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Green synthesis of metal–organic frameworks (MOFs) has attracted a lot of attention as a crucial step for practical industrial applications. In this work, green synthesis of zinc(II) metal–organic framework (Zn-MOF) has been carried out at room temperature. The Zn metal (node) was extracted from spent domestic batteries, and the linker was benzene di-carboxylic acid (BDC). The characterization of the as-prepared Zn-MOF was accomplished by PXRD, FT-IR spectroscopy, SEM, TEM, TGA, and nitrogen adsorption at 77 K. All the characterization techniques strongly supported that as-synthesized Zn-MOF using metallic solid waste Zn is similar to that was reported in the literature. The as-prepared Zn-MOF was stable in water for 24 h without any changes in its functional groups and framework. The prepared Zn-MOF was tested for the adsorption of three dyes, two anionic dyes, aniline blue (AB), and orange II (O(II)) as well as methylene blue (MB), an example of cationic dye from aqueous solution. AB has the highest equilibrium adsorbed amount, qe, of value 55.34 mg g−1 at pH = 7 and 25 °C within 40 min. Investigation of the adsorption kinetics indicated that these adsorption processes could be described as a pseudo-second-order kinetic model. Furthermore, the adsorption process of the three dyes was described well by the Freundlich isotherm model. According to the thermodynamic parameters, the adsorption of AB on the prepared Zn-MOF was an endothermic and spontaneous process. In contrast, it was non-spontaneous and exothermic for the uptake of O(II) and MB. This study complements the business case development model of “solid waste to value-added MOFs.”

Cationic ligand exchange is one of the most predominant mechanisms for the removal of ammonia from wastewater through complex formation. The complexation technique occurs between the metal ions loaded on the surface of Amberlite IR-120 and ammonia which is present in the medium. Cu(II)-loaded Amberlite IR-120 (R-Cu2+) was prepared and described using FT-IR, TGA, SEM, and EDX techniques. The prepared R-Cu2+ was applied for the elimination of ammonia from an aqueous solution. Different cations such as Co2+ and Ni2+ were loaded onto Amberlite IR-120 to study the impact of counter cation on the removal efficiency of ammonia. The ammonia removal percentage followed the order; R-Cu2+ > R-Ni2+ > R-Co2+. The effects of contact time, pH, initial concentration, temperature, and coexisting ions on the removal of ammonia from wastewater by R-Cu2+ were investigated. The equilibrium adsorbed amount of ammonia was found to be 200 mg/g at pH = 8.6 and 303 K within 60 min using 0.1 g R-Cu2+ and an initial concentration of ammonia of 1060 mg/L. The removal of ammonia using R-Cu2+ obeyed the non-linear plot of both Freundlich and Langmuir isotherms. According to the thermodynamic parameters, the adsorption of ammonia onto R-Cu2+ was an endothermic and spontaneous process. The time-adsorption data followed the pseudo-second-order and intraparticle diffusion models. Moreover, the resulting product (R-Cu(II)-amine composite) from the adsorption process exhibited high catalytic activity and could be low-cost material for the elimination of dyes such as aniline blue (AB), methyl green (MG), and methyl violet 2B (MV2B) from wastewater. Graphical Abstract

The study describes the loading of the quartz SiO2 nanoparticles (NPs) with (3-aminopropyl)triethoxysilane (APTES) linker with simultaneous lengthening of the linker through the terminal amine group by glutaraldehyde (GA). The reactive polyethylenimine (PEI) was introduced to the surface to increase the ability to capture Cu(II) ions. The composite got the abbreviation SiO2/PEI-Cu(II). The Cu(II) ions were the active center with a peroxo-complex activation state. The composite characterization included scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET) surface analyzer. The kinetics of the oxidative degradation of Rhodamine B (RhB) dye obeyed the pseudo-first order under flooding conditions. The reaction parameters including the catalyst dose, solution pH, initial concentration of reactants, and temperature got some attention. The obtained results showed that more than 91.7 ± 1% of RhB dye was degraded to CO2, NH4+, NO3–, H2O, and some inorganic acids after 30 min as confirmed by gas chromatography mass spectrometry and total organic carbon (TOC) measurements. Also, GC-MS spectra for water samples drawn from the reaction in successive periods had suggested a conceivable degradation pathway for RhB by hydroxyl radicals. Degradation starts with de-alkylation then carboxyphenyl removal followed by two successive ring-opening stages. Both the effects of the catalyst recycling and treated water reusability on the reaction rate were studied. The catalyst provided noticeable stability over three consecutive cycles.

This study demonstrates the preparation and characterization of graphene oxide (GO) nanosheets. The adsorption process of three cyanine dyes with different alkyl chain lengths (were named as R5, R7, and R10) on GO nanosheets was achieved. The impact of the alkyl chain length of the dye molecule on the adsorption process was investigated. It was noticed that the adsorption efficiency increased proportionally with the increase in the chain length. R10 has the highest adsorption capacity of 98.5 × 10−3 mol g−1 at 40°C according to the Langmuir model. The thermodynamic parameters showed that the adsorption was spontaneous and endothermic. The adsorption process was attributed to the electrostatic and π−π interactions between the dye molecules and GO surface.

To evaluate the impact of the different structure of quaternary ammonium salts (ionenes) as drug carrier of their corresponding organoclays, new nanocomposite clay-ionene (CI) drug carriers were prepared from montmorillonite (Mt) and polyquaternary ammonium salts (polyionene) and a simple bisquaternary ammonium salt. The CI drug systems were obtained by ion exchange of the sodium Mt (Na + Mt) with at least two-fold excess polyquaternary and bisquaternary ammonium salt compounds by ion exchange between sodium cations of the Na + Mt and the ammonium ions in the polyionene to produce CI systems with free quaternary ammonium halide side chains. Simple di-quaternary ammonium salts were also used to modify Mt. The structures of the prepared CI systems were characterized using Fourier transform-infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). As a model drug, sodium diclofenac (DS) was immobilized onto the CI through the remaining halide ions to provide the CI-diclofenac system (DFS). The release behavior of diclofenac from the different nanocomposites was studied at different pH values. The release behavior of the DFS showed that polyionene systems were slower than the simple bi-quaternary ammonium salts systems were. The kinetics of the release process were described using different models to explain the drug release mechanism.

The current study dealt with the preparation and characterization of graphene oxide (GO) nanosheets. The adsorption process of three cyanine dyes with different alkyl chain lengths (named R5, R7, and R10) on GO nanosheets was achieved by the batch method. The impact of the alkyl chain length of the dye molecule on the adsorption process was investigated. It was noticed that the adsorption efficiency increased proportionally with the increase in the chain length. The adsorption obeyed both of pseudo-second-order kinetics and the Langmuir isotherm model. The intraparticle and film diffusions were involved. The thermodynamic parameters showed that the adsorption was spontaneous and endothermic. In addition, the Gibbs energy, ΔGads declined as the length of the alkyl chain of the dye, was increased, and a commensuration of more favorable adsorption takes place at longer chain length. The adsorption of these dyes by GO was attributed to the electrostatic and π − π interactions as confirmed by the obtained infrared Fourier transform (FT-IR) results.

Novel bio-based nanocomposites were developed as carriers for loading and sustained-release of vanillin (Van.) and cinnamaldehyde (Cinn.) antioxidants. The composites were obtained by intercalation of chitosan (CS) into sodium montmorillonite (CS/Mt), incorporation of chitosan with polyaniline (CS/PANI) and chitosan/polyaniline/exfoliated montmorillonite (CS/PANI/Mt). The structure and morphology of composites were characterized by FTIR, XRD, SEM and TEM. The release data of Van. and Cinn. from CS and CS/Mt obeyed well zero-order equation. However, Higuchi and Korsmeyer-Peppas models fitted well the release data from CS/PANI and CS/Mt composites. Their antifungal activity was examined towards Fusarium oxysporum and Pythium debaryanum. In vitro assay, CS, Cinn., Van., CS/PANI and CS/PANI/Cinn., have a strong inhibitory effect on the linear growth of the target pathogens, even at lower concentrations. Greenhouse assay indicated that seedling treatment by the loaded CS/PANI/Cinn and CS/Mt/Cinn. reduced both disease index and disease incidence parameters of both pathogens and possessed seedlings growth promoting potential of tomato compared to untreated-infected controls.

Surface modification of sodium montmorillonite (Na+-Mt) was performed using antimicrobial agents to produce an ecofriendly nanocomposite. The adsorption performance of the nanocomposite has been evaluated for the removal of Acid Blue 25 dye (AB25) as a model organic pollutant from wastewater. Sodium montmorillonite (Na+-Mt) was modified with three different ionene compounds through ion exchange, and further modified through reaction with polyaspartate to provide three ecofriendly nanocomposites (denoted ICP-1–3). The nanocomposites were characterized using FTIR, PXRD, TEM, SEM, and BET surface area. The adsorption isotherm of AB25 onto ICP-1, ICP-2 and ICP-3 was analyzed using the Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) models. The adsorption isotherm was found to be best fitted by a Freundlich model. The thermodynamic parameters were calculated. The kinetics of the adsorption data were analyzed and the adsorption behavior was found to obey pseudo-second-order kinetics, and the intraparticle diffusion model. The adsorption mechanism was studied by FTIR.

The study describes the loading of the quartz SiO

The ferrocene-based Schiff base 3 was synthetized by reaction of ferrocenecarboxaldehyde 1 with 4-aminoantipyrine 2. However, the reaction of 1 with hydroxylamine affords ferrocenecarboxaldehyde oxime 4. Compounds 3 and 4 were fully characterized by IR, 1H, 13C and DEPT-135 NMR spectroscopy, elemental analyses and also by single crystal X-ray diffraction. Compounds 3 and 4 were used to remove anionic methyl blue dye from wastewater. The results established that both compounds have high adsorption capacity towards methyl blue. Langmuir adsorption capacity of compound 4 (464 mmol/g) is much higher than that of compound 3 (193 mmol/g) at 25 °C. The kinetics data was fitted well pseudo-second-order model. Thermodynamic studies show that the adsorption of methyl blue onto compound 3 was endothermic, while its exothermic in case of adsorption onto compound 4. The process was spontaneous for both compounds.

In this work, the effect of linkers such as alkyl quaternary ammonium and alkyl quaternary phosphonium salts intercalated with Na+-montmorillonite (Na+-Mt) via cation exchange followed by the reaction with poly(aspartate-co-succinimide) as biodegradable and superabsorbent polymer has been investigated. The prepared composites were spectroscopically characterized by elemental analysis, X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TAG), and Brunauer–Emmett–Teller (BET) surface analyzer. Polyaspartate-montmorillonite composite with quaternary phosphonium salt (Mt/IPS2) exhibited higher surface area and pore volume compared with polyaspartate-montmorillonite composite with quaternary ammonium (Mt/IPS1), due to its bulky structure. Mt/IPS2 composite displays a maximum adsorption capacity of 9.95 mmol/g for methyl blue (MB) dye which is larger than Mt/IPS1 composite with 8.55 mmol/g. The kinetic data of adsorption were evaluated with pseudo first-order, pseudo second-order and intra-particle diffusion models. The equilibrium time of 20 min toward MB adsorption and the pseudo-second-order was the best fit model for adsorption process. The adsorption isotherm of MB on the IPS1 and IPS2 has been investigated at 25, 30, and 35 °C and the data were in good agreement with the Langmuir isotherm model. Furthermore, the thermodynamic parameters namely; Gibbs free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°) were calculated and the negative ΔG° values indicate the spontaneity of the process. The adsorption mechanism was studied by FT-IR and the electrostatic interaction between cationic active sites of adsorbent surface and anionic MB dye was proposed.

The selective modification of sodium montmorillonite (Na+-Mt) surface with polyionene followed by poly (succinimde-co-aspartate) has been considered. Na+-Mt was allowed to react with well characterized polyionene in two fold excess. The resulting polyionene/Mt (IC) was further modified with poly (succinimide-co-aspartate) through an ion exchange process. The obtained polyaspartate/Mt (IPS) composite was characterized by elemental analysis, X-ray diffraction, FTIR spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and BET surface analyzer. The adsorption efficiency of IPS composite was investigated for the removal of Pb(II) and Cd(II) from aqueous solution under different experimental conditions including initial metal ions concentration, temperature and single and binary mixture systems of metal ions. The experimental data were analyzed by Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models. Langmuir model reveals that the monolayer adsorption capacity of IPS was 92.59 and 67.57 mg/g for Pb(II) and Cd(II), respectively. The modification of parent Na+-Mt enhanced their adsorption capacity by about 87.91 and 29.84% for Pb(II) and Cd(II), respectively, due to inclusion of extra active sites of polyaspartate. The mean sorption energy, E calculated from Dubinin–Radushkevich isotherm were 2.75 and 1.98 kJ/mol for the adsorption of Pb(II) and Cd(II), respectively, indicating physical adsorption process. Also, The thermodynamic parameters were calculated and indicated that the adsorption was spontaneous and exothermic process. The mechanism of cation exchange and complexation of metal ions was suggested. IPS composite has a considerable potential for the removal of heavy metal ions from aqueous solution and wastewater stream.

The aim of this research work was to evaluate the one bath dyeing of polyester/cotton blend and to compare the results with those of two bath dyeing. Polyester/cotton (50:50) blend fabrics were studied using dichlorotriazine based reactive dye and compatible disperse dye. The one bath one step method was used to shorten the dyeing process, increase yield and reduce the utility and chemical cost. Trichloroacetic acid (TCAA) was used to provide an acidic and basic medium with a change in temperature. A TCAA/sodium carbonate buffer was also used to obtain the best colour yield. In two bath dyeing disperse dye was fixed on polyester fibre in an acidic medium, whereas reactive dye was fixed on cellulosic fibre in an alkaline medium. In the final stage, the dyed fabric was evaluated by testing the light, washing and rubbing fastness and colour yield strength properties of the dye. The results clearly show that polyester/cotton fabric presents good fastness and colour strength values when the one bath one step dyeing method is used.

In the current study, the influence of polymer molecular weight on the release of metronidazole (MTZ) as a drug model from synthesized proline-based polymers was studied. Using reversible-addition fragmentation chain transfer (RAFT) polymerization, amino acid-based polymers based on N-acryloyl-L-proline (A-L-Pro-OH) with various molecular weights were prepared with relatively high conversions (55–98%, as measured by 1H NMR spectroscopy). The polymerization process was done at different ratios of [monomer]0/[CTA]0/[AIBN]0. Proline-based polymers with pre-determined molecular weights (Mn = 6000–22 600 in methylated forms) and low polydispersities (Mw/Mn = 1.30–1.37) were utilized for the immobilization of metronidazole. The kinetics release studies of the polymer-MTZ adducts were done at various pH values: 2.0, 7.4, and 8.5 phosphate buffer solutions. The obtained results proved that the hydrolytic behaviors of polymeric prodrugs robustly relied on the molecular weight of the polymer and the pH of the release media. The kinetics of the release process were described using Higuchi and Korsmeyer's models to explain the drug release mechanism.

In this paper, three new Cu(II) Schiff base complexes with three different anions (acetate, chloride, and nitrate) were successfully synthesized and characterized by elemental analysis, mass spectra, molar conductance, FT-IR, NMR,UV–vis spectroscopy, magnetic moment, ESR, and thermal analysis. The catalytic performances of these complexes in decolorization of azo dye, Acid Red 37, were evaluated. Copper(II) complexes were found to be an efficient catalyst for decolorization of Acid Red 37 in the presence of hydrogen peroxide. The catalytic investigation revealed that the Cu(II) complex with acetate anion (complex 1) performed the highest catalytic activity. The kinetics of the decolorization of AR37 with this catalyst was studied, and the observed rate constant was determined. The effects of different reaction parameters such as catalyst dosage, solution pH, initial concentration of H2O2, dye solution, and reaction temperature on the reaction rate constant were studied. The best reacting conditions should be catalyst dosage = 0.004 g, initial pH 4.0, [H2O2]0 = 0.8 M, and [AR37]0 = 1.16 M at temperature 25°C. Under these conditions, about 99% of AR37 was decolorized within 60 min. The results indicated that the Cu(II) complex with the acetate anion is a promising catalyst for wastewater treatment.

The adsorption of acid dye, namely, acid fuchsin (AF), onto sodium montmorillonite (Na+-Mt) from aqueous solutions was investigated. The adsorption process was very fast and attained equilibrium within 1 h, which was an economically favorable requisite. The Freundlich and Langmuir adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were calculated. The experimental data fit well with Freundlich model rather than the Langmuir model. The equilibrium adsorption constant, Kc, was determined and used to calculate the enthalpy and entropy of the adsorption process. The adsorption kinetics was followed up using a stopped-flow spectrophotometer under pseudo-first-order conditions. The influence of initial dye concentrations, amount of sodium montmorillonite, and temperature on the rate of adsorption were studied. The activation energy of adsorption was calculated and indicated a chemical adsorption process. The enthalpy of adsorption confirmed an exothermic process. A proper mechanism for adsorption supported by X-ray and atomic absorption data was proposed.

Adsorption of cyanine dyes from aqueous solution onto the surface of Na+-montmorillonite (Na+-MMT) was investigated spectrophotometrically. A set of four linear alkyl chain cyanine dyes (D-C5, D-C7, D-C10, and D-C18), were used in this work to evaluate the effect of carbon chain length on the efficiency of dye adsorption. The loading of the dye onto Na+-MMT surface was increased with increasing the length of alkyl chain. The effect of the contact time, initial concentration of the dye, pH of solution and temperature on the adsorption process were studied. Adsorption isotherms were established and found to correlate well with the Freundlich, Langmuir, and Dubinin–Radushkevich adsorption models. Values of the constants Kf and 1/n determined from the Freundlich isotherm decreased with the increase in the tail length of the dye (D-C5 → D-C18). The same trend was observed for the Langmuir adsorption constant, KL. The E values calculated from Dubinin–Radushkevich isotherm increased with increasing the alkyl chain length of the cyanine dyes but still less than 16 kJ mol−1, suggesting physical adsorption process. Further, the thermodynamic parameters (the enthalpy, ΔH, Gibb’s free energy, ΔG, and entropy, ΔS) characteristics of Na+-MMT/dye interaction were evaluated. The adsorption of cyanine dyes onto Na+-MMT was not spontaneous and endothermic. The magnitudes of ΔH and ΔS have dropped on going from D-C5 to D-C18. In contrast, as the size of the alkyl tail on the dye increased, Gibb’s free energy ΔG was decreased. As far as the adsorption kinetics is concerned, the present adsorption regime followed pseudo-second-order kinetic model rather than pseudo-first-order model. The intraparticle diffusion model resulted in the existence of both the bulk and intraparticle diffusions of the dye molecules into the interior pore surface of Na+-MMT particles.

A new polymeric drug carrier system using amino acid-based polymers was developed. Amino acid-based polymers with controlled molar mass and narrow molecular weight distribution have been synthesized by reversible addition-fragmentation chain transfer polymerization of four amino acid-carrying monomers having different chirality and hydrophilicity. Metronidazole (MTZ) was immobilized onto the amino acid-based polymers, and the release profiles of the polymer-MTZ adducts were investigated in phosphate buffer solutions (pH = 2.0, 7.4, and 8.5). The model drug was released by the hydrolysis of the ester group, and the release rate and behavior of the polymeric prodrugs strongly depended on the configuration of the amino acid-based polymers-MTZ adducts and the pH of the release media. The release kinetics was determined using the Higuchi and Korsmeyer equations, which revealed the release mechanism of the polymeric prodrugs. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Five new metal-organic frameworks (MOFs) of the general composition [Ph3SnCu(CN)2·L], where L=pyrazine (pyz) (1), methylpyrazine (mepyz) (2), 4,4′-bipyridine (bpy) (3), trans-1,2-bis(4-pyridyl)ethene (tbpe) (4) or 1,2-bis(4-pyridyl)ethane (bpe) (5), have been synthesized and characterized to test their potential applications as catalysts. The structures of the MOFs 1–5 mainly consist of Cu(CN)2 building blocks connected by the Ph3Sn cations and the bipodal ligand forming polymeric networks. They exhibit strong fluorescence in the solid state. Also, they are used as heterogeneous catalysts for the degradation of azo-dyes, metanil yellow (MY) by diluted solution of hydrogen peroxide as oxidant. The reaction is first order with respect to MY dye, while the factors affecting the rate constant of the degradation reaction are investigated. The activation parameters of the reaction have been estimated and a possible mechanism has been proposed.

The adsorption equilibria of proton accepting and donating analytes on porous silica beads applicable as stationary chromatographic phases were investigated by UV/vis absorption spectroscopy. Fluorescence spectroscopy was utilized to characterize the nature of the species formed at the silica surfaces after adsorption. In order to control the equilibria and states of adsorption the active silanol surface centers were partly shielded by adsorbed water or by two types of polymeric coatings, (i) polymerized 1,4-divinylbenzene (DVB) with loadings of 200 mg and 500 mg DVB/g silica, respectively, (ii) polymerized N,N′-diallyl- l -tartardiamide bis-(4-tertbutylbenzoate) (TBB) with a loading of 135 mg TBB/g silica. Acridine orange, 1,2,7,8-dibenzacridine, 3,4,5,6,-dibenzacridine, and lumichrome were used as fluorescent analytes with proton accepting or donating nitrogen centers. The fluorescence anisotropies show that the adsorbed species at the uncoated silica surface are highly immobilized. Coating considerably reduces the equilibrium constants of adsorption. polymerized N,N′-diallyl- l -tartardiamide bis-(4-tertbutylbenzoate) works much better than polymerized 1,4-divinylbenzene. In the latter case a large amount of polymer is necessary in order to produce a significant effect.

The adsorption of 2-(4′-dimethylaminostyryl)benzoxazole (DMASBO) and its benzothiazole analogue (DMASBT) onto Na-montmorillonite (Na + -MMT) was studied. The adsorption data have been fitted with Freundlich and Dubinin–Radushkevich ( D – R ) equation to find the characteristic parameters of each model. From D – R isotherm, it was concluded that the adsorption is of chemical nature. The equilibrium adsorption constant, K c , was determined and has been used to calculate the enthalpy and entropy of the adsorption process. The mechanism of the adsorption has been investigated by fluorescence, IR, X-ray and ESR spectroscopic measurements. These measurements indicate oxidation of the styryl dyes by the Lewis acidic sites of the clay and formation of radical cations at Na + -MMT surface without intercalation into the interior.

The kinetics of the oxidative degradation of an azo dye Metanil Yellow (MY) was investigated in aqueous solution using dirhodium(II) caprolactamate, Rh(2)(cap)(4), as a catalyst in the presence of H(2)O(2) as oxidizing agent. The reaction process was followed by UV/Vis spectrophotometer. The decolorization and degradation kinetics were investigated and both followed a pseudo-first-order kinetic with respect to the [MY]. The effects of various parameters such as H(2)O(2) and dye concentrations, the amount of catalyst and temperature have been studied. The studies show that Rh(2)(cap)(4) is a very effective catalyst for the formation of hydroxyl radicals HO(•) which oxidized and degraded about 92% of MY into CO(2) and H(2)O after 24 h as measured by total carbon analyzer.

The adsorption and the kinetics of the intercalation of metanil yellow dye, p-aminodiphenylamine (p-NH(2)-DPA), and benzidine by colloidally dispersed Na(+)-montmorillonte (Na(+)-MMT) have been studied. The adsorption isotherm parameters confirmed the occurrence of chemical adsorption that is based on the cation-exchange process. The selectivity of these compounds toward Na(+)-MMT follows the order metanil yellowp-NH(2)-DPAbenzidine, which reflects the stability sequence of the intercalates. The attainment of sorption equilibrium and the diffusion coefficient follows the order metanil yellowp-NH(2)-DPAbenzidine. The rate of oxidation has been quantitatively measured using a stopped-flow spectrophotometer. The rate constant follows the order benzidinep-NH(2)-DPAmetanil yellow. Addition of allyle acetate shows inhibiting effect on the reaction rate. The rate of cation exchange process between the radical cation of the organic molecule and the Na(+)-ion in the Na(+)-MMT has been monitored by using the stopped-flow instrument with an electrical conductivity detection unit. The activation energy of the electron transfer reaction is less than that of cation exchange process and has the order metanil yellowp-NH(2)-DPAbenzidine. X-ray diffraction, IR, and differential scanning colorimetry (DSC) measurements confirmed the intercalation process.