The Kinetics of an Interfacial Reaction in Microemulsions with Excess Phases

Bode, G.W.; Lade, Markus; Schomäcker, Reinhard

doi:10.1002/(sici)1521-4125(200005)23:5<405::aid-ceat405>3.0.co;2-g

Cited by 16 publications

(8 citation statements)

References 8 publications

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“…The rate with and without stirring was the same. The observation that a Winsor system is just as effective a reaction medium as a one-phase microemulsion has been observed before, for another nucleophilic substitution reaction . The fact that a Winsor I system can be used instead of a one-phase microemulsion is practically important.…”

Section: Discussionmentioning

confidence: 64%

A Nucleophilic Substitution Reaction Performed in Different Types of Self-Assembly Structures

2004

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A nucleophilic substitution reaction between 4-tert-butylbenzyl bromide and potassium iodide has been performed in oil-in-water microemulsions based on various C12Em surfactants, i.e., dodecyl ethoxylate with m number of oxyethylene units. The reaction kinetics was compared with the kinetics of reactions performed in other self-assembly structures based on very similar surfactants and in homogeneous liquids. The reaction was fastest in the micellar system, intermediate in rate in the microemulsions, and most sluggish in the liquid crystalline phase. Reaction in a Winsor I system, i.e., a two-phase system comprising an oil-in-water microemulsion in equilibrium with excess oil, was equally fast as reaction in a one-phase microemulsion. The reactions in microemulsion were surprisingly fast compared to reaction in homogeneous, protic liquids such as methanol and ethanol. The rate was independent of the microstructure of the microemulsion; however, the rate was very dependent on the type of surfactant used. When the C12Em surfactant was replaced by a sugar-based surfactant, octyl glucoside, the reaction was much more sluggish. The high reactivity in microemulsions based on C12Em surfactants is belived to be due to a favorable microenvironment in the reaction zone. The reaction is likely to occur within the surfactant palisade layer, where the water activity is relatively low and where the attacking species, the iodide ion, is poorly hydrated and, hence, more nucleophlic than in a protic solvent such as water or methanol. Sugar surfactants become more hydrated than alcohol ethoxylates and the lower reactivity in the microemulsion based on the sugar surfactant is probably due to a higher water activity in the reaction zone.

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Section: Discussionmentioning

confidence: 64%

A Nucleophilic Substitution Reaction Performed in Different Types of Self-Assembly Structures

2004

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“…To increase yield and selectivity even under mild reaction conditions ( T < 150 °C, p < 100 bar), a water-soluble, hydrophilic rhodium-ligand-complex is employed. The resulting multiphase system offers the possibility to separate the valuable rhodium catalyst from the organic product . Figure shows the novel process concept for the hydroformylation of long chain olefins in a micellar multiphase system.…”

Section: Motivationmentioning

confidence: 99%

Process Design for the Separation of Three Liquid Phases for a Continuous Hydroformylation Process in a Miniplant Scale

Müller

Kasaka

Müller

et al. 2013

Ind. Eng. Chem. Res.

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Within the framework of the Collaborative Research Centre SFB/TR 63 InPROMPT, “Integrated chemical processes in liquid multiphase systems”, a novel process concept for the hydroformylation of long chain alkenes to aldehydes in microemulsions is investigated and developed at the Berlin Institute of Technology (Technische Universität Berlin), Germany. To start the hydroformylation reaction, a hydrophilic rhodium-ligand-complex is required. By applying a nonionic surfactant, a microemulsion system is formed and thus the hydrophilic catalyst is transported into the hydrophobic alkene phase. Next to achieve a high conversion rate in the continuously stirred tank reactor, the separation of the valuable rhodium catalyst from the product phase poses a challenge. This separation is the crucial step for the technical and economic feasibility of the overall process concept and plant design. Owing to the lack of thermodynamic data for microemulsion mixtures, the design of the phase separation unit strongly depends on experimental results. Consequently, a systematic experimental approach has been developed to identify potential operating conditions and relevant design parameters. To classify and find these, a set of experimental set-ups have been investigated to characterize impact factors on the phase separation such as type of surfactant, different concentrations of surfactant, olefin, product, and water. With the information gained through the observations the relevant composition of the investigated mixture and the separation temperature are determined for the operating conditions. Finally, necessities with regards to plant and process design are revealed.

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“…Using 1,3,5-tris[4-(4′-2,2′:6′,2″-terpyridyl)phenyl]benzene ( 1 ), which is a three-way bridging tris(terpyridine) ligand, we obtained electrochromic Fe(tpy) 2 32 – 34 CONASH capsules and photoluminescent Zn 2 (SO 4 ) 2 (tpy) 2 16 , 35 CONASH capsules by a simple dropping method, a syringe pump method and an emulsion method. The formation of the CONASHs at the liquid–liquid interfaces is accelerated by the addition of surfactant such as sodium dodecyl sulfate (SDS), allowing the CONASH capsules to be formed within 15 min 36 , 37 . The surfactant also stabilizes the droplets during synthesis 38 , 39 .…”

Section: Introductionmentioning

confidence: 99%

Redox-active, luminescent coordination nanosheet capsules containing magnetite

Arai

Toyoda

et al. 2020

Sci Rep

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Two-dimensional coordination nanosheets (CONASHs) are grown at the spherical liquid–liquid interface of a dichloromethane droplet in water to form zero-dimensional nano- and micro-capsules using a simple dropping method, a syringe-pump method, and an emulsion method. Reaction of 1,3,5-tris[4-(4′-2,2′:6′,2″-terpyridyl)phenyl]benzene (1) with Fe(BF4)2 affords electrochromic Fe(tpy)2 CONASH capsules and that of ligand 1 with ZnSO4 does photoluminescent Zn2(μ-O2SO2)2(tpy)2 CONASH capsules. Fe(tpy)2 CONASH capsules containing magnetite particles were produced by the syringe-pump method by adding magnetite to the aqueous phase, with the assembly and dispersion of the magnetite-containing CONASH capsules being easily controlled with a magnet. This indicates that physicochemically functional CONASH capsules are suitable for incorporating other functional materials to develop hybrid systems.

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The Kinetics of an Interfacial Reaction in Microemulsions with Excess Phases

Cited by 16 publications

References 8 publications

A Nucleophilic Substitution Reaction Performed in Different Types of Self-Assembly Structures

A Nucleophilic Substitution Reaction Performed in Different Types of Self-Assembly Structures

Process Design for the Separation of Three Liquid Phases for a Continuous Hydroformylation Process in a Miniplant Scale

Redox-active, luminescent coordination nanosheet capsules containing magnetite

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