In the years since the mid-20th century, chemists have paid close attention to organosilanes, and N-Octadecylmethyldimethoxysilane came out of that focus. Its roots tie back to advances in surface chemistry and the ever-growing need for better waterproofing and functional materials. Companies in the silicone industry raced to develop new alkoxysilane derivatives, driven by the promise of durable coatings and hydrophobic surfaces. As research accelerated through the 1980s and 1990s, this compound found its way into labs working on everything from electronics to modern construction. You can trace its commercial push to a time when industries pushed hard for innovative molecular engineering, giving rise to specialty silanes and a raft of new chemical reactions that depended on precision and versatility.
This colorless to pale yellow liquid usually smells faintly sweet and feels oily to the touch. On paper, N-Octadecylmethyldimethoxysilane stands out for a long hydrocarbon chain paired with reactivity from those methoxy groups attached to silicon. In practice, chemists turn to this compound when they want long-lasting water repellency or tailored interfacial properties. The main appeal comes from a hydrophobic group that doesn’t let go and a silicon core eager to bond to all kinds of surfaces, from glass and stone to plastics and metals. It’s never just about creating a barrier; it’s about managing both the surface chemistry and durability in tough environments—outdoor facades, composite materials, and protective films.
Looking at its physical characteristics—density hovers around 0.85–0.87 g/cm³ at room temperature, with a boiling point above 340°C, and a melting point well below freezing. The molecular formula C21H46O2Si describes a heavy molecule tipped with a long tail, contributing to low water solubility and high lipophilicity. Its vapor pressure stays low, limiting evaporation under normal conditions. Once those methoxy groups meet water or alcohol, hydrolysis goes into overdrive, forming silanol groups that bond quickly to anything with active hydroxyls. With proper storage, it resists decomposition, but exposure to moisture opens the door to polymerization, releasing methanol in the process. Flammability stands as a safety concern—a flashpoint around 120°C calls for careful handling in both laboratories and industrial plants.
Commercial products usually carry a purity above 95%, pushed higher for use in electronics or biochemical applications. Labels should state the content of active silane, residual solvents, and total organic content—these numbers give engineers valuable cues on product consistency. Technical data sheets flag specific gravity values, refractive index (typically 1.43–1.45 at 20°C), and compatibility with target substrates. Companies use batch tracking and manufacturing codes—a practice that became standard after incidents of cross-contamination in the fine chemicals sector during the 1990s. The best industry practice means every container carries clear, robust hazard pictograms, shelf-life details, and recommended storage temperature (usually between 5°C and 30°C).
Alkoxysilane synthesis leans heavily on hydrosilylation technology, where hexadecene, methylchlorosilane, and methanol come together under catalytic influence—typically a platinum complex. The process generates reaction heat, demands precise metering of reagents, and produces hydrogen chloride as a byproduct. Once the primary silane forms, excess organics must be stripped off, typically by vacuum distillation, leaving a high-purity residual. Equipment design has improved over the years, focusing on solvent containment and real-time reaction monitoring, because workers learned quickly that unplanned water ingress—or stray catalysts—could turn a well-run reaction into a sticky, wasteful mess.
Its dual methoxy groups cut two ways: they allow fast hydrolysis when introduced to moist surfaces, and ready condensation for linkages with silicon dioxide, metal oxides, or other treated substrates. That’s a ticket to permanent surface modification, where the long hydrocarbon tail orients outward, creating water-resistant layers. I remember a research team using modified sand treated in this way to hold off salt leaching in concrete highways—that trick only worked because this silane locked in place before traffic or weather could strip it away. Further functionalization comes from crosslinking: given the right catalysts and a touch of heat, the molecule links with silanols to form durable networks, lending itself to polymer matrices, hybrid materials, and high-barrier films. This adaptability underpins its wide use in both industrial coatings and experimental nanomaterials.
You’ll see this compound listed under several names depending on the supplier or industry. Common synonyms include octadecyl(methyl)dimethoxysilane, dimethoxy(octadecyl)methylsilane, or even shorthand like ODMS or ODSilane. Global producers stamp their own trade names—Dow Corning, Gelest, and Wacker all market their versions with series numbers for easy cataloging. Old literature sometimes calls it C18–methyl dimethoxysilane, which can cause confusion for first-time buyers, particularly if they encounter stock from different regulatory regions or legacy applications.
Workplace safety and product stewardship have evolved with broader knowledge of silane hazards. Methanol release during hydrolysis worries anyone working in enclosed spaces, since inhalation or skin exposure brings serious health risks. Labs and production lines fit air extraction and leak monitors by default now. Operators don gloves, goggles, and face protection, using only spark-proof tools to prevent accidental ignition. Companies lay out spill response guides—ventilated areas, absorbent materials, and decontamination protocols—after lessons learned the hard way from factory spills. Regulatory labels warn explicitly against mixing with water during storage or use. The substance travels in certified drums or containers, meeting international codes for hazardous goods transport, as set out by REACH and the US Department of Transportation. Before any plant scales up, risk assessments look at cumulative toxicity, air emissions, and water runoff—part of the new baseline for chemical manufacturing.
Industrial designers turn to N-Octadecylmethyldimethoxysilane for coatings that keep glass shower screens clean, construction blocks dry, and electronic connectors free from moisture damage. In academic labs, scientists use it for stationary phase modification in gas chromatography columns—a method for separating volatile compounds with more precision and less interference from polar substrates. When polymer chemists tweak composite surfaces for better adhesion or shape memory, a thin layer of this silane steers both performance and lifetime. Textiles benefit as well; outdoor gear manufacturers use modified cotton and nylon, which resist rain but stay breathable. In nanoparticle synthesis, it provides steric barriers that prevent clumping, crucial for consistent performance in drug delivery or catalytic systems. I’ve seen startups spin up coatings for renewable energy devices, counting on stable water-repellent films to protect sensitive electronics from dirt or oxidation.
Innovation rarely moves in straight lines. Labs in Europe and East Asia invested heavily in new methods to monitor silane grafting efficiency, tweaking process chemistry so each molecule can bind perfectly to its target surface. While industry aims for faster silanization, academic collaborations push toward functionalized materials that do more than just protect—offering controlled release, conductivity, or self-cleaning capabilities. Many projects take inspiration from nature—lotus leaves, gecko feet—and utilize these silanes to recreate solid-liquid interfaces that combine repellency with selective adhesion. Research spinoffs extend to biomedical fields, where scientists search for low-toxicity surface treatments in implantable devices. Over the last five years, the literature base on hybrid nanomaterials has grown steadily, pointing to a future where this type of silane sits at the interface of manufacturing and experimental science.
Early studies overlooked hazards by focusing only on acute effects—later work found that repeated exposure can pose risks to skin, eyes, and lungs. Methanol, released during use, gets flagged as the primary metabolic toxin, with its established links to nervous system damage and blindness at high exposures. Chronic effects of the silane itself remain less clear, but real-world data points to low bioaccumulation, as the compound generally hydrolyzes and degrades in the environment. Ecotoxicity becomes an issue if disposal happens without treating byproducts or controlling runoff, especially into soil or water bodies near manufacturing sites. Toxicological profiles get routinely updated as animal models and in vitro data highlight inflammatory reactions or respiratory impacts. To cut down on accidents, industry and regulators set strict exposure limits and monitoring protocols, pushing for process containment and on-site neutralization systems.
Momentum carries this compound toward new frontiers—energy, life sciences, and consumer goods. Interest aligns not only with the push for greener, longer-lasting construction materials but also electronics with better resistance to climate stresses. Researchers eye modifications for smart packaging, biosensor coatings, and targeted nanoparticles for drug delivery, banking on the silane backbone’s flexibility. Sustainability questions loom over the horizon; manufacturers angle for silanes derived from bio-based alcohols or use closed-loop processes to cut emissions and limit hazardous waste. As the world weighs stricter chemical regulations and consumer safety, companies and scientists share the drive to document environmental impacts fully, pursue less hazardous analogs, and push the envelope in functional surface engineering.
Think about the last time you spilled water on a countertop and watched beads form instead of soaking in. Surface treatments like N-Octadecylmethyldimethoxysilane create this effect. In labs and factories, this silane isn’t just a fancy name on a label. It brings genuine change to materials by adding a water-resistant shield. I’ve seen industrial glass and ceramics ready for shipment after a quick treatment with this silane, holding up strong even under harsh cleaning regimens.
N-Octadecylmethyldimethoxysilane does a lot of the invisible heavy lifting. It bonds with glass, ceramics, fibers, and metals to create a barrier against moisture and grime. On construction sites, concrete crews have used it to keep moisture out of exposed surfaces. I walked through a new building last year and noticed rain rolling right off newly treated windows. Silanes like this don’t just stay on the surface; they connect with the material’s molecules, making the result last longer. That’s why architects and manufacturers care about the details—and not just appearance, but performance in rain, sun, and even chemical exposure.
Electronics have moved into every pocket and home, and water always poses a threat. Manufacturers in Asia showed me how they use N-Octadecylmethyldimethoxysilane to coat circuit boards, protecting crucial components from water and dust. In my work with electronics repair, I regularly see the impact of poor protection: boards covered in corrosion, repairs costing more than a replacement. Silane coatings do their job quietly, keeping sensitive equipment working longer and helping people trust their tools, devices, and cars. According to reports from the electronics industry, using these coatings has cut returns and maintenance by double-digit percentages.
New homes and solar panels need coatings that last, and maintenance-free finishes draw the eye for green builders. N-Octadecylmethyldimethoxysilane supports this demand. Producers appreciate materials that require fewer repeat applications and survive tough outdoor conditions. I’ve been part of projects aiming for LEED certification, and silane-based tech played a big part in protecting facades without harsh solvents. Market surveys show rising demand for sustainable, high-performance coatings, with analysts tracking steady growth for products built around silanes.
Every chemical in manufacturing has tradeoffs. Workers handling N-Octadecylmethyldimethoxysilane need good ventilation and personal protective equipment, because exposure can harm skin and lungs. I learned the hard way that rushing safety leads to headaches and worse. Transparent oversight matters. Regulators in Europe and the US set strict workplace limits, and popular suppliers publish detailed safety sheets. Responsible companies train their crews, invest in air-handling systems, and store chemicals properly. Smarter manufacturing starts here—real solutions come from balancing performance, cost, and safety.
People want materials that last, work under tough conditions, and protect the environment. N-Octadecylmethyldimethoxysilane answers that call in solar panels, walls, electronic gear, and more. Research keeps moving—scientists explore new silane blends that bond stronger, use less material, or biodegrade more easily. I keep an eye on startups and universities, where teams build on these older chemical building blocks to meet new challenges. Tomorrow’s coatings will run cleaner, last longer, and help everyone get more from the products they rely on every day.
Working with chemicals like N-Octadecylmethyldimethoxysilane calls for more than just a quick glance at the label. This kind of silane stands out for both its usefulness in surface treatment and its potential hazards. Many people in labs skip steps, thinking that gloves and goggles tick all the boxes. Having spent years handling organosilanes, I’ve learned those tricks run out quickly if things go wrong.
The first rule? Never go in without proper protection. Eye splashes sometimes happen before you even realize you’ve missed a droplet. Tight-fitting goggles, not just glasses, close that gap. Nitrile gloves handle incidental contact, but any chemical on skin can seep in fast. Change gloves after handling glassware labeled with the compound. Lab coats with elastic at the wrists cover more ground.
N-Octadecylmethyldimethoxysilane gives off vapors that you’ll smell at low levels. If the scent lingers, there’s a ventilation problem. Open benches won’t cut it. Fume hoods with strong airflow pull those vapors away from your lungs. Don’t lean your head too far into the hood while reaching for your flask. Breathing protection rarely becomes routine unless you’ve already had a headache or itchy nose after exposure, but disposable respirators rated for organics help during spills or long pouring sessions.
This compound burns easily, especially near open flames or heat guns used for cleaning glassware. Keep solvent bottles capped and avoid stacking too many things close to your workspace. A single spark travels fast on benchtops cluttered with paper towels, spatulas, and weighing boats. Don’t leave reaction mixtures running after hours without supervision—it’s tempting on busy days, but nighttime fire alarms wake up entire buildings.
Drips and spills happen with every bottle, especially if the pipette tip clogs. Instead of wiping with the nearest tissue, cover it with absorbent pads and sweep everything directly into a labeled waste bag. Wash the area down with lots of soap and water—not just a quick spritz of ethanol. Pouring things down the sink risks more trouble in the pipes and the environment.
Anyone splashed in the eye should head right for the eyewash and flush for at least fifteen minutes. Don’t squint and hope for the best. For bigger skin exposures, peel clothes away quickly and jump into the safety shower. People hesitate out of embarrassment or panic, yet every second counts in lowering long-term harm.
Teaching students or younger staff to respect chemicals means more than setting rules. Share real stories about close calls. Show them where the nearest exit, fire extinguisher, and safety shower stand. Don’t just assume newcomers will pick it up by osmosis. Hands-on walkthroughs stick more than printed guidelines buried in a binder.
The most seasoned chemists make plenty of mistakes before learning to respect every risk. True expertise shows through habits—not shortcuts. Relying on gloves, hoods, waste labels, and clean benches keeps everyone upright and productive. Conversations about safety carry weight when backed by real-world experience and honest care for colleagues. People soon realize that every step, no matter how tedious, matters in the long run.
N-Octadecylmethyldimethoxysilane isn’t a compound you run across in an average household, but it’s a staple for folks working in chemistry labs, manufacturing, and surface treatment businesses. This silane brings serious value as a coupling agent, creating water-repellent coatings and boosting adhesion between materials. Yet, sitting on a dusty shelf or left in a hot corner, it can turn from useful to risky. Everyone who handles it—whether in a college research department or an industrial warehouse—should treat it like a VIP guest with a few quirks.
Every bottle or drum should stay in a cool, dry location—think away from radiators, sunlight, or anywhere the temperature swings up and down all day. Heat speeds up decomposition, and moisture in the air triggers hydrolysis, which hurts both the product's shelf life and safety. My colleagues and I once had a small spill when someone left a container near a window, and the heat caused pressure to build up. That memory still puts me on edge. Storing silanes in a well-ventilated area, away from direct sources of heat, can save time, money, and even a trip to the emergency room.
Open bottles attract humidity like a magnet, so cap everything tightly after each use. Some labs use desiccators or dry cabinets when dealing with extra-sensitive silanes. Standard practice for me means always using air-tight, corrosion-resistant containers made of HDPE or other plastics that don’t react with the compound. Anyone who’s watched a cloudy film appear inside a bottle knows how fast a bad seal can ruin valuable material.
Every container should show clear, current labels. Outdated stickers, handwriting nobody can read, or missing hazard signs spell trouble. Regulatory agencies take labeling seriously, and for good reason: emergency responders—myself included once—rely on correct information during an accident. Mixing up chemicals because of a smudged label leads to dangerous mistakes.
N-Octadecylmethyldimethoxysilane reacts with water and moisture, which not only reduces efficiency but can create methanol gas. Methanol isn’t just volatile; it’s toxic and flammable, so keeping the chemical far from water sources and ignition points makes a real difference. In my experience, storing it across the room from any solvents or acids keeps everyone safer.
Chemicals age, and sometimes packaging can crack or leak before anyone notices. Regular checks for leaks or damage are just part of the routine for anybody I know who stores chemicals professionally. Absorbent spill kits, eye wash stations, and personal protective equipment—like gloves and goggles—sit close at hand, not locked away.
Even the best storage plan falls short without real training. In my early days, I made mistakes that better education could have prevented. A straightforward walkthrough goes further than a stack of printed guidelines. People remember hands-on training—where spills, exposure, and cleanup scenarios feel genuine.
Storing N-Octadecylmethyldimethoxysilane isn’t about following rules for their own sake. It means protecting health, saving resources, and keeping workflows uninterrupted. Quality storage pays off whether you manage a production line or teach a college class. It pays to treat every bottle with respect—because one shortcut often costs more than the time it saves.
N-Octadecylmethyldimethoxysilane carries a name that sounds like something straight out of a university exam, but it’s a recognizable compound once the parts fall into place. It features an octadecyl group—that’s just a long, 18-carbon chain—bonded to a silicon atom that also holds a methyl group and a pair of methoxy groups. The full chemical formula for this compound is C21H46O2Si, and the backbone consists of a silicon atom as the central hub. Lining up with that silicon, you get one methyl (–CH3), two methoxy (–OCH3), and a bulky octadecyl chain (–C18H37). Wrapped around this basic map rests most of the compound’s practical punch.
Placing such a lengthy hydrocarbon chain onto silicon flips the molecule from something common to a purpose-built tool. The octadecyl portion extends out, keeping the rest of the world at arm’s length. People in surface chemistry talk about “hydrophobicity” for a reason—long chains like this push away water. The methoxy groups, on the other hand, stay reactive, setting up all sorts of connections on glass, metal, or nanoparticles. That balance lets materials scientists lay down water-resistant coatings or play matchmaker between different materials.
Surface modification makes a lot of real-world materials work better. After treating silica particles with N-Octadecylmethyldimethoxysilane, those once-thirsty surfaces stop attracting water and instead repel it. This property changes the way pigments mix with paints, affects how powders flow, and keeps equipment free from corrosion. I’ve seen manufacturing lines seize up over clumping particles, and a proper silane treatment easily saves on downtime and cleaning hassles. Research on nanoparticle stabilization points back to compounds just like this, building longer-lasting and safer products.
Moving from theory to production, a few speed bumps show up. Handling organosilanes takes good ventilation and proper gloves, since the methoxy groups release methanol as they react. Methanol in even moderate amounts can be trouble for workers and the environment. Sometimes, incomplete bonds leave materials underperforming or surfaces uneven. Not every lab or factory operator feels comfortable tweaking reaction conditions, and cutting corners introduces risk.
Companies and labs can head off these issues. Closed reactors, good scrubbers, and careful training all keep people and places safe. Tracking emissions of methanol with reliable sensors keeps everyone ahead of trouble. Choosing the right curing agent or using well-purified silanes helps with bonding consistency, which stops problems before they reach production. Investing in well-thought-out protocols and routine checks prevents reactivity surprises and missed quality targets.
The story of N-Octadecylmethyldimethoxysilane isn’t just one of chemistry in a vacuum. It’s about how a single change to a molecule—like tacking on a long carbon chain—gives rise to everyday solutions in manufacturing, construction, and research. Attention to detail, good science, and respect for the hazards ties the whole process together.
The chemistry world likes to dig into details. Blending different silanes always brings up trust issues: will they play well together or not? Imagine N-Octadecylmethyldimethoxysilane as that one friend with a very long hydrophobic tail who also has two methoxy groups and a small methyl group on top. It handles surfaces in a unique way, giving treated materials some proper water repellency and a touch of anti-stick attitude. Folks often ask about its compatibility with other silanes. I’ve seen plenty of lab benches where this exact question popped up — people wanting to improve coating durability or get a surface treatment for glass, metal, or mineral fillers that’s a little more complex.
Everyone searching for “compatibility” probably wants to know: will my silane blend behave, or will I end up with separation, poor adhesion, or a mess in my curing process? I’ve blended N-Octadecylmethyldimethoxysilane with a bunch of other silanes on both glass and fillers in mineral-filled polymer systems. It doesn’t act hostile, but it’s not a one-size-fits-all partner. The bulky C18 tail does not appreciate too much mixing with highly reactive short-chain silanes, especially when those new to the lab forget key mixing order steps or try to add water way too early. Proper hydrolysis, for instance, makes a world of difference. Mess up the pH and moisture control — you get clumps, not a hybrid film.
Pairing with alkyltrialkoxysilanes or aminosilanes in artisan paint and coating shops tends to be easier. You can see each silane bringing something to the table, but the total outcome depends on solvent, temperature, water content, and time. Just last spring, I ran a project using this C18 silane next to an aminosilane in a polyethylene compound to adjust the hydrophobic-hydrophilic balance. With slow stirring and careful dosing, we got both to anchor to the filler. Water contact angle jumped up and pigment dispersion stayed smooth. But swap the aminosilane for a strongly acidic silane or try getting too greedy with the ratios, and all bets are off — you risk phase separation and incompatibility in storage.
Getting the mix right cuts down waste, lets you tune surface properties, and can drop production costs. Let’s not forget the rising regulations around process safety and environmental risks with any silicon chemical. Silane blends that go wrong can jam up production, create hard-to-clean waste, and even ruin equipment through uncontrolled condensation. I’ve watched companies spend double their budget fixing these mistakes. Reliable compatibility helps boost efficiency and, frankly, keeps everyone’s job easier.
Whenever I sit with a lab tech struggling to get a silane mixture to cooperate, I’ll point to some simple ground rules. Test batches in small amounts. Always control moisture and pH. Don’t assume two clear solutions mean you’re safe for storage. Monitor your blend for haze or viscosity changes over a week or two. For on-the-floor guidance, good tech sheets from trusted suppliers outline tested compatibility ranges. I rely on those documents, but I also run old-school glass plate drawdown tests or check by measuring the final contact angle.
If problems show up, often the easiest solution lies in changing the mixing sequence, using a co-solvent, or dialing back concentrations. Sometimes, it’s just about finding a silane partner with similar chain lengths or functional groups, so the interplay on the surface remains predictable. The key is paying attention to both the chemistry and the workflow realities—something no spreadsheet or product data table truly covers.
| Names | |
| Preferred IUPAC name | octadecyl(methyl)dimethoxysilane |
| Other names |
Dimethoxy(methyl)octadecylsilane Methyloctadecyldimethoxysilane n-Octadecyl(methyl)dimethoxysilane Dimethoxy(methyl)stearylsilane |
| Pronunciation | /ɛnˌɒk.stəˌdeɪ.sɪlˌmɛθ.ɪlˌdaɪˌmɛθ.ɒk.siˌsaɪ.leɪn/ |
| Identifiers | |
| CAS Number | 19327-29-6 |
| Beilstein Reference | 1462039 |
| ChEBI | CHEBI:179389 |
| ChEMBL | CHEMBL4298223 |
| ChemSpider | 21559549 |
| DrugBank | DB13955 |
| ECHA InfoCard | 19e52747-c0e4-4e0f-b756-205d8bda5263 |
| EC Number | 214-685-0 |
| Gmelin Reference | 480232 |
| KEGG | C14395 |
| MeSH | D000072638 |
| PubChem CID | 86769 |
| RTECS number | WU9990000 |
| UNII | K3913I2L3E |
| UN number | UN1993 |
| Properties | |
| Chemical formula | C20H44O2Si |
| Molar mass | 327.61 g/mol |
| Appearance | Colorless transparent liquid |
| Odor | Odorless |
| Density | 0.86 g/mL at 25 °C (lit.) |
| Solubility in water | insoluble |
| log P | 10.2 |
| Vapor pressure | <1 mmHg (20 °C) |
| Magnetic susceptibility (χ) | -6.3e-6 cm³/mol |
| Refractive index (nD) | 1.430 |
| Viscosity | 1.7 mPa·s (25 °C) |
| Dipole moment | 1.2062 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 259.6 J·mol⁻¹·K⁻¹ |
| Pharmacology | |
| ATC code | D09AX10 |
| Hazards | |
| GHS labelling | GHS02, GHS07 |
| Pictograms | GHS07,GHS08 |
| Signal word | Warning |
| Hazard statements | H315, H318, H411 |
| Precautionary statements | P210, P233, P240, P241, P242, P243, P261, P264, P271, P273, P280, P301+P310, P303+P361+P353, P304+P340, P305+P351+P338, P312, P337+P313, P370+P378, P403+P235, P405, P501 |
| NFPA 704 (fire diamond) | 1-2-0-~ |
| Flash point | > 104 °C |
| Autoignition temperature | 255 °C |
| LD50 (median dose) | LD50 (median dose): Oral, rat: > 20,000 mg/kg |
| NIOSH | GVG255 |
| PEL (Permissible) | PEL: Not established |
| REL (Recommended) | 3 mg/m3 |
| IDLH (Immediate danger) | NIOSH has not established an IDLH value for N-Octadecylmethyldimethoxysilane. |
| Related compounds | |
| Related compounds |
n-octadecyltrimethoxysilane octadecyltrichlorosilane octadecyltriethoxysilane dichloromethyl(stearyl)silane methyldimethoxyoctylsilane |
