Frequently Asked Questions
What alkyl chain length is best for ionic liquid electrolytes?
Short chains – C2 (ethyl) or C3 (propyl) – are optimal for electrolyte applications. At these lengths, nonpolar nanodomains remain small and disconnected, preserving fast ion transport and high ionic conductivity. Moving from C2 to C8 within the imidazolium TFSI series can reduce conductivity by roughly half.
What purity grades does RoCo® offer for imidazolium-TFSI ionic liquids?
Most CnMIM-TFSI products are available in three grades: HP (>99%, suitable for most synthesis and screening work), UP (>99.5%, for electrochemistry and analytical applications where trace halides matter), and OP (>99.9%, for battery electrolytes and high-end research). Grade selection depends on whether residual chloride or water will affect your results — the applications team can advise.
What are typical lead times for ionic liquid orders?
In-stock SKUs from the RoCo® catalog typically ship within 3-5 business days from U.S. inventory. Custom synthesis and bulk quantities are quoted on request; as a North American distributor of IoLiTec, RoCo® can also source the broader IoLiTec catalog with reduced transit time compared to direct European import.
Can I order imidazolium-TFSI ionic liquids in kilogram quantities?
Yes. Most catalog SKUs are listed in gram quantities online, but kilogram and multi-kilogram orders are available on request for scale-up and pilot work. Contact the applications team for pricing and lead time on quantities above the listed catalog sizes.
At what chain length does nanostructuring appear in imidazolium ionic liquids?
Nanostructuring becomes experimentally detectable by small-angle X-ray scattering at C4 (butyl). Below C4, the liquid appears structurally homogeneous. At C4, a broad diffraction peak emerges, and by C6 through C10 the peak sharpens progressively, indicating well-defined polar and nonpolar nanodomains.
Why do longer alkyl chain ionic liquids have higher viscosity?
Van der Waals interactions between alkyl chains within the nonpolar nanodomains are the primary driver. As chains lengthen, they entangle and interdigitate within these domains, resisting flow. Viscosity in the imidazolium TFSI series can increase by an order of magnitude between C2 and C10.
Which ionic liquid chain length is best for lubrication?
C6 to C8 is the practical optimum for most lubrication applications. At these lengths, the bicontinuous sponge-like nanostructure is fully developed, enabling thick, ordered adsorbed films at metal surfaces. Longer chains produce more robust films but at the cost of higher viscosity and more difficult handling.
Does the anion affect ionic liquid nanostructure?
The anion has minimal effect on nanoscale domain spacing. Triolo et al. showed that chloride, tetrafluoroborate, and hexafluorophosphate salts produce nearly identical domain spacings for the same cation chain length. The anion occupies the polar domain and influences local packing but does not drive the nanoscale segregation, which is controlled by alkyl chain aggregation.
What happens to ionic liquid structure above C12?
Beyond approximately C12, many ionic liquids begin forming ordered lamellar or smectic phases resembling liquid crystals. Melting points, which initially decrease with chain length, begin rising again past C10 as van der Waals cohesion between chains dominates. These materials may no longer behave as free-flowing isotropic liquids at room temperature.