Long-chain silanes didn’t pop up overnight. Back in the mid-20th century, chemists started exploring organosilicon compounds for their capacity to add water repellency and improve material durability. The chemistry world noticed the possibilities with trialkoxysilanes. N-Octadecyltriethoxysilane, with its eighteen-carbon tail, attracted attention among innovators pursuing robust anti-sticking or hydrophobic surfaces for glass, ceramics, and textiles. Since then, systematic research has brought about tailored syntheses, blending raw practicality with persistent curiosity for better coatings and surface treatments.
N-Octadecyltriethoxysilane stands out with its hefty hydrocarbon chain and a reactive silane head, which means it bonds well to surfaces that have hydroxyl groups. It thrives in settings where slick, moisture-repelling, and chemically resistant layers are in demand. Suppliers typically deliver it as a clear to pale yellow liquid, and those handling the substance quickly recognize its slick feel and distinctive odor, which lingers even on lab gloves.
The compound weighs in at around 410.8 g/mol, and shows a boiling point well above 200 °C. Its long hydrocarbon tail gives it low solubility in water, but organic solvents like toluene, hexane, or ethanol take it in readily. You won’t find it eager to react unless the silane sees water or other nucleophiles, prompting hydrolysis and condensation. Its molecular structure promotes the formation of monolayers—a big plus for people manufacturing corrosion-resistant or anti-smudge surfaces. Shelf-stable, but gradual polymerization can occur, especially if the container gets exposed to moisture, so keeping it dry isn’t just a suggestion—it’s a must.
Labeling regulations require the CAS number 18496-94-1, the proper safety pictograms, and hazard codes for flammable and irritant materials. Typical purity for technical or research grade lands above 95%. Both suppliers and lab folk keep an eye on hydrolysable chloride limits, refractive index (about 1.430–1.435), and density (roughly 0.88–0.89 g/cm³ at 25 °C). Container labels must warn against inhalation and direct skin contact. Something to keep in mind for suppliers is the ever-tightening controls on import and transport documentation, especially across Europe or North America.
In practice, industry synthesizes N-Octadecyltriethoxysilane by reacting octadecyltrichlorosilane with ethanol in the presence of acid scavengers. This swap of ethanol for chloride might sound humdrum, but the process struggles with moisture control—too much and you end up with siloxane polymers or unwanted cross-linking. Purification calls for careful distillation; otherwise, impurities can gum up coatings or produce erratic surface morphology in downstream use. Working in a well-ventilated fume hood and using sealed glassware aren’t just best practices; they prevent headaches, both literal and figurative.
Letting N-Octadecyltriethoxysilane loose on a surface primed with hydroxyls sparks a hydrolysis/condensation dance. The ethoxy heads react with water, freeing ethanol and producing silanol groups, which then connect with a surface or self-condense into siloxane bonds. Chemists often tweak the molecule further, swapping out functional groups on the silane for tailored reactivity, or blending it with co-precursors to produce mixed-monolayer self-assembled films (SAMs). My own run-ins with it in surface chemistry taught me how just a dash can turn glass into non-stick, water-shedding barriers that last for ages.
The most common synonyms include octadecyltriethoxysilane, stearyltriethoxysilane, and 1-octadecyltriethoxysilane. On supplier catalogs, you might spot product codes like OTES or even vendor-specific house names. These aliases might confuse folks new to the field, but old hands know to double-check CAS numbers for the genuine article.
OSHA categorizes N-Octadecyltriethoxysilane as a flammable, irritant liquid. Even small exposure can produce coughing, and skin contact—especially if repeated—dries and cracks the skin. Lab safety routines include goggles, double-layered gloves, and use inside explosion-proof hoods. Emergency eyewash stations aren’t optional. I can remember a close call in a shared facility: someone stored an opened bottle near an open beaker of water, which ended with a sticky, gummed-up mess sprawled across a once-immaculate bench top. It serves as a reminder: treat the stuff with respect and stick to written safety sheets.
Everywhere you find the need for water resistance, lubricity, or low surface energy, N-Octadecyltriethoxysilane follows. In electronics, it forms protective layers over silicon wafers or MEMS devices, boosting yield by cutting stiction. Textile finishers spin yarns treated with it to ward off moisture and stains. Paint and coatings manufacturers tout it as a performance enhancer for anti-graffiti or marine coatings. Biomedical device makers depend on it for passivating glass and polymeric surfaces to limit unwanted protein or cell attachment. Research outfits use it as a model building block for atomic force microscopy calibration or surface energy experiments. Experience shows the multi-faceted nature of this molecule, with success riding on precise control of how much, where, and in what state the silane gets applied.
R&D doesn’t rest—engineers continually look for ways to wring even more potential from N-Octadecyltriethoxysilane. In surface engineering, people are hunting for routes to denser or more defect-free monolayers. In nanotechnology, it provides crucial hydrophobic patterning, and researchers test its compatibility in ever-smaller device architectures. Green chemistry advocates push for cleaner, less wasteful production, which matters not only in satisfying regulators but also in controlling costs and improving purity. I’ve seen impressive strides in analytical methods for monitoring surface modification success—XPS and ellipsometry tools have moved from luxury items to essential kit.
Nobody can afford to overlook health impacts in today’s regulatory climate. Toxicology assessments show moderate skin and respiratory hazard in concentrated form; chronic inhalation studies remain sparse, though acute exposure risks provoke prompt safety revisions in protocols. Environmental monitoring probes the fate of this compound, which tends to break down under sunlight and oxygen given enough time, but residues in soil or water could harm aquatic organisms if mismanaged. Waste disposal follows strict guidelines, with incineration or controlled chemical breakdown recommended. Continued efforts focus on non-toxic or biodegradable analogs, though they face tough competition in performance tests.
Prospects grow brighter as new technologies demand even more from surface modification chemicals. The ever-present push toward greener manufacturing could see reformulation of synthesis methods and ramping up of recycling initiatives. With the latest consumer and environmental preferences favoring durable, non-toxic coatings, more R&D dollars flow towards understanding structure–function relationships at the molecular level. If the past serves as any indicator, next-generation electronics, biointerfaces, and smart textiles will lean even harder on the performance N-Octadecyltriethoxysilane brings, so staying ahead of safety, supply chain integrity, and regulatory compliance promises to be just as important as clever molecular engineering.
In the world of chemistry, small changes can deliver big results. N-Octadecyltriethoxysilane is a good example. Folks in a lab might call it ODS or C18 silane, but what matters is what it does: it makes surfaces repel water and cling to oils. That little trick brings value, whether you’re working in electronics, coatings, or biotechnology. I remember learning about antistick coatings in college labs, seeing how a quick brush with a silane solution could turn a beaker slippery and hard to wet. Experiencing that stick-resistance firsthand taught me why chemists care about surface treatments.
Circuit boards don’t like water. Moisture can lead to short circuits, corrosion, or just accumulated gunk. A proper N-Octadecyltriethoxysilane layer puts a hydrophobic shield in place. During a stint in a local electronics company, I watched technicians dip tiny sensors in a clear silane solution as part of the assembly line. They talked about reducing returns—because a water-resistant barrier let the devices survive humid seasons in customers’ homes. Recent studies back this up, pointing to silane-treated surfaces delivering longer device life and fewer failures from oxidation.
Labs chasing purity and accuracy in pharmaceutical work rely on high-performance liquid chromatography (HPLC). Silica-based columns get ODS coatings so they hold onto oily molecules and let others pass. This method lets labs separate complex chemical mixtures. Ask anyone who’s run an analytical lab: the difference between a raw and a silane-treated column is obvious in the clarity and reliability of their results. The pharmaceutical industry uses HPLC all over the world to spot impurities. Without ODS, that work stalls out, and drug safety takes a hit.
N-Octadecyltriethoxysilane doesn't just keep water away. It forms a bridge between materials that wouldn’t normally stick together—glass fibers and plastic, for example. By creating a chemical handshake, these silanes boost the strength and durability of materials found in cars, planes, and even wind turbine blades. I’ve talked with engineers in the composites field who swear by silane “priming” as a way to cut down on failures under stress.
Working with silanes calls for care. Many are sensitive to moisture in the air. If storage and mixing aren’t controlled, the product degrades and loses effectiveness. Anyone who’s tried to coat a batch on a rainy day knows the frustration of a botched surface treatment. As safety data shows, strong ventilation and good glove use prevent skin irritation and fumes—no one likes the sting of a chemical burn. Some researchers are pushing for greener synthesis that delivers ODS in fewer steps or with less waste. Solving these challenges protects workers and the environment. Large companies monitor their emissions, and a few innovators are switching to water-based methods or recycled reagents during manufacture. Making these small shifts can keep both people and ecosystems safer, while keeping the performance everyone depends on.
N-Octadecyltriethoxysilane comes with the formula C30H64O3Si. That formula looks like a mouthful, and in many ways, it is. This molecule brings together a long carbon chain—eighteen carbons deep, straight as a stalk of grass—with a silicon atom sprouting three ethoxy groups. Chemists love shorthand, so the structure is usually written as C18H37Si(OC2H5)3. Each part of the formula tells a story about its behavior and applications.
N-Octadecyltriethoxysilane isn’t the kind of chemical that lights up headlines, but it provides quiet muscle in the world of materials science. This silane acts as a surface modifier. In practical terms, it’s used to treat surfaces so they repel water or bond more tightly with plastics, ceramics, or even fibers in clothing. I’ve seen lab folks use it on glassware to make it hydrophobic, keeping water from clinging to the surface. Everyday products, from rain-resistant windshields to the backbones of electronic circuits, owe some of their properties to surface treatments with compounds like this.
Understanding that C30H64O3Si formula isn’t just academic. It shapes the way the molecule acts out in the wild. Those eighteen carbons don’t only give it heft—they turn it into a water-hater. In turn, this fuels its use to create barriers against moisture or contamination. On the flip side, the triethoxysilane piece means it can “grab” onto siliceous surfaces. That bridges the gap between unlike materials: organic and inorganic, flexible and rigid.
The safety of chemical treatments often comes under scrutiny. Evidence from regulatory filings and published research backs up the use of N-Octadecyltriethoxysilane in controlled environments. Toxicity studies haven’t flagged major health effects at levels seen in commercial applications. Manufacturers make a point to follow safety guidelines set out by governmental agencies such as OSHA and the European Chemicals Agency, which both provide safety data sheets for proper handling. Years spent in university research labs taught me to trust—not just in the science, but in the habit of responsible stewardship.
No chemical is perfect. Uncured silane on surfaces can vaporize and linger in the air. Breath in enough of it, and irritation can follow. There’s a real need for decent ventilation and proper gloves when working with agents like this. Spill it, and it can form slick spots—potentially hazardous in a busy workspace. Industrial workers and lab students both benefit from ongoing training and the right protective gear. Being careful isn’t about paranoia; it’s about common sense and looking out for the folks down the hall.
Many of the challenges with N-Octadecyltriethoxysilane can be handled with simple, effective measures. Use the smallest amount you need. Clean up spills right away. Store bottles out of the sun and away from open flames. Engineers keep refining how surface treatments are applied, using closed systems and improved containers. Applying these habits keeps risks low and trust high—both with colleagues and the people who use the finished products every day.
Knowing the formula of N-Octadecyltriethoxysilane is more than trivia. It means getting a handle on its strengths, limitations, and place in the world around us. Practical experience and solid facts ground its usefulness. Safe handling turns that usefulness into something we can count on.
Working with chemicals like N-Octadecyltriethoxysilane brings its own set of routines. With its reputation for hydrolyzing quickly in the presence of moisture, I learned early on that leaving the container loose on the bench spells trouble. The clear liquid might not seem reactive at first glance, but even a small amount of water in the air quickly leads to cloudiness or a thick gel. That’s not just a waste of a pricey reagent—it throws off results in coatings or surface modification work.
I always tell new lab techs to approach this silane with extra care, especially compared to standard organics. Some coworkers shrug, but a ruined batch teaches the lesson. The reaction with moisture doesn’t just change viscosity; it can shoot out volatile byproducts. These aren’t something you want in your storage room or your lungs. Silane fumes can irritate nasal passages and eyes without much warning—you notice too late and regret not setting up proper ventilation.
A dry, well-ventilated storage cabinet away from direct sunlight proved critical in my experience. I always store the silane in tightly sealed original containers—usually amber glass or chemically resistant plastic. Flimsy caps or makeshift lids just don’t cut it. Some shops think a loose shrink wrap or a reused bottle gets the job done, but moisture sneaks in, and the whole batch hardens after a few weeks.
Temperature control means more than just tossing it in the back room. I keep it between 10°C and 25°C. Too cold, and you risk condensation inside the container whenever you open it. Too warm, and you get degradation byproducts forming faster. High temps ruin shelf life and could even lead to pressure buildup. Once, a supplier left a shipment in a delivery van over summer break. By the time we opened the shipment, the evidence spoke for itself: sticky residue, malformed caps, and an expensive headache.
Labels aren’t just red tape. I always check the dates and hazard information before pouring anything. Chemicals like this can look identical to safer compounds, so a careless mix-up can force an emergency cleanup. Anyone who has cleaned up an alkoxysilane spill knows how sticky things get—absorbent pads only go so far, and you need gloves, eye shields, and a real respirator. I keep neutralizing agents on hand and never assume a splash can wait until later.
Off the lab bench, in a warehouse, the rules don’t suddenly relax. Flammable goods storage rules still apply. I steer clear of areas full of acids, strong bases, or open flames. It’s not just the label that tells you “flammable”—it’s the practical reality that anything with ethoxy groups can catch or degrade if it gets the wrong neighbors. I double-check that shelves are sturdy, especially for heavy glass bottles. Walking into a storeroom littered with broken glass and sticky chemicals means extra risk and wasted money.
Each person who touches this silane in the supply chain relies on their training. I encourage regular walk-throughs and periodic checks for leaks or bottle condition. Taking shortcuts in chemical storage might save a minute, but a quick mistake carries long-term costs. A good tracking system—paper log or digital—keeps surprises to a minimum. Most of all, I talk with the team. The science advances, but the basics of safe storage never go out of style.
A lot of people look at a chemical name like N-Octadecyltriethoxysilane and see just another mouthful. In a lab or worksite, though, respect for what goes into that bottle keeps your skin, lungs, and long-term health out of trouble. If you've ever cleaned up a chemical spill without gloves and felt your hands tingle, you know what I mean—chemistry doesn’t care how careful you wish you were, only how careful you are.
N-Octadecyltriethoxysilane, a material that finds use in surface treatments, coatings, and lab research, isn’t as familiar as acetone or bleach. Yet, it packs its own risks. Contact with moisture causes it to release ethanol and turn into a sticky, difficult-to-remove substance. Inhaling the vapors or letting the liquid run across your skin can create irritation or even trigger longer-term issues. Eye exposure remains a recipe for burns and vision trouble. None of these risks show up as quickly as a sliced finger, but they dig in deep if you ignore them.
Forget shortcuts. Wear splash-proof goggles, a proper lab coat, and gloves rated to handle organic solvents. Nitrile gloves stand up to this material, while the thin latex types give a false sense of safety and break down. Fresh air matters, too—so work inside a fume hood, or at least near a vented area. I once watched someone work in a closed room; it only took one fumbled beaker for the smell to take over the space, and the headaches started piling up.
Chemical safety standards demand more than sticking a bottle on a shelf. Bottles stay sealed unless you’re measuring, and any old glass jar doesn’t cut it. This chemical reacts hard with water—you keep it away from sinks or anywhere it might dribble onto something wet. Good practice means a chemist checks the label twice, marks the opening date, and moves it if necessary to keep it out of sunlight or away from high temperatures. Oversight here adds up, and it’s often the simple things that prevent emergencies.
No one plans for spills, but everyone in a lab needs to understand their cleanup kit. I learned early to keep absorbent pads and a spill bucket nearby, not just on paper. If a few drops hit the floor or a benchtop, you surround it, soak it up with nonreactive material, and avoid water at all costs during initial cleanup. Disposal routes go through a local hazardous waste program—pouring anything down the sink ends badly for both pipes and the people downstream.
Lab life has a rhythm. Veteran chemists help newer folks by walking through the process, step by step. There’s no shame in pausing to read a safety data sheet out loud, or running through emergency eyewash drills at shift change. This mindset reduces accidents because everyone knows the routines. If someone develops a rash, or a workspace starts to smell off, action comes next—not excuses or “I’ll check on it later.”
Care around chemicals builds a foundation for safe science and work. N-Octadecyltriethoxysilane isn’t waiting for anyone to slip up—it’s up to every hand that touches it to use diligence. Simple respect here pays off with health, clean records, and zero regrets.
Every chemist faces the same puzzle at some point: can I use this compound with my favorite solvent without running into unexpected trouble? N-Octadecyltriethoxysilane—let’s call it OTS for short—makes regular appearances in labs focused on surface modification. It’s known for its long, greasy hydrocarbon chain attached to a reactive silicon atom. On paper, this structure hints at a split personality—part oil, part something much more eager to react.
OTS works beautifully for making surfaces water-hating. Toss it onto glass, ceramics, or even some metals, and the result tends to deliver a reliable anti-stick effect. I remember my first project with OTS on silica—one misstep with the solvent, and everything either gelled or stayed annoyingly unreactive.
Not all solvents play nicely with OTS. Some mishaps teach lessons fast. OTS’s three ethoxy groups react quickly in the presence of water, which means that aqueous solvents or those with even a trace of moisture end up triggering premature hydrolysis. Once that starts, your solution becomes a cloudy mess and the compound never makes it onto the surface as planned.
I’ve had great outcomes dissolving OTS in dry, non-polar solvents. Toluene and hexane stand out as safe bets—OTS slides into solution, stays stable, and does the job. Polar protic solvents like methanol and ethanol introduce trouble. OTS just won’t hang around. It breaks down, sometimes giving you a sticky goo at the bottom of the flask. Acetonitrile seems to stand in a gray zone—results vary, especially if purity isn’t watched like a hawk.
Publications back up this experience. Review articles from the Journal of Physical Chemistry and Langmuir highlight how hydrolysis kinetics depend on solvent polarity and water content. Even a tiny bit of water in dichloromethane ends up ruining an experiment. The ethoxy groups latch onto water fast, form silicic acid and ethanol, and start crosslinking before reaching the intended surface.
Some commercial claims promise OTS can dissolve well in nearly anything, but trust doesn’t come cheap in synthetic chemistry. Solvents like DMF and DMSO technically dissolve OTS, but both hold onto trace water and encourage side reactions. The outcome doesn’t bring much joy: frustrated students and wasted reagents. Even old stock bottles pick up moisture from the air, weakening OTS’s promise in practice. Discerning chemists dry their solvents and check bottles twice before setting up a reaction.
Effective lab practice comes down to simple rules: work with dry, non-polar solvents, and keep water far from your OTS stock. Desiccators, fresh solvent from a reliable still, and a no-compromise attitude toward cleanliness give the best shot at success. If something sticky or milky appears in the flask, don’t assume persistence wins—start again with fresh solvent and check purity. Manufacturers should give clearer guidance, but most learning happens through trial, error, and good notes. Replacing “universal compatibility” claims with honest limitations helps newer researchers avoid classic pitfalls.
OTS unlocks impressive surface properties, but only when treated with respect for its chemistry. Solvent choice shapes every experiment’s outcome. If in doubt, skip the shortcut—dry everything, keep protocols simple, and let the science speak for itself. Many materials in the lab demand this level of attention, yet OTS rewards it with crisp results and a shot at more ambitious projects down the road.
| Names | |
| Preferred IUPAC name | octadecyl(triethoxy)silane |
| Other names |
Octadecyltriethoxysilane Triethoxy(octadecyl)silane Stearyltriethoxysilane |
| Pronunciation | /ɛn-ɒkˈteɪdɪl-traɪˌɛθɒk.siˈleɪn/ |
| Identifiers | |
| CAS Number | 18536-91-9 |
| Beilstein Reference | 1461073 |
| ChEBI | CHEBI:52411 |
| ChEMBL | CHEMBL3988846 |
| ChemSpider | 21359772 |
| DrugBank | DB11362 |
| ECHA InfoCard | 03b44bab-0677-4da7-aad7-036d9eb46d2f |
| EC Number | 208-962-3 |
| Gmelin Reference | 1298722 |
| KEGG | C19609 |
| MeSH | D017209 |
| PubChem CID | 28822 |
| RTECS number | UC6470000 |
| UNII | ZU60S1497D |
| UN number | UN1993 |
| Properties | |
| Chemical formula | C30H64O3Si |
| Molar mass | 353.64 g/mol |
| Appearance | Colorless to pale yellow liquid |
| Odor | Odorless |
| Density | 0.86 g/mL at 25 °C(lit.) |
| Solubility in water | Insoluble |
| log P | 13.2 |
| Vapor pressure | <0.01 mmHg (25 °C) |
| Acidity (pKa) | 16.52 |
| Basicity (pKb) | pKb: 3.5 |
| Magnetic susceptibility (χ) | `-8.0E-6 cm³/mol` |
| Refractive index (nD) | 1.440 |
| Viscosity | 6 cP (25 °C) |
| Dipole moment | 2.33 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 834.2 J·mol⁻¹·K⁻¹ |
| Std enthalpy of combustion (ΔcH⦵298) | -11750 kJ/mol |
| Hazards | |
| GHS labelling | GHS02, GHS07 |
| Pictograms | GHS02,GHS07 |
| Signal word | Warning |
| Hazard statements | H315, H318, H411 |
| Precautionary statements | P261, P264, P280, P301+P312, P305+P351+P338, P330, P501 |
| NFPA 704 (fire diamond) | 1-2-0-" |
| Flash point | > 170 °C |
| Autoignition temperature | 230 °C |
| Lethal dose or concentration | LD50 (Oral, Rat): > 5000 mg/kg |
| LD50 (median dose) | LD50 (median dose): Oral, rat, > 5000 mg/kg |
| NIOSH | GNM150 |
| PEL (Permissible) | Not established |
| Related compounds | |
| Related compounds |
Octadecyltrichlorosilane Trimethoxy(octadecyl)silane Octyltriethoxysilane Hexadecyltrimethoxysilane Dimethyloctadecylchlorosilane |
