New Protonated Thioborate Glasses in the xH2S + (1 â‹TM x)B2S3 Series

A new series of anhydrous protonated chalcogenide glasses, xH2S + (1 − x)B2S3, analogous to alkalimodified glasses, have been prepared. The preparation of these glasses was carried out in multiple steps. First crystalline meta-thioboric acid, c-(HBS2)3, was prepared from vitreous boron sulfide, v-B2S3. c-(HBS2)3 was then used as a precursor for protonation to prepare a series of xH2S + (1 − x)B2S3 samples with 0.0 ≤ x ≤ 0.5. The glass formation region of this system was found to be 0.0 ≤ x ≤ 0.25. The density and glass-transition temperature (Tg) of the samples were measured. While a substantial decrease in Tg of the protonated glasses has been observed, there are insignificant changes in the density of the glasses. The IR and NMR spectra of the samples in the region 0.0 ≤ x ≤ 0.5 suggest that no tetrahedral borons are formed with the incorporation of protons. The characterization shows that these materials are unique and exhibit no borate anomaly as in the alkali-modified glasses. Disciplines Ceramic Materials | Materials Science and Engineering | Physical Chemistry Comments Reprinted with permission from The Journal of Physical Chemistry B 107 (2003): 3384–3389, doi:10.1021/ jp0267095. Copyright 2003 American Chemical Society. This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/mse_pubs/58 New Protonated Thioborate Glasses in the xH2S + (1 x)B2S3 Series Annamalai Karthikeyan, Chad A. Martindale, and Steve W. Martin* Department of Materials Science and Engineering, Iowa State UniVersity of Science and Technology, Ames, Iowa 50011 ReceiVed: August 7, 2002; In Final Form: January 24, 2003 A new series of anhydrous protonated chalcogenide glasses, xH2S + (1 x)B2S3, analogous to alkali-modified glasses, have been prepared. The preparation of these glasses was carried out in multiple steps. First crystalline meta-thioboric acid, c-(HBS2)3, was prepared from vitreous boron sulfide, V-B2S3. c-(HBS2)3 was then used as a precursor for protonation to prepare a series of xH2S + (1 x)B2S3 samples with 0.0 e x e 0.5. The glass formation region of this system was found to be 0.0 e x e 0.25. The density and glass-transition temperature (Tg) of the samples were measured. While a substantial decrease in Tg of the protonated glasses has been observed, there are insignificant changes in the density of the glasses. The IR and NMR spectra of the samples in the region 0.0 e x e 0.5 suggest that no tetrahedral borons are formed with the incorporation of protons. The characterization shows that these materials are unique and exhibit no borate anomaly as in the alkali-modified glasses.