Determination of the Principal Direction of Molecular Orientation in FT-IR Measurement Using Two Polarizers

An optical arrangement using two polarizers is proposed for FT-IR measurement of orientation. Compared with conventional FT-IR using a single polarizer, the new arrangement provides much better discrimination in searching for the principal directions of orientation.

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Polarized microbeam FT-IR analysis of single fibers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100163496 ◽

1996 ◽

Vol 54 ◽

pp. 206-207

Author(s):

Liling Cho ◽

David L. Wetzel

Keyword(s):

Molecular Orientation ◽

Transition Point ◽

Polymer Fibers ◽

Single Fiber ◽

Wire Grid ◽

Polyester Fibers ◽

Ft Ir ◽

Ir Analysis ◽

The Relationship ◽

Wire Grid Polarizer

Polarized infrared microscopy has been used for forensic purposes to differentiate among polymer fibers. Dichroism can be used to compare and discriminate between different polyester fibers, including those composed of polyethylene terephthalate that are frequently encountered during criminal casework. In the fiber manufacturering process, fibers are drawn to develop molecular orientation and crystallinity. Macromolecular chains are oriented with respect to the long axis of the fiber. It is desirable to determine the relationship between the molecular orientation and stretching properties. This is particularly useful on a single fiber basis. Polarized spectroscopic differences observed from a single fiber are proposed to reveal the extent of molecular orientation within that single fiber. In the work presented, we compared the dichroic ratio between unstretched and stretched polyester fibers, and the transition point between the two forms of the same fiber. These techniques were applied to different polyester fibers. A fiber stretching device was fabricated for use on the instrument (IRμs, Spectra-Tech) stage. Tension was applied with a micrometer screw until a “neck” was produced in the stretched fiber. Spectra were obtained from an area of 24×48 μm. A wire-grid polarizer was used between the source and the sample.

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Authentication of the Ancient Easel / Paintings Through Materials Identification from the Polychrome Layers II. Analysis by Means of the FT-IR Spectrophotometry

Revista de Chimie ◽

10.37358/rc.08.4.1792 ◽

2008 ◽

Vol 59 (4) ◽

Cited By ~ 8

Author(s):

Irina Crina Anca Sandu ◽

Constantin Luca ◽

Ion Sandu ◽

Viorica Vasilache ◽

Mikiko Hayashi

Keyword(s):

Degradation Rate ◽

Animal Glue ◽

Painting Materials ◽

Ageing Rate ◽

Ir Spectrophotometry ◽

Private And Public ◽

Ft Ir

This is the second paper belonging to a study concerning the authentication of ancient easel-paintings, on canvas and wood support, from private and public collections, by using the FT-IR spectrophotometry technique for the analysis of the painting materials. Different pigments, egg binders, caseins and animal glue, often found in ancient easel-paintings on wood or canvas, have been used as standards for establishing the ageing rate of the paintings by correlation with the dates presented in the first note. The determination of the degradation rate of the painting materials is an important archaeometric characteristic used in authentication.

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Combination of Sorption Tube Sampling and Thermal Desorption with Hollow Waveguide FT-IR Spectroscopy for Atmospheric Trace Gas Analysis: Determination of Atmospheric Ethene at the Lower ppb Level

Analytical Chemistry ◽

10.1021/ac034396j ◽

2004 ◽

Vol 76 (2) ◽

pp. 464-468 ◽

Cited By ~ 19

Author(s):

Olga A. Pogodina ◽

Victor V. Pustogov ◽

Fabiano de Melas ◽

Christina Haberhauer-Troyer ◽

Erwin Rosenberg ◽

...

Keyword(s):

Ir Spectroscopy ◽

Thermal Desorption ◽

Gas Analysis ◽

Trace Gas ◽

Hollow Waveguide ◽

Ft Ir ◽

Atmospheric Trace Gas ◽

Analysis Determination ◽

Ft Ir Spectroscopy

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Influence of a Natural Plant Antioxidant on the Ageing Process of Ethylene-norbornene Copolymer (Topas)

International Journal of Molecular Sciences ◽

10.3390/ijms22084018 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4018

Author(s):

Anna Masek ◽

Angelika Plota

Keyword(s):

Mechanical Properties ◽

Food Packaging ◽

Colour Change ◽

Good Alternative ◽

Plant Origin ◽

Aging Behavior ◽

Current State ◽

Ft Ir ◽

Potential Use

In the field of polymer technology, a variety of mainly synthetic additives are used to stabilize the materials during processing. However, natural compounds of plant origin can be a green alternative to chemicals such as synthetic polyphenols. An analysis of the effect of hesperidin on the aging behavior of ethylene-norbornene copolymer was performed. The evaluation of changes in the tested samples was possible by applying the following tests: determination of the surface energy and OIT values, mechanical properties analysis, colour change measurements, FT-IR and TGA analyses. The obtained results proved that hesperidin can be effectively used as natural stabilizer for polymers. Furthermore, as a result of this compound addition to Topas-silica composites, their surface and physico-mechanical properties have been improved and the resistance to aging significantly increased. Additionally, hesperidin can act as a dye or colour indicator and only few scientific reports describe a possibility of using flavonoids to detect changes in products during their service life, e.g., in food packaging. In the available literature, there is no information about the potential use of hesperidin as a stabilizer for cycloolefin copolymers. Therefore, this approach may contribute not only to the current state of knowledge, but also presents an eco-friendly solution that can be a good alternative to synthetic stabilizers.

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