Thin-Film Selection Guide

IMPORTANT: The chemical resistances of thin-films contained in the following table are provided as a matter of informational purposes only. They are not intended to preclude actual testing and suitability of use and applications. The responsibility of acceptance, suitability, testing, evaluation and safety resides totally with the user. Chemplex^® Industries, Inc. assumes no liability whatsoever in using any Thin-film sample support window substances and assumes no liability whatsoever for any information, advertisement, inferences, reports or any other form of communication written or orally presented.

ETNOM®
Etnom® was the first thin-film substance to chemically resist attack by aliphatic and especially aromatic hydrocarbons and have the unique characteristic of contracting when exposed to petrochemical hydrocarbons. This unique characteristic allows the thin-film to remain taut when exposed to samples containing these hydrocarbons and maintain a consistent taut flat sample support window plane during the entire integration time of analysis. Etnom® is available in a variety of thicknesses ranging from 1.5 through 3.0µm; it is frequently used and ideally suitable for sulfur analysis in aliphatic and particularly aromatic hydrocarbons.  2.0, 2.5 and 3.0µm Etnom® thin-films are limited in availability only to SpectroMembrane® Carrier Frames

Zythene®
Zythene® thin-film is chemically resistant to petrochemicals and, unlike any other thin-film, is also capable to contract upon contact with aliphatic and aromatic hydrocarbons. This particular trait is responsible for establishing and maintaining taut sample support window planes during the entire integration time of analysis. Adding this unique quality to the unusually high sample retention tensile strength of Zythene®, samples are safely contained in their sample cups with a rare likelihood of rupture. Coincidentally, 6.0µm Zythene® exhibits a similar mass attenuation coefficient to 6.0µm Mylar®. This implies the % Transmittance of 6.0µm Zythene® and 6.0µm Mylar® is similar and the expectant element spectral-line intensities are also similar. However, this similarity does not negate the need for cursory calibration verification.  6.0µm Zythene® is limited in availability only to SpectroMembrane® Carrier Frames.

Prolene®
Prolene® thin-film is a two constituent element combination of carbon and hydrogen. The light carbon and hydrogen element constituents together with gauge thickness translate into mass attenuation coefficients providing high % Transmittance values, an advantage for investigating the less energetic (KeV) analyte spectral lines in low element concentrations. Prolene® represents a good general purpose thin-film for most chemical solution samples except for those consisting of ethers or aromatic and halogenated hydrocarbons. It also is characterized with a relatively high sample retention tensile strength for safely containing samples in their sample cups. Prolene® thin-film is available in 3.0 and 4.0µm gauges and in SpectroMembrane® Carrier Frames.

KAPTON®

Our 7.5µm Kapton® thin-film available from Chemplex® exhibits similar properties as the previous traditionally used type: 7.5µm gauge, high sample retention tensile strength, equivalent % Transmittance values of x-rays, chemical resistance and melting points. The difference between the other Kapton® films and the Chemplex® 7.5µm Kapton® thin-film is “it is not subject to the U.S. International Traffic in Arms Regulations (ITAR).”  Reportedly, an unknown slight difference between the ITAR controlled and the new 7.5µm Kapton® thin-film may affect the reliance on previously established calibration data. Chemplex® suggests judiciously re-examining this issue for verification prior to implementing an analytical program. 

Polypropylene
Polypropylene thin-film is available in 6.0 and 12.0 µm in SpectroMembrane® Carrier Frames. The thin-film serves a dual purpose; it is noted for its high % Transmittance for the lighter elements in low to medium concentration ranges and exceptional transmittance for the heavier element spectral lines. Reportedly, the thicker 6.0 and 12.0µm gauges are more preferable for retaining some samples and applications that demand an extraordinary higher level of security against inadvertent thin-film rupture.    

MYLAR®
At one time, Mylar® thin-film was the only substance used in the XRF spectrochemical field and supplied only in roll form. With the passage of time, Chemplex® introduced the expansion of the Mylar® product line to include additional gauges and all other forms of physical presentation such as pre-cut square sheets, pre-cut circles, perforated pre-cut squares in rolls and recently in SpectroMembrane® Carrier Frames. Mylar® is a relatively good thin-film substance for general purpose aqueous sample solution containment. It has an excellent sample retention tensile strength. It is not suitable for containing aliphatic alcohols, alkalies, esters, aromatic hydrocarbons and keytones.

 IMPORTANT: Some window materials may not be suitable for analyzing sulfur in diesel fuel, gasoline and other petroleum products containing aromatic hydrocarbons. ASTM D-6445-99 (Reapproved 2004) e1: "Samples of high aromatic content may dissolve polyester and polycarbonate films. In these cases, other materials besides these films may be used for X-ray windows, provided that they do not contain any elemental impurities. ASTM D 4294-08a: "Any film that resists attack by the sample, is free of sulfur, and is sufficiently X-ray transparent can be used. Film types can include polyester, polypropylene, and polycarbonate. However, samples of high aromatic content can dissolve polypropylene, polycarbonate and polyester."

^® SpectroCertified, Prolene, Etnom, Ultra-Polyester and Chemplex are registered trademarks of Chemplex Industries, Inc.


^® Mylar and Kapton are registered trademarks of E. I. DuPont de Nemours & Co., Inc.