CATALASE MIMIC WITH Fe (II) METALLOMICELLE

The effect of Fe (II) metallomicelle as a model of catalase, which was formed by adding surfactants (CTAB, SDS, LSS, Brij35) in Fe (II) -trien complex of molar ratios 1: 500 on the decomposition of hydrogen peroxide was investigated at 20°C and 30°C in pH 10 using KI-color and UV Spectrophotometry. A kinetic model for metallomicellar catalysis was proposed. The association constant of the ternary complex K and the rate constant of the decomposition of hydrogen peroxide k3 were obtained. The results indicate that the metallomicelles making up of Fe (II) metal complex and cationic or nonionic surfactants have obvious catalysis on the decomposition of hydrogen peroxide, but the metallomicelles making up of Fe (II) metal complex and anionic or zwitterionic surfactants have inhibition on this reaction.     

ACCELERATED CLEAVAGE OF P-NITROPHENYL PICOLINATE CATALYZED BY COPPER(II) AND ZINC(II) COMPLEXES OF D-GLUCOSAMINE SCHIFF BASE IN MICELLAE SOLUTION

Abstract

The hydrolysis of p-nirrophenyl picolinate (PNPP) catalyzed by the Cu(II) and Zn(H) complexes of d-glucosamine schiff base was investigated kinetically by observing the rates of the release of p-nitrophenol in the buffered micellor solution at different pit and 25°C. The scheme for reaction acting mode involving a ternary complex contain ligand, metal ion and substrate in micelle was establish and the reaction mechanisms were discussed The experimental results indicated that the complexes catalyzed efficiently the hydrolysis of PNPP, especially Zn(II) complex. The rate constant k_N, which shows the catalytic reactivity of complexes, WBI determined to be 0.4251 s^?1 far Cu(II) complex at pH 7 60 in micellar solution. The catalytic reactivity of Zn(II) complex were much larger than Cu(II) complex, the k_N was determined to be 3.1914 s^?1 at same pH value.     

THE EFFECTS OF MIXED MICELLES OF SURFACTANTS ON POLYMERIZATION OF ACRYLAMIDE

The polymerization of acrylamide in mixed micellar solutions of surfactants, initiated by NaHSO₃ has been studied at 20 and 3Q° C with time variable method of thermokinetics for 1. 5-order reaction. The results indicate that the mixed micellar systems of cationic or anionic with zwitterionic surfactants (SLS/ CTAB, SLS/ TTAB, SLS/ SDS) and cationic with nonionic surfactants (Brij 357sol; CTAB, Bri-J35/TTAB, Brij35/ DTAB) have catalytic effect on the polymerization in the order, at 20° C. SLS/ SDS SLS/ TTAB SLS/ CTAB Brij35/ CTAB at 30° C SLS/ SDS SLS/ TTAB≈ / CTAB Bri-j35/ DTAB= sBrij35/ TTAB as Brij35/ CTAB, while Brij35/ SDS mixed micellar system has inhibition. These effects are attributed to the effect of the Stern layer of mixed micelles on the step of initiator (HSOT) to form free radical.     

THE EFFECT OF SLNGLE AND MIXED MICELLES OF SURFACTANTS ON POLYMERIZATION OF ACRYLAMIDE

Acrylamide is conveniendy polymerized in aqueous solution lo a water soluble polymer. The measurements of kinetic parameters of polymerization of acrylamide, in aqueous and micellar solution, have been earned out by conduction calorimeter. The polymerization is initiated by sodium sulfite and sulfite-persulfate redox system. The effect of initiator and monomer concentration as well as temperature and surfactants on polymerization rale constant has been investigated. The analog thermogram method has been employed to calculate the rate constants. The activation energy is calculated from Arrhenius relationship and molecular weights are determined by viscometry. Rate equations have been derived and reaction mechanism hove been suggested. The rate of reaction is found to increase with temperature and monomer concentration.     

THE EFFECT OF MIXED MICELLES OF SURFACTANTS ON THE ALKALINE HYDROLYSIS OF ESTERS

The alkaline hydrolysis of aromatic and normal aliphatic acid esters have been studied at 25°C In mixed micellar solution of surfactants (Brij35—SDS, Brij35 — DTAB, Brij35—TTAB.Brij35-CTAB. Triton X—100 —CTAB, Triton X— 100 —SDS) with UV spectrophotometry and the method of thermokinetics The critical mice liar concentrations of the corresponding systems have also been measured with UV spectrophotometry in this paper. K_jnln micellar pseudo-phase has been calculated- The ratios of ki.to ki.for all mixed micellar systems Investigated are less than 1. The results indicate that these reactions are inhibited by the mixed micelles and the mixed micelles exhibit a greater effect of Inhibition on the reactions than those do In corresponding single ones. The reason for this is that the micropolarity of the compact Stern layer of mixed micelle is lower, and the micro viscidity Is higher. The Inhibition effect! also depend on the hydrophobic chain length of the surfactants and the hydrophobicity of the substrate.     

HYDROLYSIS OF p-NTTROPHENYL PICOLINATE CATALYZED BY ZINC(H) OR NICKEL (II) COMPLEXES OF LONG ALKYL-PYRIDINES WITH HYDROXYL GROUPS IN MICELLAR SOLUTION

The ternary complex kinetic model for metallomicellar catalysis was employed to investigate the effect of Zn²⁺ ion or Ni²⁺ion complexes of long alkyl-pyridines with hydroxyl groups in micellar solution on the hydrolysis of p-nitrophenyl picolinate in this paper. The kinetic and the thermodynamic parameters (K _N, K _r, K _M) were obtained. More worthily, the effect of pH on the hydrolysis of p-nitrophenyl picolinate in metallomicellar phase was discussed quantitatively. The rate constant (K _N) of the hydrolysis of p-nitrophenyl picolinate in metallomicellar phase was obtained and compared with Cu²⁺ ion complex system. The results indicated that Cu²⁺ ion micelle, Ni²⁺ ion micelle and Zn²⁺ ion micelle all exhibited great catalytic effects on the hydrolysis of p-nitrophenyl picolinate. and the order of activity is:Cu²⁺ ion micelle ≥ Ni²⁺ ion micelle ≥ Zn²⁺ ion micell. Moreover, the reasonability of the ternary complex kinetic model was verified further.     

THE EFFECT OF SINGLE MICELLES OF SURFACTANTS ON POLYMERIZATION OF ACRYLAMIDE

The polymerization of acrylamide in micellar solutions of cationic, anionic, zwitterionic and nonionic surfactants, initiated by NaHSO₃, has been studied at 20 and 30° C with time variable method of thermokinetics for the 1. 5-order reaction in this paper. Reaction mechanism has been suggested and rate equations have been derived. The results indicate that ionic (CTAB, TTABDTAB, SDS) and zwitterionic (SLS) surfactants catalyze the polymerization in the order SDS>SLS>DTAB ≈ TTA≈ CTAB, and nonionic surfactant (Brij35) has slight inhibition effect. These effects are mainly caused by the effect of the formation of micelle- HSO₃ complex on the step of initiator to form free radical.     

HYDROLYSIS OF P-NITROPHENYL PICOLINATE CATALYZED BY COPPER(II ) COMPLEXES OF LONG ALKYL-PYRIDINES WITH HYDROXYL GROUPS IN MICELLAR SOLUTION

ABSTRACT

A ternary complex kinetic model for metallomicellar catalysis has been proposed in this paper. Hydrolysis of PNPP influenced by Co-micelles of long alkyl-pHridines with hydroxyl groups and CTAB was investigated in aqueous buffers of pH ranging from 5. 0 to 7. 0 at 30°C at present of Cu²⁺. The kinetic and the thermodynamic parameters (K_n', K_m', K_T) were obtained by the kinetic analyses,moreover,the rate constant K_n in metallomi-cellar phase was obtained. The pK_? s of the hydroxyl groups of these complexes were determined to be 5. 62,5. 53,5. 34,5. 32,respectively by analyses of pH-rate profiles. The results indicate that pyridine ligands exhibit a great catalysis on the hydrolysis of PNPP,which increases with increasing the hydrocarbon chain length.     

热动力学对比进度法IV. 热导式热量计的单参数理论模型与热谱重建

本文建立了热导式热量计的单参数理论模型, 在此基础上系统地提出了热谱重建法, 并结合热动力学对比进度法, 对几个化学反应体系进行了热动力学研究。实验结果验证了本文方法及其理论基础的正确性。     

THE EFFECT OF CATIONIC,ANIONIC, AND NONIONIC SURFACTANT MICELLES ON THE ALKALINE HYDROLYSIS OF ESTERS

The alkaline hydrolysis of aromatic and normal aliphatic acid esters has been studied at 25°C in micellar solutions of surfactants (DTAB, TTAB, CTAB, SDS, Brij 35 and Triton X—100) with UV spectrophotometry and the method of thermokinetics in this paper. The rate constants of the alkaline hydrolysis of esters in micellar pseudophase, k_1m and K_2m have been calculated, respectively. The ratios of k_2m to k_2w or k_1w to k_1w indicate that the alkaline hydrolysis of esters arc inhibited by all of the surfactants investigated. It was supposed that such inhibition is mostly in relation to the micropolarity of micellar surface. The critical micellar concentrations of the corresponding systems have also been measured with the conductivity method and UV spectrophometry in this paper.