scholarly journals Accessibility and Location of Acid Sites in Zeolites as Probed by Fourier Transform Infrared Spectroscopy and Magic Angle Spinning Nuclear Magnetic Resonance

2018 ◽  
Vol 62 (3) ◽  
pp. 279-290 ◽  
Author(s):  
Cátia Freitas ◽  
Nathan S. Barrow ◽  
Vladimir Zholobenko
2010 ◽  
Vol 129-131 ◽  
pp. 837-841 ◽  
Author(s):  
Sheng Hua Lv ◽  
Yan Fen Ma ◽  
Rui Gong ◽  
Xiao Liang Yan ◽  
Ming Ming Hou

Degraded starch was reacted with 4-phenolsuflonate (PHS) in water in the presence of horseradish peroxidase (HRP) catalyst/H2O2/acetylacetone (ACAC) to give starch and PHS graft copolymers. The structure and properties of the graft copolymer are characterized by Fourier Transform Infrared spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR). The retanned leather exhibits excellent increased thickness and softness, good dyeing ability and eligible mechanical properties.


2017 ◽  
Vol 36 (1-2) ◽  
pp. 684-693 ◽  
Author(s):  
Wina Rongchapo ◽  
Chalermpan Keawkumay ◽  
Nattawut Osakoo ◽  
Krittanun Deekamwong ◽  
Narong Chanlek ◽  
...  

The nature of paraquat adsorption is compared between zeolite NaX and NaY which have the same faujasite structure but different Si/Al ratio, namely 1.2 and 2.2, respectively. The adsorption was proposed to occur via ion exchange and expected to increase with Al content. However, NaX had a lower paraquat adsorption capacity than NaY. The bare and paraquat-containing zeolites (PQX and PQY) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption–desorption analysis, magic-angle spinning nuclear magnetic resonance (MAS) NMR, and X-ray photoelectron spectroscopy. The presence of adsorbed paraquat was confirmed by Fourier transform infrared spectroscopy. Paraquat adsorbed in supercages of the zeolites resulting in a decrease of surface area and displacement of sodium cations. Results from 23Na MAS NMR and X-ray photoelectron spectroscopy indicated that interaction of sodium ions in the cavity of NaX was stronger than that in NaY, making it less exchangeable with paraquat.


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