Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering
Lauren Walker - Alabama A&M University
Co-Author(s): Rachel Sanders, Aschalew Kassu, Anup Sharma, Alabama A&M University, AL
In most cases, building materials are exposed to varying climatic conditions. The exposure to the different environmental conditions result gradual changes in the initial property of the materials, changing the molecular structure of the original material used for the construction. These changes can be monitored and the effects can be analyzed using non-destructive spectroscopic techniques including Raman. Raman scattering is the inelastic scattering of a photon from a molecule in which the frequency change precisely matches the difference in vibrational energy levels. Raman spectroscopy is used to characterize a wide range of materials, including gases, liquids, and solids. The objective of this research is to use spectroscopic technique to identify the distinct characteristics of silicones, which are widely used as sealant material in the construction industry. The silicones characterized include seven varieties from three different sources including GE, HDX and DAP. The results reported include the spectroscopic characterization of the materials using compact Raman system integrated with 785 nm wavelength laser. It is found that the materials have Raman bands common to most of the samples indicating the presence of some similarities in the compositions of the silicone materials. We have also observed distinct Raman bands unique to the silicone brands which can assist in identifying the various materials tested. We have successfully demonstrated the suitability of the Raman spectroscopy system with a 785 nm laser for spectral analysis and characterization of common building materials including fire barriers and silicones. The results show that fire barrier sealant and acrylic latex caulk plus silicone have a common Raman signature at 1082 cm-1 indicating the presence of C-C stretching mode in the three materials. White and acrylic latex caulk plus silicone and fire barrier sealant also have a common Raman band at about 705 cm-1, which is assigned to the C-Si-C symmetric stretching mode. References: Kassu, A., Walker, L., Sanders, R., Farley, C., Mills, J., Sharma, A. 2017. Nondestructive spectroscopic characterization of building materials. Proc. SPIE 10169, 101692V. Jayes, L., Hard, A. P., Séné, C., Parker, S. F. and Jayasooriya, U. A. 2003. Vibrational spectroscopic analysis of silicones: A Fourier transform-Raman and inelastic neutron scattering investigation,” Anal. Chem. 75, 742-746.Not Submitted
Funder Acknowledgement(s): This work was supported by the Department of Homeland Security-Scientific Leadership Award, under Grant Nos. DHS-SLA 2014-ST-062-000060, 2014-ST-062-00060-02, and the National Science Foundation (NSF) Award No. 1643799.
Faculty Advisor: Aschalew Kassu, email@example.com
Role: I participated in developing the hypothesis, conducting the experiments, and analyzing the results.