Photoacoustic Infrared Spectra (IR-PAS) of Aged and Fresh-Cleaved Coal Surfaces

1980 ◽  
Vol 34 (4) ◽  
pp. 407-408 ◽  
Author(s):  
Mark G. Rockley ◽  
J. Paul Devlin
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Infrared Spectra ◽  
Fourier Transform Infrared ◽  
Fourier Transform Infrared Spectrometer ◽  
Infrared Spectrometer ◽  
Effects Of Aging

The application of the newly developed technique of photoacoustic infrared spectroscopy, using a Fourier transform infrared spectrometer, to the measurement of the infrared spectra of single slabs of various coal types is described. The effects of aging of coal surfaces, which include both oxidation and abrasion, are clearly apparent in a comparison of the spectra of freshly cleaved and aged coal surfaces.

The KBr Pellet: A Useful Technique for Obtaining Infrared Spectra of Inorganic Species

1979 ◽  
Vol 33 (6) ◽  
pp. 581-584 ◽  
Author(s):  
R. M. Gendreau ◽  
R. Burton
Keyword(s):  
Fourier Transform ◽  
Standard Deviation ◽  
Sample Preparation ◽  
Infrared Spectra ◽  
Fourier Transform Infrared ◽  
Spectral Matching ◽  
Inorganic Species ◽  
Fourier Transform Infrared Spectrometer ◽  
Infrared Spectrometer ◽  
Sulfate Species

The reproducibility of the KBr pelleting technique for inorganic sulfates was assessed using a Fourier transform infrared spectrometer. Day-to-day variation in peak frequencies of selected bands had standard deviations ranging from 0. to 1.5 cm−1. This 1 cm−1 standard deviation was shown to be due to changes in bandshape, probably due to variations in sample preparation from operator to operator. It was concluded that the reproducibility of sulfates in KBr is sufficient to allow the design of computerized spectral matching programs to identify specific sulfate species based on band frequencies and intensities.

Fourier-Transform Infrared Spectroscopy of Environmentally Weathered Textile Fabrics for Enhanced Microplastic Identification

2021 ◽  
Author(s):  
Shreyas Patankar ◽  
Ekaterina Vassilenko ◽  
Mathew Watkins ◽  
Anna Posacka ◽  
Peter Ross
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Infrared Spectra ◽  
Environmental Fate ◽  
Uv Light ◽  
Natural Fibers ◽  
Fourier Transform Infrared ◽  
Ambient Conditions ◽  
Selection Of

<p>Microplastic pollution in oceans is among the global environmental concerns of our time. Emerging research on ocean environments indicates that microfibers, such as those originating from textiles, are some of the most commonly occurring type of microplastic contaminants. While Fourier-transform infrared spectroscopy (FTIR) is commonly used to identify and characterize pollutant samples obtained from the environment, this identification is challenging because infrared spectra of materials can be modified by exposure to the ocean, air, UV light, and other ambient conditions, in a process referred to as “weathering”. We report preliminary efforts in improving FTIR characterization of microplastics by building a library of infrared spectra of common textile fibers weathered under a selection of ambient conditions. Consumer textile materials including polyester, nylon, cotton, and other, were exposed to a selection of ambient conditions: ocean, air, and wastewater treatment stages, in a controlled weathering experiment. Infrared spectra were monitored for up to 52 weeks, with the resulting data illuminating on the environmental fate and longevity of synthetic and natural fibers. Spectral changes caused by weathering were found to depend strongly on both the composition of the material and the specific ambient conditions. This library of weathered material spectra is useful not only in easier identification of environmental microfibers, but also in helping us estimate the duration and manner of weathering that a given environmental microfiber may have experienced.</p>

Broadband terahertz dielectric measurement based on multi-beam interference and Fourier transform infrared spectrometer

2018 ◽  
Vol 32 (25) ◽  
pp. 1850298
Author(s):  
Jie Shi ◽  
Mao-Rong Wang ◽  
Kai Zhong ◽  
Chu Liu ◽  
Jia-Lin Mei ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Room Temperature ◽  
Fourier Transform Infrared ◽  
Refraction Index ◽  
Good Alternative ◽  
Dielectric Measurement ◽  
Terahertz Time Domain Spectroscopy ◽  
Fourier Transform Infrared Spectrometer ◽  
Limited Frequency ◽  
Infrared Spectrometer

We demonstrate a method for obtaining optical coefficients over a broad terahertz spectral range from 1.5 THz to 16 THz at room temperature. Based on the interferograms directly acquired by a Fourier transform infrared spectrometer (FTIR), multi-beam interference principle combining Fresnel’s formula is employed to extract the refraction index and the extinction coefficient, giving the basis for calculating dielectric coefficients. It avoids the uncertainty and phase instability while using Kramers–Kronig (KK) relations and overcomes the limited frequency range of terahertz time-domain spectroscopy (TDS). Moreover, this method has better stability and is needless of cutting useful information between neighboring interference peaks for thin samples compared with TDS, making it a general processing method for interferograms and a good alternative for terahertz dielectric measurement.

Sign in / Sign up

Export Citation Format

Share Document