A comparative study of different amorphous and paracrystalline silica by NMR and SEM/EDS

Abstract

This work aimed to research the structure models of amorphous materials. Five amorphous and paracrystalline samples (natural or artificial) were investigated via ²⁹Si/²⁷Al nuclear magnetic resonance (NMR) and field emission scanning electron microscopy/energy dispersive spectroscopy (FE-SEM/EDS). The results of NMR showed the resonances of different specimens: -93.2 ppm, -101.8 ppm, -111.8 ppm for natural pozzolana opal shale (POS). These peaks were assigned to the Q²(2OH), Q³(OH)/Q⁴(1Al) and Q⁴ respectively. The results of ²⁷Al MAS NMR indicated that Al substituted for Si site in tetrahedral existing in the POS, while the Al/Si atomic ratio in opal was low (around 0.04). For the alkali-silicate-hydrate gel, there were at least three resolved signals assigned to Q⁰ and Q¹, respectively. For the fused silica glass powder, there were the primary signals centered about at the range from -107 to -137 ppm, which were assigned to Q⁴ units. In addition, the peaks at around -98 and -108 ppm were corresponding to Q³(1OH) and Q⁴ units existing in aerogel silica structure.

Keywords

amorphous and paracrystalline silica / the structure models / NMR / Al-substituted

References

[1] Jones J B, Sanders J V, Segnit E R. Structure of Opal[J]. Nature, 1964, 204: 990-991.

[2] Akitt J W, Greenwood N N, Lester G D. Nuclear Magnetic Resonance and Raman Studies of the Aluminium Complexes formed in Aqueous Solutions of Aluminium Salts containing Phosphoric Acid and Fluoride Ions[J]. Journal of chemical society(A), 1971 2450-2457.

[3] Wang L J, Zhao S Y. Synthesis and Characteristics of Mesoporous Silica Aerogels with One-step Solvent Exchange/Surface Modification[J]. Journal of Wuhan University of Technolotgy-Mater. Sci. Ed., 2009, 24(4): 613-618.

[4] Kureti S, Weisweiler W. A Novel Sol-gel Method for the Synthesis of c-Aluminium Oxide: Development of the Sol-gel Transformation and Characterization of the Xerogel[J]. Journal of Non-Crystalline Solids., 2002, 303(2): 253-261.

[5] Ren L F. The Discovery and Research of Light Shale Compose of Cristobalite and Tridymite[J]. Bulletin of the Chinese Ceramic Society., 1982, 2: 13-17.

[6] Liu Y, Zheng SL, Du GX, et al. Photocatalytic Degradation Property of Nano-TiO₂/Diatonite for Rodamine B Dye Wastewater[J]. International Journal of Modern Physics B, 2009, 23: 1683-1688.

[7] Zheng S L, Bai C H, Gao R Q. Preparation and Photocatalytic Property of TiO2/Diatomite-based Porous Ceramics Composite Materials[J]. International Journal of Photoenergy, 2012, 10: 1-4.

[8] Sun Z M, Bai C H, Zheng S L, et al. A Comparative Study of Different Porous Amorphous Silica Minerals Supported TiO2 Catalysts[J]. Applied Catalysis A: General, 2013, 458: 103-110.

[9] Jones J B, Segnit E R. The Nature of Opal I. Nomenclature and Constituent Phases[J]. Journal of the Geological Society Society of Australia, 1971, 18: 57.

[10] Graetsch H, Gies H I. Topalovi. NMR, XRD and IR Study on Microcrystalline Opals[J]. Phys. Chem. Minerals, 1994, 21(3): 166-175.

[11] Onal M, Kahraman S, Sarikaya Y. Differentiation of a-Crisrobalite from Opals in Bentonites fromTurkry[J]. Applied Clay Science, 2007, 35: 25-30.

[12] Langer K, Flörke O W. Near Infrared Absorption Spectra(4 000- 9 000 cm-1) of Opals and The Role of “Water” in these SiO₂·nH₂O Mineral[J]. Fortschrift Der Miner, 1974, 52: 17-51.

[13] Saminpanya S, Sutherland F L. Silica Phase-Transformations During Diagenesis Within Petrified Woods Found in Fluvial Deposits from Thailand-Myanmar[J]. Sedimentary Geology, 2013, 290: 15-26.

[14] Wise J R, Kelt K. Inferred Diagenetic History of a Weakly Silicified Deep Sea Chalk[J]. Gulf Coast Association of Geological Societies Transactions, 1972, 22: 177-203.

[15] Flörke O W, Jones J B, Segnit E R. Opal-CT Crystals[J]. Neues Jahrbuch fur Mineralogie Monatshefte, 1975, 8: 369-377.

[16] Brown L D, Ray A S, Thomas P S. 29Si and 27Al NMR Study of Amorphous and Paracrystallin Opals from Australia[J]. Journal of Non-Crystalline Solids, 2003, 332(1-3): 242-248.

[17] Dai Z, Tran T T, Jorgen S. Aluminum Incorporation in the C-S-H Phase of White Portland Cement-Metakaolin Blends Studied by 27Al and 29Si MAS NMR Spectroscopy[J]. Journal of the American Ceramic Socirty, 2014, 97(8): 2662-2671.

[18] Hu C G, Hu S G, Ding Q J, et al. Effect of Curing Regime on Degree of Al3+ Substituting for Si4+ in C-S-H Gels of Hardened Portland Cement Pastes[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2014, 29(3): 546-522.

[19] Gross A F, Le V H, Kirsch B L, et al. Correlations between Silica Chemistry and Structural Changes in Hydrothermally Treated Hexagonal Silica/Surfactant Composites Examined by in situ X-ray Diffraction[J]. Chem. Mater., 2001, 13(10): 3571-3579.

[20] Graetsch H, Gies H, Topalovic I. NMR, XRD and IR Study on Microcrystalline Opals[J]. Physics and Chemistry of Minerals, 1994, 21(3): 166-175.

[21] Hinman N W, Kotler J M. Aluminum in Silica Phases Formed in Hot Springs[J]. Procedia Earth and Planetary Science, 2013, 7: 365-368.

[22] Fritsch E, Gaillou E, Rondeau B, et al. The Nanostructure of Fire Opal[J]. Journal of Non-crystalline Solids, 2006, 352(38-39): 3957-3960.

[23] Wang C L, Zheng S L, Liu G H, et al. Preparation of Wollastonite Coated with Nano-aluminium Silicate and Its Application in Filling PA6[J]. Surface Review and Letters, 2010, 17: 265-270.

[24] Sun Z M, Zheng L M, Zheng S L, et al. Preparation and Characterization of TiO2/acid Leached Serpentinite Tailings Composites and Their Photocatalytic Reduction of Chromium(VI) [J]. Journal of Colloid and Interface Science, 2013, 8(404): 102-109.

[25] Baasner A, Schmidt B C, Webb R L. Fluorine Speciation as a Function of Composition in Peralkaline and Peraluminous Na2O-Glasses: A Multinuclear NMR Study[J]. Geochimica et Cosmoclumica Acta, 2014, 132: 151-169.

[26] Maruyama I, Nishioka Y, Matsui G K. Microstructural and Bulk Property Changes in Hardened Cement Paste During the First Drying Process[J]. Cement and Concrete Research, 2014, 58: 20-34.

[27] Gwenn L S, Mohsen B, H H, Frank W, et al. Hydration Degree of Alkali-activated Slags: A 29Si NMR Study[J]. The American Ceramic Society, 2011, 94: 4541-4547.

[28] Ma H N, Wang B M, Zhao L, et al. Preparation and Properties of PMMA Modifi ed Silica Aerogels from Diatomite[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2014, 29(5): 877-884.

[29] Wang L J, Zhao S Y. Synthesis and Characteristics of Mesoporous Silica Aerogels with One-step Solvent Exchange/Surface Modification[J]. J. Wuhan University of Technology -Mater. Sci. Ed., 2009, 24(4): 613-618.

[30] Shi F, Wang L J, Liu J X. Synthesis and Characterization of Silica Aerogels by a Novel Fast Ambient Pressure Drying Process[J]. Mater. Lett., 2006, 60(29-30): 3718-3722.

[31] Dressler M, Nofz M, Malz F, et al. Aluminum Speciation and Thermal Evolution of Aluminas Resulting from Modified Yoldas Sols[J]. Journal of Solid State Chemistry, 2007, 9(180): 2409-2419.

[32] Jessica M E, Stephen B R. Tem and X-ray Diffraction Evidence for Cristobalite and Tridymite Stacking Sequences in Opal[J]. Clays and Clay Minerals, 1996, 4(44): 492-500.

[33] Francois B, Bittencourt R D, Robert M D, et al. Role of Aluminum in the Structure of Brazilian Opals[J]. Eurpean Journal of Mineralogy, 1990, 5(2): 611