Chemical Characterization of Historical Brickwork of the Church Convento in Pagsanjan, Laguna

  • Jan-Michael C. Cayme Chemistry Department, College of Science, De La Salle University, 2401 Taft Avenue, Malate, Manila
  • Aniano, Jr. N. Asor Chemistry Department, College of Science, De La Salle University, 2401 Taft Avenue, Malate, Manila
  • Maveen Kim Alexis T. Alano School of Chemical Engineering and Chemistry, Mapua Institute of Technology, Intramuros, Manila
  • Eric T. Miranda School of Chemical Engineering and Chemistry, Mapua Institute of Technology, Intramuros, Manila
Keywords: clay brick, atomic absorption spectroscopy, infrared spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, thermogravimetric analysis, cultural heritage conservation

Abstract

This study reports the chemical composition of historical brickworks from Franciscan-built church complexes in the Philippines. An old brick sample from the Spanish colonial period church convento at Pagsanjan, Laguna was characterized by atomic absorption spectroscopy (AAS), infrared spectroscopy (IR), thermogravimetric analysis (TGA), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). Conventional hot plate aqua regia (1:3 HNO3:HCl, v/v) digestion method was employed to extract iron, calcium, and magnesium from the brick sample. The combined AAS and EDX results yielded a percentage composition of iron ranging from 5.48 to 6.62%, calcium ranging from 1.50 to 3.72%, while magnesium ranges from 0.083 to 0.12%, respectively. These amounts were compared to a similar AAS and EDX study made on a historical brick sample from Ilocos Norte. The presence of possible pores on the brick’s microstructure was confirmed by SEM. Minerals consisting of hematite, kaolinite, illite, quartz, and calcite were present in the sample, as well as trace amounts of other minerals based on IR peak intensities. Upon heating to about 800⁰C using TGA, the loss of bound water from the sample’s internal surface structure and the decomposition of brick minerals and carbonates are evident.
Published
2016-09-26
How to Cite
Cayme, J.-M., Asor, A. J., Alano, M. K. A., & Miranda, E. (2016). Chemical Characterization of Historical Brickwork of the Church Convento in Pagsanjan, Laguna. KIMIKA, 27(1), 29-40. https://doi.org/https://doi.org/10.26534/kimika.v27i1.29-40
Section
Research Articles