggi. Pengaglomeratan merupakan satu masalah dalam pemprosesan Y-TZP bersaiz nano kerana pengaglomeratan sentiasa menjejaskan ciri mekanik dan optik. Justeru, pemprosesan berkoloid diperlukan untuk mengurangkan pengaglomeratan dalam Y-TZP. Kestabilan koloid ampaian Y-TZP telah memainkan peranan yang penting dalam menjayakan pemprosesan berkoloid. Dalam kajian ini, pemprosesan berkoloid telah dijalankan melalui beberapa peringkat iaitu penambahan bahan penyerak, pelarasan pH dan pemendapan. Perubahan dalam saiz zarah dan keupayaan zeta pada tahap yang berbeza telah dicatat. Ampaian Y-TZP telah diguna untuk menghasilkan jasad anum melalui kaedah tuangan slip. Jasad anum telah disinter dan seterusnya ketumpatan dan kelutcahayaan spesimen diuji. Keputusan uji kaji menunjukkan aglomerat lembut telah berjaya dipisah melalui penstabilan elektrosterik dengan penambahan bahan penyerak dan pelarasan pH. Proses pemendapan yang seterusnya berjaya memisahkan aglomerat keras dan meningkatkan kestabilan koloid. Dengan kestabilan koloid yang baik, kelutcahayaan Y-TZP telah ditingkatkan sebanyak 30%. Kajian ini telah menunjukkan peringkat pemprosesan berkoloid yang berbeza dan membuktikan kestabilan koloid yang tinggi dan saiz zarah yang kecil adalah penting untuk penghasilan Y-TZP berkelutcahayaan tinggi.

 

Kata kunci: Kelutcahayaan; kestabilan koloid; tuangan slip; zirconia

REFERENCES

Amat, N.F., Muchtar, A., Ghazali, M.J. & Yahaya, N. 2014. Suspension stability and sintering influence on yttria-stabilized zirconia fabricated by colloidal processing. Ceramics International 40(4): 5413-5419.

Baldissara, P., Llukacej, A., Ciocca, L., Valandro, F.L. & Scotti, R. 2010. Translucency of zirconia copings made with different cad/cam systems. The Journal of Prosthetic Dentistry 104(1): 6-12.

Bowen, P., Carry, C., Luxembourg, D. & Hofmann, H. 2005. Colloidal processing and sintering of nanosized transition aluminas. Powder Technology 157(1-3): 100-107.

Chen, Y.M., Smales, R.J., Yip, K.H.K. & Sung, W.J. 2008. Translucency and biaxial flexural strength of four ceramic core materials. Dental Materials 24(11): 1506-1511.

Chin, C.H., Muchtar, A., Azhari, C.H., Razali, M. & Aboras, M. 2015. Optimization of pH and dispersant amount of Y-TZP suspension for colloidal stability. Ceramics International 41(8): 9939-9946.

Groza, J.R. 1999. Nanosintering. Nanostructured Materials 12(5-8): 987-992.

Heffernan, M.J., Aquilino, S.A., Diaz-Arnold, A.M., Haselton, D.R., Stanford, C.M. & Vargas, M.A. 2002. Relative translucency of six all-ceramic systems. Part I: Core materials. The Journal of Prosthetic Dentistry 88(1): 4-9.

Jiang, L., Liao, Y., Wan, Q. & Li, W. 2011. Effects of sintering temperature and particle size on the translucency of zirconium dioxide dental ceramic. Journal of Materials Science: Materials in Medicine 22(11): 2429-2435.

Kelly, J.R., Nishimura, I. & Campbell, S.D. 1996. Ceramics in dentistry: Historical roots and current perspectives. The Journal of Prosthetic Dentistry 75(1): 18-32.

Kim, M.J., Ahn, J.S., Kim, J.H., Kim, H.Y. & Kim, W.C. 2013. Effects of the sintering conditions of dental zirconia ceramics on the grain size and translucency. Journal of Advanced Prosthodontics 5(2): 161-166.

Leong, C.H., Muchtar, A., Tan, C.Y., Razali, M. & Chin, C.H. 2017. Sintering of hydroxyapatite under nitrogen atmosphere for improved microhardness. Sains Malaysiana 46(9): 1635- 1640.

Lewis, J.A. 2000. Colloidal processing of ceramics. Journal of the American Ceramic Society 83(10): 2341-2359.

Liu, Y. & Gao, L. 2003. Deflocculation study of aqueous nanosized Y-TZP suspensions. Materials Chemistry and Physics 78(2): 480-485.

Ma, J. & Lim, L.C. 2002. Effect of particle size distribution on sintering of agglomerate-free submicron alumina powder compacts. Journal of the European Ceramic Society 22(13): 2197-2208.

Muchtar, A. & Lim, L.C. 1998. Indentation fracture toughness of high purity submicron alumina. Acta Materialia 46(5): 1683-1690.

Ozturk, O., Uludag, B., Usumez, A., Sahin, V. & Celik, G. 2008. The effect of ceramic thickness and number of firings on the color of two all-ceramic systems. The Journal of Prosthetic Dentistry 100(2): 99-106.

Rafferty, A., Alsebaie, A.M., Olabi, A.G. & Prescott, T. 2009. Properties of zirconia-toughened-alumina prepared via powder processing and colloidal processing routes. Journal of Colloid and Interface Science 329(2): 310-315.

Rami, M.L., Meireles, M., Cabane, B. & Guizard, C. 2009. Colloidal stability for concentrated zirconia aqueous suspensions. Journal of the American Ceramic Society 92: 50-56.

Stawarczyk, B., Özcan, M., Hallmann, L., Ender, A., Mehl, A. & Hämmerlet, C.F. 2012. The effect of zirconia sintering temperature on flexural strength, grain size, and contrast ratio. Clinical Oral Investigations 17(1): 1-6.

Sulaiman, T.A., Abdulmajeed, A.A., Donovan, T.E., Ritter, A.V., Vallittu, P.K., Närhi, T.O. & Lassila, L.V. 2015. Optical properties and light irradiance of monolithic zirconia at variable thicknesses. Dental Materials 31(10): 1180-1187.

Ting, J.M. & Lin, R.Y. 1995. Effect of particle size distribution on sintering. Journal of Materials Science 30(9): 2382-2389.

Tong, H., Tanaka, C.B., Kaizer, M.R. & Zhang, Y. 2016. Characterization of three commercial Y-TZP ceramics produced for their high-translucency, high-strength and high-surface area. Ceramics International 42(1, Part B): 1077-1085.

Trunec, M. & Pouchly, V. 2016. Colloidal processing of low-concentrated zirconia nanosuspension using osmotic consolidation. Ceramics International 42(10): 11838-11843.

Wollmershauser, J.A., Feigelson, B.N., Gorzkowski, E.P., Ellis, C.T., Goswami, R., Qadri, S.B., Tischler, J.G., Kub, F.J. & Everett, R.K. 2014. An extended hardness limit in bulk nanoceramics. Acta Materialia 69: 9-16.

Xie, Z., Ma, J., Xu, Q., Huang, Y. & Cheng, Y.B. 2004. Effects of dispersants and soluble counter-ions on aqueous dispersibility of nano-sized zirconia powder. Ceramics International 30(2): 219-224.

Zakaria, H., Muhamad, N., Sulong, A.B., Ibrahim, M.H.I. & Foudzi, F. 2014. Moldability characteristics of 3 mol% yttria stabilized zirconia feedstock for micro-powder injection molding process. Sains Malaysiana 43(1): 129-136.

Zhang, H., Li, Z., Kim, B.N., Morita, K., Yoshida, H., Hiraga, K. & Sakka, Y. 2012. Effect of alumina dopant on transparency of tetragonal zirconia. Journal of Nanomaterials 2012: 5.

Zhang, Y. 2014. Making yttria-stabilized tetragonal zirconia translucent. Dental Materials 30(10): 1195-1203.

 

 

*Corresponding author; email: muchtar@ukm.edu.my

 

 

 

 

previous