KMnO4 Concentration Research Articles

Effects of KMnO4 Treatment on the Flexural, Impact, and Thermal Properties of Sugar Palm Fiber-Reinforced Thermoplastic Polyurethane Composites

Global warming has had a great impact on environmental changes since the last decade. Eco-friendly industrial products are of great importance to sustain life on earth, including using natural composites. Natural fibers used as fillers are also environmentally valuable because of their biodegradable nature. However, compatibility issues between the fiber and its respective matrix is a major concern. The present work focused on the study of the flexural, impact, and thermal behaviors of environmentally friendly sugar palm fibers (SPF) incorporated into a composite with thermoplastic polyurethane (TPU). Two techniques (extrusion and compression molding) were used to prepare these composites. The fiber size and dosage were kept constant at 250 µm and 30 wt.% SPF, respectively. The effects of potassium permanganate (KMnO4) treatment on the flexural, impact, and thermal behaviors of the treated SPF with 6% NaOH-reinforced TPU composites were investigated. Three different concentrations of KMnO4 (0.033%, 0.066%, and 0.125%) were studied for this purpose. The characterization of the flexural and impact properties of the new TPU/SPF composites was studied as per American Society for Testing Materials ASTM standards. Thermogravimetric analysis was employed for thermal behavior analysis of the TPU/SPF composites. The best flexural strength, impact strength, and modulus properties (8.118 MPa, 55.185 kJ/m2, and 262.102 MPa, respectively) were obtained with a 0.033% KMnO4-treated sample. However, all flexural strength, impact strength, and modulus properties for the KMnO4-treated samples were lower than the sample treated only with 6% NaOH. The highest thermal stability was also shown by the sample treated with 0.033% KMnO4. Therefore, this method enhanced the thermal properties of the TPU/SPF composites with clear deterioration of the flexural and impact properties.

Simultaneous removal of SO2 and NOx from flue gas by wet scrubbing using a urea solution

ABSTRACTNitrogen oxides (NOx) and sulfur dioxide (SO2) are major air pollutants, so simultaneously removing them from gases emitted during fossil fuel combustion in stationary systems is important. Wet denitrification using urea is used for a wide range of systems. Additives have strong effects on wet denitrification using urea, and different mechanisms are involved and different effects found using different additives. In this study, the effects of different additives, initial urea concentrations, reaction temperatures, initial pH values, gas flow rates, and reaction times on the simultaneous desulfurization and denitrification efficiencies achieved using wet denitrification using urea were studied in single factor experiment. The optimum reaction conditions for desulfurization and denitrification were found. Desulfurization and denitrification efficiencies of 97.5% and 96.3%, respectively, were achieved at a KMnO4 concentration 5 mmol/L, a reaction temperature of 70°C, initial urea solution pH 8, a urea concentration of 9%, and a gas flow rate of 40 L/h. The concentrations of the desulfurization and denitrification reaction products in the solution were determined. NOx was mainly transformed into N2, and the and concentrations in the solution became very low. The reactions involved in SO2 and NOx removal using urea were analyzed from the thermodynamic viewpoint. Increasing the temperature was not conducive to the reactions but increased the rate constant, so an optimum temperature was determined. The simultaneous desulfurization and denitrification kinetics were calculated. The urea consumption and , , and generation reactions were all zero order. The generation rate was greater than the generation rate. The simultaneous desulfurization and denitrification process and mechanism were studied. The results provide reference data for performing flue gas desulfurization and denitrification in factories.

A Styrofoam-nano manganese oxide based composite: Preparation and application for the treatment of wastewater

Nano-composites were synthesized by the reaction of waste polystyrene (PS) and KMnO4. The structure of the composite was controlled by the solvent/non-solvent system and the concentration of KMnO4. The FTIR spectra indicated the functionalization of PS and the attachment of NMO with the polymer chains. The maximum adsorption capacities (qmax) were 10,000 and 5000 Bq g−1, for U and Th respectively. Different but controllable sorption/desorption behaviours were noted between Th and U, which could be promising in the separation of Th and U from their mixture.

Design of an optical sensor for ethylene based on nanofiber bacterial cellulose film and its application for determination of banana storage time

In this work, new ethylene gas sensor was developed on the basis of portable bacterial cellulose (BC) nanofiber film doped with KMnO4 (K‐BC). The relationship between the concentration of KMnO4 (8 × 10−3, 8 × 10−4, and 8 × 10−5 mol L−1) and the optical and morphological properties of ethylene sensor was investigated. The Fourier‐transform infrared results showed that some new interactions have occurred between BC membrane and KMnO4. The significant reduction in the relative intensity of the characteristic X‐ray diffraction peak of BC in the doped films clearly indicates that the crystalline fraction decreases as a result of KMnO4 addition. The fabricated K‐BC was used for determination of ethylene concentration. The color, clarity, and absorbance of film at different concentrations of ethylene (10‐2000 μg mL−1) were determined by spectrophotometer. Moisture absorption and water vapor permeability of BC were increased by the addition of KMnO4. Finally, the ethylene optical sensor was used for detection and determination of ethylene concentration in the bunch banana packages.

Transformation of Methylparaben by aqueous permanganate in the presence of iodide: Kinetics, modeling, and formation of iodinated aromatic products

This work investigated impacts of iodide (I−) on the transformation of the widely used phenolic preservative methylparaben (MeP) as well as 11 other phenolic compounds by potassium permanganate (KMnO4). It was found that KMnO4 showed a low reactivity towards MeP in the absence of I− with apparent second-order rate constants (kapp) ranging from 0.065 ± 0.0071 to 1.0 ± 0.1 M−1s−1 over the pH range of 5–9. The presence of I− remarkably enhanced the transformation rates of MeP by KMnO4 via the contribution of hypoiodous acid (HOI) in situ formed, which displayed several orders of magnitude higher reactivity towards MeP than KMnO4. This enhancing effect of I− was greatly influenced by solution conditions (e.g., I− or KMnO4 concentration or pH), which could be well simulated by a kinetic model involving competition reactions (i.e., KMnO4 with I−, KMnO4 with MeP, HOI with KMnO4, and HOI with MeP). Similar enhancing effect of I− on the transformation kinetics of 5 other selected phenols (i.e., p-hydroxybenzoic acid, phenol, and bromophenols) at pH 7 was also observed, but not in the cases of bisphenol A, triclosan, 4-n-nonylphenol, and cresols. This discrepancy could be well explained by the relative reactivity of KMnO4 towards phenols vs I−. Liquid chromatography-tandem mass spectrometry analysis showed that iodinated aromatic products and/or iodinated quinone-like product were generated in the cases where I− enhancing effect was observed. Evolution of iodinated aromatic products generated from MeP (10 μM) treated by KMnO4 (50-150 μM) in the presence of I− (5-15 μM) suggested that higher I− or moderate KMnO4 concentration or neutral pH promoted their formation. A similar enhancing effect of I− (1 μM) on the transformation of MeP (1 μM) by KMnO4 (12.6 μM) and formation of iodinated aromatic products were also observed in natural water. This work demonstrates an important role of I− in the transformation kinetics and product formation of phenolic compounds by KMnO4, which has great implications for future applications of KMnO4 in treatment of I−-containing water.

PENINGKATAN KINERJA IPAL LUMPUR AKTIF DENGAN PENAMBAHAN UNIT BIOFILTER (STUDI KASUS IPAL PASARAYA BLOK M, KAPASITAS 420 M3/HARI)

WWTP system selection is determined by the characteristics of the waste water. Wrong WWTP system will cause quality of treated water difficult to meet the Quality Standard and also lead to high operating costs. Added Biofilter unit to Pasaraya Blok M WWTP system, provide very encouraging result. For more than one year, WWTP operation always in good performance. The concentration of BOD, COD and KMnO4 can be derived more than 90%, as well as TSS can be reduced over 90%. The concentration of all pollutants in treated water far below the government quality standards, so it’s not polluted to the environment. WWTP Pasaraya Blok M already has Liquid Waste Disposal License Certificate (IPLC), as a legal statement or certificate that allowed them to dispose of treatment water into the water body. Pasaraya Blok M also performs self-monitoring for operational of WWTP and periodic analysis to an accredited laboratory. Keywords : domestic waste water, waste water treatment plants, organic pollutants, activated sludge, biofilter, treatment efficiency

The Effect of KMnO4 and K3[Fe(CN)6] Concentrations on Electrical Production in Fuel Cell Microbial System with Lactobacillus bulgaricus Bacteria in a Tofu Whey Substart

Microbial Fuel Cell (MFC) is a bioelectrochemical system that utilize metabolism of microorganisms to produce electrical energy. Microbial fuel cell is a bioelectrochemical system involving redox reactions that required an oxidizing agent in the process The purpose of this study was to determine the effect of various concentration of electrolyte solution KMnO4 and K3[Fe(CN)6] on electricity produced by microbial fuel cell system with Lactobacillus bulgaricus in tofu whey substrate. The principle of this study was bioelectrochemistry that changes chemical energy into electrical energy which involves a redox reaction by utilizing microbes. This study used a microbe Lactobacillus bulgaricus and substrate tofu whey with 0.39 % carbohydrate content in dual chamber MFC system using a salt bridge as a conductor of protons from anode to cathode. Anode compartment contains a mixture of microbes that have been cultured and phosphate buffer with pH 7 while cathode compartment contained electrolytes KMnO4 or K3[Fe(CN)6] in some various concentration that is 0.25 M; 0.2 M; 0.15 M; 0.1 M and 0.01 M with added potassium phosphate buffer pH 7. The MFC system using Lactobacillus bulgaricus and substrate tofu whey with 0.39% carbohydrate content and electrolyte solution KMnO4 generated maximum potential difference of 99.2 mV at concentration of 0.2 M which was higher than system with electrolyte solution K3[Fe(CN)6] 0.2 M that produced maximum potential difference of 48.6 mV.

Optimization of discharge printing of indigo denim using potassium permanganate via response surface regression

PurposeThis paper aims to investigate the feasibility of potassium permanganate (KMnO4) as an efficient discharging agent for indigo-dyed denim fabrics and identification of key variables for its cost-efficient implication.Design/methodology/approachResponse surface methodology, which is a statistical technique for the optimization of process variables, was used to study the effect of three key variables, i.e. KMnO4 concentration, printing paste pH and reaction time on whiteness and strength of discharged printed fabric. Regression models were developed to predict response variables, i.e whiteness, tensile strength and tear strength of discharge printed denim.FindingsIt was found that some captivating discharge printing effects could be produced using appropriate KMnO4 concentration, printing paste pH and reaction time without any significant loss in the fabric strength.Practical implicationsThis study highlights the practical implication of KMnO4 to be used as a safe and effective discharging agent under different conditions and to optimize the parameters using statistical analysis to ensure minimum loss in textile properties. The use of denim has evolved over the decades from a rough and tough workwear to highly fashionable apparel. Various dry and wet processing techniques have been introduced in recent years for the value-addition of denim – discharge printing is one of them. As lab to bulk reproducibility requires some sort of experience and adjustments in main parameters, the practical feasibility on the bulk scale should be adjusted in advance by means of the lab scale experimentation.Originality/valueThe KMnO4 oxidation process is considered eco-friendly because manganese dioxide, which is formed when permanganate is reduced, can be recycled. Thus, the use of KMnO4 can be considered as an eco-friendly safe process for the discharging of indigo dyes.

One-pot preparation of MnO x impregnated cotton fibers for methylene blue dye removal.

Using natural cotton fibers (CF) as a matrix, a series of novel MnOx impregnated cotton fibers (designated as Mn-X@BCF) were prepared in this study through a one-pot sono-assisted KMnO4 reduction process with no additional reducers. The as-prepared Mn-X@BCF was covered by a uniform and dense layer of MnOx nanospheres (10–30 nm), the amount of which was significantly improved by CF pretreatment and linearly correlated with KMnO4 concentration. Specifically, when KMnO4 concentrations increased from 5 mmol L−1 to 100 mmol L−1, the impregnation ratios of MnOx on BCF increased from 0.34% to 14.98% accordingly. Mn-X@BCF showed substantial removal for the typical dye MB. Under the studied conditions, MB removal equilibrium was reached within 10 minutes and solution pH showed no significant influence over a wide pH range (2–11). MB adsorption by Mn-25@BCF obeyed the pseudo-second-order kinetic model and Langmuir model well. The calculated maximum adsorption capacity (Qm) of Mn-25@BCF was 46.3 mg g−1, close to the cumulative adsorption capacity (Qc 45 mg g−1) of MB determined during the eight cycles of adsorption. It was proposed that adsorption followed by partial oxidation was the main mechanism of MB removal by Mn-X@BCF. The as-prepared Mn-25@BCF has great potential as an efficient and low-cost material for dye wastewater treatment because of its inexpensive and renewable source of raw materials, fast MB removal kinetics, wide working pH range and easy solid–liquid separation.

Studies on biochemical constituents of sapota (Manilkara zapota L.) at different stages of ripening during storage

Sapota fruits (Var. Cricket Ball) of three different ripening stages i.e. mature(? 13 kg/cm2), half ripe (6-7 kg/cm2), and full ripe (2-3 kg/cm2), were packed with newspaper soaked with 3 dosages (1000 ppm, 2000 ppm and 3000 ppm) of ethylene absorbent (KMnO4) along with control and stored at normal room temperature by packing in cardboard boxes. It was observed that specific gravity, ascorbic acid and total phenols decreased whereas cumulative loss in weight and malondialdehyde content increased with increasing period of storage. Fruits packed in different concentrations of KMnO4 soaked paper had less cumulative loss and retained more content of specific gravity, ascorbic acid and total phenols in all three stages. But less malondialdehyde content was observed. The effect of KMnO4 increased with increasing concentrations of KMnO4 in all three stages. As a result, more desirable content was noted in fruits packed with 3000 ppm concentration of KMnO4in mature fruits. This work relates to enhancement of shelf life of sapote so that it may be transported to far off places.

Evaluation of engineered hydrochar from KMnO4 treated bamboo residues: Physicochemical properties, hygroscopic dynamics, and morphology

In this study, a novel approach was developed to prepare engineered hydrochar from KMnO4 treated bamboo residues through hydrothermal carbonization. The hydrochar yields were within a specified range of 61.8–67.8% at 180 °C and 39.8–45.0% at 260 °C, respectively. The higher temperature led to the higher C content, lower H/C and O/C ratio, whereas the ash content increased with increasing KMnO4 concentration, causing the increase of solid yield as well as the decrease of C content. Pseudo-second kinetic model was optimal to describe bamboo hydrochar’s hygroscopic dynamic, and the engineered hydrochar produced at 260 °C and 1.0 wt% concentration obtained the better hydrophobicity of 0.82%. SEM-EDS and XRD analysis confirmed the existence of manganese carbonate on the surface of engineered hydrochar, from which we inferred the chemical complexation between KMnO4 and hydrochar.

Influence of KMnO₄ Concentrationon Infrared Emissivity of Coatings Formed on TC4 Alloys by Micro-Arc Oxidation.

Ceramic coatings with high emissivity were fabricated on TC4 alloys by micro-arc oxidation technique (MAO) in mixed silicate and phosphate electrolytes with varying KMnO4 addition. The microstructure, phase and chemical composition were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), and the infrared emissivity of the MAO coatings was measured in a waveband of 5–20 μm. The results show that the thickness of the coatings increased with the addition of KMnO4, but the roughness of the coatings first decreased and then increased slightly due to the inhibitory effect of KMnO4 on Na2SiO3 deposition. The main phase composition of the coatings was anatase and rutile TiO2, amorphous form of SiO2 and MnO2. The infrared emissivity value of the coatings strongly depended on KMnO4 concentration, the coating formed at the concentration of 0.8 g/L KMnO4 reached the highest and an average of up to 0.87 was observed.

Characterization and properties of PEO coatings on 7075 Al alloy grown in alkaline silicate electrolyte containing KMnO4 additive

Plasma electrolytic oxidation (PEO) was used to modify the surface of 7075 Al alloy by applying a bipolar pulsed-current in a silicate based electrolyte containing 0 to 3gL−1 KMnO4. For the coating produced in the base electrolyte, crystalline γ-Al2O3 was the main phase, while the coatings formed at the presence of KMnO4 consisted of α-Mn2O3 containing Si and Al oxides. A pancake structure was observed on surface of the coating produced in the base electrolyte, while a foam feature along with some volcano-like areas was detected on the surface of the coatings produced in the presence of KMnO4. The KMnO4 changed the discharge type leading to diminish the pores at the metal/coating interface and also increased the coating thickness. The Nyquist plots of the coatings in 3.5wt% NaCl solution at pH4 showed two capacitive loops related to the outer porous and inner compact layers, where the resistance of inner layer was very high indicating that it could determine the overall corrosion performance. The inner layer resistance increased with increasing KMnO4 concentration. At prolonged immersion times, the barrier property of the coatings was lost to some extent, but the coating produced in 3gL−1 KMnO4 solution showed superior corrosion performance due to its lower permeability. The corrosion current density of the specimen coated in the presence of 3gL−1 KMnO4 was ~3 times lower than that observed for the specimen coated in the base electrolyte.

Hydrothermal preparation of CS@MnO2 with different morphologies for supercapacitor electrode materials

This paper exhibits a rapid one-step hydrothermal method to prepare three different morphologies (spininess, columnar, lamelliform) of MnO2 covered on the surface of carbon spheres (CS@MnO2) by the control of KMnO4 concentration and hydrothermal temperature. All these CS@MnO2 composites were applied in supercapacitor electrode material, and the superior electrochemical performance of CS@MnO2 indicates that the combination of CS and MnO2 has a synergy effect on the enhancement of electrochemical performance. Among these samples, it is worth noting that the columnar morphology of CS@MnO2 exhibited the best performance achieving the max capacitance 178Fg−1 as the supercapacitor electrode material.

Metal-Assisted Chemical Etching of GaAs Using Au Nanodots

III-V compound semiconductors have attracted attention as next-generation materials and potential alternatives to silicon-based semiconductors because of their excellent properties including superior carrier mobility and direct band gap. In a previous study, we fabricated microbump arrays of InP [1] and line patterns and pillar arrays of GaAs using metal-assisted chemical etching [2]. However, the dimensions of the resultant patterns ranged from several micrometers to several tens of micrometers. To the best of our knowledge, no study has reported the formation of ordered GaAs nanostructures with submicron-scale or smaller periodicity using metal-assisted chemical etching. Thus, we attempted to clarify the etching mechanism of GaAs on the nanometer scale. In this study, we investigated the effects of etchant composition and temperature on the morphology of the etched GaAs during metal-assisted chemical etching using Au nanodot arrays as a catalyst. A through-hole porous alumina mask with an ordered array of openings was set on an n-type GaAs. Subsequently, a 20-30 nm thick Au layer was evaporated through the alumina mask using a mixed vacuum deposition system. The periodicity of Au nanodot arrays, which were formed on GaAs substrate, was 100 nm and the diameter of Au dot was 50-60 nm corresponding to the dimensions of anodic alumina mask. After the formation of Au dot arrays on GaAs substrates, the specimens were immersed in a mixed solution of HF and KMnO4. When the specimen was etched in a HF containing relatively low concentration of KMnO4 at high temperature, Au dots sank into the GaAs substrate. The positive holes (h+), which were generated by reduction of oxidant (i.e., KMnO4) at Au surface, are thought to be consumed immediately at the Au/GaAs interface. As a result, Au dot arrays sank into the substrate, resulting in the formation of pore arrays. On the other hand, in the case of high concentration of KMnO4, h+ diffused into the surrounding Au-coated GaAs; thus, site-selective etching occurred on the exposed GaAs surface. Attempts to clarify the effects of the concentration of oxidizing agent on the generation of h+ and morphology of etched are currently underway.[1] H. Asoh, T. Yokoyama and S. Ono, Jpn. J. Appl. Phys., 49, 046505 (2010).[2] H. Asoh, Y. Suzuki and S. Ono, Electrochim. Acta, 183, 8-14 (2015).

Optimization of PAHs Oxidation from a Concentrate of Soil Attrition Using Potassium Permanganate

ABSTRACTThe treatment of soils contaminated with organic compounds, such as polycyclic aromatic hydrocarbons (PAHs), by attrition produced large amounts of highly concentrated attrition sludge (PAH – attrition concentrate – PAC). This paper studied the performance of an oxidation process using potassium permanganate (KMnO4) to degrade PAHs that were initially present in attrition concentrates. The influence of operating conditions (temperature, concentration of KMnO4 and reaction time) was studied, and these parameters were optimized using a response surface methodology (RSM). The results showed that the temperature and the reaction time had a significant and positive effect on the degradation of PAHs for the experimental domain studied (temperature between 20 and 60°C and reaction time between 1 and 7 h). The interaction between the temperature and the concentration of KMnO4 significantly influenced the degradation of the PAHs. The temperature and the concentration of KMnO4 were the main parameters that influenced the degradation of both phenanthrene (Phe) and benzo [a] pyrene (BaP). For benzo [a] anthracene (BaA), the temperature was the most influential factor. According to our results, the optimal conditions were defined as [KMnO4] = 0.4 M for 5.5 h at 60°C. These optimal conditions led to degradations of 42.9%, 40.8%, 41.0% and 46.0% of the total PAHs, Phe, BaA and BaP, respectively.

Sub-10-nm Graphene Nanoribbons with Tunable Surface Functionalities for Lithium-ion Batteries

A systematic study to reveal the relationship between the surface oxygen-containing functionalities of sub-10-nm GNRs and their electrochemical properties for lithium-ion batteries has been presented. Sub-10-nm GNRs with controlled oxygen-containing groups were synthesized by a green and scalable intercalation-assisted unzipping SWCNTs. Detailed materials characterizations including TEM, XRD, Raman and XPS indicate that KNO3 could be an effective intercalation agent to facilitate the SWCNT unzipping by reducing the strong Van der Waals force attraction of bundled SWCNT. The levels of surface functionalities of sub-10-nm GNR were tuned by carefully controlling the KMnO4 concentration during the unzipping process. The electrochemical analysis suggests that the as-produced sub-10-nm GNR with 31.4 atomic percent (atom %) oxygen-containing functional groups showed the highest capacity of 490.4mAhg−1 after 100 cycles. This work proposed that sub-10-nm GNRs with appropriate oxygen-functional groups can be a promising electrode material for high performance lithium-ion batteries.

Nanoscaled Platforms Based on SiO2 and Al2O3 Impregnated with Potassium Permanganate Use Color Changes to Indicate Ethylene Removal

The development of novel tools/devices to monitor and oxidize ethylene (C2H4), a volatile compound responsible for the ripening and senescence in plants, can be a potential approach to maintain and provide information on the postharvest quality of fruits and vegetables. Here, we propose nanoscaled platforms based on silica (SiO2) and alumina (Al2O3) nanoparticles impregnated with potassium permanganate (KMnO4) that use color changes to indicate ethylene removal. SiO2 and Al2O3 in the microscale and nanoscale were impregnated with varied concentrations of KMnO4 through a simple mixture route, which systems were capable of oxidizing the ethylene in a closed atmosphere under relative humidity of 45, 60, 75, and 90%. Ethylene removal and color changes were monitored using gas chromatography and colorimetry, respectively. The nanoscaled platforms impregnated with KMnO4 were capable of scavenging ethylene more efficiently for 1-h exposure. Additionally, the color changes experienced by the nanoscaled platforms, arising from the chemical reduction of potassium permanganate, function as an indicator of ethylene removal, which is particularly suitable for postharvest application.

A novel process for separation of polycarbonate, polyvinyl chloride and polymethyl methacrylate waste plastics by froth flotation

A novel process was proposed for separation of ternary waste plastics by froth flotation. Pretreatment of plastics with potassium permanganate (KMnO4) solution was conducted to aid flotation separation of polycarbonate (PC), polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) plastics. The effect of pretreatment parameters including KMnO4 concentration, treatment time, temperature and stirring rate on flotation recovery were investigated by single factor experiments. Surface treatment with KMnO4 changes selectively the flotation behavior of PC, PVC and PMMA, enabling separation of the plastics by froth flotation. Mechanism of surface treatment was studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). Effect of frother concentration and flotation time on flotation behavior of plastic mixtures was further studied for flotation separation. The optimized conditions for separation of PC are KMnO4 concentration 2mmolL−1, treatment time 10min, temperature 60°C, stirring rate 300rpm, flotation time 1min and frother concentration 17.5mgL−1. Under optimum conditions, PVC and PMMA mixtures are also separated efficiently by froth flotation associated with KMnO4 treatment. The purity of PC, PVC and PMMA is up to 100%, 98.41% and 98.68%, while the recovery reaches 96.82%, 98.71% and 98.38%, respectively. Economic analysis manifests remarkable profits of the developed process. Reusing KMnO4 solution is feasible, enabling the process greener.

Synthesis of manganese oxide sols by KMnO4 reduction with polyvinyl alcohol in an aqueous medium

Manganese oxide sols were synthesized using the chemical condensation method by KMnO4 reduction with polyvinyl alcohol in an aqueous medium. The resulting gels were characterized by the manganese oxide content of 0.07–0.19 wt %, pH 9.5–10.2, and ζ-potential of–(20.3–42.9) mV. Spectrophotometric, turbidimetric, and dynamic light scattering methods were employed to determine how the particle size, ζ-potential, pH, and manganese oxide content in the resulting sols were affected by the KMnO4 concentration and the KMnO4 : polyvinyl alcohol ratio. The most stable sols preserved stability for over180 days and remained stable up to 0.5 M KCl, CaCl2, and AlCl3 concentrations.