Excess Of Sodium Hydroxide Research Articles

Facile one-step synthesis and characterization of MnO nanoneedles and their application in solar photocatalysis

Manganese oxide (MnO) colloidal nanoneedles have been successfully synthesized by a facile one-step method based on the alkaline reaction of the precursor manganese acetate salt and excess sodium hydroxide. X-ray diffraction and FT-IR spectroscopy confirmed the synthesized MnO nanoneedles phase and structure. The optical properties of synthesized MnO nanoneedles were studied by UV–Vis absorption spectroscopy. Optical particle size and band gap of synthesized MnO colloidal nanoneedles were calculated. HR-TEM/SEM images and EDX allow us to determined particle shape and size. The photocatalytic activity of the MnO nanoneedles was evaluated using the Congo red azo dye in an aqueous solution under solar light irradiation. The results showed that nanoneedles, compared with commercial ZnO nanoparticles, exhibited high photocatalytic activity. The photocatalytic studies also showed that various parameters such as band gap, size, shape, and rate constant velocity remarkably affected the remotion rate of Congo red azo dye.

Reaction of KHP with excess NaOH or TRIS as standard reactions for calibration of titration calorimeters from 0 to 60°C.

Calibration of titration calorimeters is an ongoing problem, particularly with calorimeters with reaction vessel volumes < 10 mL in which an electrical calibration heater is positioned outside the calorimetric vessel. Consequently, a chemical reaction with a known enthalpy change must be used to accurately calibrate these calorimeters. This work proposes the use of standard solutions of potassium acid phthalate (KHP) titrated into solutions of excess sodium hydroxide (NaOH) or excess tris(hydroxymethyl)aminomethane (TRIS) as standard reactions to determine the collective accuracy of the relevant variables in a determination of the molar enthalpy change for a reaction. KHP is readily available in high purity, weighable for easy preparation of solutions with accurately known concentrations, stable in solution, not compromised by side reactions with common contaminants such as atmospheric CO2, and non-corrosive to materials used in calorimeter construction. Molar enthalpy changes for these reactions were calculated from 0 to 60°C from reliable literature data for the pKa of KHP, the molar enthalpy change for protonation of TRIS, and the molar enthalpy change for ionization of water. The feasibility of using these reactions as enthalpic standards was tested in several calorimeters; a 50 mL CSC 4300, a 185 μL NanoITC, a 1.4 mL VP-ITC, and a TAM III with 1 mL reaction vessels. The results from the 50 mL CSC 4300, which was accurately calibrated with an electric heater, verified the accuracy of the calculated standard values for the molar enthalpy changes of the proposed reactions.

Acid-responsive polydiacetylene-Na+ assemblies with unique red-to-blue color transition

Polydiacetylenes (PDAs), conjugated and stimuli-responsive polymers, are of interest for colorimetric sensing technologies. Commercially available PDAs with carboxylic headgroup do not show any colorimetric response to acid. To achieve acid-responsive property, the headgroups of PDAs are often modified with some functional moieties, involving complicated synthetic processes. This contribution presents a facile approach to develop acid-responsive materials via co-assembly of PDA and excess sodium hydroxide (NaOH). After low-temperature incubation and photopolymerization, the mixtures of 10,12-tricosadiynoic acid (TCDA) and NaOH develop into red-phase poly (TCDA-Na+) assemblies. A unique red-to-blue color transition occurs when the poly (TCDA-Na+) assemblies are exposed to hydrogen chloride (HCl) acid both in aqueous solution and gas phase. Increasing the concentrations of NaOH and TCDA monomer during the self-assembly process affects the molecular organization and morphologies of the resultant poly (TCDA-Na+) assemblies, which in turn govern the sensitivity to acid. The results of this study offer a simple and inexpensive method for developing acid-responsive PDAs, extending their colorimetric sensing applications.

Lithium isotope separation by precipitation method coupled with solvent extraction with 1-Hydroxy-4-(p-toluidino) anthraquinone

This paper reported a novel chelating agent and a green precipitation-extraction separation strategy for lithium isotope enrichment. 1-Hydroxy-4-(p-toluidino) anthraquinone and anisole were used as chelating agent and diluent, respectively. Three phases including organic phase, aqueous phase and precipitation could be preparated. The experiment indicated that excess sodium hydroxide was helpful to promote the single-stage precipitation rate and equilibrium time. The isotope result indicated that 6Li was concentrated in the aqueous phase and 7Li was concentrated in precipitation phase. The maximum single-stage lithium isotope speration factor reached to 1.013 ± 0.001. By doing thermodynamic analysis of the reaction, the free energy change (ΔG), enthalpy change (ΔH) and entropy change(ΔS) of the separation process were −8.97 J mol−1, −21.37 J mol−1 and −0.0438 J mol−1 K−1 at 283 K. The results of DFT simulation and wave function analysis indicated that a lithium ion combined with a chelating agent anion formed a stable six-member ring between two oxygen, which was more stable than sodium ions combined with chelating agent anions (the Gibbs free energy of the lithium ions reaction was more negative). As interaction analysis result showed, the Li-O bond in complex interaction was significantly stronger than the Li-O bond interaction in aqueous phase, which was the theroy that led to the enrichment of 7Li in organic phase. In the activated carbon treatment experiment, it was found that part of lithium chelator solved in aqueous phase, which resulted in that the lithium abundance of aqueous phase hardly changed. In order to increase the abundance of 6Li in aqueous phase, it is necessary to add adjuvant to reduce the water solubility of lithium chelate. Overall, an economical and environmental-friendly precipitation method with a certain application prospect for lithium isotope separation was proposed, and the direction of improving the separation performance was pointed out in this paper.

Structural properties of lithium doped V3O8 nanorods synthesized by hydrothermal method

The structural properties of lithium-doped trivanadate(Li-doped-V3O8)nanorods have been prepared by using vanadium pentoxide xerogelas reducing agent via hydrothermal method of lithium nitrate in the presence of excess sodium hydroxide. The resulting Li doped V3O8 nanorods materials were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and William- hall plot analysis. Spectroscopic results indicated the successful formation of lithium-doped V3O8 nanorods. The surface morphologies of lithium-doped V3O8 nanorods were obtained to be dependent on the molar ratio of lithium nitrate to vanadium pentoxide. As obtained, nanorods have a particle size in the range of 22.5 nm and 27 nm. The SEM images of vanadium dioxide and Li doped V3O8 reveal the nanorods to have dimensions on the order of 2–4 µm and 1–2 µm in length and 20–30 nm in diameter. The EDX diffraction measures the elemental composition of nanorods. The XRD studies confirm the formation of the compound and crystallinity structure of nanomaterials VO2 and Li doped V3O8. By the Williamson-Hall plot, which displays the structural flaws of nanomaterials, the strain is measured. The unique properties of these Li doped V3O8 make them attractive use in lithium-ion batteries (LIBs) application.

Alkali-assisted facile and scalable preparation of fluorescent sulfur-doped carbon dots with excellent optical and biological properties from thioctic acid

The preparation of high-performance heteroatom-doped fluorescent carbon dots (CDs) from renewable biomass or biometabolites hold an extensive attention. Here, we report an excess sodium hydroxide (NaOH) assisted method for the preparation of sulfur-doped carbon dots (S-CDs) at lower temperatures by using thioctic acid (TA). Excessive NaOH can promote the thermal decomposition process of thioctic acid in the hydrothermal process, thereby realizing rapid reaction rate (critical time 1 h) and scalable synthesis at low temperature (120 °C). The amount of NaOH and the reaction time were identified as the main factors affecting the synthesis, and the reaction of NaOH with disulfide bonds contributed the most to the generation of fluorescent S-CDs. This in-situ sulfur doping process resulted in excellent fluorescence properties, high relative quantum yield of 11.5%, low biotoxicity, good biocompatibility and excellent solubility, etc. In addition, this as-prepared fluorescent S-CDs showed excellent concentration dependence on ferric ions (Fe3+) and can achieve high-precision and selective detection. This work may provide a high-efficiency synthesis strategy for S-CDs for biological and detection applications.

A Non-Football Cage Type Dodecanuclear Organostannoxane: Synthesis, Structure and NDR Behavior

A new dodecanuclear organostannoxane with an unprecedented structure comprising four O-capped clusters is isolated using 2-(phenylazo)phenyl substitution on the tin center. The formation of [(RSn)12(µ3-O)4(µ2-O)3(µ2-OH)21] [Cl]·5PhCH3·THF (1) is achieved by the complete hydrolysis of RSnCl3 [R = 2-(phenylazo)phenyl] in the presence of excess sodium hydroxide in refluxing ethanol/water (1:1) mixture. Complex 1 crystallizes in the triclinic space group P-1. The absence of N→Sn intramolecular coordination in the molecular structure of 1 illustrates the hemi-labile nature of N→Sn intramolecular coordination. Each tin atom in complex 1 is hexacoordinated, possessing distorted octahedral geometry. All the 12 Sn centers in complex 1 are held together through four µ3-O2− three µ2-O2−, and twenty-one µ2-OH− ligands resulting in the formation of a central Sn12 oxo-hydroxo core having four o-capped clusters in the framework. I-V characteristic curve of complex 1 based device displayed an interesting negative differential resistance (NDR) behavior in the voltage range of 1.0–1.8 V with excellent repeatability of 200 cycles.

Molten-Salt Synthesis of O3-Type Layered Oxide Single Crystal Cathodes with Controlled Morphology towards Long-Life Sodium-Ion Batteries.

Sodium layered oxides show great promise as affordable alternatives to lithium layered oxides, but their poor cycle life and air stability limit their practical potential. Micron-scale single crystals with greater packing density and lower surface area can overcome these challenges and improve performance compared to the traditional polycrystalline morphology. Herein, the authors present the synthesis of layered O3-type Na(Ni0.3 Fe0.4 Mn0.3 )O2 single-crystals with greatly improved cycle life and air stability. A molten-salt synthesis technique is adopted with excess sodium hydroxide to obtain platelet-like single crystals. Because the main mechanisms of both capacity fade and air degradation occur as a result of surface reactions at the opening of the sodium diffusion channels, particle morphology is found to be a critical metric for materials performance. More important than particle size or total surface area, the smaller proportion of exposed edge planes in the platelet morphology greatly reduces the amount of harmful surface reactions. Furthermore, the molten-salt method is found to eliminate the need for coprecipitated precursors and even form better morphology, starting from metal oxides instead of coprecipitated hydroxides.

Anoxic treatment for thiosulfate separation from formate containing dithionite industrial effluent and electrochemical sulfur recovery

The present work deals with utilization of formate present in the dithionite industrial effluent for thiosulfate separation and electrochemical sulfur recovery. In anoxic treatment, Pseudomonas aeruginosa and Proteus mirabilis were used for formate utilization and thiosulfate reduction. The organisms utilized sodium formate as a carbon source and thiosulfate as a terminal electron acceptor, it degraded the organic compounds fully present in the effluent. Thiosulfate got reduced to sulfide or hydrogen sulfide, where thiosulfate reduction was insignificant. Impact of iron surface on anoxic thiosulfate reduction was also investigated in the present study. An electrochemical two chambered membrane cell was used to recover sulfur from the biogenic sulfide electrolyte. Three different types of surface pattern (flattened, twisted and cylindrical) of Ti-TiO2/IrO2/RuO2 coated mesh anodes were used to comparing the sulfide to sulfur conversion process. Rotating cylindrical mesh electrode gave maximum sulfur recovery efficiency (96%) when compared to twisted (91%) and flattened (61%) electrodes. In this process, excess sodium hydroxide was also recovered at the catholyte during biogenic sulfide oxidation.

Studies on ionic mass transfer in an electrolytic cell in the presence of triangle teethed baffles

Mass Transfer data obtained using diffusion – controlled cathodic reduction of ferricyanide ion at the microelectrodes fixed on the electrode support in an electrolytic cell in the presence of a Triangle teethed baffles fixed on the cell wall. The electrolyte used in this study was eqimolal potassium ferricyanide, potassium ferrocyanide and excess sodium hydroxide. The mass transfer coefficient increased with increase in flow rate of the electrolyte and width of baffle and decreased with increase in spacing between the baffles. The experimental data are correlated as following: J D = 39.81 R e - 0.63 w s 0.271 .

Hydrolysis kinetics of PMDA/ODA polyimide for monomer recovery using sodium hydroxide in high-temperature water

Monomer recovery from polyimide hydrolysis in high-temperature water was investigated using batch-type reactors with respect to the effects of reaction time, temperature, and sodium hydroxide concentration. Direct observation of the polyimide decomposition in high-temperature water revealed that gas bubbles were produced above 423 K and polyimide dissolution occurred above 573 K. The monomers 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid, PMA) and 4,4ʹ-diaminodiphenyl ether (4,4ʹ-oxydianiline, ODA) were produced in the early stages of the reaction. The generated PMA decomposed to form carbon dioxide after a reaction time of 10 min at 573 K, while the ODA was relatively stable. Moderate temperature and sodium hydroxide concentration promoted polyimide hydrolysis, whereas overcracking of the polyimide occurred in the presence of excess sodium hydroxide at high temperature. A reaction time of 5 min and alkali concentration of 22 mmol/kg were found to be the optimal conditions for monomer recovery at 573 K.

Solid-State Recrystallization Pathways of Sodium Aluminate Hydroxy Hydrates.

Crystallization of Al3+-bearing solid phases from highly alkaline Na2O:Al2O3:H2O solutions commonly necessitates an Al3+ coordination change from tetrahedral to octahedral, but intermediate coordination states are often difficult to isolate. Here, a similar Al3+ coordination change process is examined during the solid-state recrystallization of monosodium aluminate hydrate (MSA) to nonasodium bis(hexahydroxyaluminate) trihydroxide hexahydrate (NSA) at ambient temperature. While the MSA structure contains solely oxolated tetrahedral Al3+, the NSA structure is a molecular aluminate salt solely based upon monomeric octahedral Al3+. Spontaneous recrystallization of MSA and excess sodium hydroxide hydrate into NSA over 3 days of reaction time was clearly evident in X-ray diffractograms and in Raman spectra. In situ single-pulse 27Al magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy and 27Al multiple quantum (MQ) MAS NMR spectroscopy showed no evidence of intermediate aluminates, suggesting that transitional states, such as pentacoordinate Al3+, are short-lived and require spectroscopy with greater time resolution to detect. Such research is advancing upon a detailed mechanistic understanding of Al3+ coordination change mechanisms in these highly alkaline systems, with relevance to aluminum refining, corrosion sciences, and nuclear waste processing.

Lactic Acid Production from High Concentration of Invert Sugar in Semi-Batch Reactor

The objective in this study is the production of high yield of lactic acid production from invert sugar in alkaline degradation at mild reaction condition. The invert sugar was immediately and continuously added into an alkaline solution in a batch and semi-batch reactor, respectively. The effect of batch and semi-batch, initial concentration of sodium hydroxide and initial of concentrated raw materials were studied. Semi-batch provided better yield than batch reactor. High sodium hydroxide concentration with low invert sugar in semi-batch operation was found to have high lactic acid. The feed concentration of invert sugar at 30, 45 and 70% provided lactic acid yield around 65-68% for excess sodium hydroxide base at 50°C and 10 hr.

Facile Synthesis of ZnO Nanofoam on ZnO Nanowire for Hydrogen Gas Detection

Background: ZnO nanofoam cluster was deposited on ZnO nanowires using SiO2/Si substrate. Nanocrystalline ZnO nanofoam cluster was grown on Chemical Bath Deposition (CBD) grown ZnO nanowires by consecutive immersion (50 times) of the sample into Sodium Zincate (Na2ZnO2) bath (0.125M) kept at room temperature and into the de-ionized (DI) water maintained at 80oC. Methods: Sodium Zincate was prepared by reacting Zinc Sulphate (ZnSO4) and excess Sodium Hydroxide (NaOH) in aqueous solution. By simple Chemical Bath Deposition (CBD) technique ZnO nanowires of length of 1-1.5 µm with diameter 2-3 nm were deposited on SiO2 coated &lt;100&gt; p-Si substrate. The ZnO nanofoam cluster area was found to be ~(0.5 x 0.5) µm2. After structural and morphological characterizations by FESEM, EDX and AFM, the sensor was tested for three different H2 concentrations (0.1, 0.5 and 1%) taking N2 as carrier gas at four different operating temperatures (50ºC, 75ºC, 100ºC and 125ºC). Results: The sensor offered ~98% response magnitude at very low operating temperature 100ºC at 1000 ppm H2 gas with very fast response time (16 sec) and recovery time (52 sec). The unique structure of nanofoam covers multidimensional area having more molecular surface interactions thus permitting better response in gas sensing. The I-V characteristics was studied to indicate ohmic nature of the silver contacts for four operating temperatures with 1% hydrogen in N2 and it was also observed that amplitude of current is higher with the presence of H2. Conclusion: Finally the stability study of the H2 sensor was also done in presence of carrier gas (N2) over a span of 24 hours (6 hr daily).

Analysis of the causes of leakages and preventive strategies of boiler water-wall tubes in a thermal power plant

The reasons for the failures of a boiler water-wall tube used in the thermal power plant were investigated in this paper. The material of water-wall tube was made of medium-carbon steel, SA-210 Grade C, which is pearlitic heat-resistant steel with a working temperature lower than 500 °C and is widely used in boilers tubes. To investigate the causes of failure, various techniques including macroscopic inspection, chemical composition analysis, mechanical performance testing, optical microscopy observation and Energy Dispersive Spectroscopy (EDS) were carried out. Corrosive products were found on the inner wall of the tube’s bulge positions. The thickness of the tube wall covered by the corrosive products reduced due to the corrosion. The boiler water quality was analyzed and it was found that there was excessive Sodium Hydroxide (NaOH), which was the main corrosion-induced substance. Metallographic examination results showed that the microstructure in the corroded area has aged. Based on the analysis results, failure causes can be drawn: excessive NaOH in the boiler water was the main reason for the corrosion. The characters of alkaline corrosion products provided the condition that corrosion can proceed continuously which caused the thinning of the water-wall tube. As the process proceeds, it reduces performance of the tube and creates bulge which finally causes leakage.

Adsorption Synthesis of Iron Oxide-Supported Gold Catalyst under Self-Generated Alkaline Conditions for Efficient Elimination of Carbon Monoxide

Goethite- and hematite-supported highly dispersed gold catalysts for carbon monoxide oxidation were synthesized by gold precursor adsorption onto the support materials in self-generated alkaline solutions. The support materials were prepared by reacting iron nitrate with excess sodium hydroxide. The residual minor alkali incorporated into the support could provide suitable alkaline conditions at approximately pH 8 for the hydrolysis of tetrachloroaurate anions and the subsequent adsorption process. Gold species underwent autoreduction to achieve activation during the synthesis. An increase in pH or temperature to 80 °C decreased the gold loading of the catalysts. The optimal catalysts could achieve complete oxidation of carbon monoxide at −20 °C.

Experimental investigation of nitrogen isotopic effects associated with ammonia degassing at 0–70 °C

Ammonia degassing is a common process in natural alkaline waters and in the atmosphere. To quantitatively assess the nitrogen cycle in these systems, the essential parameter of nitrogen isotope fractionation factors associated with ammonia degassing is required, but still not constrained yet. In this study, we carried out laboratory experiments to examine the nitrogen isotope behavior during ammonia degassing in alkaline conditions. The experiments started with ammonium sulfate solution with excess sodium hydroxide. The reaction can be described as: NH4+ + OH− (excess) → NH3·nH2O → NH3 (g)↑. Two sets of experiments, one with ammonia degassing under static conditions and the other with ammonia degassing by bubbling of N2 gas, were carried out at 2, 21, 50, and 70 °C. The results indicate that kinetic isotopic effects are dominated during efficient degassing of ammonia in the bubbling experiments, which yielded kinetic nitrogen isotope fractionation factors αNH3(g)–NH3(aq) of 0.9898 at 2 °C, 0.9918 at 21 °C, 0.9935 at 50 °C and 0.9948 at 70 °C. These values show a good relationship with temperature as 103lnαNH3(g)–NH3(aq) = 14.6 − 6.8 × 1000/T. In contrast, isotopic effects during less efficient degassing of ammonia in the static experiments are more complicated. The results do not match either kinetic isotope fractionation or equilibrium isotope fractionation but sit between these two. The most likely cause is that back dissolution of the degassed ammonia occurred in these experiments and consequently shifted kinetic isotope fractionation toward equilibrium isotope fractionation. Our experimental results highlight complicated isotopic effects may occur in natural environments, and need to be fully considered in the interpretation of field data.

Improved Electrocatalytic Activity and Durability of NiMn2O4-CNTs as Reversible Oxygen Reaction Electrocatalysts in Zinc-air Batteries

Faced with the increasingly serious energy crisis, fuel cells, as a clean and efficient power source, have become the most promising energy conversion devices and attracted significant attention during the last decades. Oxygen reduction reaction (ORR) at the cathode of fuel cells plays a decisive role in determination of the performance, and electrocatalysts with high-performance ORR are essential for practical applications. However, some big technical challenges are still encountered due to their inherently sluggish of cathodic ORR, which usually requires a significant number of noble metal catalyst [1, 2]. To overcome these bottlenecks, great attention has been paid to pursue non-precious metal or metal-free carbonaceous materials. Mesoporous carbon materials have been used for ORR due to their preeminent textural characteristics, high surface area, mechanical stability and mesoporous structure. However, the properties of mesoporous carbon materials base on not only the sizes and loction of the pore, but the heteroatoms doped into the carbon framework. It is believed that the quantity of N-doped and S-doped in carbon will be vastly different, if it was annealed at various reaction temperatures [3]. Herein, we use N and S co-doped mesoporous carbon which is prepared by polyquaternium-7 as a starting material to investigate the reaction with N2 at various temperatures. Nitrogen and sulfur co-doped mesoporous carbons were prepared by homogeneously mixing polyquaternium-7 and ferrous sulphate and silica. After drying overnight, the resulting solid was ground to a fine powder and then calcined at 600, 700, 800, 900 and 1000 for 1 hour in a nitrogen atmosphere. The silica was washed off in excess sodium hydroxide and dried. The excess metal Fe was removed in sulfuric acid at 85 ℃. Finally, the resulting catalytic graphite was pyrolyzed at 600 to 1000 ℃ for 1 hour again. Results of electrochemical characterizations for ORR were studied by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) employing rotating disk electrode (RDE) technique. It is found that the temperature of the heat treatment is a significant parameter in synthesizing the high performance ORR catalysts.

Synthesis of highly environmental stable copper–silver core–shell nanoparticles for direct writing flexible electronics

In this study, Cu@Ag core–shell nanoparticles (NPs) with highly environmental stability were synthesized successfully by combining the NaBH4 reduction method with the transmetallation reaction, and the Cu@Ag nano-ink was prepared for direct writing flexible electronics. The structure, component, thermal stability and oxidation resistance of Cu NPs and Cu@Ag core–shell nanoparticles were characterized and discussed systematically. The results showed that Cu NPs could be obtained via the reduction of Cu2+ ions by using cetyltrimethylammonium bromide (CTAB) as a dispersing agent under an excess of sodium hydroxide (NaOH) and sodium borohydride (NaBH4) in aqueous solution. And the Cu@Ag core–shell nanoparticles with uniform Ag shell and Cu core can be fabricated with the transmetallation reaction that Ag+ ions were reduced by the copper atoms on the surface of Cu NPs at pH 7, and the Cu core were kept from oxidation from the Ag shell. Besides, Cu@Ag nano ink were fabricated by dispersing Cu@Ag core–shell nanoparticles in ethylene glycol, and Cu@Ag conductive pattern were directly drawn on ordinary photo paper using a roller pen filled with 30 wt% Cu@Ag nano ink. The electrical resistivity of the conductive Cu@Ag pattern obtained from the nano ink was as low as 13.8 μΩ cm−1 due to the continuous interconnections between the nanoparticles established when thermal sintered at 150 °C for 1 h under N2. When the conductive wires of a lamp were connected to the two ends of the written conductive line, the lamp was illuminated immediately. It demonstrated that the complicated Cu@Ag nano-ink pattern had very good conductivity and applicability. This work provides an effective approach to prepare Cu@Ag core–shell nano-ink for direct writing flexible electronics.

Process Intensification with Coaxially Placed Entry Region Vanes Assembly Turbulence Promoter in Homogeneous Flow

The entry region vane turbulence promoters are inserted at the downstream of a circular electrolytic cell and limiting current data are measured at the copper micro electrodes fixed on an electrode support. The effect of flow rate of the electrolyte, effect of velocity on mass transfer at the wall, effects of geometric parameters diameter of the vane (dv) from 0.02 m to 0.04 m, the angle of the vane (γ) from 15° to 60°, sectorial angle (α)/number of the vanes (N) from 4 to 8, diameter of the annular rod of mass transfer is investigated. The electrolyte was equimolal potassium ferricyanide, potassium ferrocyanide and excess sodium hydroxide. Limiting current data had been obtained for the reduction of potassium ferricyanide ion. The mass transfer correlation is based on the law of the wall similarity. The effect of each parameter was studied in terms of friction factor. A model was developed for mass transfer. The correlation may be extended to a wider range of parameters by virtue of the law of the wall. The experimental data on mass transfer was modelled in terms of mass transfer function and Reynolds number geometric parameters.