Absorption Of Methyl Orange Research Articles

Green Synthesis of Silver Nanoparticles using Lawsonia inermis for Enhanced Degradation of Organic Pollutants in Wastewater Treatment

<p>In response to the growing demand for eco-friendly and efficient catalysts in wastewater treatment, this study introduces a novel, biosynthesized silver nanoparticle (AgNP) using leaf extract from Lawsonia inermis, a widely available plant. We employed a unique concentration mixture of 0.015 mg/mL leaf extract and 2.0 mM silver nitrate to achieve optimal results under atmospheric conditions. Comprehensive characterization was conducted through X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and ultraviolet-visible absorption spectroscopy. Remarkably, these Lawsonia inermis-synthesized AgNPs (LI-AgNPs) demonstrated superior catalytic degradation of organic pollutants, such as 4-nitrophenol, methylene blue, eosin yellow, and methyl orange. Among them, 4-nitrophenol was reduced most efficiently, following pseudo-first order kinetics. The LI-AgNPs exhibited unprecedented catalytic potential, evidenced by a sharp decline in methyl orange absorption and the emergence of a new hydrazine compound signal at 280 nm. With a catalytic loading as low as 0.2 mg/mL, we achieved an astounding 82.5% dye removal. This innovative approach advances the field of environmental remediation</p>

Tailoring the optical limiting response of methyl orange via protonation

In order to realize effective optical limiting (OL), it is necessary to utilize materials that exhibit distinct traits, such as a large and rapid nonlinear optical response, high photothermal stability, and cost-effectiveness. In the present study, the nonlinear optical (NLO) response of methyl orange (MO) is modified by inducing conformational and structural changes through appropriate modification of pH conditions. The NLO properties of MO under two different pH conditions were investigated via the z-scan technique under 7 nanoseconds excitation in the visible region (532 nm). From z-scan results, the nonlinear absorption coefficient of pristine MO and protonated-MO (P-MO) was estimated. Compared to MO, the nonlinear absorption coefficient of P-MO increased by 3.6 times, and it can be attributed to the redistribution of energy levels of MO, which favored resonant absorption in the system. Molecular energy shift and the corresponding apparent red shift in the absorption spectrum of MO are confirmed from both experimental and theoretical analysis. The mechanism behind the nonlinear absorption (NLA) and OL activity of MO is found to be effective two-photon absorption. The closed aperture (CA) z-scan data reveal a negative nonlinear refraction response of MO and P-MO. These findings suggest an efficient way to tune the NLO response of MO through protonation, and this method readily applies to numerous nonlinear optical applications, including but not limited to OL.

Spectrophotometric investigation on interactions of dye with surfactant in aqueous as well as alcoholic media

The interaction of the methyl orange (MO) dye with cetyltrimethylammonium bromide (CTAB) in propanol, butanol, and water was studied using spectrophotometry method. The NLREG approach was used to compute the distribution constant which is the lower as carbon number increases which resembles that value of distribution constant 0.07161476, 0.00060913, 0.00010865 is of water, 1-propanol, 1-butanol media respectively. The Benesi-Hilderbrand and Hashemi and Sun equations were also used to determine the binding constant (Kb) and Gibbs free energy of binding (ΔG°). As the alkyl chain lengthened, the ΔG° value shifted more negatively in comparison to water. The spontaneous nature of CTAB binding with MO was suggested by the negative value of ΔG°. As the concentration of CTAB in the water & alcoholic media increased, the MO absorption dramatically blue-shifted from 464 nm (water) to 440–450 nm (propanol, butanol). These findings showed that the alkyl chain plays a role in reducing absorbance. The MO absorbance in the water, 1-propanol or 1-butanol media decreased with increasing CTAB concentration (hyperchromic shift).

High-performance multifunctional porous iron Acetylacetonate/N, O-doped carbon nanospheres for electromagnetic wave absorption at 2–18 GHz and methyl orange absorption

Nowadays, multifunction is regarded as an advanced development direction of new-generation electromagnetic wave absorption (EMWA) materials to fulfill the ever-growing demands in complex environment and situation. Environmental pollution and electromagnetic pollution are all difficult problems for human beings all the time. Now, there is no multifunctional materials for collaborative treatment of environmental and electromagnetic pollution. Herein, We synthesized nanospheres with divinyl benzene (DVB) and N-[3-(dimethylamino)propyl]methacrylamide (DMAPMA), using a simple one-pot method. After calcination at 800 ℃ in N2, porous N, O-doped porous carbon materials were prepared. By regulating the mole ratio of DVB and DMAPMA, the ratio was 5:1 reached excellent EMWA property. Remarkably, the introduction of iron acetylacetonate into the reaction of DVB and DMAPMA was effective in enhancing the absorption bandwidth to 8.00 GHz at a 3.74 mm thickness, which depended on the synergistic effects from dielectric and magnetic losses. Simultaneously, the Fe-doped carbon materials had a methyl orange adsorption capacity. The adsorption isotherm conformed to the Freundlich model. After methyl orange absorption, the EMWA property did not greatly change. Thus, this research paves the way for the creation of multifunctional materials to solve environmental pollution and electromagnetic pollution together.

Methyl Orange Absorption Using Chitosan from Shrimp Skin as an Adsorbent

In the coloring process, the textile industry generally uses synthetic (artificial) dyes, methyl orange (MO). In this study, the adsorption of methyl orange (MO) dye with chitosan was investigated in a series of batch laboratory studies. The adsorption equilibrium study used a MO solution with a concentration of 10 to 50 mg/L with an adsorbent weight of 3 g put into an Erlenmeyer and shaken until the adsorption reached an equilibrium condition. Meanwhile, the adsorption kinetics used a MO solution with an initial concentration of 10 and 20 mg/L with a volume of 100 mL with an adsorbent weight of 3 g and the solution was adjusted to pH 2. Effective operating parameters such as pH, initial concentration of dye (C0) and contact time at adsorption has been investigated. The results showed that the adsorption capacity of methyl orange (MO) dye from chitosan increased with an increasing acid content, and it was found that a solution of pH 2 was the optimal pH value for MO adsorption. The adsorption parameters for the Langmuir and Freundlich isotherms were determined by nonlinear regression and the equilibrium data were best explained by the Langmuir isotherm model, this was indicated by the high value of the correlation coefficient (R2), which was 0.9595. The maximum adsorption capacity was 0.1297 mg/g. Adsorption kinetics can be successfully applied to pseudo second-order kinetic models. The pseudo second-order model results show that the adsorption process is controlled by chemical sorption (chemisorption).

Chitosan- and Alginate-Based Hydrogels for the Adsorption of Anionic and Cationic Dyes from Water.

Novel hydrogel systems based on polyacrylamide/chitosan (PAAM/chitosan) or polyacrylic acid/alginate (PAA/alginate) were prepared, characterized, and applied to reduce the concentrations of dyes in water. These hydrogels were synthetized via a semi-interpenetrating polymer network (semi-IPN) and then characterized by Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), and their swelling capacities in water were measured. In the adsorption experiments, methylene blue (MB) was used as a cationic dye, and methyl orange (MO) was used as an anionic dye. The study was carried out using a successive batch method for the dye absorption process and an equilibrium system to investigate the adsorption of MO on PAAM/chitosan hydrogels and MB on PAA/alginate in separate experiments. The results showed that the target hydrogels were synthetized with high yield (more than 90%). The chemical structure of the hydrogels was corroborated by FTIR, and their high thermal stability was verified by TGA. The absorption of the MO dye was higher at pH 3.0 using PAAM/chitosan, and it had the ability to remove 43% of MO within 10 min using 0.05 g of hydrogel. The presence of interfering salts resulted in a 20–60% decrease in the absorption of MO. On the other hand, the absorption of the MB dye was higher at pH 8.5 using PAA/alginate, and it had the ability to remove 96% of MB within 10 min using 0.05 g of hydrogel, and its removal capacity was stable for interfering salts.

Enhanced Dye Degradation through Multi‐Particle Confinement in a Porous Silicon Substrate: A Highly Efficient, Low Band Gap Photocatalyst

AbstractA platform is introduced for fabrication of a reusable and highly efficient low band gap photocatalyst by confining gold nanoparticles (AuNPs) in the pores of a nanopatterned Si monolith (AuNSM). Due to their size, a maximum of two AuNPs can assemble in a single pore, thus preventing agglomerations. Their access to the analyte provides more active sites for redox reaction, leading to enhanced efficiency. While proximity of nanoparticles enhances coupling efficiency, confinement prevents rapid recombination of photogenerated charge carriers, a major factor contributing to low efficiency of photocatalytic materials. Degradation of methyl orange (MO) is used to determine the photocatalytic efficacy of AuNSM compared to 1) bare silicon and 2) AuNPs randomly dispersed on silicon. After 90 min of exposure to UV light (λ = 353 nm) in the AuNSM, the MO absorption is <1%, indicating near complete degradation, while it is still 85% and 70% for systems (1) and (2), respectively. Finite element method simulations of the confined structure suggest that the AuNPs act as a mediator/receptacle for photogenerated charges rather than a source of them at this wavelength and thus enhance the performance of the photocatalyst by creating more effective Schottky junctions—preventing recombination of electrons and holes—rather than by a localized surface plasmonic resonance effect.

A facile preparation of ZnFe2O4–CuO-N/B/RGO and ZnFe2O4–CuO–C3N4 ternary heterojunction nanophotocatalyst: characterization, biocompatibility, photo-Fenton-like degradation of MO and magnetic properties

To improve the low photocatalytic efficiency, powerful UV light activation, and facile electron transport of ZnFe2O4–CuO the combination of different C3N4 and N/B/RGO nanosheets in ZnFe2O4–CuO–C3N4 and ZnFe2O4–CuO-N/B/RGO ternary nanoheterojunction fabricated that lead to decrease recombination of electron/hole pairs and high photocatalytic efficiency for degradation of MO organic pollutants. The ZnFe2O4, ZnFe2O4-N/B/RGO, CuO-N/B/RGO, ZnFe2O4–CuO, ZnFe2O4–CuO-N/RGO, ZnFe2O4–CuO-B/RGO, ZnFe2O4–CuO-RGO, ZnFe2O4–CuO-N/B/RGO and ZnFe2O4–CuO–C3N4 photocatalysts were fabricated by sol–gel technique using melamine, zinc nitrate, ferric nitrate and copper nitrate hexahydrate as precursors. The prepared ZnFe2O4–CuO–C3N4 photocatalysts have a narrower bandgap than that of ZnFe2O4–CuO-N/B/RGO ternary heterojunction, resulting in higher photocatalytic activity for Fenton-type photodecomposition of methyl orange (MO). The activity of the compounds as a photocatalyst can be attributed to an electron transfer process on the surface of the photocatalyst, where the ZnFe2O4–CuO–C3N4 is a powerful electron donor and electron acceptor for the oxidized MO under ultra-violet (UV) light irradiation. ZnFe2O4–CuO–C3N4 ternary heterojunction photocatalyst show a red shift (lowest bandgap) in absorption and excellent photocatalytic degradation of MO. The particle sizes of ZnFe2O4 and CuO nanoparticles (NPs) were in the ranges of ~ 650–750 and ~ 50–150 nm, respectively. The CuO and ZnFe2O4 samples were displayed spherical and cubic morphology in FESEM images, respectively. Among the as-prepared nanostructures ZnFe2O4–CuO–C3N4 show the highest photocatalytic activity and eliminate 95.84% (80 min) of methyl orange under UV light irradiation.

Structured carbon fiber cloth-templated ZIF-8 by binder-free method for efficient dyes removal from water

Organic dyes pollution of contaminated water is posing serious environmental crisis. In this work, the robust absorbent of organic dyes has been proposed by using carboxyl-modified carbon fiber (CF) cloths as scaffolds to structure ZIF-8 powder with specific shape (area: 10 × 10 cm2 and thickness: 2 mm). The grinding ZnO and 2-methylimidazole powder was deposited on –COOH groups functionalized CF-cloth via an in situ non-solvent synthesis process without using binder. This as-synthesized robust absorbent was assembled layer-by-layer with four folds of ZIF-8 layers by inserting three folds of CF (3k, T300) between ZIF-8 layers. The surface microstructure of ZIF-8 and robust absorbent has been investigated and compared by X-ray diffraction. The techniques including Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), and X-ray photoelectron spectroscopy (XPS) have been proposed to confirm the interfacial adhesion and surface modification of CF cloths layers in robust adsorbent. Moreover, compared to ZIF-8, CF-ZIF-8 composite exhibited improved thermal stability by the thermal gravimetric (TG) analysis. The CF-ZIF-8 composite exhibited two types of adsorption curves by using UV absorption spectra, which could discriminate six kinds of organic dyes by charge effect. The UV absorption of MB(Methylene Blue), CV(Crystal Violet) and TB(Toluidine Blue) dropped dramatically and exhibited only 4.5%, while the UV absorption of RB19 (Reactive Blue 19), RhB (Rhodamine B) and MO (Methyl Orange) exhibited 58.2%, 58.3% and 70.0% of original absorption intensity after conducted adsorption processes of 700 min, respectively. The as-synthesized robust adsorbent would be easily adapted and recycled from wasted water of real industry fields, which may attract more attentions to build the bridge between MOFs powder materials to carbon fiber cloth for real use.

Novel magnetic CoFe2O4/layered double hydroxide nanocomposites for recoverable anionic adsorbents for water treatment

Nanocomposites based on magnetic Cobalt Ferrite (CoFe2O4) and Cu/Al layered double hydroxide (LDH) particles, and their calcined equivalent CoFe2O4/layered double oxide (LDO) composites, were synthesized, characterized and tested as recoverable adsorbents for Methyl Orange (MO) dye. The nanocomposites presented magnetic behavior that depends on the relative amount of CoFe2O4 with respect to the LDH, allowing their separation under small magnetic fields. Moreover, the presence of CoFe2O4 during the synthesis of LDH largely affected the absorption of MO on both LDH and LDO particles. While pure LDH and LDO showed values of maximum monolayer adsorption capacities (qe) of 151 and 807 mg/g, respectively, low amount of CoFe2O4 increased the MO absorption to 262 and 1355 mg/g for LDH and LDO, respectively. High concentrations of CoFe2O4 otherwise decreased the MO adsorption capacity of both layered particles. The higher MO adsorptions in the nanocomposites may be viewed as coming from changes in the layer structure due to the presence of magnetic nanoparticles disrupting the interactions between the platelets. With both their high level of anionic dye adsorption and strong magnetic character, these materials have been posited to form a valuable material for water remediation in the future.

THE SYNTHESIS OF SPHERICAL SHAPE AMINO FUNCTIONALIZED PEI-TGIC COVALENT ORGANIC FRAMEWORKS: SYNTHESIS, CHARACTERIZATION, AND METHYL ORANGE ABSORPTION

In here, the synthesis of covalent organic framework (COF) from the reaction of polyethyleneimine (PEI) and triglycidyl isocyanurate (TGIC) in dimethylformamide at 90 oC were carried out. The surface are, pore volume and pore size values of PEI-TGIC COFs observed as 23.4 m2/g, 0.143 cm3/g, and 22.5 nm, respectively. Moreover, the surface charge of PEI-TGIC COFs increased to +46.1±2.6 mV from +18.3±1.7 mV, after protonation of amine groups of PEI-TGIC COFs. Moreover, the potential usage of PEI-TGIC based COFs in absorption methyl orange (MO) dye from aqueous media was testing. It was observed that, the PEI-TGIC COF absorbed 156.6±4.9 mg/g MO, and the protonated PEI-TGIC (p-PEI-TGIC) COFs absorbed 202.4±5.3 mg/g MO from aqueous media in 30 min. The MO absorption by PEI-TGIC COF fitted with pseudo-first-order kinetic model, whereas MO absorption by p-PEI-TGIC COF fitted with pseudo-second-order kinetic model.

3D graphene nanoedges as efficient dye adsorbents with ultra-high thermal regeneration performance

Free standing 3D graphene nanoedges with a high surface area, density of armchair oriented graphene edges, crystallinity and thermal stability in air was scalably produced via the electrolytic exfoliation of graphite in molten NaCl-LiCl, and the performance of this material as an effective adsorbent for removal of methyl orange (MO) from aqueous solutions was comprehensively evaluated. The graphene material before and after being used in the adsorption process was characterized by various techniques including electron microscopy, X-ray diffraction (XRD) and Raman and FTIR analysis. High resolution TEM examination of the graphene nanoedges demonstrated the presence of a high fraction of single-, double- and few-layer graphene nanosheets together with graphitic layers with a thickness of <10 nm. The graphene material exhibited an excellent MO absorption capability at a wide pH range from 2 to 11. The presence of the π - π interaction and hydrogen bonds between the MO and graphene edges were found to be responsible for the high MO adsorption. Three kinetic models; Frendluich, Temkin and Langmuir, were employed to evaluate the experimental equilibrium data, and the latter provided the best fit to the adsorption process, based on which the monolayer sorption capacity was found to be 27.932 mg/g. The electrolytic 3D graphene possesses an impressive thermal stability in air up to about 500 °C. Based on this, a simple, cost-effective and ultra-scalable thermal treatment was employed for the regeneration of the adsorbent, resulted in an efficient recovery of the 3D geraphene. Moreover, the regenerated adsorbent exhibited a remarkable absorption performance. These characteristics make the molten salt graphene an interesting candidate as an economic and efficient adsorbent for the treatment of wastewaters.

Photocatalytic activity of hydrothermally synthesized Al2O3graphene nanocomposite

In this study, Al2O3-graphene nanoplatelets (GNP) nanocomposite was evaluated on its properties and performance towards methyl orange (MO) dye. Al2O3-GNP nanocomposite was prepared by conventional hydrothermal at 200°C for 24 h. The result showed the crystallite size of Al2O3 is decreased and internal strain increased with the increased GNP content. The particle size of nanocomposite becomes larger with the increment GNP amount in the nanocomposite. Nanocomposite with lower graphene contents (20 wt%) and higher Al2O3 contents performed (80 wt%) the optimum for the MO absorption with efficiency of 75% in visible light.

Facile synthesis of ZnO/Ag composites with the enhanced absorption and degradation of MB and MO under visible light

ABSTRACTZnO/Ag composites were successfully synthesized. In this paper, the flower-shaped precursor was first prepared by a typical hydrothermal reaction at 150°C. The structure, morphology and component of the as-synthesized materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The photocatalytic activity of these materials was evaluated by measuring the degradation ratio of methylene blue (MB) and methyl orange (MO) solutions under visible light irradiation. The result showed that flower-like Ag/ZnO composites exhibited enhanced catalytic performance. PL spectra indicated the surface modification of ZnO microflowers by the load of Ag nanoseeds enhanced the interfacial charge transfer kinetics between the Ag and ZnO, which improved the separation efficiency of the photogenerated electron-hole pairs.

A facile strategy for the preparation of a porous flower-like Fe3O4/Cu2O/Ag nanocomposite with unexpected and recyclable photocatalytic activity under visible light irradiation

In this work, a novel magnetic and ordered Fe3O4/Cu2O/Ag ternary composite was successfully synthesized via one-pot method in the presence of Fe3O4 nanoparticles. The glycol-ethanol mixed system was used as both solvent and reductant for the simultaneous formation of Cu2O and Ag. The porous and hollow flower-like Fe3O4/Cu2O/Ag composite was self-assembled by many nanosheets with an average thickness of 10nm and exhibited unexpected photocatalytic activity for the degradation of methyl orange (MO) under visible light. The degradation rate of MO in aqueous solution (1×10−4molL−1) reached to 97.7% within 40min. The (111) facet of Cu2O exhibited higher activity for the absorption of MO. Furthermore, ternary composite could be easily recycled by applying an external magnetic field without significant decrease of the catalytic activity even after running 5 times, which presented higher stability and efficiency than Fe3O4@Cu2O. This work would provide a new sight for the construction of visible light-responsive photocatalysts with high performance.

Fluorescence behavior of cis-methyl orange stabilized in cationic premicelles

The cis-isomer of methyl orange (MO), stabilized in cationic premicelles, has been found to be fluorescence active when excited at wavelength ⩽270nm. An intense fluorescence band with maximum at 575nm along with a broad moderate intensity band in the range of 370–530nm and a low intensity band at 361nm have been observed. The major band at 575nm has been attributed to S1→S0 (n–π*) fluorescence unlike the other azobenzenes where the S2→S0 (π–π*) fluorescence is usually reported. UV–Vis spectral and surface tension study indicate that the dye exists in the trans form in dye-surfactant ionpair (DSIP) at very dilute concentrations of the surfactant. But the polar cis-isomer is stabilized by micellization of the DSIPs as the concentration of the surfactant is increased. The fluorescence and hence the cis-isomer again disappear when normal micelles are formed above the normal CMC of the surfactant. It has been suggested that the symmetry forbidden S1→S0 (n–π*) transition of MO becomes allowed due to the formation of the twisted cis-form. TD-DFT calculations have been used as an auxiliary tool to identify the possible structures and electronic transitions responsible for the specific absorption and fluorescence properties of MO observed in presence of premicellar cationic surfactants.

Study on Decolorization of Methyl Orange Dye Wastewater by DC Stream Discharge with MgO-CuO-Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; Catalyst

The decolorization of methyl orange wastewater by DC stream discharge with MgO-CuO-Al2O3 catalyst was investigated. The removal efficiency was studied for different experimental parameters. Results showed that the removal efficiency by discharge with catalyst was better than discharge only. The removal efficiency was 98% under the condition of applied voltage 18kV, current 9mA, volume of catalyst 20cm3, initial concentration 40mg/L with treatment for 10min. The intensity of methyl orange absorption peak (465nm) gradually weakened and disappeared by discharge with catalyst, the conjugated system composed of azo group and benzene in the molecular structure was destroyed, methyl orange molecules were degraded effectively.

Absorption of Methyl Orange by Modified Fly Zeolites

In the present study, three kinds of zeolite (NaP1, NaA, and NaX) were synthesized by a hydrothermal method. These zeolites were modified by cetyl trimethyl-ammonium bromide (CTAB), and used to adsorb methyl orange (MO). NaP1 had the highest adsorption capacity, with a 99.7% MO removal percentage. An orthogonal experiment was conducted to determine the influence of adsorbent dosage, solution pH, initial MO concentration, contact time, and solution temperature on NaP1. The results showed that the initial MO concentration had the most significant effect. The adsorption isotherms of the zeolites are in a good agreement with the Langmuir formula, and the adsorption mechanism is also discussed.

Mechanism of Electrical Percolation of w/o Microemulsions Formed by Nonionic Surfactants

A study was carried out on the mechanism of electrical conductivity percolation of H2O/C16EO20/n-butanol/heptane microemulsions. Electrical conductivity, UV-vis spectroscopy and FTIR spectra were used to study the diluted “dry” microemulsions with the mass ratio of C16EO20/n-butanol/heptane = 3:3:4. The results of electrical conductivity showed that the percolation occurred around φw = 20 wt% and the transition of w/o microemulsions to bicontinueous microemulsions happened when φw = 45 wt%. From the UV-vis absorption spectra, it was found that the absorption of methyl orange (MO) in microemulsions shifted red than that of in oil phase, but the maximal absorption peak (λmax) remained unchanged when φw > 20 wt%. It implied that the position of MO solubilized in microemulsions was unvaried after free water appeared in the core. FTIR spectra revealed that the OH band of water in microemulsions moved to high frequency at low φw (< 20 wt%) and became broader at high φw. It indicated that the added water only caused the hydration of EO at low φw, the hydration completed when φw > 20 wt% and then the residual water entered into the core with properties similar to bulk water. The presence of free water as ions exchange medium will cause the electrical conductance increased. The percolation appeared after the hydration of EO completed.

On the Possibility That Cyclodextrins' Chiral Cavities Can Be Available on AOT n-Heptane Reverse Micelles. A UV−Visible and Induced Circular Dichroism Study

The formation of reverse micelles (RMs) of sodium 1,4-bis(2-ethylhexyl)sulfosuccinate (AOT) in n-heptane including two different beta-cyclodextrin (beta-CD) derivatives (hydroxypropyl-beta-CD, hp-beta-CD, and decenyl succinyl-beta-CD, Mod-beta-CD) is reported. Both cyclodextrins can be incorporated into AOT RMs in different zones within the aggregate, while beta-CD cannot. Using UV-vis and induced circular dichroism (ICD) spectroscopy and different achiral molecular probes (some azo dyes, p-nitroaniline and ferrocene), it was possible to determine that Mod-beta-CD is located with its cavity at the oil side of the AOT RM interface, while for hp-beta-CD the cavity is inside the RM water pool. Among the molecular probes used, methyl orange (MO) was the only one which gave the ICD signal when dissolved in the AOT RMs with hp-beta-CD, so a detailed study of MO behavior in homogeneous media was also performed to compare with the microheterogeneous media. The solvatochromic behavior of the dye depends not only on the polarity of the media but also on other specific solvent properties. A Kamlet-Taft analysis shows that the MO absorption spectrum shifts to longer wavelength with an increase in the solvent polarity-polarizability (pi*) and the hydrogen donor ability (alpha) of the medium. MO appears to be almost 3 times more sensitive to the pi* parameter than to the alpha parameter. In addition, from the MO absorption spectral changes with the hp-beta-CD concentration, the association equilibrium constants in pure water (K11W) and inside the RMs (K11RM) were computed. The results show that K11W is almost 10 times larger than the value inside the RMs. The latter can be explained considering that MO resides anchored to the RM interface through hydrogen bond interaction with the hydration bound water. This study shows for the first time that the cyclodextrin chiral cavity is available for a guest in an organic medium such as the RMs; therefore, we have created a potentially powerful nanoreactor with two different confined regions in the same aggregate: the polar core of the RMs and the chiral hydrophobic cavity of cyclodextrin.