Mrs/Miss Bansal,

There is needed solid-state NMR.

Dear Sir. Concerning your issue about the most appropriate solvent to dissolve glass for NMR spectroscopy. It isn't surprising that considerable attention is directed toward carefully choosing solvents for NMR experiments. Today, solvents must provide an effective medium in which to dissolve a sample to the required concentration and filling-factor . . . must contribute no interfering resonances . . . and must provide a lock signal to assure spectrometer stability. This presents stringent challenges for manufacturers of NMR solvents when added to the obvious need for chemical purity. To make your use of solvents in NMR easier, we provide below an explanation of the important factors to consider when choosing and handling deuterated solvents in NMR. Although glass has the appearance of a solid, it is really a highly viscous liquid. It is a supercooled liquid that has amorphous and isomorphic qualities. Glass is amorphous because it lacks a crystalline form and it is isomorphic because it refracts light at the same angle in all directions. In this demonstration, the solubility of two types of glass (soft-glass and borosilicate glass) is compared. Soft glass (also known as soda-lime or non-borosilicate glass) is composed of 75% silica (SiO2), 20% soda ash (Na2CO3), and 5% lime (CaO). When the powdered soft glass is placed into the distilled water and phenolphthalein solution, hydrolysis of the glass occurs. Hydrolysis of glass produces sodium hydroxide (NaOH) and calcium hydroxide Ca(OH)2. Na2CO3(s) + 2H2O(l) → H2CO3(aq) + 2NaOH(aq) CaO(s) + H2O(l) → Ca(OH)2(aq) The change in color of the solution is caused by the presence of the hydroxide ions (OH–). In a pH range of 8 to 10, the phenolphthalein indicator turns a red or pinkish color. Water alone does not contain enough hydroxide ions to give a pH between 8–10. Therefore, the glass must be adding hydroxide ions to the solution, since after the addition of the glass, the pH was great enough to turn the phenolphthalein solution pink. This demonstrates the solubility of some of the components of the glass. Borosilicate glass (also known as the tradename Pyrex®) is composed of soda-lime glass and 5–10% boric oxide (B2O3). The boric oxide present in borosilicate glass causes the glass to be acidic. Also, borosilicate glass is not very soluble in water. Therefore, there will be a slight or no color change of the phenolphthalein in the solution. I think the following below links may help you in your analysis:

https://www.lehigh.edu/imi/teched/GlassCSC/Lecture_11-12_Martin.pdf http://www.tcm.phy.cam.ac.uk/~jry20/gipaw/inorg_app.pdf

https://www.lehigh.edu/imi/teched/GlassCSC/Lecture_14_Martin.pdf

http://discovery.ucl.ac.uk/1470766/1/27.08.15Postviva.pdf

https://www.flinnsci.ca/api/library/Download/8dcab9ea172e4fe0b33fefbdd59f6383

https://www.wilmad-labglass.com/Support/NMR-and-EPR-Technical-Reports/Sample-Solvents-in-NMR-Spectroscopy/

https://www.hw.ac.uk/schools/engineering-physical-sciences/documents/Sample_Preparation.pdf

Thanks

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Neetu,

You need solid state NMR to study glass structure. In any case, the structure of borosilicate glasses is well studied. Read my recent article published in Acta Biomaterialia. It will help.

Ashutosh