Ozone (O3) is a highly reactive gas used in a variety of industrial and scientific applications, including chemical oxidation processes and combustion research. While its strong oxidizing properties make it valuable for these applications, they also present challenges when storing, transferring, or measuring ozone at low concentrations. For applications involving trace levels measured in parts per million (ppm) or parts per billion (ppb), maintaining a consistent gas concentration is important for achieving accurate and reliable results.
What is the compatibility of our SilcoNert® 2000 coating with ozone - particularly in trace-level gas sampling and storage applications? Independent research published in Applications in Energy and Combustion Science provides valuable insight. The researchers used a SilcoNert 2000 coated stainless steel tank to prepare and store ozone and oxygen mixtures and reported no ozone depletion during a 48-hour observation period.
Ozone is an unstable form of oxygen composed of three oxygen atoms. Its chemical reactivity makes it useful in oxidation processes, but it also means ozone can decompose or participate in unwanted reactions during storage and handling. For researchers and engineers working with ozone-containing gas mixtures, maintaining the intended concentration throughout the sampling process is an important consideration.
This challenge becomes particularly significant when working with trace concentrations. Even relatively small changes in ozone concentration can affect analytical measurements, experimental repeatability, and the interpretation of results. If ozone decomposes or reacts with components of the sampling system before reaching the analytical instrument, the measured concentration may not accurately represent the original gas mixture.
The materials used throughout a gas handling system can influence sample stability. Storage vessels, tubing, fittings, and other components introduce surfaces that may interact with reactive compounds. Reducing unwanted surface interactions is therefore an important consideration when designing systems intended to preserve the composition of sensitive gas samples.
SilcoNert 2000 is SilcoTek's flagship inert coating for trace-level gas sampling and analytical applications. Applied through chemical vapor deposition (CVD), the coating creates a thin, chemically protective layer of functionalized amorphous silicon on the surface of compatible components. This surface treatment is designed to reduce unwanted interactions between reactive compounds and the underlying substrate, helping minimize adsorption and improve analytical performance.
Unlike traditional coating methods that require direct access to the surface, SilcoTek's CVD process is non-line-of-sight. This allows the coating to reach internal surfaces and complex geometries, including tubing, fittings, and other components commonly found in gas sampling systems. By treating surfaces throughout the flow path, SilcoNert 2000 can help address potential sources of analyte loss that may otherwise affect measurements.
SilcoNert 2000 is used in analytical applications involving reactive compounds such as sulfur species, mercury, and ammonia. SilcoTek's published chemical compatibility guidance also identifies ozone as compatible with the SilcoNert coating family at room temperature. While this compatibility information provides a useful starting point, independent experimental research offers additional insight into the coating's performance when exposed to ozone-containing gas mixtures.
A 2023 study by Kaczmarek and colleagues, titled Activation effect of ozone and DME on the partial oxidation of natural gas surrogates and validation of pressure-dependent ozone decomposition, investigated the behavior of ozone in chemical reaction systems. Published in Applications in Energy and Combustion Science, the research examined ozone decomposition and its influence on oxidation chemistry under different temperature and pressure conditions.
Because ozone concentration was an important variable in the experiments, the researchers needed a reliable method of preparing and storing ozone-containing gas mixtures. Unwanted ozone depletion during storage could introduce uncertainty into the experimental conditions and affect the interpretation of the results. To support consistent gas preparation, the researchers incorporated a SilcoNert 2000 coated stainless steel storage tank into their experimental setup.
Although the primary purpose of the research was to investigate ozone decomposition and oxidation chemistry, the authors also evaluated ozone stability in the coated storage tank. This aspect of the study provides a particularly useful reference for researchers and engineers considering SilcoNert 2000 for ozone handling applications.
The researchers conducted ozone decomposition experiments at pressures of 1, 10, and 20 bar and temperatures ranging from 298 to 598 K. Two ozone concentrations were investigated: 100 ppm and 5,000 ppm in oxygen. The 100 ppm experiments were performed across the investigated pressures, while the 5,000 ppm experiments were conducted at 1 bar to evaluate the influence of ozone concentration on decomposition behavior.
Because the ozone generator was limited to a pressure of 4 bar, the researchers prepared ozone and oxygen mixtures in advance using a stainless steel tank coated with SilcoNert 2000. The tank was initially filled with the generated ozone and oxygen mixture at pressures up to 4 bar. Additional oxygen was then introduced to increase the tank pressure to as much as 35 bar, and the mixtures were prepared at least one hour before testing to promote a homogeneous gas composition.
During the experiments, the stored ozone and oxygen mixture was combined with an additional oxygen stream to achieve the desired ozone concentrations entering the reactor. This distinction is important because the reported 100 ppm and 5,000 ppm values represent the experimental gas concentrations, rather than necessarily the concentrations present in the storage tank throughout the entire preparation process.
To evaluate the inertness of the SilcoNert 2000 coating, the researchers sampled the ozone and oxygen mixture from the storage tank at specified intervals over a 48-hour period. This evaluation allowed them to determine whether ozone depletion occurred while the gas mixture was stored in the coated stainless steel vessel.
The researchers reported no ozone depletion in the SilcoNert 2000 coated stainless steel tank during the 48-hour observation period. This finding provides direct experimental evidence that the coated vessel maintained ozone stability under the storage conditions evaluated in the study.
For applications involving reactive gas storage and handling, this result is significant because it demonstrates that an ozone-containing mixture could be stored in a SilcoNert 2000 coated vessel without observed concentration loss over the tested period. Maintaining stable gas concentrations was important to the researchers' ability to conduct controlled ozone decomposition experiments, and the coated storage tank helped support that experimental requirement.
It is important to distinguish these storage stability findings from the study's broader investigation of ozone decomposition. The researchers also examined how temperature and pressure influenced ozone decomposition inside a heated reactor, observing that decomposition began at approximately 423 K under certain experimental conditions. These results describe the behavior of ozone during the reactor experiments and should not be interpreted as evidence of ozone loss or coating degradation within the SilcoNert 2000 coated storage tank.
For customers working with ozone concentrations in the ppm range, the findings provide a useful reference when evaluating materials for gas storage and sampling systems. The study demonstrates that a SilcoNert 2000 coated stainless steel vessel was successfully used to prepare and store ozone-containing mixtures without observed depletion over 48 hours. This is particularly relevant when preserving the original gas composition is necessary for reliable analytical measurements or controlled experimental processes.
The research also provides an important distinction for applications involving even lower ozone concentrations. Although SilcoNert 2000 is designed for trace-level analytical applications, the ozone stability findings in this study do not directly establish performance at ppb concentrations. At lower concentrations, even small amounts of analyte loss may become more significant relative to the total ozone present, making application-specific testing especially valuable.
Customers evaluating SilcoNert 2000 for ppb-level ozone sampling should therefore consider the published results as supporting evidence rather than a guarantee of performance at their target concentrations. The study provides a documented example of ozone stability in a coated storage vessel, but additional testing may be necessary to confirm performance under different concentrations, exposure periods, gas compositions, and operating conditions.
Selecting the appropriate surface treatment for an ozone-containing environment requires consideration of the complete application rather than ozone concentration alone. Temperature, pressure, exposure duration, gas composition, and component materials can all influence the suitability of a coating. Understanding these conditions is particularly important when working with highly reactive gases or when analytical accuracy depends on maintaining very low concentrations.
SilcoNert 2000 is designed to provide an inert surface for demanding analytical applications, and SilcoTek's published specifications identify a maximum functionalization temperature of 400°C in oxidative atmospheres. However, the coating's temperature capability should not be confused with the temperature-dependent stability of ozone itself. The independent research demonstrates that ozone decomposition can begin at elevated temperatures, even when the materials used in the experimental system are suitable for those operating conditions.
Another consideration is the distinction between ozone compatibility and oxygen service certification. Although the independent study successfully used a SilcoNert 2000 coated tank to store ozone and oxygen mixtures, SilcoTek generally discourages the use of its coated components in applications requiring certified oxygen service. This guidance should be evaluated separately from the ozone stability findings when determining whether the coating is appropriate for a particular application.
For customers considering SilcoNert 2000 in ozone sampling, storage, or transfer applications, discussing the operating conditions with SilcoTek's technical service team can help determine whether the coating is appropriate and whether additional validation is recommended.
Maintaining stable ozone concentrations is an important challenge in gas sampling, storage, and experimental applications, particularly when working with reactive compounds at trace levels. Unwanted changes in gas composition can introduce uncertainty into analytical measurements and affect the reliability of experimental results, making material selection an important part of system design.
The independent research conducted by Kaczmarek and colleagues provides valuable evidence of SilcoNert 2000's compatibility with ozone-containing gas mixtures. By demonstrating no observed ozone depletion over a 48-hour period in a SilcoNert 2000 coated stainless steel tank, the study offers a published example of the coating's ability to support stable ozone storage under the conditions investigated.
While additional validation may be needed for ppb-level concentrations and applications operating outside the tested conditions, these findings provide a useful starting point for researchers and engineers evaluating inert surface coatings for ozone handling. For applications where unwanted surface interactions could compromise sample integrity, SilcoNert 2000 offers a potential solution supported by independent experimental evidence.
Have questions about SilcoNert 2000 compatibility with ozone or other reactive gases? Contact SilcoTek's technical service team to discuss your application and determine whether SilcoNert 2000 may be an appropriate solution.
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