THE INFRARED SPECTRA AND STRUCTURE OF POLYALDEHYDES: IV. THE HIGHER POLYALDEHYDES

1959 ◽  
Vol 37 (10) ◽  
pp. 1718-1721 ◽  
Author(s):  
A. Novak ◽  
E. Whalley
Keyword(s):  
Infrared Spectroscopy ◽  
Infrared Spectra

The polymers of n- and iso-butyraldehyde and n-valeraldehyde, which were made by subjecting the aldehydes to pressures of about 8 kb, have been examined by infrared spectroscopy. They are homologues of polyformaldehyde, having the formula HO(CHR•O)nH.

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>

scholarly journals Influence of alkyl chain length and fluorine atoms substitution on infrared spectra of chiral liquid crystalline esters

2017 ◽  
Vol 66 (3) ◽  
pp. 63-74
Author(s):  
Anna Drzewicz ◽  
Marzena Tykarska ◽  
Magdalena Żurowska
Keyword(s):  
Molecular Structure ◽  
Infrared Spectroscopy ◽  
Liquid Crystals ◽  
Infrared Spectra ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Rigid Core ◽  
Helicoidal Structure

The infrared spectra were registered for series of three-ring liquid crystalline esters, differing in the structure of alkyl chain, in the substitution of benzene ring by fluorine atoms and in the type of helicoidal structure in the chiral smectic CA phase with antiferroelectric properties. The influence of molecular structure on the shift of signals coming from carbonyl group, located in the rigid core, was observed. Keywords: liquid crystals, helicoidal structure, chiral smectic CA phase, antiferroelectric crystalline phase, infrared spectroscopy

scholarly journals Analysis of infrared spectra of blood serum of patients with multiple myeloma

2021 ◽  
Vol 2103 (1) ◽  
pp. 012052
Author(s):  
D A Chernyshev ◽  
E S Mikhailets ◽  
E A Telnaya ◽  
L V Plotnikova ◽  
A D Garifullin ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Principal Component Analysis ◽  
Infrared Spectroscopy ◽  
Blood Serum ◽  
Infrared Spectra ◽  
Early Stage ◽  
Principal Component ◽  
Healthy Donors ◽  
Components Analysis ◽  
Serious Disease

Abstract Multiple myeloma (MM) is a serious disease that is difficult to diagnose especially at early stage. Infrared spectroscopy is a promising approach for diagnosing MM. The principal component analysis (PCA) allows us to reduce the dimension of the data and keep only the important variables. In this study, we apply principal components analysis to infrared (IR) spectra of blood serum from healthy donors and multiple myeloma patients. As a result of the analysis by PCA, it was possible to visualize the separation of patient’s and donor’s samples into two clusters. The result indicates that this method is potentially applicable for diagnosis of multiple myeloma.

Spectral Interpretation and Qualitative Analysis of Organophosphorus Pesticides Using FT-Raman and FT-Infrared Spectroscopy

1996 ◽  
Vol 50 (5) ◽  
pp. 565-571 ◽  
Author(s):  
Peter A. Tanner ◽  
Kim-Hung Leung
Keyword(s):  
Raman Spectroscopy ◽  
Infrared Spectroscopy ◽  
Infrared Spectra ◽  
Temperature Effects ◽  
Organophosphorus Pesticides ◽  
Spectral Interpretation ◽  
Ft Raman Spectroscopy ◽  
Safe Technique ◽  
Characteristic Group ◽  
Ft Raman

FT-Raman spectroscopy is a selective and safe technique for the qualitative identification of organophosphorus pesticides and is not accompanied by sample photodecomposition. Spectra of 14 target pesticides were recorded, and the phosphorus characteristic group frequencies are discussed. Preliminary investigations of solvent and temperature effects upon the infrared spectra were also carried out.

How many cells are enough for single-cell infrared spectroscopy?

2020 ◽  
Vol 56 (26) ◽  
pp. 3773-3776 ◽  
Author(s):  
Yadi Wang ◽  
Wentao Dai ◽  
Yue Wang ◽  
Jixiang Liu ◽  
Zhixiao Liu ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Single Cell ◽  
Infrared Spectra ◽  
Similarity Distance

The similarity distance among single-cell infrared spectra reveals that at least 15 cells are required to achieve robust results with 95% confidence.

Low-temperature infrared studies of some acid–base reactions

1983 ◽  
Vol 61 (9) ◽  
pp. 2077-2088 ◽  
Author(s):  
Theresa Huston ◽  
I. C. Hisatsune ◽  
Julian Heicklen
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectroscopy ◽  
Low Temperature ◽  
Infrared Spectra ◽  
Acid Base ◽  
Reaction Systems ◽  
Solid States ◽  
Infrared Studies

Low-temperature infrared spectroscopy has been used to examine the systems NH3 + H2O, NH3 + HCl, H2O + HCl, NH3 + HNO3, and NH2OH + HNO3. Hydrogen-bonding in the solid states greatly reduces the reactivities in these systems. Temperatures where reactions initiated in the systems NH3(s) + HCl(g), HNO3(s) + NH3(g), H2O(s) + HCl(g), and NH2OH(s) + HNO3(s) were, respectively, −145, −130, −127, and −125 °C. Infrared spectra of 2NH3•H2O, NH3•H2O, NH4Cl•3NH3, NH4NO3•3NH3, NH4NO3•2HNO3, NH2OH2+NO3−, NH3OH+NO3−, H3O+Cl−, H5O2+Cl−, and H5O2+Cl−•H2O have been identified in these reaction systems.

Standard free energy of the equilibrium between the trans-monomer and the cyclic-dimer of acetic acid in the gas phase from infrared spectroscopy

2015 ◽  
Vol 17 (11) ◽  
pp. 7477-7488 ◽  
Author(s):  
Manuel Goubet ◽  
Pascale Soulard ◽  
Olivier Pirali ◽  
Pierre Asselin ◽  
Florent Réal ◽  
...  
Keyword(s):  
Free Energy ◽  
Acetic Acid ◽  
Infrared Spectroscopy ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Standard Free Energy ◽  
Cyclic Dimer

The dimerization equilibrium of acetic acid in the gas phase at 298 K has been characterized from the analysis of jet-cooled and static cell infrared spectra supported by calculations.

Adsorption of water and 18O exchange of surface hydroxyl groups on silica

1970 ◽  
Vol 48 (15) ◽  
pp. 2454-2456 ◽  
Author(s):  
B. A. Morrow ◽  
A. Devi
Keyword(s):  
Infrared Spectroscopy ◽  
Infrared Spectra ◽  
Sample Temperature ◽  
Hydroxyl Groups ◽  
Surface Hydroxyl ◽  
Silanol Groups ◽  
Surface Hydroxyl Groups ◽  
Adsorption Of Water ◽  
Exchange Technique

Infrared spectroscopy has been used to show that the surface hydroxyl groups on highly dehydrated silica will exchange with 18O-labeled water. The degree of exchange depends on the sample temperature and is a maximum at about 400 °C, where approximately 65% of the silanol groups contain 18O. The use of the 18O exchange technique for assigning surface-adsorbate stretching modes is illustrated by considering the infrared spectra of BF3 chemisorbed on silica.

Organic functional group composition of particulate matter from fresh and aged wood burning and coal combustion

2020 ◽  
Author(s):  
Amir Yazdani ◽  
Nikunj Dudani ◽  
Satoshi Takahama ◽  
Amelie Bertrand ◽  
André S. H. Prévôt ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Particulate Matter ◽  
Infrared Spectra ◽  
Atmospheric Aerosols ◽  
Coal Combustion ◽  
Organic Aerosol ◽  
High Abundance ◽  
Mid Infrared ◽  
Aerosol Mass ◽  
Wood Burning

<p>Particulate matter (PM) affects visibility and climate through light scattering, direct and indirect radiative forcing, and affecting cloud formation [1]. In addition, exposure to ambient fine PM is estimated to have caused 8.9 million deaths worldwide in 2015 [2]. Organic matter (OM), can make up more than half of total fine atmospheric PM, and yet its composition, formation mechanisms, and adverse health effects are not fully characterized due to its sheer compositional complexity. Biomass burning (e.g., residential wood burning, wildfires, and prescribed burning) and coal combustion (for heat and power generation) are two major OM sources, for which the impact of atmospheric aging - including secondary organic aerosol (SOA) formation - is not yet fully clear [3].</p><p>In this study, we investigated the effect of aging on composition and mass concentration of organic aerosols of wood burning (WB) and coal combustion (CC) emissions using two complementary methods, i.e., mid-infrared spectroscopy and aerosol mass spectrometry (AMS). For this purpose, primary aerosols were injected into the Paul Scherrer Institute (PSI) environmental chamber and aged using hydroxyl and nitrate radicals to simulate day-time and night-time oxidation processes in the atmosphere. In these experiments, aerosols reached an oxidative age comparable to that of atmospheric aerosols. A time-of-flight AMS instrument was used to measure the high-time-resolution composition of non-refractory fine PM, while we collected PM<sub>1 </sub>aerosols on PTFE filters before and after four hours of aging for off-line Fourier transform-infrared spectroscopy (FT-IR) measurements.</p><p>AMS and FT-IR estimates of organic aerosol mass concentration were highly correlated (r<sup>2</sup>=0.92); both indicating an approximately three-fold increase in organic aerosol concentration after aging. The OM/OC ratio, indicating the extent of oxidation also agreed closely between the two instruments and increased, on average, from 1.6 (before aging) to 2 (after aging). Mid-infrared spectroscopy, which is able to differentiate among oxygenated species, shows a distinct functional group composition for aged WB aerosols (high abundance of carboxylic acids) and CC aerosols (high abundance of non-acid carbonyls) and detects considerable amounts polycyclic aromatic hydrocarbons (PAHs) for both sources. Mid-infrared spectra of fresh WB and CC aerosols are reminiscent of their parent compounds with differences in specific functional groups suggesting the dominant oxidation pathways for each emission source. Finally, the comparison of mid-infrared spectra of aged WB aerosols in the environmental chamber with that of ambient samples affected by residential wood burning and wildfires reveals interesting similarities regarding the high abundance of alcohols and visible signatures of lignin. This finding is useful for interpreting sources of atmospheric aerosols and better interpretation of their complex mid-infrared spectra.</p><p>--------------------------</p><p>REFERENCES</p><p>[1] M. Hallquist et al., “The formation, properties and impact of secondary organic aerosol: current and emerging issues,” Atmos Chem Phys, 2009.</p><p>[2] R. Burnett et al., “Global estimates of mortality associated with long-term exposure to outdoor fine particulate matter,” Proc. Natl. Acad. Sci., 2018.</p><p>[3] A. Bertrand et al., “Primary emissions and secondary aerosol production potential from woodstoves for residential heating: Influence of the stove technology and combustion efficiency,” Atmos. Environ., 2017.</p>

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