Journal of Sol-Gel Science and Technology

, Volume 75, Issue 3, pp 508–518 | Cite as

Physisorption data for methyl-hybrid silica gels

Original Paper

Abstract

The porous structure of inorganic silica and methyl-ormosil gels were studied using nitrogen adsorption at 77 K. Organically, modified silica gels were produced from mixtures of tetraethoxysilane (TEOS) and triethoxy(methyl)silane (MTES), under basic and acid sol–gel catalysis. Starting from pure TEOS, mixtures of increasing MTES content have been prepared. Although not new, silica-based surface morphology is still a challenging subject, particularly when related to silica functionalise systems. N2 adsorption isotherms were used, and the validity of BET model has been discussed for ormosil systems. The pore size distribution of inorganic and hybrid sol–gel silica materials were calculated by using the adsorption branch of the N2 isotherm. Compared with inorganic silica gel, the microstructure of the resulting hybrid gel has been modified—sorption capacities and average pore radius have intensely increased. Acid and basic catalyst determine the type of gel microstructure. Further, the presence of the more flexible ≡Si–CH3 bonds is the responsible for the increasing mobility during gelation, and for the presence of not energetically equivalent terminal groups, which will affect the final pore structure by the suppleness capacity. The rigid and regular pore shape assumption is no more valid. For MTES content higher than 2 mol%, the N2 isotherms reached no more the equilibrium. N2 adsorption isotherms are though not very suitable for surface characterisation of hybrid silica gels, over a limit organic moiety concentration.

Graphical Abstract

Keywords

N2 adsorption Surface area Pore size distribution Organic hydrophobic groups Infrared 

References

  1. 1.
    Ebelmen M (1846) Sur les combinaisons des acides borique et silicique avec les ethers. Ann Chim Phys 16:129–166Google Scholar
  2. 2.
    Livage J, Henry M, Sanchez C (1988) Sol–gel chemistry of transition oxides. Prog Solid State Chem 18:259–341CrossRefGoogle Scholar
  3. 3.
    Brinker CJ, Scherrer G (1990) The physics and chemistry of sol–gel processing. Academic Press, San DiegoGoogle Scholar
  4. 4.
    Mackenzie JD (1994) Structures and properties of Ormosils. J Sol-Gel Sci Technol 2:81–86CrossRefGoogle Scholar
  5. 5.
    Sanchez C, Ribot FN (1994) Design of hybrid organic-inorganic materials synthesized via sol–gel chemistry. J Chem 18:1007–1047Google Scholar
  6. 6.
    Babonneau F, Thorne K, Mackenzie JD (1989) Dimethyldiethoxysilane/tetraethoxysilane copolymers: precursors for the silicon–carbon–oxygen system. Chem Mater 1:554–558CrossRefGoogle Scholar
  7. 7.
    Renlund GM, Prochazka S, Doremus RH (1991) Silicon oxycarbide glasses. Part I. Preparation and chemistry. J Mater Res 6(12):2716–2722CrossRefGoogle Scholar
  8. 8.
    Schmidt H, Steten OV DP 27 58 507, 28.12.1977Google Scholar
  9. 9.
    Schmidt H, Scholze H DP 27 58 415, 12.07.1979Google Scholar
  10. 10.
    Schmidt H (1985) New type of non-crystalline solids between inorganic and organic materials. J Non- Cryst Solids 73:681–691CrossRefGoogle Scholar
  11. 11.
    Wilkes GL, Orter B, Huang H (1985) “Ceramers”: hybrid materials incorporating polymeric/oligomeric species into inorganic glasses utilizing a sol–gel approach. Polymer Preprints (American Chemical Society, Division of Polymer Chemistry) 26(2):300–302Google Scholar
  12. 12.
    Schwertfeger F, Glaubitt W, Schubert U (1992) Hydrophobic aerogels from tetramethoxysilane/methyltrimethoxysilane mixtures. J Non-Cryst Solids 145:45CrossRefGoogle Scholar
  13. 13.
    Pandey PC (1999) A review on ormosil-based biomaterials and their applications in sensor design. J Indian Inst Sci 79:415–430Google Scholar
  14. 14.
    Tripathi VS, Kandimalla VB, Ju H (2006) Preparation of ormosil and its applications in the immobilizing biomolecules. Sens Actuators, B 114:1071–1082CrossRefGoogle Scholar
  15. 15.
    Kandimalla VB, Tripathi VS, Ju H (2006) Immobilization of biomolecules in sol–gel biological and analytical applications. Crit Rev Anal Chem 36(2):73–106CrossRefGoogle Scholar
  16. 16.
    Young SK (2002) Silica-based sol–gel organic-inorganic nanocomposite materials: a review of different material technologies. Army Res Lab ARL-TR-2732:1–24Google Scholar
  17. 17.
    Yoshi KA, Pandley PC, Chen W, Mulchandani A (2004) Ormosil encapsulated pyrroloquinoline quinone-modified electrochemical sensor for thiols. Electroanalysis 16(23):1938–1943CrossRefGoogle Scholar
  18. 18.
    Yildirin A, Khudiyew T, Daglar B, Budunoglu H, Okyay AK, Bayindir M (2013) Superhydrophobic and omnidirectional antireflective surfaces from nanostructured ormosil colloids. ACS Appl Mater Interfaces 5(3):853–860CrossRefGoogle Scholar
  19. 19.
    Liu C, Zhang H, Komarneni S, Pantano SG (1994) Porous silicon oxycarbide glasses from organically modified silica gels of high surface area. J Sol-Gel Sci Technol 1:141–151CrossRefGoogle Scholar
  20. 20.
    Sharp KG (1994) A two-component, non-aqueous route to silica gel. J Sol-Gel Sci Technol 2:35–41CrossRefGoogle Scholar
  21. 21.
    Polevaya Y, Samuel J, Ottolenghi M, Avnir D (1995) Apparent low surface areas in microporous SiO2 xerogels. J Sol-Gel Sci Technol 5:65CrossRefGoogle Scholar
  22. 22.
    Nair BN, Elferink JW, Keizer K, Verweij H (1997) Preparation and structure of microporous silica membranes. J Sol-Gel Sci Technol 8(1–3):471–475Google Scholar
  23. 23.
    Farenholtz W, Smith D, Hua D (1992) Formation of microporous silica gels from a modified silicon alkoxide. I. Base-catalyzed gels. J Non-Cryst Solids 144:45–52CrossRefGoogle Scholar
  24. 24.
    Schmidt H (1989) Organic modification of glass structure, new glass or new polymer? J Non-Cryst Solids 112:419–423CrossRefGoogle Scholar
  25. 25.
    Chevalier PM, Corriu RJP, Moreau JJE, Chi Man MW (1997) Chemistry of Hybrid organic-inorganic access to silica materials through chemical selectivity. J Sol-Gel Sci Technol 8:603–607Google Scholar
  26. 26.
    Brunauer S, Emmet PH, Teller E (1938) On a theory of the van der Waals adsorption of gases. J Am Chem Soc 60:309–319CrossRefGoogle Scholar
  27. 27.
    Thomson W (1871) On the equilibrium of vapour at a curved surface of liquid. Philos Mag S 42:448–452Google Scholar
  28. 28.
    Barret EP, Joyner LG, Halenda PP (1951) The determination of pore volume and area distributions in porous substances. I. Computations from nitrogen isotherms. J Am Chem Soc 73:373–380CrossRefGoogle Scholar
  29. 29.
    Sing KS, Everett DH, Haul RAW, Moscou L, Pierotti RA, Rouquérol J, Siemieniewska T (1985) Reporting physisorption data for gas/solid systems—with special reference to the determination of surface area and porosity. Pure Appl Chem 57(4):603–619 (IUPAC) CrossRefGoogle Scholar
  30. 30.
    Brunauer S, Deming LS, Deming WS, Teller E (1940) On a theory of the van der waals adsorption of gases. J Am Chem Soc 62:1723–1732CrossRefGoogle Scholar
  31. 31.
    Almeida RM (1994) Int J Optoelect 9(2):135Google Scholar
  32. 32.
    Almeida RM, Guiton TA, Pantano CG (1990) Characterization of silica gels by infrared reflection spectroscopy. J Non-Cryst Solids 121:193–197CrossRefGoogle Scholar
  33. 33.
    Weast RC (ed) (1983–1984) Handbook of Chemistry and Physics, 64th edn. CRC PressGoogle Scholar
  34. 34.
    Smith LA (1960) Infrared spectra-structure-correlations for organosilicon compounds. Spectrochim Acta 16:87–105CrossRefGoogle Scholar
  35. 35.
    Colthup NB, Daly LH, Wiberly SE (1964) Introduction to infrared and Raman spectroscopy. Academic Press, New YorkGoogle Scholar
  36. 36.
    Galeener FG (1979) Band limits and the vibrational spectra of tetrahedral glasses. Phys Rev B 19:4292–4298CrossRefGoogle Scholar
  37. 37.
    Kamitsos EI, Patsis AP, Kordas G (1993) Infrared-reflectance spectra of heat-treated sol–gel-derived silica. Phys Rev B 48:12499–12501CrossRefGoogle Scholar
  38. 38.
    Duran A, Serna C, Fornes V, Navarro JMF (1986) Structural considerations about SiO 2 glasses prepared by sol–gel. J Non-Cryst Solids 82(1):69–77CrossRefGoogle Scholar
  39. 39.
    Boonstra AH, Mulder CAM (1988) Effect of hydrolytic polycondensation of tetraethoxysilane on specific surface area of SiO2 gels. J Non-Cryst Solids 105:201–206CrossRefGoogle Scholar
  40. 40.
    Ro JC, Chung IJ (1991) Structures and properties of silica gels prepared by the sol–gel method. J Non-Cryst Solids 130(1):8–17CrossRefGoogle Scholar
  41. 41.
    Brinker CJ (1988) Hydrolysis and condensation of silicates effects on structure. J Non-Cryst Solids 100:31–50CrossRefGoogle Scholar
  42. 42.
    Klein LC, Gallo JA, Garvey GJ (1984) Densification of monolithic silica gels below 1000°C. J Non-Cryst Solids 63:23–33CrossRefGoogle Scholar
  43. 43.
    Zhuravlev LT (2000) The surface chemistry of amorphous silica. Colloids Surf A 173:1–38CrossRefGoogle Scholar
  44. 44.
    Menon VC, Komarneni S, Park M, Schmucker M, Schneider H (1998) Synthesis of hydrophilic and hydrophobic high surface area xerogels at pHs below silica isoelectric point. J Sol-Gel Sci Technol 11:7–16CrossRefGoogle Scholar
  45. 45.
    Gregg SJ, Sing KSW (1982) Adsorption, surface area and porosity. Academic Press, London, p 132Google Scholar
  46. 46.
    Bois L, Maquet J, Babonneau F, Mutin H, Bahloul D (1994) Structural characterization of sol–gel derived oxycarbide glasses. 1. Study of the pyrolysis process. Chem Mater 6:796–802CrossRefGoogle Scholar
  47. 47.
    Sing AK, Pantano CG (1997) Surface chemistry and. structure of silicon oxycarbide gels and glasses. J Sol-Gel Sci Technol 8:371–376Google Scholar

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.Departamento de Engenharia Química, Instituto Superior TécnicoUniversidade de LisboaLisbonPortugal

Personalised recommendations