Effect Of Alkyl Chain Length Research Articles

Effect of Variations in the Alkyl Chain Lengths of Self-Assembled Monolayers on the Crystalline-Phase-Mediated Electrical Performance of Organic Field-Effect Transistors.

Self-assembled monolayers (SAMs) of organic molecules are frequently employed to improve the electrical performance of organic field-effect transistors (OFETs). However, the relationship between SAM properties and OFET performance has not been fully explored, leading to an incomplete understanding of the system. This study investigates the effect of the SAM alkyl chain length on the crystalline phase of pentacene films and OFET performance. Two types of SAMs—with alkyl chain lengths of 10 (decyltrichlorosilane, DTS) and 22 (docosyltrichlorosilane, DCTS)—were examined, and variations in the performance of pentacene-based OFETs with the nature of the SAM treatment were observed. Despite the similar surface morphologies of the pentacene films, field-effect mobility in the DCTS-treated OFET was twice that in the DTS-treated OFET. To find the reason underlying the dependence of the OFET’s electrical performance on the SAM alkyl chain length, X-ray diffraction measurements were conducted, followed by a phase analysis of the pentacene films. Bulk and thin-film phases were observed to coexist in the pentacene film grown on DTS, indicating several structural defects in the film; this can help explain the dependence of the OFET electrical performance on the SAM alkyl chain length, mediated by the different crystalline phases of pentacene.

Densities and viscosities of (ethylene glycol - water) and (1,3-propanediol - water) binary mixtures at high temperatures of 373.2 and 473.2 K and high pressures up to 40 MPa

Densities and viscosities of ethylene glycol - water and 1,3-propanediol - water binary mixtures have been measured over the whole composition range at 373.2 K and 473.2 K and at pressures up to 40 MPa. The excess molar volumes combined with partial molar volumes, and viscosity deviations have been calculated from the measurement data. The activation Gibbs free energy of viscous flow has been also evaluated from the density and viscosity data. These results were compared with the previously reported results of the monohydric alcohol - water mixtures with the same carbon numbers to discuss the effect of hydroxyl group and alkyl chain length on these properties in the wide range of temperature and pressure. The physical properties of the alcohol - water mixtures were strongly influenced by the molecular structure of the alcohol molecules under the studied conditions. In particular, the excess molar volumes and viscosity deviations showed very different behaviors for monohydric and dihydric alcohol - water mixtures.

Effect of alkyl chain length and temperature on volumetric, acoustic and apparent molar properties of pyrrolidinium based ionic liquids in acetonitrile

Detailed analysis of volumetric and acoustic properties of the dilute solution of ionic liquids (ILs) and acetonitrile play a significant role in the potential engineering field and process design. Moreover, these studies can provide relevant knowledge about the types and scope of the intermolecular interactions governed between the solute and solvent. In this work, three iodide based pyrolidium ILs, i.e. 1-butyl-1-methyl pyrrolidinium iodide, [BMPY]I and 1-methyl-1-pentyl pyrrolidinium iodide, [PeMPY]I and 1-hexyl-1-methyl pyrrolidinium iodide, [HMPY]I were synthesized and studied their density and sound velocity in acetonitrile as a function of molality in the range of 0.05–0.4 mol·kg−1 and temperature in the range from 293.15 to 328.15 K at atmospheric pressure. The impact of chain length of cation and temperature were premeditated by using well-known volumetric and acoustic factors. In addition, by employing the experimental data, the apparent molar volume (Vϕ), apparent molar isentropic compression (Ks,ϕ), and limiting apparent molar expansion (Eφ∞) were calculated. Further, the apparent molar properties at infinite dilution were examined by using Redlich-Mayer type equations. Furthermore, measured and calculated properties have been analysed to understand the solute-solvent interaction in studied systems. For the studied systems, infinite dilution apparent molar properties were increased with cationic chain length on the ILs, however, decreased with temperature.

Comments on “Effect of alkyl chain length of 1-alkanols on solution behavior of bactericidal antibiotic in terms of thermo-acoustic parameters”

A polemic is given concerning the volumetric properties for fosfomycin calcium dissolved in 1-alkanol mono-solvents reported in the published paper by Naseem. The author’s measured densities and apparent molal volumes are not consistent with values given in the published study.

Thermo-physical and tribological characteristics of ionic liquid-based rice bran oil as green cutting fluid

During machining, the cutting fluids play an essential role in cooling and lubrication. In order to reduce the friction forces, the excessive amount of the cutting fluids are generally used. This, in turn, leads to wastage of the cutting fluids which results in a serious impact on the environment, health and cost of production. Therefore, the judicious use of lubricants is the foremost concern in the manufacturing industry. In order to mitigate these drawbacks, various alternatives have been developed in the last decade. In the present paper, ionic liquids have been proved as favourable sustainable alternative additives in the base oil. The effect of alkyl chain length of ionic liquids with base oil on the thermo-physical and tribological characteristics of cutting fluids including viscosity, wettability, anticorrosion behaviour, thermal stability, and coefficient of friction have been analysed. In the present study, pyrrolidinium and hexafluoro-phosphate (PF6) have been used as cation and anion, respectively, with rice bran oil as base oil. The five different ionic liquids have been dispersed in base oil by 1.0 wt%. It has been found that longer alkyl chain length showed the favourable results as compared to the shorter one. Results indicated that ionic liquid based cutting fluid attained ample enhanced thermophysical and tribological properties as compared to the neat rice bran oil. There has been 5.08% and 4.29% improvement in viscosity and thermal conductivity for IL4 + RBO in comparison to neat RBO. In addition, the wettability, coefficient of friction, and wear volume have been reduced by 20.34%, 53.79% and 57.87% correspondingly.

Effect of alkyl chain length and halide ions on the corrosion inhibition potential of imidazolium and pyridinium based ionic liquids: Computational studies

In the present investigation, thirty imidazolium and pyridinium based ionic liquids are undertaken for DFT based computational study to demonstrate the anticorrosive potential. Results showed that imidazolium and pyridinium based ionic liquids act as effective anticorrosive materials and their corrosion inhibition performance depends on the nature of alkyl groups and halide ions. Among the studied imidazolium based ionic liquids, 3-octyl-1H-imidazol-3-ium chloride (IM-C8-Cl), 3-hexadecyl-1H-imidazol-3-ium bromide (IM-C16-Br) and 3-butyl-1H-imidazol-3-ium iodide (IM-C4-I) behave as the best among the chloro, bromo and iodide substituted imidazolium based ionic liquids, respectively. In the pyridinium based ionic liquids, 1-hexadecylpyridin-1-ium chloride (Pyr-C16-Cl), 1-dodecylpyridin-1-ium bromide (Pyr-C12-Br) and 1-octylpyridin-1-ium iodide (Pyr-C8-I) act as the best corrosion inhibitors among the chloro, bromo and iodide substituted pyridinium based ionic liquids, respectively. Adsorption behavior of pyridinium and imidazolium based ionic liquids and corrosion inhibition using them has also been proposed in the present study.

Alkyl Chain Length Effects of Imidazolium Ionic Liquids on Electrical and Mechanical Performances of Polyacrylamide/Alginate-Based Hydrogels.

Conductive hydrogels with stretchable, flexible and wearable properties have made significant contributions in the area of modern electronics. The polyacrylamide/alginate hydrogels are one of the potential emerging materials for application in a diverse range of fields because of their high stretch and toughness. However, most researchers focus on the investigation of their mechanical and swelling behaviors, and the adhesion and effects of the ionic liquids on the conductivities of polyacrylamide/alginate hydrogels are much less explored. Herein, methacrylated lysine and different alkyl chain substituted imidazole-based monomers (IMCx, x = 2, 4, 6 and 8) were introduced to prepare a series of novel pAMAL-IMCx-Ca hydrogels. We systematically investigated their macroscopic and microscopic properties through tensile tests, electrochemical impedance spectra and scanning electron microscopy, as well as Fourier transform infrared spectroscopy, and demonstrated that an alkyl chain length of the IMCx plays an important role in the designing of hydrogel strain sensors. The experiment result shows that the hexyl chains of IMC6 can effectively entangle with LysMA through hydrophobic and electrostatic interactions, which significantly enhance the mechanical strength of the hydrogels. Furthermore, the different strain rates and the durability of the pAMAL-IMC6-Ca hydrogel were investigated and the relative resistance responses remain almost the same in both conditions, making it a potential candidate for wearable strain sensors.

Carboxylate functionalized imidazolium-based zwitterions as benign and sustainable solvent for cellulose dissolution: Synthesis and characterization

Cellulose is most abundant biopolymer on earth and can be utilized as sustainable resources for many applications, however, their utilization at great extent is limited due to lack of benign and recyclable solvent. While N-methylmorpholine-N-oxide (NMMO), used in Lyocell process, is thermally unstable and may undergoes runaway conditions, commercialization of ionic liquid as solvent still suffers from recyclability issues. Herein, we present the synthesis of a series of zwitterions, composed of tethered alkyl imidazolium cation and carboxylate anion, and investigated their cellulose dissolution characteristics. Effect of alkyl chain length of imidazolium ring on its dissolution efficiencies was studied and amongst synthesized zwitterions, the hexanoate derivatives exhibited 13% (w/w) cellulose dissolution at 100–125 °C. Thermal stability of zwitterions and their cellulose solution was characterized by DSC-TGA and found to be more stable than the NMMO and Lyocell solution. Rheological studies indicate that cellulose solution in zwitterions are viscoelastic and in spinnable range of fibre processing. Structural and morphological characterization of regenerated cellulose using elemental analysis, FTIR, DSC-TGA, GPC, XRD and SEM showed that zwitterions have no adverse effect on its physicochemical and morphological properties. A method for recovery and purification of solvent after cellulose dissolution and regeneration is also presented.

Synthesis and characterization of alkyl-methacrylate-maleic anhydride copolymer for use as a biodiesel flow improver

Methacrylic acid was esterified with four alcohols: 1-decanol, 1-dodecanol, 1-tetradecanol, and 1-cetanol. Afterwards, the obtained monomers were copolymerized with maleic anhydride. The synthesized monomers and copolymers were characterized by 1H-NMR (Nuclear magnetic resonance) and Fourier transform infrared (FTIR) spectroscopy. The ability of the obtained copolymers to reduce the pour point of waste cooking oil-based biodiesel was investigated. The results showed that the polymer additive with the alkyl chain C14H29- demonstrated the best flow improvement performance. At a concentration of 1000 ppm, this polymer additive reduced the pour point of waste cooking oil-based biodiesel from 12 to 5oC.In this study,the effect of alkyl chain length, molecular weight, as well as the concentration of the additives on the pour point of biodiesel was also discussed.

Molecular Structural Evolution of Near-Infrared Cationic Aggregation-Induced Emission Luminogens: Preclinical Antimicrobial Pathogens Activities and Tissues Regeneration

Molecular Structural Evolution of Near-Infrared Cationic Aggregation-Induced Emission Luminogens: Preclinical Antimicrobial Pathogens Activities and Tissues Regeneration

Effect of Alkyl Chain Length on the Photophysical, Photochemical, and Photobiological Properties of Ruthenium(II) Polypyridyl Complexes for Their Application as DNA-Targeting, Cellular-Imaging, and Light-Activated Therapeutic Agents.

A family of six Ru(II) polypyridyl complexes (1-6) which contain phenanthroline-based ligands functionalized with alkyl chains of different lengths (one methyl group, 10 and 21 carbon alkyl chains) and either 1,10-phenanthroline (phen) or 1,4,5,8-tetraazaphenanthrene (TAP) as ancillary ligands have been synthesized and characterized. The influence of the alkyl chain length on their photophysical and photochemical properties as well as in their photobiological applications has been elucidated by monitoring the changes in their MLCT-centered absorption and emission bands. The presence of one methyl group or 10 carbon alkyl chains does not seem to significantly affect the photophysical and photochemical properties of the resulting Ru(II) complexes when compared to the well-known [Ru(phen)3]2+ and [Ru(TAP)2phen]2+. However, an effect on their emission properties and in their ability to photosensitize singlet oxygen is observed for the Ru(II) complexes containing 21 carbon alkyl chains. The binding of these complexes to salmon testes DNA (stDNA) was investigated by observing the changes in the photophysical properties. Complexes 1, 2, 4, and 5 all showed changes in their MLCT bands that could be analyzed using conventional fitting methods, such as the Bard equation. In contrast, complexes 3 and 6, possessing long aliphatic chains, gave rise to nonclassic behavior. In addition to these analyses, both thermal denaturation and circular dichroism studies of 1-6 were carried out in the presence of stDNA which confirmed that these complexes bind to DNA. Confocal microscopy and viability studies in HeLa cervical cancer cells reveal an alkyl chain-length dependence on the cellular uptake and cytotoxicity of the resulting Ru(II) complexes due to an enhancement of their lipophilicity with increasing alkyl chain length. Thus, complexes containing 10 and 21 carbon alkyl chains are rapidly taken up into HeLa cells and, in particular, those with 21 carbon alkyl chains show a significant phototoxicity against the same cell line. Therefore, this study provides further insight into the possible modulation of the photophysical, photochemical, and photobiological properties of Ru(II) polypyridyl complexes by varying the length of the alkyl chains attached to the polypyridyl ligands coordinated to the Ru(II) center and the nature of the auxiliary groups, which we show has a significant effect on photophysical and biological properties.

Effect of alkyl chain length of imidazolium cations on foam properties of anionic surface active ionic liquids: Experimental and DFT studies

Two anionic surface active ionic liquids (SAILs), 1-hexyl-3-methylimidazolium dodecyl sulfate ([Hmim][C12H25SO4]) and 1-octyl-3-methylimidazolium dodecyl sulfate ([Omim][C12H25SO4]) were synthesized using imidazolium ionic liquids (ILs) and sodium dodecyl sulfate (SDS). The critical micelle concentration (CMC) values, thermodynamic properties, and aggregation parameters were determined using surface tension measurements, steady state fluorescence tests, and electrical conductivity measurements. CMC values (from surface tension) of [Hmim][C12H25SO4] and [Omim][C12H25SO4] were 1.075 mmol/L and 0.278 mmol/L, respectively. The micellization process of [Omim][C12H25SO4] and [Hmim][C12H25SO4] was spontaneous, endothermic, and entropy-driven. Foaming performances (foaming ability, foam stability, and foam composite index) of three SAILs ([Bmim][C12H25SO4], [Hmim][C12H25SO4], and [Omim][C12H25SO4]) were determined using Ross-Miles methods. The foaming abilities of SAILs followed the order: [Hmim][C12H25SO4] > [Bmim][C12H25SO4] > [Omim][C12H25SO4]. While the foam stabilities and foam composite index (FCI) of SAILs followed the order: [Omim][C12H25SO4] > [Hmim][C12H25SO4] > [Bmim][C12H25SO4]. The structure effect of three SAILs ([Bmim][C12H25SO4], [Hmim][C12H25SO4], and [Omim][C12H25SO4]) on foam performances were analyzed by density functional theory (DFT) calculations. Binding energy of three SAIL hydrates followed the trend: [Omim][C12H25SO4](H2O)n > [Hmim][C12H25SO4](H2O)n > [Bmim][C12H25SO4](H2O)n. DFT results showed the increase of alkyl chain length of imidazolium cation was beneficial to the stability of SAIL hydrates, which resulted in higher foam performances. The information will shed light on rapid screening of novel surface active ionic liquids for surfactant foam enhanced remediation (SFER).

New reactive ionic liquids as carriers in polymer inclusion membranes for transport and separation of Cd(II), Cu(II), Pb(II), and Zn(II) ions from chloride aqueous solutions

Three new reactive ionic liquids (RILs) based on the imidazole derivatives were synthesized and used as carriers in polymer inclusion membranes (PIMs) composed of cellulose triacetate (CTA) as a polymer matrix and o–nitrophenyl octyl ether (NPOE) as a plasticizer. The effect of alkyl chain length (C1, C4, and C8) in the imidazolium cation of RILs on the transport and separation properties was evaluated. From among three synthesized RILs only the RIL with the longest alkyl chain (RILC8_Br) can be successfully applied as the carrier for Cd(II) removal from multicomponent aqueous chloride solution containing also Cu(II), Pb(II), and Zn(II) ions. The effects of the stripping phase composition, HCl concentration in the feed solution, and the carrier content in the membrane on the separation performance and transport effectiveness were studied. The results indicate that the RILC8_Br ionic liquid enables selective transport of Cd(II) ions and their active concentration in the stripping solution with the fluxes reaching a value of 2.7 × 10−10 mol/cm2s. In the investigated feed solution concentration range, the selectivity order was found to be Cd(II) > Zn(II) > Pb(II) ≫ Cu(II) and it was independent of the experimental conditions. For a description of the transport kinetics a model similar to the first-order reversible reaction equations was applied and its applicability was proved.

Molecular dynamics simulation of extractive desulfurization of diesel oil model using magnetic ionic liquids

This paper serves as a molecular dynamics (MD) study on the desulfurization of diesel oil model using magnetic ionic liquids (MILs). In this regard, three different MILs, namely, [emim][FeCl4], [bmim][FeCl4] and [hmim][FeCl4] have been used to remove the dibenzothiophene (DBT) from n-dodecane as diesel oil model. The effects of alkyl chain length of cation in MIL, temperature, initial sulfur content and mass ratio of MIL to diesel oil on two vital parameters of desulfurization process i.e. percentage of S-removal and Nernst partition coefficient (KN) were investigated. These two parameters were calculated based on the method proposed by Feng and Mi (Ind. Eng. Chem. Res. 2014, 53, 20234-20240), in which they used the radial distribution function (RDF) plots obtained by Conductor-like Screening Model for Real Solvents (COSMO-RS) to evaluate the desulfurization of fuel oil, quantitatively. Our results showed that the [bmim][FeCl4] has the highest DBT-philisity and its S-removal efficiency increases with increasing temperature and the concentration of the MIL. Furthermore, from the investigation of the initial sulfur content in diesel oil model it is concluded that the MIL can be a good extractor for oil refinery applications with a wide range of sulfur content in diesel oil. The results of RDF and combined distribution function (CDF) plots and also Voronoi tessellation analysis showed that the DBT molecules are adsorbed mainly by the MIL molecules compared with the n-dodecane which leads to DBT-removal. Also, it is found that the DBT molecules interact with the cation of MIL more than its anion. The results of domain analysis showed that the n-dodecane subset is stiffer than the MIL and DBT subsets. Altogether, the Fe-containing MILs can be a good sulfur extractor with high S-removal efficiency, lower toxicity than common volatile organic solvents, and low cost compared to the other common methods such as hydrodesulfurization (HDS), for future oil refinery applications.

Single-Use Electrochemical Platform for Monitoring of Antimicrobial Activity in Comparison to Minimum Inhibitory Concentration Assay

Determination of antimicrobial properties of (bio)molecules has been conventionally performed using minimum inhibitory concentration (MIC) assay based on visual monitoring of turbidity which may cause incorrect interpretations. Surfactants are widely used as disinfectants because of their antimicrobial properties, especially in todays’ world struggling with infections. In this study, surfactants are chosen as the model molecules for the fabrication of a voltammetric biosensor for monitoring antimicrobial activity for the first time in the literature. The antimicrobial effect of anionic and cationic surfactants on E. coli and S. aureus and the effect of alkyl chain length of cationic surfactants were investigated. Anodic peak current (Ia) value was measured by cyclic voltammetry (CV) in a redox probe containing K3[Fe(CN)6] and K4[Fe(CN)6] ions to understand the biointeraction mechanisms. The effect of the surfactants on the microorganisms was characterized by optical microscopy, SEM, and FTIR. The electrochemical biosensor could detect the antimicrobial properties of the surfactants by obtaining consistent results with MIC assay and spectroscopy. While cationic surfactants were more effective on the microorganisms, hexadecyltrimethylammonium bromide (CTAB) is the most effective surfactant by reaching a low MIC level. This article has novelty using disposable PGEs in combination with the CV technique for antimicrobial activity evaluation.

Demulsification of stable seawater/Arabian heavy crude oil emulsions using star-like tricationic pyridinium ionic liquids

Green oil-field chemicals based on ionic liquids (ILs) are highly recommended as demulsifiers for heavy crude oil emulsions due to their low vapor pressure, high thermal and chemical stability against degradation in harsh processing conditions. Novel multifunctional tricationic pyridinium ionic liquids (TCPyILs) were synthesized by the reaction of cyanuric chloride with tetraethylene glycol followed by its linking with quaternized aminopyridinium bromide using Bis(chloroethyl) ether as a linker. The chemical structures, surface and interfacial activities and thermal stabilities of the prepared pyridinium ILs were investigated. The amphiphilicity, surface and interfacial activity of the prepared TCPyILs recommended their application as chemical additives in petroleum industry. To the best of our knowledge, it is the first time to apply TCPyILs as demulsifiers for W/O emulsions with high stability and low droplet size (around 2 μm). Comparing with traditional monocationic pyridinium ILs, the prepared TCPyILs had higher efficiencies to demulsify W/O emulsions with different Vol %. The effects of alkyl chain lengths, demulsifier doses and RSN values on the demulsification activities were studied. The results indicated that TCPyILs with nonyl and tetradecyl alkyl chains had better and higher demulsification efficiency comparing with those containing hexadecyl alkyl chains. The demulsification efficiencies of TNPy and TTPy ILs for W/O (50/50, 30/70 and 10/90 vol%) reached 100% even at low concentrations.

Effects of anions and alkyl chain length of imidazolium-based ionic liquids at the Au (111) surface on interfacial structure: a first-principles study

The interfacial structure and adsorption mechanism of imidazolium-based ionic liquids (ILs) on Au (111) surface were investigated via first-principles calculation. Electron density analysis and Bader charge analysis were used to explore the electronic structure of Au (111)-ILs interface. Computations show that the alkyl chain length and anions play a significant role in designing Au (111)-ILs interfacial structure. On the one hand, the stability of interface and adsorption energy tend to be enhanced as the alkyl chain length increases. It attributes to the methylene group of alkyl chain which could easily anchor on the gold interface. On the other hand, the difference in anions makes the adsorption behavior quite different. The adsorption energy follows the order: [Cnmim][Br] > [Cnmim][Cl] > [Cnmim][TFSA] > [Cnmim][OAc] > [Cnmim][PF6] > [Cnmim][BF4]. The nonfluorinated ILs (containing Br, Cl, and O atoms of anions) always have a drastic charge transfer among gold-ILs interface. However, the larger van der Waals (vdWs) volumes of the fluorinated anions have a more diffused electron density which lead to the relatively weak interaction. To sum up, a detailed and systematic investigation of the variation of anions and alkyl chain length of ILs which will affect the interfacial structure is fully studied. The above study could be helpful to understand electrode-electrolyte microscopic interface and design of functional materials for energy storage.

Front Cover: Effect of Alkyl Chain Length of N‐Alkyl‐N′‐(2‐benzylphenyl)ureas on Gelation (Chem. Asian J. 13/2021)

Urea derivatives that were substituted with a 2-benzylphenyl group and an alkyl group function as low-molecular-weight gelators for various organic solvents and ionic liquids. Those with long alkyl chains are effective for the gelation of polar solvents. However, they are not suitable for the gelation of non-polar solvents, whereas urea derivatives with short alkyl chains are effective. Ionic liquids are similar to polar solvents in that urea derivatives with long alkyl chains are the most effective gelators. More information can be found in the Full Paper by Masamichi Yamanaka et al.

Achieving Organic Smart Fluorophores by Controlling the Balance between Intermolecular Interactions and External Stimuli.

Organic smart fluorophores (OSFs) are highly desirable over the past decades because of their potential applications in advanced photonic devices. However, it is still difficult and challenging to obtain such materials with tunable photophysical properties and high emission efficiency based on robust construction strategies. Therefore, we proposed a simple and efficient strategy for constructing OSFs by balancing the competition between intermolecular interactions and external stimuli via molecular structure design. In this work, four pyrene derivatives (T1-Py, T4-Py, T12-Py, and S12-Py) with tunable stimuli-responsive properties were designed and synthesized. The tunable intermolecular interactions in solution states were successfully demonstrated by the molecular structure and solution concentration-dependent luminescence properties. The effect of alkyl chain length on molecular packing in solid states was investigated by polarized optical microscopy and powder and single-crystal X-ray diffraction; the results show that with the increase in molecular chain length, the molecular packing of the compounds gradually changed from π-π stacked compact mode to X-crossing stacked loose mode, which leads to different stimuli-responsive phenomena of these compounds. The strategy provided herein facilitates the construction of multistimuli-responsive (thermochromism, mechanochromism, and vapochromism) OSFs with adjustable emission color. Harnessing the heat-responsive luminescence properties and great solubility of T12-Py, the optical information anticounterfeiting based on temperature was demonstrated by printing different concentrations of T12-Py solution on filter papers. Much more, this research may provide broad implications for the design of organic smart materials based on intermolecular interactions.

Effect of Alkyl Chain Length of N-Alkyl-N'-(2-benzylphenyl)ureas on Gelation.

Urea derivatives that were substituted with a 2-benzylphenyl group and an alkyl group functioned as low molecular weight gelators for various organic solvents and ionic liquids. Urea derivatives with long alkyl chains were effective for the gelation of polar solvents. However, they were not suitable for the gelation of non-polar solvents, whereas urea derivatives with short alkyl chains were effective. Ionic liquids were similar to polar solvents in that urea derivatives with long alkyl chains were the most effective gelators. The physical properties of the formed supramolecular gels were analyzed by dynamic viscoelasticity measurements using a rheometer.