Sains Malaysiana 43(2)(2014): 261–265

Using a Pilot Plant to Synthesise ZnO Powder: Particle Characterisation and Marine Toxicity Studies

(Menggunakan Loji Pandu untuk Mensintesis Serbuk ZnO: Pencirian Partikel dan Kajian Ketoksikan Marin)

S. MAHMUD*¹& Z. DIN²

  ¹Zinc Oxide Research & Innovation (ZORI) Team, Nano-Optoelectronic Research Lab

School of Physics, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia

²Academy of Sciences Malaysia, 902-4 Jalan Tun Ismail, 50480 Kuala Lumpur

Malaysia

Diserahkan: 7 Januari 2013/Diterima: 19 Julai 2013

ABSTRACT

A zinc oxide (ZnO) pilot plant furnace was used to synthesize ZnO nanoparticles at very high capacities in a range of 1-4 t/month. The 4-t custom-designed furnace was used to synthesize ZnO particles possessing primary nanoparticles resembling rods and grains. At a combustion temperature of 1000-1300°C, zinc vapour was oxidized into ZnO powder in order to produce granular ZnO (ZG) particles. By blowing air into the combustion chamber, ZnO nanorods (ZR) were produced. The ZR specimen exhibited higher XRD intensities, stronger photocatalysis and higher electrical resistance compared to that of ZG sample. However, the ZR sample showed a stronger toxicity to marine phytoplankton, Isochrysis galbana, by starting to inhibit cell growth at 8 mg/L ZnO concentration in seawater whereas ZG sample started showing growth inhibition at a higher ZnO concentration of 32 mg/L. The toxicity of ZnO primary nanoparticles was probably attributed to the dissolution, release and uptake of free zinc ions especially for the case of the higher surface area of ZR particles that exhibited relatively higher zinc concentration on the particle surface, based on the elemental mapping of the electron spectroscopy imaging results.

Keywords: Isochrysis galbana; pilot plant; toxicity; ZnO

ABSTRAK

Satu tanur loji pandu zink oksida (ZnO) digunakan untuk menghasilkan partikel nano ZnO pada kapasiti tinggi dalam julat 1-4 t/bulan. Dengan reka bentuk-khusus, tanur seberat 4 t ini digunakan untuk mensintesis partikel ZnO yang memiliki partikel nano primer menyerupai rod dan butiran. Pada suhu pembakaran 1000-1300°C, wap zink dioksidakan menjadi ZnO untuk menghasilkan partikel butiran ZnO (ZG). Dengan meniup udara ke dalam kebuk pembakaran, nanorod ZnO (ZR) dihasilkan. Sampel ZR mempamerkan keamatan XRD yang lebih tinggi, fotokatalisis yang lebih kuat dan kerintangan elektrik yang lebih tinggi jika dibandingkan dengan ciri sampel ZG. Walau bagaimanapun, sampel ZR menunjukkan ketoksikan yang lebih kuat terhadap fitoplankton marin, Isochrysis galbana dengan merencat pertumbuhan sel pada kepekatan 8 mg/L ZnO dalam air laut manakala sampel ZG menunjukkan rencatan pertumbuhan sel pada kepekatan 32 mg/L. Ketoksikan partikel nano primer ZnO mungkin disebabkan oleh pelarutan, pembebasan dan pengambilan ion bebas zink terutama untuk kes partikel ZR yang memiliki keluasan permukaan yang lebih tinggi dan kepekatan zink relatif yang lebih tinggi di permukaan partikel, berdasarkan kepada data pemetaan unsur daripada maklumat pengimejan elektron spektroskopi.

Kata kunci: Isochrysis galbana; ketoksikan; loji pandu; ZnO

RUJUKAN

Karali, T., Can, N., Valberg, L., Stephanov, A.L., Townsend, P.D., Bucha, Ch., Ganeev, R.A., Ryasnyansky, A.I., Belik, H.G., Jessett, M.L. & Ong, C. 2005. Optical properties and luminescence of metallic nanoclusters in ZnO:Cu. Physica B: Condensed Matter 363: 88-95.

Mahmud, S. 2011. One-dimensional growth of zinc oxide nanostructures from large micro-particles in a highly rapid synthesis. Journal of Alloys and Compounds 509(9): 4035- 4040.

Martinez, M.P., Chakroff, J.B. & Pantastica, J.B. 1975. Direct phytoplankton counting technique using the hemacytometer. Philippine Agricultural Scientist 59: 43-50.

Moezzi, A., McDonagh, A.M. & Cortie, M.B. 2012. Zinc oxide particles: Synthesis, properties and applications. Chemical Engineering Journal 185-186: 1-22.

Nafchi, A.M., Alias, A.K., Mahmud, S. & Robal, M. 2012. Antimicrobial, rheological, and physicochemical properties of sago starch films filled with nanorod-rich zinc oxide. Journal of Food Engineering 113(4): 511-519.

Overnell, J. 1975. The effect of heavy metals on photosynthesis and loss of cell potassium in two species of marine algae. Marine Biology 29: 99-103.

Shi, J., Hong, J.H., Ding, Y., Yang, Y., Wang, F., Cai, W. & Wang, X. 2011. Evolution of zinc oxide nanostructures through kinetics control. Journal of Materials Chemistry 21: 9000-9008.

Wagner, S., Bloh, J., Kasper, C. & Bahnemann, D. 2011. Toxicological issues of nanoparticles employed in photocatalysis. The Green Journal 1(2): 171-188.

*Pengarang untuk surat-menyurat; email: shahromx@usm.my