N-Octadecyltriethoxysilane stands out among organosilane compounds used for advanced material surface modification. Built on a silane core linked to a long C18 alkyl chain, this clear to pale yellow chemical carries the molecular formula C24H52O3Si, giving it a molecular weight of about 416.76 g/mol. Raw material users handling this compound would recognize it by its characteristic density, usually around 0.85-0.89 g/cm³ at 25°C. You'll see it most often as a liquid in drums or bottles, but under colder storage, waxy flakes and even solid pearls can appear. The long alkyl tail gives it unique hydrophobic properties, something chemists have leaned on in coatings, nanotechnology, and textiles.
At room temperature, N-Octadecyltriethoxysilane keeps its liquid form, letting handlers pump, pour, and dilute it without fuss. Its triethoxysilane moiety can react with water, breaking down the ethoxy groups and forming strong siloxane bonds with silica surfaces. The octadecyl chain, basically straight-chain hydrocarbon, shields treated surfaces from water, helping materials repel stains or resist wetting. Whether lab techs need a reagent for prepping glass, improving adhesion, or adding anti-fingerprint coatings to electronics, they reach for this silane for its reliable reactivity and versatility. Its boiling point averages between 340-350°C, and you generally find flash points above 130°C, which makes it safer compared to many volatile solvents.
N-Octadecyltriethoxysilane comes with tight purity requirements. Most suppliers guarantee material above 98% purity, which matters a lot for consistent results. Typical analyses report low moisture content, trace levels of acid (often cited as less than 0.1%), and thorough screening for impurities. Sometimes sellers offer crystalline forms or supply the material as a solution in organic solvents like toluene or ethanol to suit process demands. The HS Code for global trade sits at 2931.90, which helps end-users and logistics providers move it predictably across borders.
Dealing with N-Octadecyltriethoxysilane, one learns to expect changes in physical state with temperature. Cool storage rooms and winter shipments will solidify the liquid, so buyers occasionally receive it as flakes or waxy pellets. These forms dissolve easily once brought to room temperature, and mixing gently helps re-liquify the chemical for pipetting or pouring. Though most applications go with the standard liquid, those needing slow release or precise dosing may request pearls or larger granules to cut down on static and spillage. Regardless of form, every batch gets sealed tightly to avoid air exposure, which could start unwanted hydrolysis or gel formation.
Surface scientists and engineers see immediate value in this silane. After treating glassware, lab glass resists fogging and chemistry setups need cleaning less often. Textiles picked up new qualities, shrugging off water and dirt when finished with a silane treatment bath. Wood and stone coatings last longer—builders rely on tested silane formulas for high-traffic flooring and decorative concrete. The hydrophobic layer formed is both thin and durable, not easily scraped off. Microelectronics and solar panel manufacturers count on treated substrates to remain clear and contamination-resistant, especially as atmospheric dust and pollution settle.
As someone who’s seen chemical plants in operation, clear labeling and secure storage remain top priorities. N-Octadecyltriethoxysilane should never touch bare skin or splash near unprotected eyes. Breathing high concentrations of vapor could irritate the nose or throat, so use in rooms with active ventilation systems is best. Workers wear gloves, safety glasses, and often a lab coat or apron when decanting or moving containers. Since it reacts slowly with moist air, spills can get slippery as gels form, making cleanup a regular challenge in production areas. The chemical classifies as harmful under GHS, so transport gets restricted by Isopropyl Fire (3) regulations where applicable. Users who handle raw materials should always have spill kits and chemical-resistant gloves nearby, ensuring any leaks or drips don’t escalate into larger safety risks.
Experienced buyers scrutinize their suppliers’ quality control certificates. Each drum or bottle carries a batch number, date of manufacture, and a copy of typical property data—users compare these to in-house tests for things like density and refractive index. Specialized processes, such as those for nanoscale coatings, depend on input silane working exactly as expected, with no excess acidity or cloudiness that signals premature hydrolysis. Whenever a company switches lots or vendors, test panels or beakers get prepped to check behavior on real-world substrates. Close attention at this stage saves time and expense downstream, as failed coatings or poor bonding can lead to costly reruns.
In my experience, problems with N-Octadecyltriethoxysilane almost always trace back to moisture or temperature swings during storage. Tight seals and dry nitrogen blankets go a long way toward preventing premature gelling. Storage rooms kept between 10 and 30°C, with silica gel desiccants, stretch shelf life well past a year, even for partial drums. Large projects benefit from smaller containers or pre-diluted solutions, both to cut down on exposure and to make dosing simpler on the factory floor. Technical support teams recommend opening containers only as needed and always transferring leftovers back into airtight packaging. Training plant staff in simple leak and exposure responses stops most small mishaps from growing into bigger incidents. Continual review of product certificates against lab results ensures surface quality stays high, and raw material lots deliver the expected results every time.
