Imidazole Monomer Research Articles

Imidazole-mediated stability of block copolymer micelles and its application in drug delivery

Block copolymer micelles have emerged as a safer alternative for delivering drugs in biomedical applications. Recent studies have shown that the stability of these micelles can significantly impact the efficiency of drug delivery. Here, we propose a method to regulate the stability of block copolymer micelles by introducing a third monomer. Specifically, we synthesized the block copolymer PDPA18-b-P(Vim18-co-P(EG)5MA21) through reversible addition-cracking chain transfer (RAFT) polymerization based on PDPA19-b-P(P(EG)5MA)18. The diblock three-component copolymer is a unique copolymer, in which the hydrophilic block being doped the third monomer with pH-sensitive property, resulting in distinctive physiological properties. Both PDPA18-b-P(Vim18-co-P(EG)5MA21) and PDPA19-b-P(P(EG)5MA)18 can self-assemble into micelles with a core-shell structure. In the case of PDPA19-b-P(P(EG)5MA)18 micelles, the solvophobic PDPA19 block forms the core, while the solvophilic P(P(EG)5MA)18 block forms the shell. To regulate the stability of the block copolymer micelles, an imidazole intermediate layer with pH-responsiveness is introduced between PDPA core and P(P(EG)5MA) shell. The introduction of the imidazole monomer affect the stability of block copolymer micelles and the release kinetics of drugs. We validated that these PDPA18-b-P(Vim18-co-P(EG)5MA21) micelles exhibit higher stability under neutral conditions and show enhanced drug release in mildly acidic conditions compared to PDPA19-b-P(P(EG)5MA)18 micelles. Overall, this report demonstrates that copolymerization of imidazole monomer is a powerful approach to mediated the stability of block copolymer micelles for drug delivery applications.

Robust Vanillin-Derived Poly(thioether imidazoles) as Both a Latent Curing and Toughening Agent for One-Component Epoxy Resins.

One-component epoxy resins based on latent curing agents have garnered research attention owing to their outstanding storage stability and excellent processability, while their development considerably depends on the design and preparation of sustainable latent curing agents. Herein, taking structural advantage of lignin-derived vanillin, a biobased polymerizable aromatic imidazole monomer with α,ω-diene functionality was designed and prepared, which was applicable in subsequent thiol-ene polymerization, yielding a series of robust poly(thioether imidazoles) with excellent tunability of the structure and properties. The findings indicated that the precursors comprising poly(thioether imidazole) and commercially available epoxy resins could keep their fluidity at 25 °C for over 90 days and rapidly cured into resins under elevated temperature, demonstrating that the poly(thioether imidazole) can serve as both a latent curing and toughening agent for one-component epoxy resins because of homopolymerization initiated by imidazole groups and the introduction of an aliphatic chain in the as-prepared poly(thioether imidazole) matrix.

Conjugated Polymer /Multi Wall Carbon Nanotubes Composite Characterisation for Application in Volatile Organic Compounds Sensors

Polyimidazole multi-walled carbon nanotubes (MWCNTs) nanocomposite film were synthesised by chemical oxidation of imidazole monomer and addition of MWCNTs to the conductive polymer (CP) solution in 1:1 ratio. Chemical characterisation using FTIR where there is an increased in intensity of peaks in the control sample from 2823 and 2937 cm-1 to 2833 and 2947 cm-1 in Plm/MWCNTs composite respectively and Raman spectroscopy in which Plm/MWCNTs shows the so-called D-band (attributed to disordered sp2 and non-sp2 carbon defects in graphitic sheets) and G-band (attributed to the C–C vibration with the sp2 hybridized orbital in graphene structures) peaks at 1355 cm-1 and 1593 cm-1, but chemical analysis confirmed the mixing of the polymer and the MWCNTs. Electrical measurements using current voltammetry (CV) that shows a reversible wave that is the typical behavior of conductive surfaces in the presence of the redox couple and Impedance measurements in which the largest semicircle was obtained with Plm/CNTs film that corresponds to a film resistance on the real axis of 350 MΩ which is an indication of a higher electron transfer rate in the redox probe and good electrical behaviour. The overall results have shown that the composite has a significant electrical conductivity and can be applied in sensing volatile organic compounds in the environment.

Green preparation of quaternized vinylimidazole-based anion exchange membrane by photopolymerization

• AEMs were prepared via environmental friendly, highly efficient and single step ultraviolet polymerization method. • Non-toxic ethanol and water were used as solvents and the reaction mass efficiency was higher than 94%. • The performance of the membrane could be finely adjusted by the varying the content of imidazolium monomer. • The prepared membrane showed excellent desalination performance with the NaCl removal ratio as high as 99%. At present, most preparation processes of ion exchange membranes inevitably involve toxic solvents and complicated synthetic procedure. Herein, we reported a one-pot ultraviolet induced polymerization route to prepare quaternized imidazole-based anion exchange membranes. During the preparation processes, only environmentally friendly ethanol and water were used as solvents. The effects of mass ratio of quaternized imidazole monomer, crosslinker and vinylimidazole comonomer diluent on membrane structures and properties were carefully investigated to optimize the performance of anion exchange membrane. In optimized conditions, reliable mechanical properties as well as good electrochemical property could be achieved. The best-performing membrane showed a resistance of 1.86 Ω·cm 2 (reaching the level of a normal homogeneous membrane) and desalination ratio as high as 99% (superior to the commercial anion exchange membrane Fuji type II (98%)). Besides, the reaction mass efficiency of all membranes was above 94%, indicating the high raw material utilization, low energy consumption and environmentally friendliness of the proposed synthetic route. This research would shed light on the development and commercialization of the green synthetic route for ion exchange membranes.

Green antimicrobial adsorbent containing grafted xanthan gum/SiO2 nanocomposites for malachite green dye

Recently, removal of synthetic dyes, especially cationic dye of malachite green (MG), and inhibition of the growth of pathogenic microorganism from drinking water have gained much interest due to their high toxic potency for aquatic biosystems. Herein, a new dye adsorbent with outstanding antibacterial activity was fabricated based on xanthan gum (XG) and SiO2 nanoparticles through ultrasonication followed by the crosslinking polymerization with vinyl imidazole monomer. The nano adsorbents were characterized with various techniques such as FTIR, XRD, SEM, EDX, and TEM. The nanocomposites were applied as a filter for discarding MG dye and killing the growth of bacterial strains such as E.coli and S.aureus which are considered as the common impurities for drinking water. The data revealed that a maximum adsorption capacity was recorded as 99.5% (Qmax = 588.2 mg/g) at optimum conditions including 10 mg nanocomposite, 10 mL of MG dye (450 ppm), pH = 7, the temperature of 30 °C, and the adsorption time was adjusted within 6 h. The process of dye adsorption was applied to the common isotherm models of Langmuir, Temkin, and Freundlich, and the findings showed that the adsorption behavior was well fitted with the Langmuir one (R2 = 0.9983). Moreover, different adsorption kinetic models such as pseudo-first order, pseudo-second order, and intra-particle diffusion were studied for understanding the mechanism of MG adsorption onto nanocomposite surface. It was found that both intraparticle diffusion and pseudo-first-order have participated evenly in the adsorption mechanism of MG dye. Ultimately, the as-prepared nanocomposites were tested against the growth of S. aureus, and E.coli manifesting a superior inhibition diameter as 23.5 ± 0.50, and 25.33 ± 0.47 mm against E.coli, and S. aureus, respectively. Therefore, our new XG-g-PVI/SiO2 adsorbent is a very promising adsorbent for the fast and efficient capture of dyes from aqueous solutions.

Synthesis and Characterization of 4‐Vinylimidazolium/Styrene‐Cografted Anion‐Conducting Electrolyte Membranes

AbstractThe β‐hydrogen‐free imidazole monomer, 2‐methyl‐N‐methyl‐4(5)‐vinylimidazole (2M4VIm), is synthesized to prepare anion exchange membranes (AEMs). The radiation‐induced graft polymerization of 2M4VIm and styrene is performed in poly(ethylene‐co‐tetrafluoroethylene), followed by N‐alkylation and ion exchange reactions to prepare 4‐vinylimidazolium‐containing AEM (2M4VIm/St‐AEM). AEMs that have a 6/4 2M4VIm/St molar ratio and 1.7 mmol g−1 ion exchange capacity (IEC) result in 75 mS cm−1 conductivity and 60% water uptake at room temperature in water, demonstrating enhanced values compared to previously reported 2‐methyl‐N‐vinylimidazolium‐containing AEMs (2MNVIm/St‐AEM) that have a similar comonomer ratio and IEC. The small‐angle neutron scattering measurements of dry and swollen 2M4VIm/St‐AEM reveal hydrophilic/hydrophobic two‐phase separation, as observed for 2MNVIm/St‐AEM with a similar Im/St composition. 2M4VIm/St‐AEMs exhibit higher alkaline stability in 1 m KOH at 80 °C at an early stage owing to the suppression of imidazolium β‐elimination but lower long‐term stability than that of 2MNVIm/St‐AEM due to the ring‐opening reaction of the imidazolium group due to its outward orientation from the graft main chain.

Preparation of SiO2 grafted polyimidazole solid electrolyte for lithium-ion batteries

Solid electrolytes have emerged as a promising alternative to liquid electrolytes for application in solvent-free lithium rechargeable batteries. Composite polymer electrolytes based on polymer and nanoparticle exhibit acceptable ion conductivity due to the interaction between nanofillers and polymer. However, the application of composite polymer electrolytes is hindered by the agglomeration of nanofillers at high concentration. Herein, in this study, the polymer electrolytes with branched polyimidazole were synthesized by radical polymerization based on functionalized SiO2 nanoparticles and imidazole monomers. Different from the reported methods of blending ceramic particles with polymers, we introduce an in situ synthesis of branched polymer electrolyte based on functionalized SiO2 nanoparticles. The stronger chemical interactions between SiO2 nanospheres and polymer chains could significantly suppress the aggregation of the nanoparticles and improve temperature stability. Among all of the electrolyte films, SiO2-MOBIm6-BF4 shows the best ion conductivity of 5.96 × 10−5 S cm−1 at 25 °C and the value reaches to 9.54 × 10−4 S cm−1 at 95 °C. This is mainly due to the long methylene chain increasing the flexibility of the chain segment and the molecular mobility, which is benefit to lithium-ion transportation. The electrochemical stabilization window can reach 4.85 V at room temperature, and the LiFePO4/SiO2-MOBIm6-BF4/Li battery was assembled with the electrolyte based on SiO2-MOBIm6-BF4. The first discharge capacity can reach 158.3 mAh g−1, and the batteries show good cycle performance.

Synthesis of new imidazole-based monomer and copolymerization studies with methyl methacrylate

In this study, copolymers were synthesized using methyl methacrylate (MMA) and 2-allyloxymethyl-1-methylimidazole (AOMMI) monomers at various ratios. For this purpose, hydroxyl end-functionalized imidazole was initially prepared with 1-methylimidazole and then it was used to prepare allyl-derived imidazole monomers. Finally, the synthesis of copolymers (poly(MMA-co-AOMMI)) was carried out using different proportions of commercial MMA and AOMMI monomers. Photopolymerization method was preferred as polymerization technique. The polymerization was carried out in solvent-free medium and benzophenone was used as the initiator. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR) and elemental analysis were used for the structural characterization of the obtained copolymers. Molecular weights and the thermal behaviour of the synthesized copolymers were analysed with gel permeation chromatography (GPC) and thermogravimetry (TG) techniques, respectively. The surface of the products was tried to be illuminated using scanning electron microscopy (SEM). According to the obtained FTIR, NMR and elemental analysis results, the copolymers were successfully synthesized. A number average molecular weights of poly(MMA-co-AOMMI) samples were found 13,500 (MMA:2/AOMMI:1), 16,600 (MMA:1/AOMMI:2) and 17,300 (MMA:1/AOMMI:1) according to the mixing ratios. When the thermal stabilities of the synthesized copolymers were observed, it has been seen that those containing imidazole had higher stability than the neat PMMA.

Synthesis and Optical Properties of π-Conjugated Polymers Containing Fused Imidazole Skeleton

Fused imidazole monomers (1b, 1i, and 2b) having the octyl group were synthesized by the microwave-assisted intramolecular direct arylation, which were subjected to the cross-coupling polymerization. For obtaining π-conjugated polymers with better solubility, fused imidazole monomers (si-1b and si-3b) having the bulky trisiloxane-terminated decyl chain were likewise synthesized and polymerized. On the basis of absorption and emission spectra of obtained π-conjugated polymers in conjunction with the X-ray crystal structure of model compounds and theoretical calculation, the fused structure and coupling partner were found to affect the optical properties in CHCl3 solution as a result of steric and electronic factors. The spectroscopic measurements in film revealed that the bulky trisiloxane group helps π-conjugated polymers to form the π-stacked structure upon thermal annealing. The proton doping experiment was also carried out to find out that the protonation of imidazole nitrogen results in the different peak shift depending on the comonomer structure.

Geometry of an Isolated Dimer of Imidazole Characterised by Rotational Spectroscopy and Ab Initio Calculations.

An isolated, gas-phase dimer of imidazole is generated through laser vaporisation of a solid rod containing a 1:1 mixture of imidazole and copper in the presence of an argon buffer gas undergoing supersonic expansion. The complex is characterised through broadband rotational spectroscopy and is shown to have a twisted, hydrogen-bonded geometry. Calculations at the CCSD(T)(F12*)/cc-pVDZ-F12 level of theory confirm this to be the lowest-energy conformer of the imidazole dimer. The distance between the respective centres of mass of the imidazole monomer subunits is determined to be 5.2751(1) Å, and the twist angle γ describing rotation of one monomer with respect to the other about a line connecting the centres of mass of the monomers is determined to be 87.9(4)°. Four out of six intermolecular parameters in the model geometry are precisely determined from the experimental rotational constants and are consistent with results calculated ab initio.

Application of Heterocyclic Polymers in the Ratiometric Spectrophotometric Determination of Fluoride.

Herein we report the use of heterocyclic functional polymers in the ratiometric spectrophotometric determination of fluoride (F-). Polymers incorporating benzo[d][1,2,3]triazole moieties linked to the polymer backbone via urea links are demonstrated to have utility for the ratiometric detection of the F- ion, with a detection limit in the order of ∼2 μM. The hydrogen-bonding recognition between the benzo[d][1,2,3]triazole moiety and F- ion was investigated using UV-vis spectrophotometry and NMR analysis. The importance of the urea linkage was elucidated by investigating a second benzo[d][1,2,3]triazole functional monomer wherein the heterocyclic group is attached to the polymerizable group via a carbamate linkage. The replacement of the urea link with a carbamate group led to significantly reduced F- sensitivity. Moreover, by examining an analogous benzo[d]imidazole monomer it was demonstrated that having a nitrogen atom in the 2-position of the heterocycle was important for maximizing the sensitivity of the assay. Taken together, these results demonstrated that the urea-substituted benzo[d][1,2,3]triazole motif greatly enhances F- ion detection. Importantly, the F- ion sensing capability of the monomer is retained after incorporating into a diblock copolymer using reversible addition-fragmentation chain transfer (RAFT) polymerization.

Self-association of organic solutes in solution: a NEXAFS study of aqueous imidazole.

N K-edge near-edge X-ray absorption fine-structure (NEXAFS) spectra of imidazole in concentrated aqueous solutions have been acquired. The NEXAFS spectra of the solution species differ significantly from those of imidazole monomers in the gas phase and in the solid state of imidazole, demonstrating the strong sensitivity of NEXAFS to the local chemical and structural environment. In a concentration range from 0.5 to 8.2 mol L(-1) the NEXAFS spectrum of aqueous imidazole does not change strongly, confirming previous suggestions that imidazole self-associates are already present at concentrations more dilute than the range investigated here. We show that various types of electronic structure calculations (Gaussian, StoBe, CASTEP) provide a consistent and complete interpretation of all features in the gas phase and solid state spectra based on ground state electronic structure. This suggests that such computational modelling of experimental NEXAFS will permit an incisive analysis of the molecular interactions of organic solutes in solutions. It is confirmed that microhydrated clusters with a single imidazole molecule are poor models of imidazole in aqueous solution. Our analysis indicates that models including both a hydrogen-bonded network of hydrate molecules, and imidazole-imidazole interactions, are necessary to explain the electronic structure evident in the NEXAFS spectra.

New polyelectrolytes based on 4‐vinyl‐1,2,3‐triazole and 1‐vinylimidazole

AbstractCopolymers of 4‐vinyl‐1,2,3‐triazole and 1‐vinylimidazole (VI) were obtained by radical copolymerization of (4‐vinyl‐1H‐1,2,3‐triazol‐1‐yl)methyl pivalate with VI followed by alkali hydrolysis. Reactivity ratios of the triazole and imidazole monomers are 0.51 and 0.30, respectively. Theoretical quantum‐chemical calculations by the PM3 semiempirical method give close values, which show that the obtained reactivity ratios reflect the activity of the vinyl groups. Polyelectrolyte properties of the copolymers were studied by potentiometric titration. Hydrogen bonds between the protonated triazole cycle and the triazole or imidazole units were found to considerably influence the solubility and solution properties of the copolymers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Preparation and characterization of composite cryogels containing imidazole group and use in heavy metal removal

In this study, cryogels containing imidazole functional groups were prepared by two different approaches and were used in the removal of Pb 2+, Cd 2+, Zn 2+ and Cu 2+ ions from aqueous solutions. In the first approach, poly(2-hydroxyethyl methacrylate- n-vinyl imidazole) [poly(HEMA-VIM)] cryogel was prepared using n-vinyl imidazole monomer. In the second approach, in order to increase the surface area, poly(HEMA-VIM)/poly(HEMA) composite cryogel was prepared by embedding the poly(HEMA-VIM) particles prepared with suspension polymerization into poly(2-hydroxyethyl methacrylate), poly(HEMA) cryogel. Both poly(HEMA-VIM)] cryogel and poly(HEMA-VIM)/poly(HEMA) composite cryogels were characterized by swelling studies, Fourier transform infrared spectroscopy, elemental analysis, surface area measurements and scanning electron microscopy. The surface area of poly(HEMA-VIM) cryogel was found to be 39.7 m 2/g while the surface area of poly(HEMA-VIM)/poly(HEMA) composite cryogel was 78.6 m 2/g as expected. The optimum adsorption conditions for metal uptake such as pH, metal ion concentration, and adsorption time were studied. Performed experiments showed that composite formation increased the adsorption capacity of the cryogel. The amounts of decreasing adsorption capacity were calculated as 38.5% for Cu 2+, 39.1% for Pb 2+, 66.9% for Zn 2+ and 69.9% for Cd 2+. The maximum adsorption capacities of the composite cryogel in the affinity order on mass basis were found to be Pb 2+(7620 μg/g) > Cd 2+(5800/μg) > Zn 2+(4340 μg/g) > Cu 2+(2540 μg/g) while on molar basis the order was Zn 2+(66.4 μmol/g) > Cd 2+(51.6 μmol/g) > Cu 2+(40.0 μmol/g) > Pb 2+(36.8 μmol/g). These results fitted well the Langmuir adsorption model. Competitive adsorption studies were performed with solutions containing the four heavy metal ions at 20 mg/L metal ion concentration. The binding capacities of the composite cryogel were found to be Pb 2+(1498.2 μg/g) > Cu 2+(742.5 μg/g) > Cd 2+(550.4 μg/g) > Zn 2+(450.5 μg/g) in competitive manner. It was observed that composite cryogels could be repeatedly used without significant loss in the adsorption capacity after ten repetitive adsorption–desorption processes.

Enantioselective ester hydrolysis catalyzed by imprinted polymers.

Highly cross-linked network polymers prepared by molecular imprinting catalyzed enantioselectively the hydrolysis of N-tert-butoxycarbonyl phenylalanine-p-nitrophenyl ester (BOCPheONP). The templates were designed to allow incorporation of the key catalytic elements, found in the proteolytic enzyme chymotrypsin, into the polymer active sites. Three model systems were evaluated. These were constructed from a chiral phosphonate analogue of phenylalanine (series A, C) or L-phenylalanine (series B) attached by a labile ester linkage to an imidazole-containing vinyl monomer. Free radical copolymerization of the template with methacrylic acid (MAA) and ethylene glycol dimethacrylate (EDMA) gave a highly cross-linked network polymer. The templates could be liberated from the polymers by hydrolysis, giving catalytically active sites envisaged to contain an enantioselective binding site, a site complementary to a transition state like structure (series A, C), and a hydroxyl, imidazole, and carboxylic acid group at hydrogen bond distance. As predicted, the enantiomer of BOCPheONP complementary to the configuration of the template was preferentially hydrolyzed with D-selectivity for the series A polymers (kD/kL = 1.9) and L-selectivity for the series B polymers (kL/kD = 1.2). The maximum rate enhancement, when compared with a control polymer, prepared using a benzoyl-substituted imidazole monomer as template, was 2.5, and comparing with the imidazole monomer in solution, a maximum rate enhancement of 10 was observed. The catalytic activity was higher for polymers subjected to the nucleophilic treatment. This was explained by a higher site density and flexibility of the polymer matrix caused by this treatment. In a comparison of template rebinding to polymers imprinted with a template containing either a carboxylate (planar ground state structure) or a phosphonate (tetrahedral transition state like structure) functionality, it was observed that imprinted polymers are able to discriminate between a transition state like and a ground state structure for transesterification. However the influence of transition state stabilization on the observed rate enhancements remains obscure. Only at acidic pH's was catalysis observed, whereas at basic pH's the polymers inhibit the reaction. At a later stage, the catalytic activity of the polymers for nonactivated D- and L-phenylalanine ethyl esters was investigated. A rate enhancement of up to 3 was observed when compared to the blank. Most important, however, the polymers imprinted with a D template preferentially hydrolyzed the D-ethyl ester and exhibited saturation kinetics.

Synthesis and physical properties of N‐substituted polyimides based on imidazole

AbstractAB‐type monomers based on imidazole for the preparation of polyimides were synthesized by carrying out a substitution at the 1‐position of 2‐amino‐4,5‐dicyanoimidazole, followed by hydrolysis. Thus, pendant groups such as hexyl and 2,4‐dinitrophenyl as an aliphatic long chain and an electron‐withdrawing group, respectively, were introduced at the 1‐position of the imidazole monomer. A solid‐state polymerization was employed to prepare the poly(imidazoleimide)s in the form of a film from poly(imidazoleamic acid chloride)s by heating up to 180–200°C. The carbonyl stretching peaks of the imide ring appear at 1808 (sym) cm−1 and 1756 (antisym) cm−1. The effects of monomer structure on reactivity and the degree of imidization were investigated by comparing the viscosity of the resultant polymers and intensity of carbonyl peak at 1808 cm−1. The difference in the hydrolysis rate between polyimides having short or long aliphatic pendant groups at the 1‐position was observed using FT‐IR. The inherent viscosity of the N‐hexyl polyimide was 1.26 dL/g in N‐methyl pyrrolidinone (NMP) and 0.22 dL/g in the case of N‐2,4‐dinitrophenyl poly(amic acid) in methanesulfonic acid at 30°C. The structural, physical, and material properties of the polyimides were characterized by infrared, nuclear magnetic resonance, luminescence, viscosimetric methods, differential scanning calorimetry, thermogravimetric analysis, optical microscopy, and wide angle x‐ray scattering. Solution properties were also investigated by monitoring the viscosity as a function of time at 30°C. Luminescence spectroscopy of the poly(1‐methyl imidazole imide) and poly(1‐methyl imidazoleamic acid) films shows an emission band centered at 535 and 505 nm, respectively. Thermal properties are described comparing the weight loss and decomposition temperature as a function of the polymer structure and the degree of imidization. © 1993 John Wiley & Sons, Inc.

Theoretical studies on hydration of pyrrole, imidazole, and protonated imidazole in the gas phase and aqueous solution

Ab initio calculations using HF/6-31G * and MP2/6-31G * total geometry optimization were carried out in the gas phase for water, pyrrole, imidazole, and protonated imidazole monomers and various monohydrates of each organic. Optimized geometries for the ring systems are in good agreement with the experimental structures; normal frequencies are systematically overestimated. Using MP2/6-311++G ** single point calculations, the gas-phase protonation free energy of imidazole was within 2.3 kcal/mol of the experimental value

Catalytic Action of Imidazole in Nonaqueous Solutions of Nonionic Surfactants

In order to examine the catalytic action of imidazole in nonaqueous solutions of nonionic surfactants, the pseudo-first-order rate constants (kobs) for the reaction between p-nitrophenyl acetate and imidazole in carbon tetrachloride was measured as a function of the concentration of imidazole at fixed molar ratios (0.5, 1.0, 2.0) of imidazole to surfactants. By analyzing of kobs-[Imidazole] profile obtained, the second and third rate constants (k2, m and k3, m) for imidazole monomer and the catalytic rate constant (kA) for imidazole aggregates were obtained. Both k2, m and kA values increase with the increase in the molar ratio or the oxyethylene chain length of surfactants, but the increase is small for k2, m. The catalytic action of imidazole in water solubilized into the imidazole/surfactant/CCl4 systems is enhanced with decrease in polarity of the interior of aggregates.