Alkyl Chain Spacer Research Articles

Length of alkyl chain spacer modulates aggregation behavior and coordination capability of histidyl bolaamphiphiles

Length of alkyl chain spacer modulates aggregation behavior and coordination capability of histidyl bolaamphiphiles

Structural Analysis of Aggregates Formed by Linear- and Star-type Quaternary Ammonium Salt-Based Trimeric Surfactants Using Rheology and Small-Angle X-ray Scattering.

We performed a structural analysis of aggregates formed by two types of trimeric surfactants based on quaternary ammonium salts─linear-type 3Cnlin-s-Q and star-type 3Cntris-s-Q─featuring varying alkyl chain lengths (n) and spacer chain lengths (s) in aqueous solutions. We performed rheology, dynamic light scattering, and small-angle X-ray scattering measurements on the trimeric surfactants and investigated the effects of the alkyl chain length, spacer chain length, spacer skeleton structure, and surfactant concentration on their aggregation behavior. Linear-type 3C12lin-3-Q transitioned from gel solutions to worm-like micelles at high concentrations, and 3C14lin-3-Q became gel solutions over a wide range of concentrations. In contrast, all other studied surfactants formed ellipsoidal micelles. The minor and major axes of the ellipsoidal micelles formed by liner-type 3Cnlin-3-Q increased with the increasing alkyl chain length. As the spacer chain length of 3Cnlin-s-Q increased from 3 to 6, and as the spacer skeleton expanded from linear-type 3Cnlin-s-Q to star-type 3Cntris-s-Q, the surfactants formed ellipsoidal micelles without the formation of aggregates with a high-order structure, demonstrating this behavior over a broad concentration range.

Click chemistry inspired facile one-pot synthesis of mannosyl triazoles and their hemagglutination inhibitory properties: The effect of alkyl chain spacer length between the triazole and phthalimide moieties in the aglycone backbone

An efficient one-pot synthesis of a new series of mannosyl triazoles has been achieved through CuAAC reaction where the alkyl chain spacer between the phthalimide moiety and the triazole ring in the aglycone backbone is varied from one methylene to six methylene units. The target compounds were evaluated in terms of their inhibitory potency against FimH using hemagglutination inhibition (HAI) assay. It was found that the length of four methylene units was the optimum for the fitting/binding of the compound to FimH as exemplified by compound 11 (HAI = 1.9 μM), which was approximately 200 times more potent than the reference ligand 1(HAI = 385 μM). The successful implementation of one-pot protocol with building blocks 1-7 and the architecture of ligand 11 will be the subject of our future work for developing more potent FimH inhibitors.

Arginine Gemini-Based Surfactants for Antimicrobial and Antibiofilm Applications: Molecular Interactions, Skin-Related Anti-Enzymatic Activity and Cytotoxicity.

The antimicrobial and antibiofilm properties of arginine-based surfactants have been evaluated. These two biological properties depend on both the alkyl chain length and the spacer chain nature. These gemini surfactants exhibit good activity against a wide range of bacteria, including some problematic resistant microorganisms such us methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Moreover, surfactants with a C10 alkyl chain and C3 spacer inhibit the (MRSA) and Pseudomonas aeruginosa biofilm formation at concentrations as low as 8 µg/mL and are able to eradicate established biofilms of these two bacteria at 32 µg/mL. The inhibitory activities of the surfactants over key enzymes enrolled in the skin repairing processes (collagenase, elastase and hyaluronidase) were evaluated. They exhibited moderate anti-collagenase activity while the activity of hyaluronidase was boosted by the presence of these surfactants. These biological properties render these gemini arginine-based surfactants as perfect promising candidates for pharmaceutical and biological properties.

High-performance di-piperidinium-crosslinked poly(p-terphenyl piperidinium) anion exchange membranes

Anion exchange membranes (AEMs) are the core component of anion exchange membrane fuel cells (AEMFCs), among which poly(aryl piperidinium) (PAP) based AEMs have been studied. Herein, we report some scalable di-piperidinium cationic crosslinkers to enhance the mechanical properties, ionic conductivity and alkaline stability of PAP-based AEMs. The results show that the morphology of AEMs can be affected by adjusting the length of crosslinker. PTP-DPC/C6-50% shows a high OH− conductivity (80 °C, 131.2 mS cm−1) due to its microphase separation. It also has excellent elongation at break (20.8%) and tensile strength (36.5 MPa). The peak power density of the PTP-DPC/C6-50% based cell can reach 616.2 mW cm−2 under H2–O2 conditions. The crosslinked network formed by long alkyl spacer chains is helpful to improve the alkaline stability of the AEM. After alkaline stability test, the conductivity of the PTP-DPC/C10-50% membrane maintained at 92.2%.

Phase behaviour of ester-linked cyanobiphenyl dimers and fluorinated analogues: the direct isotropic to twist-bend nematic phase transition

ABSTRACT Typically, the twist-bend nematic (NTB) phase appears below the temperature of the conventional nematic (N) phase. The direct formation of the NTB phase from the isotropic (Iso) phase is significantly rare. In this study, we discovered that certain ester-linked bent-shaped dimers exhibit a direct Iso–NTB phase transition. We synthesised two homologous series of ester-linked cyanobiphenyl-based dimers (COOn) and their fluorinated analogues (F-COOn) containing different numbers of carbon atoms (n) in the alkyl spacer chains (n = 3, 5, 7, 9, 11, and 13). The phase transitions of these dimers were investigated using polarised optical microscopy and differential scanning calorimetry. The long-spacer COOn (n = 7, 9, 11, and 13) exhibited the usual Iso–N–NTB phase sequence, whereas the short-spacer COOn (n = 3 and 5) showed the direct Iso–NTB phase transition. Lateral fluorination significantly reduced the phase-transition temperatures for F-COOn compared to COOn. The short-spacer F-COOn (n = 3 and 5) did not exhibit any liquid crystal phases. The F-COOn with longer spacers (n = 9, 11, and 13) displayed the Iso–N–NTB sequence, whereas F-COO7 showed the direct Iso–NTB transition. Additionally, we analysed a single-crystal structure of F-COO7 to investigate its molecular conformation and superimposition.

Study on the partially cross-linked poly(styrene-b-(ethylene-co-butylene)-b-styrene) anion exchange membrane remotely (spaced hexyl) grafted double cation separated by different alkyl groups

In order to improve the alkali stability and OH− conductivity of Poly (styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS)-based anion exchange membranes (AEMs), double cations with different alkyl intervals are remotely grafted onto the SEBS skeleton with hexyl as a linker through reactions such as acylation and ketone reduction. Then, SEBS-0.8Cn-0.2C6 cross-linked membranes were prepared to study the effect of the length of the alkyl chain between the dications on the ion transport and other properties. The OH− conductivity of SEBS-0.8C4-0.2C6 cross-linked membrane can reach 85.27 mS cm−1 at 80 °C, and the peak power density can reach 225 mW cm−2 at a current density of 450 mA cm−2. As the dicationic spacer alkyl chains became longer, the swelling rate and water uptake of the membranes increased, resulting in significant improvements in mechanical properties and chemical stability. After soaking in 2 M NaOH solution at 80 °C for 1200 h, the conductivity of SEBS-0.8C6-0.2C6 decreased by only 5.76%. Optimizing the side chain structure of SEBS skeleton can effectively improve the comprehensive performance of AEM.

Electrorheological effect and dielectric properties of Poly(ionic liquid) microspheres with different length of alkyl chain spacer between ion pair and backbone

Imidazolium-based poly(ionic liquid) analogues having different lengths of alkyl chain spacer between ion pair and backbone, named as P[ECnVim][PF6] (n = 2, 3, 6), were synthesized. Then, P[ECnVim][PF6] were transformed into microspheres by an evaporation-induced phase separation method. The influence of the length of alkyl chain spacer on the electro-responsive electrorheological effect and dielectric property of P[ECnVim][PF6] microsphere suspensions were studied. It showed that as the length of alkyl chain spacer increased, the electrorheological effect increased but the working temperature range of electrorheological effect became narrow. By combining dielectric spectra analysis and activation energy measurement, it was clarified that the influence of the length of alkyl chain spacer on electrorheological effect was mainly associated with the change of ionic conductivity and interfacial polarization, which was further related to the change of elastic potential energy of ion motion in P[ECnVim][PF6] with different lengths of alkyl chain spacer between ion pair and backbone. However, the working temperature range of electrorheological effect depended on the change of glass transition temperature with the length of alkyl chain spacer. The result provides the structure-property relationship insight for the design of poly(ionic liquid)-based electro-responsive electrorheological materials.

Fouling Resistance and Release Properties of Poly(sulfobetaine) Brushes with Varying Alkyl Chain Spacer Lengths and Molecular Weights

We examined the effects of alkyl carbon spacer length (CSL) and molecular weight on fouling resistance and release properties of zwitterionic poly(sulfobetaine methacrylate) brushes. Using surface-initiated atom transfer radical polymerization, we synthesized two series of brushes with CSL = 3 and 4 and molecular weight from 19 to 1500 kg ·mol-1, corresponding to dry brush thickness from around 6 to 180 nm. The brush with CSL = 3 was nearly completely wet with water (independent of molecular weight), whereas the brush with CSL = 4 exhibited a strong increase in water contact angle with molecular weight. Though the two-brush series had distinct wetting properties, both series of brushes exhibited similarly great resistance against fouling by Staphylococcus epidermidis bacteria and Aspergillus niger fungi spores when submerged in water, indicating that neither molecular weight nor CSL strongly affected the antifouling behavior. We also compared the efficacy of brushes against fouling by fungi and silicon oil in air. Brushes grafted to filter paper were strongly fouled by fungi and silicon oil in air. Grafting the polymers to the filter paper, however, greatly enhanced removal of the foulant upon rinsing. The removal of fungi and silicon oil when rinsed with a salt solution was enhanced by 219 and 175%, respectively, as compared to a blank filter paper control. Thus, our results indicate that these zwitterionic brushes can promote foulant removal for dry applications in addition to their well-known fouling resistance in submerged conditions.

Surface adsorption and bulk properties of polyoxyethylene–polyoxypropylene random copolymer-type double-chained surfactants in quaternary-ammonium-salt-type amphiphilic gemini ionic liquids

Recently, a few studies have been reported on the layer structure of ionic liquids using X-ray and neutron scattering. However, the nanostructural features of ionic liquids remain unclear. Herein, the surface adsorption and bulk properties of polyoxyethylene (EO)–polyoxypropylene (PO) decyl tetradecyl ether-type nonionic surfactants (C10-C12POxranEO24PO13−x, where x represents the length of the PO chain linked to alkyl chains; x = 0, 5, 8, and 13) in quaternary-ammonium-salt-type amphiphilic gemini ionic liquids containing oxygen or nitrogen in the spacer (2C12(Spacer) NTf2, where (Spacer) = (2-O-2), (2-O-2-O-2), (2-N-2), (2/2-N-2), and n represents the alkyl chain length; n = 10, 12, and 14 for the 2-O-2 spacer, and n = 12 for all others) are elucidated by surface tension, small- and wide-angle X-ray scattering, and viscosity measurements. The surface tension of the C10-C12POxranEO24PO13−x surfactants in the gemini ionic liquids containing oxygen in the spacer increased as the surfactant concentration increased, and it became comparable to that of C10-C12POxranEO24PO13−x alone, indicating that the gemini ionic liquid adsorbed at the air–liquid interface was replaced with C10-C12POxranEO24PO13−x following its addition. In the bulk, 2Cn(Spacer) NTf2 and C10-C12POxranEO24PO13−x formed a layered structure, and the layer spacing depended on the alkyl chain length and spacer structure of the gemini ionic liquid and the length of the PO chain linked to the alkyl chains of the surfactants.

Effect of spacer alkyl chain length on retention among three imidazolium stationary phases under various modes in high performance liquid chromatography

The properties of ionic liquids (ILs) greatly influenced the retention of solutes on IL-functionalized stationary phases. In this work, three IL-functionalized stationary phases (Sil-C4Im, Sil-C7Im, and Sil-C10Im) were prepared by modifying silica gel with three ionic liquid silane reagents differing in spacer alkyl chain lengths, which refers to the alkyl chain between the imidazolium and the sulfur atom. The preparation was proved through a range of characterization techniques, including elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). The effects of chromatographic conditions, such as acetonitrile content, salt concentration, pH, and column temperature, were studied to explore the retention mechanism of three stationary phases, which indicates that three IL-stationary phases provide interactions with solutes in reverse-phase liquid chromatography (RPLC), hydrophilic interaction liquid chromatography (HILIC), and ion exchange chromatography (IEC). The column efficiency is 83,686 plates/m for aminobenzoic acid, and the column also has excellent repeatability of retention time with relative standard deviations (RSDs) between 0.24% and 0.34% (n = 12). A variety of analytes, including five nucleosides and nucleobases, six alkylbenzenes, two polycyclic aromatic hydrocarbons (PAHs), and four inorganic anions, were separated well on three IL-functionalized stationary phases. It was found that the spacer alkyl chain length influenced selectivity by comparing the retention of the three IL-functionalized stationary phases.

Lophine-cinnamoyl hybrids: Synthesis, photophysical properties and a spectroscopic and molecular dynamics approach towards interactions with bovine serum albumin

Lophine and cinnamic acid derivatives have gained considerable attention due their chemical, biological and fluorescence emission properties. Herein we reported the synthesis of a new family of lophine-cinnamoyl hybrids connected by a methylene chain with two to nine carbon atoms. The hybrids show absorption in the ultraviolet and emission in the blue-violet region independent of the length of the alkyl chain spacer. Non-covalent interactions of the hybrids to bovine serum albumin (BSA) were investigated by UV–Vis absorption and fluorescence spectroscopy. Overall, the hybrids display moderate affinities for BSA (binding constants in the range 10–14 × 104 M−1) and can be effectively employed as protein probes using BSA as a model. The theoretical calculations showed preferential interactions of the hybrids with the binding pocket located near to Trp213 and the number of binding sites equal to 1 are in agreement with the experimental data obtained through the Stern-Volmer approach.

Effect of Molecular Structure of Photoswitchable Surfactant on Light-Responsive Shape Transition of Block Copolymer Particles

Photoactive shape-changing particles offer a promising platform for smart materials with tunable properties at high spatiotemporal resolutions. Herein, a series of spiropyran-based surfactants with different alkyl spacer lengths are developed to achieve photoactive, shape-changing particles through confined self-assembly of polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) within an evaporative emulsion. The length of the alkyl chain spacer between the spiropyran headgroup and ionic chain-end is modulated from hexyl to ethyl decanoate to provide surfactants with tunable amphiphilicity. Under UV light, the hydrophilic ring-opened merocyanine surfactants produce onion-like microspheres with a P4VP surface. Conversely, by exposure to visible light, the ring-closure reaction of the spiropyran moieties shifts their hydrophobicity and yields striped ellipsoids with axially stacked PS and P4VP blocks. This sphere-to-ellipsoid transition is observed only for surfactants that contain spacers longer than or equal to octyl. The effects of photoswitchable surfactants on their interfacial properties and corresponding morphological evolution of the particles are investigated to elucidate the mechanism of the shape transition of the photoactive particles.

Improved performance of vanadium redox flow battery with tuneable alkyl spacer based cross-linked anion exchange membranes

We synthesize cross-linked aliphatic polymer with side chain grafted imidazole based anion exchange membranes (AEMs) using alkyl chain spacer. Prepared AEMs exhibit excellent stabilities, ionic conductivity, and vanadium ion impervious nature. These AEMs with rigid polymer matrix show low swelling ratio in spite of high molality of exchangeable functional groups. Cross-linked methylmethacrylate-co-vinyl imidazole copolymer (CMVI) with C3 spacer (CMVI-C3) possess 1.21 meq/g ion exchange capacity, and 8.1 × 10−2 S/cm conductivity. Well optimized CMVI-C3 AEM shows extremely low VO2+ permeability (1.96 × 10−9 cm2 s−1) in comparison to Nafion 117 (16.34 × 10−9 cm2 s−1), due to blocking property of CMVI AEMs for VO2+. At 120.0 mA cm−2, relatively high Coulombic (98.8%), energy (78.2%), and voltage (80.5%) efficiencies of CMVI-C3 AEM in comparison with Nafion 117 membrane, has been attributed to synergetic balance between hydrophobic and hydrophilic segments. The CMVI-C3 AEM maintains the high performance and good integrity during in-situ VRFB cycle performance assessment up to 200 cycles. Simple method for the preparation, good stabilities, and high performance are attractive features of CMVI-C3 AEM for vanadium redox flow battery.

Increasing donor-acceptor spacing for reduced voltage loss in organic solar cells

The high voltage losses ({V}_{{loss}}), originating from inevitable electron-phonon coupling in organic materials, limit the power conversion efficiency of organic solar cells to lower values than that of inorganic or perovskite solar cells. In this work, we demonstrate that this {V}_{{loss}} can in fact be suppressed by controlling the spacing between the donor (D) and the acceptor (A) materials (DA spacing). We show that in typical organic solar cells, the DA spacing is generally too small, being the origin of the too-fast non-radiative decay of charge carriers ({k}_{{nr}}), and it can be increased by engineering the non-conjugated groups, i.e., alkyl chain spacers in single component DA systems and side chains in high-efficiency bulk-heterojunction systems. Increasing DA spacing allows us to realize significantly reduced {k}_{{nr}} and improved device voltage. This points out a new research direction for breaking the performance bottleneck of organic solar cells.

Lowering Electrocatalytic CO2 Reduction Overpotential Using N-Annulated Perylene Diimide Rhenium Bipyridine Dyads with Variable Tether Length

We report the design, synthesis, and characterization of four N-annulated perylene diimide (NPDI) functionalized rhenium bipyridine [Re(bpy)] supramolecular dyads. The Re(bpy) scaffold was connected to the NPDI chromophore either directly [Re(py-C0-NPDI)] or via an ethyl [Re(bpy-C2-NPDI)], butyl [Re(bpy-C4-NPDI)], or hexyl [Re(bpy-C6-NPDI)] alkyl-chain spacer. Upon electrochemical reduction in the presence of CO2 and a proton source, Re(bpy-C2/4/6-NPDI) all exhibited significant current enhancement effects, while Re(py-C0-NPDI) did not. During controlled potential electrolysis (CPE) experiments at Eappl = -1.8 V vs Fc+/0, Re(bpy-C2/4/6-NPDI) all achieved comparable activity (TONco ∼ 25) and Faradaic efficiency (FEco ∼ 94%). Under identical CPE conditions, the standard catalyst Re(dmbpy) was inactive for electrocatalytic CO2 reduction; only at Eappl = -2.1 V vs Fc+/0 could Re(dmbpy) achieve the same catalytic performance, representing a 300 mV lowering in overpotential for Re(bpy-C2/4/6-NPDI). At higher overpotentials, Re(bpy-C4/6-NPDI) both outperformed Re(bpy-C2-NPDI), indicating the possibility of coinciding electrocatalytic CO2 reduction mechanisms that are dictated by tether-length and overpotential. Using UV-vis-nearIR spectroelectrochemistry (SEC), FTIR SEC, and chemical reduction experiments, it was shown that the NPDI-moiety served as an electron-reservoir for Re(bpy), thereby allowing catalytic activity at lower overpotentials. Density functional theory studies probing the optimized geometries and frontier molecular orbitals of various catalytic intermediates revealed that the geometric configuration of NPDI relative to the Re(bpy)-moiety plays a critical role in accessing electrons from the electron-reservoir. The improved performance of Re(bpy-C2/4/6-NPDI)dyads at lower overpotentials, relative to Re(dmbpy), highlights the utility of chromophore electron-reservoirs as a method for lowering the overpotential for CO2 conversion.

Design, Synthesis, and Cytotoxicity Assessment of [64Cu]Cu-NOTA-Terpyridine Platinum Conjugate: A Novel Chemoradiotherapeutic Agent with Flexible Linker.

Maximum benefits of chemoradiation therapy with platinum-based compounds are expected if the radiation and the drug are localized simultaneously in cancer cells. To optimize this concomitant effect, we developed the novel chemoradiotherapeutic agent [64Cu]Cu-NOTA-C3-TP by conjugating, via a short flexible alkyl chain spacer (C3), a terpyridine platinum (TP) moiety to a NOTA chelator complexed with copper-64 (64Cu). The decay of 64Cu produces numerous low-energy electrons, enabling the 64Cu-conjugate to deliver radiation energy close to TP, which intercalates into G-quadruplex DNA. Accordingly, the in vitro internalization kinetic and the cytotoxic activity of [64Cu]Cu-NOTA-C3-TP and its derivatives were investigated with colorectal cancer (HCT116) and normal human fibroblast (GM05757) cells. Radiolabeling by 64Cu results in a >55,000-fold increase of cytotoxic potential relative to [NatCu]Cu-NOTA-C3-TP at 72 h post administration, indicating a large additive effect between 64Cu and the TP drug. The internalization and nucleus accumulation of [64Cu]Cu-NOTA-C3-TP in the HCT116 cells were, respectively, 3.1 and 6.0 times higher than that for GM05757 normal human fibroblasts, which is supportive of the higher efficiency of the [64Cu]Cu-NOTA-C3-TP for HCT116 cancer cells. This work presents the first proof-of-concept study showing the potential use of the [64Cu]Cu-NOTA-C3-TP conjugate as a targeted chemoradiotherapeutic agent to treat colorectal cancer.

Influence of Alkyl Chain Spacer Length on the Charge Carrier Mobility of Isotactic Poly(N-carbazolylalkyl acrylates).

In the search for semiconducting polymer alternatives to conjugated polymers, stereoregular nonconjugated pendant electroactive polymers (NCPEPs) have recently shown competitive hole mobilities with conjugated polymers and a dramatic increase in mobility relative to atactic analogues. Here we investigate one of the key structural variables of NCPEPs: the flexible alkyl spacer that separates the electroactive pendant from the backbone. We investigate a straightforward postpolymerization functionalization synthetic method to synthesize such polymers with high isotacticity using poly(N-carbazolylalkyl acrylate) as a model system, where the alkyl chain spacer in the NCPEPs is varied from 2 to 12 carbons. We observed that the hole mobility increased from the two-carbon spacer, resulting in the highest mobility upon thermal annealing with a four-carbon spacer for 75% isotactic polymers and with a six-carbon spacer for 87% isotactic polymers. As such, we have demonstrated an important role of the spacer chain in influencing mobility. For all spacer lengths, higher mobilities were measured with the more isotactic polymer. While physical characterization of the largely amorphous polymers yielded little insight into the structure-function relationships, DFT and MD simulations indicated helical structures for the polymers where intermolecular short-range π-stacking is observed and is affected by spacer chain length. This work demonstrates that both the degree of stereoregularity and the spacer chain length play a role in determining the hole mobility in NCPEPs.

Antimicrobial and Toxicity Evaluation of Imidazolium-Based Dicationic Ionic Liquids with Dicarboxylate Anions.

Imidazolium-based dicationic ILs (DILs) presenting antimicrobial activity and relatively low toxicity are highly desirable and are envisioned for use in live tissue to prevent bacterial or fungal infections. In this context, we present here DILs with dicarboxylate anions [Cn(MIM)2[Cn(MIM)2][CO2-(CH2)mCO2], in which n = 4, 6, 8, and 10, and m = 0, 1, 2, 3, 4, and 5. The results showed that DILs with an alkyl chain spacer of ten carbons were active against yeasts and the bacterial strains tested. However, most of the DILs were cytotoxic and toxic at 1 mM. By contrast, DILs with alkyl chains possessing less than ten carbons were active against some specific Candidas and bacteria (mainly S. aureus), and they showed moderate cytotoxicity. The best activity against Gram-positive bacteria was observed for [C4(MIM)2][Pim] toward MRSA. For the DILs described herein, their level of toxicity against C. elegans was lower than that of most of the mono- and dicationic IL analogs with other anions. Our results showed that the presence of carboxylate anions reduces the toxicity of DILs compared to DILs containing halide anions, which is particularly significant to the means of designing biologically active compounds in antimicrobial formulations.

Effect of dicationic ionic liquids on cloud points of tergitol surfactant and the formation of aqueous micellar two-phase systems

A cloud point evaluation was performed for the nonionic surfactant Tergitol 15-S-7 in aqueous solutions of McIlvaine buffer (pH 7.0). Cloud point temperatures of the selected nonionic surfactant were studied in relation to the effect that the addition of dicationic ionic liquids (ILs) had on the systems. The dicationic ILs with different alkyl spacer lengths were derived from 1, n-bis(3-methylimidazolium-1-yl)alkane bromide ([BisAlk(MIM)2][2Br]) — in which Alk = But, Hex, Oct, and Dec. The dicationic ILs with longer alkyl spacer chains (Alk ≥ 6) led to an increase in the Tergitol’s cloud point values, due to their ability to fold their structures in solution, which increase the interactions of ILs with tergitol in the mixed micelles. This increase was even more pronounced when the concentration of the dicationic ILs was increased. Furthermore, the addition of dicationic ILs increased the micelles size; however, the hydrodynamic diameter of mixed micelles did not depend on the length of the ILs’ alkyl spacer chains. The Tergitol/IL systems with lower critical micellar concentration values will result in higher cloud point values, due to the greater colloidal dispersion stability.