OSA's Digital Library

Applied Spectroscopy

Applied Spectroscopy

| PUBLISHED BY SAS — AVAILABLE FROM SAS AND OSA

  • Vol. 67, Iss. 4 — Apr. 1, 2013
  • pp: 441–447

Determination of the Network Structure of Sensor Materials Prepared by Three Different Sol-Gel Routes Using Fourier Transform Infrared Spectroscopy (FT-IR)

Larissa B. Cappeletti, Edwin Moncada, Joel Poisson, Ian S. Butler, and João Henrique Z. Dos Santos

Applied Spectroscopy, Vol. 67, Issue 4, pp. 441-447 (2013)


View Full Text Article

Acrobat PDF (415 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations
  • Export Citation/Save Click for help

Abstract

Solid acid-base sensor materials were prepared by encapsulating three pH indicators (alizarin red, brilliant yellow, and acridine) within a silica matrix using a sol-gel approach through three different routes: (1) non-hydrolytic, (2) acid-catalyzed, and (3) base-catalyzed. Raman and Fourier transform infrared spectroscopies were used to evaluate the silica-indicator interactions. Because vibrational bands assigned to functional groups present in the indicator molecules were not detected, the main silica stretching mode ν<sub>Si-O</sub> between approximately 1300 and 1000 cm<sup>-1</sup> was used to detect the presence of our indicators within the silica matrix. The large band centered at 1100 cm<sup>-1</sup> was deconvoluted into four components corresponding to the longitudinal optic and transversal optic modes of the silicon monoxide (SiO)<sub>4</sub> and (SiO)<sub>6</sub> siloxane rings. Using the component area of each mode, it was possible to calculate the percentage of each structure. Such percentages ranged from 49% to 70% (SiO)<sub>6</sub> for the analyzed samples, within a confidence level of 95% (<i>p</i> = 0.05). (The confidence limits were 53-62%.) These results could be related to the pH indicator content, indicating that the quantity of the encapsulated molecule affects the (SiO)<sub>6</sub> percentage values. In addition, a comparison with the radius of gyration obtained by small angle X-ray scattering was done. These results indicate that the analyte accesses the receptor elements through the passages between the siloxane rings but not through the siloxane rings themselves.

Citation
Larissa B. Cappeletti, Edwin Moncada, Joel Poisson, Ian S. Butler, and João Henrique Z. Dos Santos, "Determination of the Network Structure of Sensor Materials Prepared by Three Different Sol-Gel Routes Using Fourier Transform Infrared Spectroscopy (FT-IR)," Appl. Spectrosc. 67, 441-447 (2013)
http://www.opticsinfobase.org/as/abstract.cfm?URI=as-67-4-441


Sort:  Journal  |  Reset

References

References are not available for this paper.

Cited By

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited