High-temperature stable transition aluminas nanoparticles recovered from sol–gel processed chitosan-AlOx organic–inorganic hybrid films
- 17 Downloads
Five and ten weight percent-alumina-containing chitosan-AlOx films were prepared via sol–gel processing. The films were AlOx-agglomerate-free. These organic–inorganic films were degraded by heating at 500 °C. The solid powder residues were found by means of thermogravimetry, X-ray diffractometry, infrared spectroscopy, and electron microscopy to consist of alumina (Al2O3) nanoparticles entraping volatile components, whose thermal removal encouraged ambient oxygen uptake. The surface microstructure and morphology of the recovered alumina nanoparticle were inspected by high-resolution transmission and scanning electron microscopy. Also, the surface chemistry and texture were evaluated by X-ray photoelectron spectroscopy and N2 sorptiometry. Coalescences of globular nanoparticles of γ-/η-Al2O3 were the dominant composition of the 800 °C calcination product of the recovered alumina, irrespective of the alumina-content of the film. Upon increasing the calcination temperature up to 1100 °C, an enhanced polymorphic transition into agglomerated nanoparticles of the seldom encountered Iota-(ι-)Al2O3 took place. The high thermal stability of the otherwise unstable transition aluminas (at ≥950 °C) may suggestively owe to its polymorphic interdependence and/or persistent nanoscopic nature (average particle size = ca. 3–4 nm; specific surface area = ca. 80–60 m2/g). The surface chemical composition for the recovered transition aluminas nanopowders promises versatile acid–base properties for catalysis applications. Accordingly, the highly abundant bio-waste, chitosan, was successfully utilized as a novel synthesis medium for catalytic-grade alumina nanoparticles.
KeywordsAlumina Sol–gel synthesis Nanoparticle Chitosan Organic–inorganic composite Bio-waste materials
The authors gratefully acknowledge the support provided by the Research Administration of Kuwait University, under Grant Number’s SC06/13 and GS 03/01, GS01/01, GS01/03, GS01/05 and GE03/08. They also appreciate help given by the Nanoscopy Science Center at Kuwait University in performing AFM, TEM and HRTEM measurements.
This work was supported by Kuwait University [grant number SC06/13].
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 7.Shirai T, Watanabe H, Fuji M, Takahashi M (2009) Structural properties and surface characteristics on aluminum oxide powders. Ann Rep Ceram Res 9:23–31Google Scholar
- 13.Schüth F, Unger K (1997) In: Ertl G, Knözinger H, Weitkamp J (eds) Handbook of heterogeneous catalysis. Wiley, Weinheim, pp 72–86Google Scholar
- 14.Ertl G, Knözinger H, Weitkamp J (eds) (1997) Handbook of heterogeneous catalysis. Wiley, Weinheim, pp 1–5Google Scholar
- 16.Wilson SJ (1979) Phase transformations and development in microstructure in boehmite-derived transition aluminas. Proc Br Ceram Soc 28:281–294Google Scholar
- 22.Boudart M (1997) In: Ertl G, Knözinger H, Weitkamp J (eds) Handbook of heterogeneous catalysis. Wiely, Weinheim, pp 1–11Google Scholar
- 24.Ali AAM, Zaki MI (2011) Thermal and spectroscopic studies of polymorphic transitions of zirconia during calcination of sulfated and phosphate Zr(OH)4 precursors of solid acid catalysts. Thermochim Acta 36(1–2):17–25Google Scholar
- 26.Uchida Y, Sawabe Y, Mohri M, Shiraga N, Matsui Y (1995) Nearly monodispersed single crystal particles of α-alumina. in Adair JH, Casey JA, Clive A Randall, Venigalla S (eds) Handbook on Science, Technology, and Applications of Colloidal Suspensions,Ceramic Transactions, Vol. 54, The American Ceramic Society, pp 159–165Google Scholar
- 27.Kadokura H, Umezaki H, Higuchi Y (1987) Process for producing high purity metallic compound. US. Patent, No. 4, 650, 895,1987Google Scholar
- 36.Muzzarelli RAA (1977) Chitin. Pergamon Press, OxfordGoogle Scholar
- 37.Tonny W, Tuhin MO, Islam R, Khan RA (2014) Fabrication and characterization of biodegradable packaging films using starch and chitosan: effect of glycerol. J Chem Eng Chem Res 1(5):343–352Google Scholar
- 45.International Center for Diffraction Data, 12 Campus Boulevard, Newtown Square, PA 19073-3273, USAGoogle Scholar
- 46.Snyder RL (1999) In: Lifshin E (ed) X-ray characterization of materials. Wiley, Weinheim, Toronto, 4–103Google Scholar
- 49.Gadsden JA (1975) Infrared spectra of minerals and related inorganic compounds. Butterworths, LondonGoogle Scholar
- 50.Wefers K, Mirsa C (1987) Oxides and hydroxides of aluminum. ALCOA Laboratories, PennsilvaniaGoogle Scholar
- 51.Santos PS, Santos HS, Toledo SP (2000) Standard transition aluminas. Electr Microsc Stud Mater Res 3:104–114Google Scholar
- 53.Fischer RX, Schneider H, Schmuecker M (1994) Crystal structure of Al-rich mullite. Am Miner 79(9–10):983–990Google Scholar
- 54.Lecloux AJ (1981) Texture of catalysts. Catal Sci Eng 2:171–229Google Scholar
- 55.Rouquerol F, Rouquerol J, Sing K (1999) Adsorption by powders & porous solids principles, methodology and applications. Academic Press, San Diego, pp 440–441Google Scholar
- 56.Gregg SJ (1982) Adsorption of gases—tool for the study of the texture of solids. In: Rouquerol J, Sing KSW (eds) Adsorption at the gas–solid and liquid–solid interface. Elsevier, AmsterdamGoogle Scholar
- 57.Gregg SJ, Sing KSW (1967) Adsorption, surface area and porosity. Academic Press, London, p 153–164Google Scholar
- 58.Wagner CD, Riggs WM, Davis LE, Moulder JF (1979) In: GE Muilenberg (ed) Handbook of X-ray photoelectron spectroscopy. Perkin-Elmer Corp., Minnesota 55344Google Scholar