fig4

Figure 4. Sample tube for in-situ NMR characterization of crystallization process. (A) The first MAS NMR cell sused for in situ studies of hydrothermal synthesis of zeolite sreported by Shi et al. Copyright © 1996, American Chemical Society^[59]; (B) Quartz glass ampoules by Liu et al. Copyright © 2009 Elsevier Inc. All rights reserved^[60]; (C) HPHT cell for liquid state NMR. HPHT MAS NMR cells suitable for in situ NMR studies of zeolite synthesis under hydrothermal conditions. Copyright © 2000 Wiley^[61]; (D) PEEK insert for Bruker 7 mm MAS rotor. Copyright © 2006 Elsevier Inc^[62]; and (E) 7.5 mm ZrO₂ rotor for Chemagnetic/Varian MAS probe. Copyright © 2016, American Chemical Society^[63]. NMR: Nuclear magnetic resonance; MAS: magic angle spinning; HPHT: high pressure high temperature; PEEK: polyether ether ketone.