Glass samples, proton spectra

Proton spectrum of a thin glass sample having high boron content irradiated by a 4 MeV a-particle beam (Peisach and Pretorius 1973)... 

A routine sample for proton NMR on a 300 MHz instrument consists of about 10 mg of the compound in about 0.5 ml of solvent in a 5-mm o.d. glass tube. Microprobes that accept a 1.0 mm, 2.5 mm, or 3 mm o.d. tube are available and provide higher sensitivity. Under favorable conditions, it is possible to obtain a spectrum on 100 ng of a compound of modest molecular weight in a 1.0 mm microtube (volume 5 pi) on a 600 MHz instrument. 

Fig. 4.10. Thermal analysis and proton NMR second moment curves of trans-l,4-polybutadiene. The heat capacity for the solid (glass and low temperature crystal form I) have been computed by fitting at low temperature to an approximate skeletal vibration spectrum. The gradual decrease of the second moment of the proton resonance spectrum below T comes mainly from increasing mobility in the amorphous phase, Ref. The melting curve is of an approximately 90% crystalline sample. Ref.. Compare also to Fig. 1.3...

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