FT-IR Studies of Interaction between Zeolitic Hydroxyl Groups and Small Molecules. 2. Adsorption of Oxygen, Hydrogen, and Rare Gases on H-Mordenite at Low Temperatures

1995 ◽  
Vol 99 (40) ◽  
pp. 14805-14812 ◽  
Author(s):  
Fumitaka Wakabayashi ◽  
Tatsuya Fujino ◽  
Junko N. Kondo ◽  
Kazunari Domen ◽  
Chiaki Hirose
Keyword(s):  
Small Molecules ◽  
Low Temperatures ◽  
Hydroxyl Groups ◽  
Rare Gases ◽  
Ir Studies ◽  
Ft Ir

FT-IR studies of the interaction between zeolitic hydroxyl groups and small molecules. 1. Adsorption of nitrogen on H-mordenite at low temperature

1993 ◽  
Vol 97 (41) ◽  
pp. 10761-10768 ◽  
Author(s):  
Fumitaka Wakabayashi ◽  
Junko Kondo ◽  
Akihide Wada ◽  
Kazunari Domen ◽  
Chiaki Hirose
Keyword(s):  
Low Temperature ◽  
Small Molecules ◽  
Hydroxyl Groups ◽  
Ir Studies ◽  
Adsorption Of Nitrogen ◽  
Ft Ir

Low-Temperature Thermocatalytic Degradation of Polyethene Films by Nano-Titanium Dioxide in Water

2014 ◽  
Vol 804 ◽  
pp. 47-50
Author(s):  
Ke Li ◽  
Xue Gang Luo ◽  
Mian Wang ◽  
Fang Wei Qi ◽  
Pei Wu ◽  
...  
Keyword(s):  
Small Molecules ◽  
Low Temperatures ◽  
Composite Films ◽  
Decomposition Temperature ◽  
Degradation Behavior ◽  
Melt Blending ◽  
Ft Ir ◽  
Branched Chains ◽  
Nano Titanium Dioxide ◽  
Scanning Electron

nanoTiO2powders were utilized as thermocatalyst for catalytic degradation of polyethylene in water. LDPE/TiO2composite films were prepared by the method of melt blending. The aging experiments were conducted in ovens under temperatures of 30 °C, 40 °C and 50 °C, respectively. The thermocatalytic degradation behavior towards the composite films was characterized by fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG) and scanning electron microscopy (SEM). Results show that both pure LDPE films and LDPE /TiO2composite films can be degraded even under low temperatures in water. After thermal degradation for 90 days at 50 °C, the composite film with 2wt% nanoTiO2was oxidized the most acutely: the quantity of branched chains decreased to some extent and lots of small molecules were detected, the decomposition temperature was also reduced by 28.2 °C. Besides, the surface of the films became rougher than that of the film before degradation.

scholarly journals The Temperature-Dependent Adsorption Behaviour of Benzene Molecules in ZSM-5 Zeolite Pores: TPD and FT-IR Spectroscopy Studies

2005 ◽  
Vol 23 (2) ◽  
pp. 95-107 ◽  
Author(s):  
Arati Sahasrabudhe ◽  
Salil Varma ◽  
Narendra M. Gupta
Keyword(s):  
Benzene Molecule ◽  
Hydroxyl Groups ◽  
Fixed Amount ◽  
Oh Groups ◽  
Ir Studies ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Spectroscopy Studies ◽  
Ir Spectroscopic

Temperature-programmed desorption (TPD) and in situ Fourier-transform infrared (FT-IR) spectroscopic methods were employed to investigate the effect of loading and sample temperature on the state of benzene molecules inside the channels of NaZSM-5 zeolite. TPD profiles revealed the existence of at least three distinct states of benzene adsorption, characterized by desorption peak maxima at ca. 120°C, 170°C and 220°C, respectively. Based on the growth behaviour of these bands, it is suggested that the benzene molecules occupy sinusoidal channels, straight channels and external surfaces, in that order. A reverse trend was observed during the subsequent flushing of the sample at varying temperatures. A virtually fixed amount of benzene was occluded at these three locations, depending upon the loading. The FT-IR studies revealed that the benzene molecule exists in a compressed state in the zeolitic channels, with the molecular clusters formed in the process dispersing only at temperatures above 150°C. For initial benzene loadings of up to ca. 1.5 molecules/unit cell, the spectrum obtained showed that in the O—H stretch region the bridge-bonded OH groups and hydroxyl groups associated with the internal zeolitic channels were perturbed simultaneously. The results show that even for a loading lower than necessary for saturation, a considerable amount of benzene remains condensed at the external surface of ZSM-5 zeolite.

In Situ FT-IR Studies of Oxide and Oxynitride Sol-Gel-Derived Thin Films

1984 ◽  
Vol 32 ◽  
Author(s):  
David M. Haaland ◽  
C. Jeffrey Brinker
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
High Temperature ◽  
Low Temperatures ◽  
Sol Gel ◽  
Ir Studies ◽  
Oxynitride Glass ◽  
Vibrational Bands ◽  
Ft Ir

ABSTRACTA high-temperature infrared cell was developed to study the gel-to-glass conversion of sol-gel-derived thin films. FT-IR spectra of matched thin-film borosilicate sol-gel samples were taken as the samples were heated at 100°C intervals to 700°C in either air or ammonia. The gels were converted to oxide and oxynitride glasses, respectively, by these heat treatments. The gel-to-glass conversion could be followed and compared for these two treatments by monitoring changes in the vibrational bands present in the spectra. Comparisons between the infrared spectra of NH3-treated and air-treated films heated above 500°C reveal the appearance of new B-N bonds at the expense of B-O-Si bonds for the NH3-fired films. These spectra also exhibit changes which may indicate the formation of Si-N bonds. Thus, ammonolysis reactions can result in thin-film oxynitride glass formation at relatively low temperatures.

FT-IR study of the interaction of oxygen, argon, helium, nitrogen and xenon with hydroxyl groups in H-Y zeolite at low temperatures

1997 ◽  
Vol 8 (1-2) ◽  
pp. 29-37 ◽  
Author(s):  
Fumitaka Wakabayashi ◽  
Junko N. Kondo ◽  
Kazunari Domen ◽  
Chiaki Hirose
Keyword(s):  
Low Temperatures ◽  
Hydroxyl Groups ◽  
Y Zeolite ◽  
Ft Ir ◽  
Ir Study

scholarly journals Synthesis, Fabrication, and Characterization of Functionalized Polydiacetylene Containing Cellulose Nanofibrous Composites for Colorimetric Sensing of Organophosphate Compounds

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1869
Author(s):  
A K M Mashud Alam ◽  
Donovan Jenks ◽  
George A. Kraus ◽  
Chunhui Xiang
Keyword(s):  
Solid State ◽  
Hydroxyl Groups ◽  
Colorimetric Sensing ◽  
Electrospinning Technique ◽  
Hazardous Chemical ◽  
Tensile Tester ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Landmark Study

Organophosphate (OP) compounds, a family of highly hazardous chemical compounds included in nerve agents and pesticides, have been linked to more than 250,000 annual deaths connected to various chronic diseases. However, a solid-state sensing system that is able to be integrated into a clothing system is rare in the literature. This study aims to develop a nanofiber-based solid-state polymeric material as a soft sensor to detect OP compounds present in the environment. Esters of polydiacetylene were synthesized and incorporated into a cellulose acetate nanocomposite fibrous assembly developed with an electrospinning technique, which was then hydrolyzed to generate more hydroxyl groups for OP binding. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Instron® tensile tester, contact angle analyzer, and UV–Vis spectroscopy were employed for characterizations. Upon hydrolysis, polydiacetylene esters in the cellulosic fiber matrix were found unaffected by hydrolysis treatment, which made the composites suitable for OP sensing. Furthermore, the nanofibrous (NF) composites exhibited tensile properties suitable to be used as a textile material. Finally, the NF composites exhibited colorimetric sensing of OP, which is visible to the naked eye. This research is a landmark study toward the development of OP sensing in a protective clothing system.

Effects of ultra-high pressures (>3.6 GPa) on the electrical resistance of polyaniline by in situ FT-IR studies

1997 ◽  
Vol 280 (5-6) ◽  
pp. 469-474 ◽  
Author(s):  
Xing-Rong Zeng ◽  
Ke-Cheng Gong ◽  
Ke-Nan Weng ◽  
Wan-Sheng Xiao ◽  
Wen-Hong Gan ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
High Pressures ◽  
Ir Studies ◽  
Ft Ir

FT-IR studies on the acidity of gallium-substituted mesoporous MCM-41 silica

2004 ◽  
Vol 85 (1) ◽  
pp. 145-150 ◽  
Author(s):  
Gemma Turnes Palomino ◽  
Juan José Cuart Pascual ◽  
Montserrat Rodrı́guez Delgado ◽  
José Bernardo Parra ◽  
Carlos Otero Areán
Keyword(s):  
Ir Studies ◽  
Ft Ir ◽  
Mcm 41

Enhanced Thermal Stability of Esterified Lignin in Different Solvent Mediums

2018 ◽  
Vol 9 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Sharifah Nurul Ain Syed Hashim ◽  
Sarani Zakaria ◽  
Chin Hua Chia ◽  
Sharifah Nabihah Syed Jaafar
Keyword(s):  
Thermal Stability ◽  
Alkaline Solution ◽  
Room Temperature ◽  
Hydroxyl Groups ◽  
Aqueous Alkaline Solution ◽  
Alkali Lignin ◽  
Weight Percentage ◽  
H Nmr ◽  
Ft Ir ◽  
Thermal Stability Of

In this study, soda alkali lignin from oil palm empty fruit bunch (EFB-AL) and kenaf core (KC-AL) are esterified with maleic anhydride under two different conditions, namely i) pyridine at temperature of 120°C for 3h and ii) aqueous alkaline solution at room temperature for 4h. As a result, the weight percentage gain (WPG) of the esterified EFB-AL (EFB-EL) and esterified KC-AL (KC-EL) in pyridine demonstrated a higher compared to aqueous alkaline solution. The FT-IR results of EFB-EL and KC-EL in both solvents exhibited some changes at the carbonyl and hydroxyl groups. Furthermore, the esterification process induced the carboxylic peak to appear in both alkali lignin samples. The outcome is confirmed by conducting H-NMR analysis, which demonstrated ester and carboxylic acid peaks within the spectral analysis. Finally, the TGA results showed both EFB-EL and KC-EL that are exposed to aqueous alkaline actually possessed better thermal stability and higher activation energy (Ea) compared to the esterified samples in pyridine.

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