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Materialscientists and engineers are engaged in developing a variety of recipes for producing functional materials, comprised of particles with uniform morphological features. There is a need to develop conditions for the synthesis of a number of inorganic and ceramic systems in pure and in core-shell configurations comprising of monodispersed particles. They are of great relevance and immense technological importance. For example, zinc oxide (ZnO) particles of reasonable uniformity employed to fabricate planar chemical sensors for the detection of ethanol, ammonia, and automobile exhaust gases have shown that the sensitivity and response/recovery time of these sensors were better than those made with commercial ZnO powder. One of the objectives of this collaborative investigation was to understand the role of starting precursors, experimental conditions and shape-modifying additives that control and impart exotic morphologies. Another objective is to optimize the process parameters for higher yield. The technique will be extended to double and higher oxides of relevance and direct impact in the renewable energy arena. mstructural Evolution in Mono-shaped and Mono-sized Functional Ceramics: Case Study of ZnO Ikram Ul Haq * and Abdul-Majeed Azad *National Center of Excellence in Physical Chemistry, University of Peshawar, Pakistan. Department of Chemical Engineering, The University of Toledo, Toledo, OH 43606-3390. MOTIVATION RESULTS AND ANALYSES Acknowledgement : The financial support to Professor Ikram Ul Haq under the auspices of Summer 2010 Visiting Faculty Researcher Program Award by the University of Toledo’s Office of Research is gratefully acknowledged. EXPERIMENTAL DETAILS Materials • Zinc nitrate hexhydrate • Urea • Hexmethylene tetramine • Ethanol •Ethylene glycol Fabrication Protocol • Make zinc nitrate, hexmethylene tetramine and urea solutions • Heat urea to boiling & add ZN; heat HETA to boiling & add ZN • Heat ZN with EG or EtOH and add urea or HETA • Mix equal volume of equimolar ZN and HETA and age in a sonicator at 70˚C for 2, 4 and 8h. Characterization • XRD, SEM and EDS Sial ZN + Urea (500 ml batch): without (L) and with (R) 4% ethylene glycol Sial ZN + HETA (200 ml batch): with 4.5% EG (L) vs. with 4.5% EtOH (R) Sial ZN + Urea: 200 ml (L) vs. 500 ml batch (R) ZN + Urea (500 ml batch): aged for 5 min. ZN + Urea (500 ml batch): aged for 10 min. ZN + Urea (500 ml batch): aged for 15 min. ZN + Urea +4% ethylene glycol (500 ml batch) aged for 15 min: no urea pre-heating & urea pre-heating for 30 min. 500 ml batch solution aged for 15 min: 0.014 M ZN + 0.17 M Urea (L) and 0.028 M ZN + 0.17 M Urea (R) 500 ml batch of L: Urea + ZN (Fischer, ca. 1992) and R: Urea + ZN (Sigma-Aldrich, ca. 2010) ZN+HETA (1:1mol): 70ºC/4h 0.035M ZN+0.4M Urea:100 ml/20 min. 0.007M ZN+4v% EG+0.08M Urea: 500 ml/30 min. 0.014M ZN+0.17M Urea: 500 ml/45 min. 0.009M ZN+0.11M Urea: 750 ml/60 min. Heat 680 ml of (0.01M ZN+3v% EG) for 20 min. Add 20 ml of 4M Urea and heat mixture for 20 min. 0.035M ZN+10v% EtOH+0.5M Urea: 100 ml/½ h
