Chemical Changes to Woody Polymers Due to High-Temperature Thermal Treatment Assessed with near Infrared Spectroscopy

2016 ◽  
Vol 24 (6) ◽  
pp. 555-562 ◽  
Author(s):  
Jakub Sandak ◽  
Anna Sandak ◽  
Ottaviano Allegretti
Keyword(s):  
Infrared Spectroscopy ◽  
Thermal Treatment ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Treatment Temperature ◽  
Absorption Bands ◽  
Chemical Changes ◽  
Novel Method ◽  
Treatment Procedures ◽  
Original Approach

Near infrared spectroscopy and an original approach for visualisation of spectra are proposed here for characterisation of vacuum thermally modified samples of eight wood species representing softwoods and hardwoods. Significant changes in absorption bands were observed in conjunction with an increase of treatment temperature. A novel method for visualisation of the degradation patterns (xylograms) is capable of highlighting peculiarities in chemical changes to woody polymers due to the thermal treatment. This method also allows observation of kinetics and permits comparison of thermal stability of investigated species. Such knowledge might be helpful for further optimisation of thermal treatment procedures at an industrial scale. Furthermore, xylograms as a simple and illustrative method might be suitable for visualisation of other modification processes of wood as well as of other materials.

Near Infrared Spectroscopy of Aurichalcite (Zn,Cu2+)5(CO3)2(OH)6

2007 ◽  
Vol 15 (2) ◽  
pp. 115-121 ◽  
Author(s):  
B. Jagannadha Reddy ◽  
Ray L. Frost
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Divalent Cations ◽  
Spectral Feature ◽  
Adsorbed Water ◽  
Absorption Bands ◽  
Bending Vibrations ◽  
Show Evidence ◽  
Spectroscopy Studies

In this endeavour, near infrared spectroscopy studies show evidence of variable composition in aurichalcite minerals of zinc copper carbonate hydroxides. The observation of a broad feature in the electronic part of the spectrum around 11,500 cm−1 (870 nm) is a strong indication of Cu2+ substitution for Zn2+ in the mineral. Overtones of OH vibrations in the spectra from 7250 to 5400 cm−1 (1380–1850 nm) show strong hydrogen bonding in these carbonates. A band common to spectra of all carbonates appears near 5400 cm−1 (1850 nm) due to the combination of both OH-stretching and HOH-bending vibrations, which may be attributed to adsorbed water. Aurichalcite minerals display a spectral sequence of five absorption bands with variation of both band positions and intensities and this is the chief spectral feature observed in the range 5200–5100 cm−1 (1920–2380 nm) due to vibrational processes of the carbonate ion. The frequency shift of carbonate bands suggests the effect of divalent cations and/or variations of the Zn/Cu ratio in aurichalcite minerals.

Characterization of molecular orientation under tensile deformation by near infrared spectroscopy

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Masami Mizushima ◽  
Takanobu Kawamura ◽  
Kenji Takahashi ◽  
Koh-hei Nitta
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Tensile Deformation ◽  
Crystal Form ◽  
Orientation Function ◽  
Chain Axis ◽  
Stretching Vibration ◽  
Novel Method

AbstractWe present a novel method for characterizing orientation behavior of typical polyethylene (PE) materials such as HDPE, LLDPE, and LDPE. The chain orientation to the stretching direction was examined under uniaxial deformation by near infrared spectroscopy. Then we obtained directly the orientation function of PE chain axis (c-axis) from the CH stretching vibration of NIR spectra as a function of extension time or strain. We compared the present method with the conventional infrared IR method where the orientation function of PE c-axis (chain-axis) has been indirectly obtained from the b-and a-axis’s assuming the orthogonal crystal form by using the CH2 rocking vibrations in IR spectra

Quantitative Analysis of Epoxy Resin Cure Reaction: A Study by Near-Infrared Spectroscopy

2002 ◽  
Vol 56 (11) ◽  
pp. 1413-1421 ◽  
Author(s):  
C. Billaud ◽  
M. Vandeuren ◽  
R. Legras ◽  
V. Carlier
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Epoxy Resins ◽  
Model Compound ◽  
Near Infrared ◽  
Curing Process ◽  
Absorption Bands ◽  
Cure Reaction ◽  
Quantitative Results ◽  
Epoxy Resin Cure

Near-infrared spectroscopy was used to quantify the cure reaction of 4,4′-methylene- bis-(2,6-diethylaniline) (MDEA)–epoxy resins (E/A = 1.4) carried out at 72 and 160 °C. The absorption bands of the functional groups of interest in MDEA–epoxy resins are assigned according to the literature. A new assignment at 6580 cm−1 is also proposed for the secondary amine: it was supported by a synthesized model compound. Two different spectrum treatments were proposed. The first one is based only on a normalization at 4610–4620 cm−1, while the second one needs the subtraction of the normalized spectrum of a post-cure sample. To follow the curing process, amines and epoxy were studied at the same time in the combination and the overtone regions. The results are compared. In the combination region, quantitative results are obtained from absorbance measurements, while in the overtone region spectrum decompositions and area measurements are necessary. Complementary and reliable information are so obtained and allow us to calculate conversions of epoxide and amine I and concentrations in amine II, amine III, hydoxyl groups, and ether links. Kinetics are also established. The curing process mechanism is at last discussed for both curing temperatures.

Fullerene Based Nanomaterials for Biomedical Applications: Engineering, Functionalization and Characterization

2013 ◽  
Vol 633 ◽  
pp. 224-238 ◽  
Author(s):  
Lidija Matija ◽  
Roumiana Tsenkova ◽  
Jelena Munćan ◽  
Mari Miyazaki ◽  
Kyoko Banba ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Biomedical Applications ◽  
Near Infrared ◽  
Biological Properties ◽  
Cage Structure ◽  
Carbon Cage ◽  
Novel Method ◽  
Medicine Analysis ◽  
New Skin

Since their discovery in 1985, fullerenes have attracted considerable attention. Their unique carbon cage structure provides numerous opportunities for functionalization, giving this nanomaterial great potential for applications in the field of medicine. Analysis of the chemical, physical, and biological properties of fullerenes and their derivatives showed promising results. In this study, functionalized fullerene based nanomaterials were characterized using near infrared spectroscopy, and a novel method - Aquaphotomics. These nanomaterials were then used for engineering a new skin cream formula for their application in cosmetics and medicine. In this paper, results of nanocream effects on the skin (using near infrared spectroscopy and aquaphotomics), and existing results of biocompatibility and cytotoxicity of fullerene base nanomaterials, are presented.

scholarly journals Evaluation of Chemical Quality on Juices and Wine Produced from Mamao Fruit (Antidesma Puncticulatum Miq.) Within Near-Infrared Spectroscopy

2021 ◽  
Vol 20 (5) ◽  
pp. 255-260
Author(s):  
Kongphope Chaarmart ◽  
Sureeporn Narongwongwattana ◽  
Ronnarit Rittiron ◽  
Worawat Sa-Ngiamvibool
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cross Validation ◽  
Chemical Quality ◽  
Absorption Bands ◽  
Calibration Equation ◽  
Water Composition

The chemical quality of juices and wine produced from Mamao fruit was evaluated by Fourier transform near-infrared (FT-NIR). The calibration equation was created by the cross-validation method to be si+mulated the accuracy. Statistical values composed of correlation coefficient (R), standard error of cross-validation (SECV) and bias were used. Brix values and acidity values of Mao juice and the Brix, acidity, and alcohol values of Mao wine products were evaluated through the standard and cross-validation relation. It was found that was observed with NIR spectrometer to be absorbed in the same IR wavelength (1450 nm) which indicated that the water is the main composition. Based on FT-NIR analysis, the spectrum latices of juices and wine were revealed in the same range of the absorption bands at 1450 nm and 1940 nm to be confirmed the water composition. Also, the FT-NIR spectra from region 2258-2312 nm in Mao wine product have been predicted to the Ethanol functions.

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