Aqueous Solution Of Potassium Permanganate Research Articles

The study of capillarity phenomena by means of ImageJ software

"Capillarity phenomena appear due to different molecular forces acting between fluid molecules located at the interface with either another fluid or a solid. The macroscopic description of the phenomenon can be done in terms of surface tension. In this paper, we determined the surface tension coefficient of aqueous solution of potassium permanganate by means of Jurin's law and also made diameter measurements and capillary ascents on images by using ImageJ software. Furthermore, we studied the capillary phenomena between two parallel and non- parallel plates. In the case of non-parallel plates, employing a special plugin of the ImageJ software, we determined the equation of the rectangular hyperbola drawn by the surface of liquid rising between plates. These experiments can be performed at elementary level and, additionally, used as a stimulus to discover more advanced topics."

ВЛИЯНИЕ РЕЖИМОВ СИНТЕЗА НА ЭЛЕКТРОХИМИЧЕСКИЕ ХАРАКТЕРИСТИКИ КОМПОЗИТОВ НА ОСНОВЕ МНОГОСТЕННЫХ УГЛЕРОДНЫХ НАНОТРУБОК И ОКСИДА МАРГАНЦА, ЛЕГИРОВАННОГО ОКСИДОМ СЕРЕБРА

In this work, promising electrode materials for asymmetric supercapacitors based on multiwalled carbon nanotubes and manganese oxide doped with silver oxide were obtained and studied. To form the composites, the method of exposure of carbon material in an aqueous solution of potassium permanganate with the addition of silver nitrate in various quantities was used. It has been established that an increase in the amount of silver nitrate during the formation of the composite leads to an increase in the mass loading of the composite with both silver oxide and manganese oxide, which provides higher electrochemical characteristics of the material. The maximum specific capacity of the composite with a high content of manganese and silver was about 146 and 65 F/g at discharge current densities of 0.1 and 1.0 A/g, respectively. The high capacitive characteristics of the composite are ensured by a combination of the electrochemical activity of manganese oxide and the low electrical resistance of silver oxide.

Rubberized geopolymer composites: Effect of filler surface treatment

Existing waste tire management strategies such as landfill, warehousing, incineration, and pyrolysis are associated with significant emissions of hazardous compounds including gases, heavy metals, and oils. A sustainable rubber waste disposal strategy is immobilizing them in a crushed form in eco-friendly geopolymer (GP) matrices. However, the implementation of this approach is constrained by the strength degradation of rubberized geopolymer composites. In order to solve this problem, this article includes a comparative investigation of the effect of various physical and chemical pre-treatments of tire crumb rubber (CR) with NaOH, H2SO4, (CH3)2CO and KMnO₄ solutions, as well as ultraviolet radiation, on the mechanical performances and microstructure of rubberized fly ash-based GP composites. It has been established that the best effects are demonstrated by treatment with an aqueous solution of potassium permanganate; oxidative reactions with the solution lead to the formation of surface-active functional groups on the rubber. As a result, there is more than a twofold increase in the hydrophilicity of CR particles, estimated from the mass of adsorbed water vapor (from 1.5 to 3.3 wt%). This provides a strong adhesive contact of the filler with the geopolymer matrix, which favorably affects the change in the mechanical properties of the composites. The compressive strength in this case has been increased from 12.8 MPa (GP/untreated CR composite) to 15.5 MPa at addition of 10.0 wt% KMnO4 treated CR. Further optimization of the composition and of the curing mode of the geopolymer binder can potentially provide an additional positive effect in this aspect.

Facile Molecular Catalysis for Isomerization of Glucose to Fructose Using KMnO4 in Water

AbstractThis research demonstrates the eco‐friendly conversion of glucose to fructose in an aqueous solution of potassium permanganate (KMnO4) via a hydrothermal method. A series of reactions have been completed at different temperatures, times, and concentrations of the catalyst. The examination of the glucose to fructose transformation was determined by using quantitative HPLC, and 13C‐NMR analyses. 29% fructose yield was found with 68% fructose selectivity, at 90 °C for an 8 h reaction in aqueous solution. The catalytic activity of KMnO4 was correlated with its Lewis acidity. The outcomes of these experiments provided a better understanding of sugar transformations in the KMnO4 aqueous solution. The mechanism of glucose isomerization has been proposed based on supporting transformations utilizing Lewis acids for the isomerization of glucose.

Electrophysical Characteristics of Atmospheric Pressure Discharge with Aqueous Potassium Permanganate Solution as Cathode

Electrophysical parameters of atmospheric pressure discharge with an aqueous potassium permanganate solution as a cathode have been determined. The cathode potential drop, the electric field strength in the positive column of the discharge, and the current density depending on the solution concentration and the discharge current have been found, as well as the emission coefficient γ .

A hollow fiber prepared through combining polymethacrylate with manganese oxide as reusable oxidant with valence-selfstabilizing function for cation blue decolorization

By hydrolyzing polymethacrylate hollow fiber in sulfuric acid and then treating it in the aqueous solution of potassium permanganate, we obtained a hollow fibrous oxidant in which in-situ generated manganese oxide was immobilized by partly-hydrolyzed polymethacrylate. The prepared oxidant could oxidize cation blue into colorless substance; thus, it was very efficient at decolorizing cation blue. The results of TOC, FTIR and NMR revealed that the decolorization of cation blue was mainly caused by the cleavage of its double bond of C and N. The oxidant could interact with water to produce oxygen species such as O2·- during decolorization. The oxygen species could help the oxidant to keep its Mn valence unchanged; thus, the oxidant was stable and reusable in decolorizing cation blue. The oxidant could be used up to 5 cycles without any loss in its oxidation activity. It only took less than 30 min to remove 95% of cation blue from 10 mL of its solution with the concentration of 20 mg/L for each cycle.

Minimization of the perianal infection rate of hematological malignancies with agranulocytosis by quality control circle activity and patient-hospital-student win-win concept.

ObjectiveThe agranulocytosis-associated perianal infection (PI) rate ranges from 60% to 100% among patients with hematopoietic malignancies. In this study, we assessed the efficacy of a quality control circle (QCC) to minimize the PI rate.MethodsAmong 274 patients with severe immunodeficiency (agranulocytosis of ≥2 weeks) in our bone marrow transplantation center, the PI rate was 17.20%. A QCC was established following the 10 steps of the plan-do-check-act (PDCA) model; this was scientifically supported by culturing the bacterial colony from patients’ perianal skin to determine the sanitization effect and interval time. Because a warm aqueous solution of potassium permanganate is recommended for sanitization, the bacterial colony culture was also used to determine the proper drug concentration, water temperature, and soaking time. All procedures were standardized. Patients, hospital staff, and medical students were enrolled into the QCC team based on the patient–hospital–student (PHS) win–win concept.ResultsAfter establishment of the PDCA model, the PI rate among 253 patients decreased from 17.20% to 5.93% and remained at 5.25% during the following year. The medical expenses and length of hospital stay consequently decreased.ConclusionThe QCC and PHS win–win concept can reduce the PI rate and promote medical quality.

Crystal structures and thermal decomposition of permanganates AE[MnO4]2·n H2O with the heavy alkaline earth elements (AE=Ca, Sr and Ba)

Abstract Reexamination of the syntheses and crystal structures as well as studies of the thermal decomposition of the heavy alkaline earth metal permanganates Ca[MnO4]2·4 H2O, Sr[MnO4]2·3 H2O and Ba[MnO4]2 are the focus of this work. As an alternative to the very inelegant Muthmann method, established for the synthesis of Ba[MnO4]2 a long time ago, we employed a cation-exchange column loaded with Ba2+ cations and passed through an aqueous potassium-permanganate solution. We later used this alternative also with strontium- and calcium-loaded columns and all the compounds synthesized this way were indistinguishable from the products of the established methods. Ca[MnO4]2·4 H2O exhibiting [CaO8] polyhedra crystallizes in the orthorhombic space group Pccn with the lattice parameters a=1397.15(9), b=554.06(4) and c=1338.97(9) pm with Z=4, whereas Sr[MnO4]2·3 H2O with [SrO10] polyhedra adopts the cubic space group P213 with a=964.19(7) pm and Z=4. So the harder the AE 2+ cation, the higher its demand for hydration in aqueous solution. Consequently, the crystal structure of Ba[MnO4]2 in the orthorhombic space group Fddd with a=742.36(5), b=1191.23(7) and c=1477.14(9) pm with Z=8 lacks any crystal water, but contains [BaO12] polyhedra. During the thermal decomposition of Ca[MnO4]2·4 H2O, the compound expels up to two water molecules of hydration, before the crystal structure collapses after the loss of the third H2O molecule at 157°C. The crystal structure of Sr[MnO4]2·3 H2O breaks down after the expulsion of the third water molecule as well, but this already occurs at 148°C. For both the calcium and the strontium permanganate samples, orthobixbyite-type α-Mn2O3 and the oxomanganates(III,IV) AEMn3O6 (AE=Ca and Sr) remain as final decomposition products at 800°C next to amorphous phases. On the other hand, the already anhydrous Ba[MnO4]2 thermally decomposes to hollandite-type BaMn8O16 and BaMnO3 at 800°C.

Evaluation of the kinetic oxidation of aqueous volatile organic compounds by permanganate

The use of permanganate solutions for in-situ chemical oxidation (ISCO) is a well-established groundwater remediation technology, particularly for targeting chlorinated ethenes. The kinetics of oxidation reactions is an important ISCO remediation design aspect that affects the efficiency and oxidant persistence. The overall rate of the ISCO reaction between oxidant and contaminant is typically described using a second-order kinetic model while the second-order rate constant is determined experimentally by means of a pseudo first order approach. However, earlier studies of chlorinated hydrocarbons have yielded a wide range of values for the second-order rate constants. Also, there is limited insight in the kinetics of permanganate reactions with fuel-derived groundwater contaminants such as toluene and ethanol. In this study, batch experiments were carried out to investigate and compare the oxidation kinetics of aqueous trichloroethylene (TCE), ethanol, and toluene in an aqueous potassium permanganate solution. The overall second-order rate constants were determined directly by fitting a second-order model to the data, instead of typically using the pseudo-first-order approach. The second-order reaction rate constants (M−1s−1) for TCE, toluene, and ethanol were 8.0×10−1, 2.5×10−4, and 6.5×10−4, respectively. Results showed that the inappropriate use of the pseudo-first-order approach in several previous studies produced biased estimates of the second-order rate constants. In our study, this error was expressed as a function of the extent (P/N) in which the reactant concentrations deviated from the stoichiometric ratio of each oxidation reaction. The error associated with the inappropriate use of the pseudo-first-order approach is negatively correlated with the P/N ratio and reached up to 25% of the estimated second-order rate constant in some previous studies of TCE oxidation. Based on our results, a similar relation is valid for the other volatile organic compounds studied.

Corollary of Additives on Gamma and Pulse Radiolytic Degradation of Aqueous Potassium permanganate Solution

The effect of additives on the reduction of potassium permanganate solutions, induced by 60Co γ-rays and highly accelerated electrons, has been investigated in acidic medium. In gamma radiolytic degradation of potassium permanganate in acidic medium in the presence of additives such as manganese dioxide (MnO2), potassium sulphate (K2SO4), sodium persulphate (Na2S2O8), ammonium chloride (NH4Cl) and mixture of potassium sulphate and ammonium chloride (K2SO4+NH4 Cl), the value of G(-MnO4−) is found to be higher at lower dosages and gradually decreases as the dose is increased. G(-MnO42-) is also observed to increase with an increase in the amount of the additives. In pulse radiolysis of acidic potassium permanganate solutions there is formation of MnO42- when K2SO4 and Na2S2O8 are used as additives. MnO43- peak is observed with additive mixture of K2SO4+NH4Cl. The kinetics of the reaction was also studied for various concentrations of potassium permanganate solutions with additives and first order spectra were obtained.

Cathodic Synthesis of Birnessite Films for Pseudocapacitor Application

Cathodic reduction of an aqueous solution of potassium permanganate in the presence of various alkaline metals except for Na+ ions led to a deposition of birnessite-type layered MnO2. Thehighest crystallinity was achieved in a bath containing 2 mMK MnO4 and 50 mM KCl by applying a constant potential of 0 V vs Ag/AgCl. The cathodic formation of birnessite was prevented by the presence of divalent cations, and Na+ ions yielded an amorphous or low crystalline product. The birnessite film thus formed showed excellent pseudocapacitive characteristics in its as-deposited state; i.e., a specific capacitance as high as 322 F g-1 at a potential scan rate of 2 mV s-1, which is much higher than that (75F g-1) of the birnessite film prepared anodically from Mn2+ ions.

A simple chemical method for deposition of electrochromic potassium manganese oxide hydrate thin films

A new chemical method for fast deposition of electrochromically active thin films of birnessite-type potassium manganese oxide (K0.27MnO2·xH2O) has been developed. The chemical deposition has been performed at room temperature by a reaction of aqueous solutions of potassium permanganate and manganese(II) chloride. The prepared thin films have thickness from 50 to 250nm depending on the number of the deposition cycles. The composition and the structure of the K-birnessite films are studied by XRD, IR spectroscopy and TG/DTA analyses. Electrochemical studies using four different electrolytes such as aqueous K2SO4, Li2SO4, KNO3, and LiClO4 in PC have been performed. The electrochromic activity has been explored by cyclic voltammetry and VIS spectrometry. The best electrochromic properties are obtained using aqueous KNO3, where the difference in the transmittance at 400nm between the bleached and colored state is 40% for both as-deposited and annealed films. The obtained data allow the prepared K-birnessite thin films in aqueous KNO3 electrolyte to be proposed as a promising system for electrochromic applications.

Nanorods of cryptomelane via soft chemistry method and their catalytic activity

α-MnO2 nanorods were obtained by a fast redox transformation of aqueous solution of potassium permanganate. The formation mechanism of 1D nanocrystals proceeds via a first pH- and temperature sensitive stage followed by cation/anion control of the nanorod growth. A high surface area and nanostructuring allowed to achieve superb catalytic activity in a CO oxidation process compared to a conventionally prepared manganese dioxide.

Synthesis of Nano-MnO<sub>2</sub>/CNTs Composite and Electrochemical Properties as Electrode Material for Supercapacitor

The manganese oxides (MnO2) with nanostructures was fabricated with non-aqueous alcohol and aqueous solution of potassium permanganate (KMnO4) at room temperature. The test results show that the nano-MnO2 well coated on the surface of carbon nanotube (CNT), while the specific capacitance of the composites with MnO2 deposited on singlewall carbon nanotube (SWNT) was better than coated on multiwalled carbon nanotube (MWNT). The specific capacitance of MnO2 coated on SWNT film can reach 769F/g at scan rate of 5mv/s in the first cycle.

Efficient production of ultrapure manganese oxides via electrodeposition

A new process for the production of electrolytic amorphous nanomanganese oxides (EAMD) with uniform size and morphology is described. EAMD are produced for the first time by cathodic deposition from a basic aqueous solution of potassium permanganate at a constant temperature of 16°C. The synthesized materials are characterized by XRD, SEM, TEM, and HRTEM. The materials produced at 5.0V at constant temperature are amorphous with homogeneous size and morphology with an average particle size around 20nm, which appears to be much lesser than the previously reported anodic EAMD. A potentiostatic electrodeposition with much lesser deposition rate (with respect to previously reported anodic depositions) is considered to be the reason behind the very low and homogenous particle size distribution due to the lesser agglomeration of our as-synthesized nanoparticles.

High-sensitivity online detection for microfluidics via cavity ringdown spectroscopy

We report the coupling of cavity ringdown spectroscopy (CRDS) with a microfluidic chip fabricated using a rapid prototyping method, in order to demonstrate high-sensitivity, non-contact online detection in microfluidics. Conventional UV-vis absorption techniques are largely ineffective for microfluidic detection due to the small sample volumes and short path lengths. The multipass absorption achieved in cavity ringdown spectroscopy increases the effective absorption pathlength by several orders of magnitude, and hence enhances the detection sensitivity. A cavity ringdown spectrometer, operating at a single wavelength of 532 nm for the purposes of the proof-of-concept measurements presented here, has been developed for online detection on a polymer/glass microchip fabricated by frontal photopolymerisation. High sensitivity absorption measurements on liquid samples with volumes of tens to hundreds of nanolitres and absorption pathlengths ranging from tens to hundreds of microns are demonstrated. A series of proof-of-concept experiments show that the technique has the ability to monitor both static and time-varying analyte concentrations. Firstly, the detection limit of the system is estimated from a three-standard-deviation error analysis of absorption measurements made on dilute aqueous solutions of potassium permanganate (natural absorption coefficient (4805 ± 10) M−1 cm−1 at 532 nm). The detection limit was found to be ∼210 nM for a 466 μm pathlength, corresponding to an absorption of 1.0 × 10−3 cm−1. Online pH measurements on a 20 nL sample are performed by monitoring the absorption of phenolphthalein indicator present at millimolar concentrations. Finally, CRDS has been applied, for the first time, to monitoring chemical reaction kinetics on a microfluidic chip, tracking the oscillation period of the well-known Belousov–Zhabotinsky reaction.

Composite films prepared by immersion deposition of manganese oxide in carbon nanotubes grown on graphite for supercapacitors

Manganese oxide/carbon nanotube (CNT) composite films on graphite were prepared by growing CNTs on the substrate using chemical vapor deposition (CVD), followed by immersion in an aqueous solution of potassium permanganate. The CVD growth created favorable conditions for deposition of the oxide on the electrode, and an aligned porous structure of the composite films, which originated from the CNT growth, could be managed. Electrochemical behaviors of the CNT and the composite films for supercapacitors were studied in 1 M Na2SO4 solution. While the oxide deposition in the CNT films was identified as contributing to capacitance enhancement, it was also found that a mild heat treatment could improve performance of the composite films.

2, 4-Ionene Supported Permanganate: A Novel, Efficient and Selective Solid Phase Oxidizing Agent for Oxidation of Organic Compounds

Abstract2, 4-ionene supported permanganate is easily prepared by treatment of 2, 4-ionene with an aqueous solution of potassium permanganate. This reagent could be used as a stable, mild and efficient oxidizing agent to produce carbonyl compounds from hydroxyl compounds or arenes, and disulfides from thiols in either heterogonous or solvent free conditions. In addition, aromatization of different types of 2-arylimidazolines and 2-alkylimidazolines to corresponding imidazoles was achieved in good yields in acetonitrile at room temperature.

A neotaphonomic experiment in pollen oxidation and its implications for archaeopalynology

Oxidation is considered to be a major taphonomic process involved in differential pollen preservation. An experimental protocol has been developed in the laboratory to test the impact of oxidation on pollen concentrations. Seven modern pollen taxa were selected among common trees, shrubs and herbaceous plants from the European flora, with regard to their typical pollen morphology ( Pinus, Alnus, deciduous Quercus, Cichorioideae, Caryophyllaceae, Ericaceae and Poaceae). An aqueous solution of potassium permanganate (KMnO 4) was used to oxidise the pollen grains. The impact of oxidation was measured as a function of increasing oxidation intensity and increasing exposure time. For each taxon, the pollen concentration (grains µl − 1) was measured following each oxidation stage. The results show that all pollen taxa are affected by oxidation. Both low oxidant concentrations and short oxidation exposure times led to a fast decrease in pollen concentrations. The thickness of the exine and a specific morphology appear to be the deciding factors controlling the ability to withstand oxidation. A simulation of the impact of oxidation was performed on two model pollen spectra simulating a forested and an open environment. Significant differences were recorded between the initial and final pollen rates. The AP/NAP ratio is modified to a greater extent in the spectrum associated with the open environment. However, over-representation of a specific taxon in a pollen spectrum cannot be attributed to the impact of oxidation alone. For instance, when Cichorioideae are recorded with high frequencies in pollen analyses carried out in an archaeological context, oxidation should not be regarded as the only taphonomic process responsible for this over-representation. The differential conservation of pollen is a complex process in which oxidation represents but one of a variety of interacting taphonomic factors (such as pollen transport, bacterial activity, temperature, pH, hygrometry).

Permanganate transfer and reduction by D‐glucose in benzene–cetyltrimethylammoniumbromide aqueous solution: A kinetic study

AbstractThe addition of cationic surfactant, cetlytrimethylammoniumbromide (CTAB), in benzene and aqueous potassium permanganate solution brought the MnO from the aqueous phase to the organic phase. At 525 nm, the absorbance of the organic phase increased until it reached a maximum, and then decreased with [CTAB]. The effect of [CTAB] on the reduction of permanganate by D‐glucose in a benzene–CTAB system has been studied spectrophotmetrically. The observed effect on the rate constant is catalytic up to a certain concentration of CTAB; thereafter, a saturation phenomenon is observed with an increased concentration of CTAB. The oxidation reaction obeyed the first‐order kinetics with respect to the D‐glucose. On addition of H2SO4, there was a decrease in the rate constants. There is evidence for the existence of manganese as a water‐soluble colloidal MnO2. A detailed mechanism with the associated reaction kinetics is presented and discussed. © 2008 Wiley Periodicals, Inc. 40: 496–503, 2008