Hydrogen Peroxide In Aqueous Solution Research Articles

Environmentally Friendly Bleaching Process of the Cellulose Fibres Materials Using Ozone and Hydrogen Peroxide in the Gas Phase.

The paper presents the new eco-friendly method of bleaching process of the cellulose fibre materials. Cellulose materials were bleached using hydrogen peroxide (both in aqueous solution, vapours, ozone and by the combined action of gaseous hydrogen peroxide and ozone. The method using hydrogen peroxide in aqueous solution presents the standard procedure and was used as the comparison technique. The bleaching processes using gaseous oxidants were carried out in a prototype device for dry, low-temperature treatment of fibrous materials with the use of oxidising agents in the gas phase. The influence of the innovative gas-phase bleaching method on the cotton samples' properties was analysed by Scanning Electron Microscopy (SEM), evaluation of the colour and whiteness, assessment of the polymerisation degree (DP), analysis of the mechanical properties and sorption capacity as well as microbiological assessment against colonies of Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The comparison of the obtained results led to the conclusion that the bleaching processes using gas-phase agents-vaporised hydrogen peroxide, ozone or their combination-are non-invasive. The applied bleaching processes resulted in a slightly lower whiteness parameters than standard bath bleaching. After the bleaching processes with ozone and vaporised hydrogen peroxide separately, the decrease in the DP and tensile strength was similar to that observed after the bleaching with aqueous H2O2. When both processes were used together, a higher reduction in DP and tensile strength was noticed. Both oxidising agents showed a strong biocidal effect against bacteria. Gas-phase bleaching procedures, due to the lower temperature (35 °C vs. 98 °C) and minimal water consumption, have economic and environmental advantages, which allows their use in semi-industrial applications. It has been shown that the treatment of cotton fabrics using ozone and hydrogen peroxide in the gas phase allows to simultaneously obtain the bleaching and disinfection effect.

Pilot-scale Validation of the Modeling of NOx Reactive Absorption Process Using Aqueous Solutions Containing Nitric Acid and Hydrogen Peroxide

NOx are harmful pollutants emitted by many industries and must be removed before the gases are released into the atmosphere. Among the various techniques used for NOx removal, reactive absorption by hydrogen peroxide in a packed column has the advantage of being able to transform NOx into nitric acid which can be recycled and reused in the plants. This work aimed at modeling the NOx absorption by means of aqueous solutions of hydrogen peroxide and nitric acid, applied in a packed column operating under different representative conditions. The model established using the Aspen software considers the equilibrium and the kinetics of the reactions taking place both in the gas phase and in the liquid phase as well as the thermodynamic properties of the chemical (molecular and ionic) components estimated using the Electrolyte NRTL model. It allows predicting NOx absorption performances in terms of efficiency and selectivity. The model was validated by comparing simulation results with experimental ones obtained in a pilot-scale absorption column and published previously. The predicted values are in satisfactory agreement with the experimental data showing a deviation between 5 and 8%. Therefore, the model developed in this work could be advantageously used to design industrial-scale reactive NOx absorption columns.

Pyolytics as a product of the physical–chemical repurposing of antiseptics and an alternative to larval therapy for chronic wounds

The traditional treatment of chronic wounds involves daily cleansing of the wound surface from purulent necrotic masses using mechanical and medicinal methods, accompanied by regular replacement of wound dressing. In this case, medicinal wound cleansing lasts 10–15 mins from the time of replacement of the old wound dressing with the new one. According to established practice, medicinal sanitation of infected and purulent wounds during dressing involves irrigation of the wound surface with cleansing solutions, antiseptics, and/or antibiotics. In severe cases, the above therapy is supplemented with live larvae of the necrophage fly, which are injected into purulent necrotic masses and left in them under wound dressing until wounds are completely cleansed from pus. Nevertheless, the generally accepted course of treatment of chronic wounds remains ineffective. The use of pyolytics and their supplementation with wound dressings in the form of warm wet compresses, which create a local greenhouse effect in wounds, was reported to accelerate the healing of chronic wounds. Pyolytics are a group of antiseptics developed in Russia. They are warm alkaline solutions of hydrogen peroxide; when they interact with purulent necrotic masses, these solutions dissolve very quickly and foam them. Because of the interaction with pyolytics, thick purulent masses immediately turn into fluffy oxygenated foam. Pyolytics have been developed because of the physicochemical repurposing of aqueous solutions of sodium hydrogen carbonate and hydrogen peroxide. To accelerate the healing of chronic wounds, a recommendation was to irrigate the surface of chronic wounds with 3% hydrogen peroxide and 2–10% sodium bicarbonate solutions, heated to 37–45°C, which have alkaline activity at pH 8.4–8.5 and are enriched with dissolved carbon dioxide or oxygen (due to excess pressure of 0.2 atm). This study presented the importance of treating chronic wounds using politics and treatment outcomes using pyolytics along with warm moist dressing compresses, demonstrating a wound-healing effect. Consequently, physical and chemical reprofiling of antiseptics may make them effective pyolytics, and the combination of pyolytics with warm wound dressings such as warm moist compresses, which create a local greenhouse effect on wounds, accelerates the healing of chronic wounds.

Cyanide removal from aqueous solution by oxidation with hydrogen peroxide in the presence of activated alumina-supported copper catalyst

<p>Cyanide compounds are widely used in some electroplating, chemical and metallurgical industries. They are often found in their liquid discharges. This work highlights the performance of an activated alumina-supported copper catalyst in the removal of cyanide by oxidation with hydrogen peroxide in aqueous solution. The influence of catalyst dose, initial molar ratio of hydrogen peroxide/cyanides, temperature, and catalyst reuse was studied. The activated alumina-supported copper significantly enhanced the reaction rate showing a good catalytic activity. The efficiency of cyanide elimination was increased after 30 minutes of oxidation from 48% to 98% by increasing the catalyst dose from 1 to 10 g/L. Rising the temperature from 30°C to 40°C promoted cyanide removal. The catalyst can be recycled four times and show good stability. The kinetics of cyanide oxidation was revealed to be pseudo-first order with regarding cyanides. The rate constants as well as the activation energy were determined.</p>

Synthesis of Selenium-Containing N-Quinazolinyl Acroleins via a 3,3-Radical Rearrangement Cascade Reaction.

An effective approach for the construction of 2-aryl-3-(3-oxo-1-aryl-2-(organoselanyl)prop-1-en-1-yl)quinazolin-4(3H)-ones was developed. Excellent to almost quantitative yields were obtained by the cascade reaction of propargyl quinazoline-4-yl ethers, diselenides, and 70% tert-butyl hydrogen peroxide aqueous solution under metal-free and mild conditions. The synthesized hybrids, with conglomeration of quinazolinone, organoselenium, aldehyde, and fully substituted alkene moieties in one molecule, will have the potential for applications in development of new drugs or drug candidates.

MoS2/MoO3 heterojunctions enabled by surface oxidization of MoS2 nanosheets for high-performance room-temperature NO2 gas sensing

Transition-metal dichalcogenides (TMDs) have emerged as ideal candidates for room-temperature gas sensing due to their remarkable semiconductor properties. However, bare TMDs typically exhibit drawbacks such as low sensitivity, slow response, and low recovery speeds, which limit their applicability. In comparison to single materials, enhancing the sensing performance of the material can be achieved through the realization of heterostructures. Therefore, the key to improving the performance of metal-sulfide gas sensors lies in the controlled construction of unique heterostructures. In this work, surface heterostructures composed of molybdenum disulfide (MoS2) nanoflowers loaded with molybdenum trioxide (MoO3) enabled are realized through the surface oxidization of MoS2 nanosheets for high-performance room-temperature detection of NO2 gas. The heterostructures were easily constructed by oxidizing flower-like MoS2 using a hydrogen peroxide aqueous solution. The gas sensor based on the MoS2/MoO3 heterojunction exhibits a response of 18.9 % to 1 ppm NO2, which is nine times higher than that of the MoS2 sensor (2.1 %). Furthermore, even at a NO2 concentration as low as 50 ppb, the sensor response can reach 6.9 %. The sensor displays good repeatability and excellent selectivity. The enhanced gas-sensing performance of the MoS2/MoO3 heterostructure may result from the unique structure of MoS2 and the p-n heterojunction formed at the interfaces. The proposed design strategy and the surface heterostructure constructed in this work can provide guidance for the development of high-performance gas-sensitive materials and devices.

Rooting out ultraweak photon emission a-mung bean sprouts

It is well known that life has evolved to use and generate light, for instance, photosynthesis, vision and bioluminescence. What is less well known is that during normal metabolism, it can generate 1–100 photons s−1 cm–2 known as ultra-weak photon emission (UPE), biophoton emission or biological autoluminescence. The highest generation of these metabolic photons seem to occur during oxidative stress due to the generation and decay of reactive oxygen species (ROS), and their interaction with other components of the cell. To study this further, we have configured a sensitive detection system to study photon emission in germinating mung beans.Here we investigated growing mung beans over 7 days at a constant temperature of 21 ± 1 °C in a light tight box, using dual top and bottom opposing photomultiplier tubes. Over this time period we showed that in total, mung beans grown from seeds generated an average of 5 ± 1 counts s−1 above background. As the new bean stems grew, they showed a gradual linear increase in emission of up to 30 ± 1 counts s−1, in agreement with previous literature. In addition to this “steady-state” emission we also observe delayed luminescence and drought-stress response emission previously observed in other species. Finally, we also observe episodic increased emission events of between 2 and 15 counts s−1 for durations of around 3 h detected underneath the sample, and assign these to the growing of secondary roots.We then induce secondary root formation using aqueous solutions of growth hormones hydrogen peroxide (H2O2, 167 µM) or 3-indole acetic acid (IAA, 0.5 µM) for watering. Both hormones show prolonged increase in emission above steady-state, over days 3–5 with at least 3 times the number of secondary roots formed compared with water alone. We also observed a significant peak increase in photon emission (474 and 1738 cps vs. 28 and 55 cps for water alone) for the H2O2 which we attribute to direct ROS reaction emission as confirmed by measurement on dead plants.Altogether we have expanded upon and demonstrated an instrument and biological system for reliably producing and measuring intrinsic metabolic photons, first observed 100 years ago by Alexander Gurwitsch.

An Iron Macrocyclic Complex Containing Four "Hybrid" Pyridinium Amidate/Amidate N-Donors as a Catalyst for Oxidations With Hydrogen Peroxide.

The macrocyclic pro-ligand [H4L][OTf]2, which contains four carboxamide functions and two conjugated pyridinium groups, is easily deprotonated by the weak base sodium acetate to give the corresponding neutral pro-ligand [H2L]. Metalation of [H2L] with iron(II) chloride proceeds rapidly to form the macrocyclic complex, [FeIIICl(L)]. This is an effective catalyst for the oxidation of the organic dye orange II by hydrogen peroxide in aqueous solution and the kinetic parameters for this reaction have been determined. In striking contrast to an analogous iron-TAML complex that contains two phenyl groups in place of the two pyridinium groups, [FeIIICl(L)] is a very active oxidation catalyst at pH 7 and is also highly stable towards acid promoted demetallation at pH 5 or above. The results show that the two pyridinium groups bring greatly enhanced catalytic properties to [FeIIICl(L)].

8-Oxoguanine-DNA-Glycosylase Gene Polymorphism and the Effects of an Alternating Magnetic Field on the Sensitivity of Peripheral Blood.

The production of reactive oxygen species (ROS) in animals and cells often results from exposure to low-intensity factors, including magnetic fields. Much of the discussion about the initiation of oxidative stress and the role of ROS and radicals in the effects of magnetic fields has centered on radical-induced DNA damage. The DNA concentration in the final solution was determined spectrophotometrically. Typing of the polymorphic variant rs1052133 of the 8-oxoguanin DNA glycosylase (hOGG1) gene was performed by polymerase chain reaction. An enzyme immunoassay was performed to determine the level of 8-oxyguanine in DNA. To process samples exposed to an alternating magnetic field, the authors developed a device for the automated study of biological fluids in an alternating magnetic field. The content of hydrogen peroxide in aqueous solutions of DNA was determined using the spectrophotometric method. It was experimentally determined that an increase in the concentration of hydrogen peroxide in an aqueous medium by 3-5 times under the action of a low-frequency magnetic field reduces the resistance of the genomic material to oxidative modification and the accumulation of 8-oxyguanine in DNA. A model is proposed for the mechanism of action of a low-frequency magnetic field on aqueous solutions of nucleic acids and proteins, which satisfies the model of a chemical oscillator for the transformations of reactive oxygen species in an aqueous medium. The model illustrates the oscillating nature of the processes occurring in an aqueous solution of DNA and makes it possible to predict changes in the concentration of hydrogen peroxide in an aqueous solution of biopolymers, depending on the frequency of the acting low-intensity magnetic field. The key element in the mechanisms involved in the effects of low-intensity magnetic field on living systems is the occurrence of ROS generation in the aquatic environment of chemical oscillators, in which the competition of physical and chemical processes (electron transfers, reactions of decay and addition of radicals, spin magnetically induced conversion, synthesis, and decay of the longest-lived form-hydrogen peroxide) is controlled by a magnetic field.

The Reaction of Muonium with Hydrogen Peroxide in Aqueous Solution.

Rate constants for the reactions of muonium (Mu) (the ultralight isotope of the hydrogen atom) with H2 O2 in H2 O and D2 O2 in D2 O have been determined at various temperatures and pH (pD) values. The data are consistent with the three reactions: , , and the equivalent for the deuterated entities. A significant positive H/D isotope effect was found for the undissociated peroxide, while for the anions the effect was negligible or slightly in the opposite direction. In addition, for concentrated solutions of peroxide a study of the muon spin polarization as a function of applied transverse magnetic field yielded results consistent with the rate constants determined from the direct decay measurements, and indicated that the reaction products are diamagnetic, most likely MuH and MuOH, i. e., no muoniated radical products are formed. These results are potentially relevant for management of the radiolysis products in nuclear industry.

TiO2/MWCNT/Nafion-Modified Glassy Carbon Electrode as a Sensitive Voltammetric Sensor for the Determination of Hydrogen Peroxide.

In this work we describe a straightforward approach for creating a nanocomposite comprising multiwalled carbon nanotubes (MWCNTs) and titanium dioxide (TiO2) using the hydrothermal technique, which is then characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectrometer (EDS), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA) to assess its properties. Nafion is employed as a reticular agent for the nanocomposite on the glassy carbon electrode (GCE), creating the MWCNT/TiO2/Nafion/GCE system. The electrochemical behavior of the system was evaluated using cyclic voltammetry, revealing its remarkable electrocatalytic activity for detecting hydrogen peroxide in water. The developed sensor showcased a broad linear response range of 14.00 to 120.00 μM, with a low detection limit of 4.00 μM. This electrochemical sensor provides a simple and highly sensitive method for detecting hydrogen peroxide in aqueous solutions and shows promising potential for various real-world applications, particularly in H2O2 monitoring.

PEROXIDASE-LIKE ACTIVITY OF MAGNETIC NANOPARTICLES IN THE PRESENCE OF BLOOD PROTEINS

The generation of hydroxyl radicals from hydrogen peroxide in aqueous solutions containing magnetic nanoparticles (MNPs), hemoglobin (Hb), immunoglobulin G (IgG), and human serum albumin (HSA) has been determined. The dependence of the rate of formation of the oxidized product of o-phenylenediamine (o-PDA) on the concentration of MNPs in solution, as well as on the concentration of proteins, was obtained. The peroxidase-like activity of MNPs was shown to decrease in the presence of HSA and IgG, while the addition of Hb to the reaction mixture was leading to its decrease and increase depending on protein concentration. The obtained effects can be used in the development of systems based on MNPs for theranostics, in particular, for suppression of tumor growth, and in predicting the ability of particles to catalyze the generation of reactive oxygen species (ROS) in vivo.

Effects of chloride solution on the corrosion behaviour of dissimilar friction stir butt welded joints of aluminium alloys

The corrosion behaviour of dissimilar friction stirs butt welded joints of cold-rolled AA6061-T6 and additively manufactured AlSi10Mg aluminium alloys was investigated by immersion tests in aqueous sodium chloride and hydrogen peroxide solutions. Optical microscopy was employed to investigate corrosion responses and to understand the corrosion mechanisms of stir weld regions. For the same material positioning, with the decrease in tool rotational speed, the corrosion rate was observed to increase. At the same tool rotational speed, a weld joint having AA6061-T6 on the advancing side and additively manufactured AlSi10Mg on the retreating side exhibited a lower tendency to corrode towards the test solution. The predominant corrosion mechanism for the dissimilar friction stir butt welded joints was observed to be pitting corrosion.

Zr-MOF catalyzed selective oxidation of anilines to azoxybenzenes in aqueous H2O2 solution

A highly efficient and organic solvent-free synthetic strategy for the selective oxidation of anilines to azoxybenzenes was developed by employing porous Zr-MOFs as catalysts in aqueous hydrogen peroxide solution. The impact of cluster nodes, pore size, and linker functionalities on the catalytic performance of Zr-MOFs was fully evaluated and discussed. Featuring abundant bridging Zr-OH-Zr catalytic sites and confined microenvironments, the pristine UiO-66(Zr) could create abundant reactive oxygen species (ROS) with high H2O2 efficiency, affording quantitative yield of azoxybenzene under mild conditions. Furthermore, the UiO-66(Zr)/H2O2 heterogeneous catalytic system exhibited broad and size-selective substrate scope and excellent stability in consecutive catalytic cycles. Mechanism studies demonstrated that the azoxybenzenes were produced through radical pathway on bridging Zr-OH-Zr sites. This study provided alternative strategies exploiting green catalytic systems with porous MOFs, which might further expand the potential application of the MOFs family.

Catalytic activity of Mn(III) porphyrin complex supported onto cross linked polymers in the green oxidation of malathion with hydrogen peroxide in aqueous solution

Developing effective, affordable, and recoverable heterogeneous catalysts is one of the foremost challenges in modern chemistry. Mn(III) complexes of 5-(4-aminophenyl) −10, 15, and 20-triphenyl porphyrin 1 immobilized covalently on polymethyl methacrylate (PMMA) 2 and poly(methyl methacrylate –co- styrene) (PMMA/ST) 3 were synthesized, characterized, and applied for degradation of malathion with H2O2 in aqueous solution. Mn(III) porphyrin complex anchored on cross linked polymers 4 and 5 show high catalytic activity for malathion (pesticide) degradation in an aqueous solution with green oxidant H2O2. The catalytic efficacy of malathion degradation was highest with the Mn(III) porphyrin complex covalently anchored on (polymethyl methacrylate-co-styrene) 5. The optimum conditions, including the effect of pH, catalyst concentration, and H2O2 concentration on the degradation of malathion, were investigated. The reuse and stability of catalysts were examined, and the findings proposed that the Mn(III) porphyrin complex 5 has no noticeable changes in the removal efficiency up to five consecutive cycles. GC–MS analyses showed that the degraded compounds and intermediates formed from malathion degradation were non-toxic to E. coli bacteria. For the degradation of dissolved malathion pesticides in an aqueous solution, the use of Mn(III) porphyrin complex 5 in the presence of H2O2 has the potential to be advantageous.

In-situ regeneration of NbOX/TiO2 catalyst deteriorated due to coke deposition via supercritical water oxidation

In this study, supercritical oxidation was used as a method for in situ regeneration of deteriorated NbOX/TiO2 catalyst during glycerol dehydration in supercritical water at 400 ℃ and 30 MPa. When the dehydration reaction using NbOX/TiO2 was conducted, coking of the catalyst occurred, and the activity of the catalyst decreased over time. The regeneration process was conducted by simply changing the feed material from an aqueous glycerol solution to an aqueous hydrogen peroxide solution. After regeneration, the catalytic activity was similar to that of the fresh catalyst. The regeneration time can be shortened by increasing the flow rate of the aqueous solution.

Sideways propelled bimetallic rods at the water/oil interface.

The motion of self-propelling microswimmers is significantly affected by confinement, which can enhance or reduce their mobility and also steer the direction of their propulsion. While their interactions with solid boundaries have already received considerable attention, many aspects of the influence of liquid-liquid interfaces (LLI) on active particle propulsion still remain unexplored. In this work, we studied the adsorption and motion of bimetallic Janus sideways propelled rods dispersed at the interface between an aqueous solution of hydrogen peroxide and oil. The wetting properties of the bimetallic rods result in a wide distribution of their velocities at the LLI. While a fraction of rods remain immotile, we note a significant enhancement of motility for the rest of the particles with velocities of up to 8 times higher in comparison to those observed near a solid wall. Liquid-liquid interfaces, therefore, can provide a new way to regulate the propulsion of bimetallic particles.

Research of the activity of Fe-pillared montmorillonites in aqueous dye solution

High specific surface area, large micropore volume, concentration of surface acid sites, and increased density of sorption sites make montmorillonite pillared as an excellent adsorbent and catalyst to remove contaminants from wastewater. The studies are aimed at establishing the adsorption and catalytic activity of Fe pillared montmorillonite based on Krantau and Navbakhor bentonite in relation to dyes from solutions. It has been shown that the introduction of Fe3+ ions into the interlayer space of a natural sample increases the activity with respect to the anionic dye by more than 2 folds. Despite the large specific surface area of the original Navbakhor clay, compared to Krantau clay, the activity for Congo red is greater in the pillar of the latter. It has been established that Fe-pillared materials are active catalysts for the oxidation of dyes by hydrogen peroxide in aqueous solutions and lead to its 100% conversion. An increase in the temperature of catalytic oxidation ranged from 25 to 55°C increases the discoloration degree of Congo red solution under homogeneous conditions by 1.5 folds or more, and under conditions of heterogeneous catalysis at least three folds.

The Baeyer–Villiger Oxidation of Cycloketones Using Hydrogen Peroxide as an Oxidant

Baeyer–Villiger oxidation can synthesize a series of esters or lactones that have essential application value but are difficult to be synthesized by other methods. Cycloketones can be oxidized to lactones using molecular oxygen, peroxy acids, or hydrogen peroxide as an oxidant. Hydrogen peroxide is one of the environmental oxidants. Because of the weak oxidation ability of hydrogen peroxide, Bronsted acids and Lewis acids are used as catalysts to activate hydrogen peroxide or the carbonyl of ketones to increase the nucleophilic performance of hydrogen peroxide. The catalytic mechanisms of Bronsted acids and Lewis acids differ in the Baeyer–Villiger oxidation of cyclohexanone with an aqueous solution of hydrogen peroxide as an oxidant.

Improved hydroxyl radical production by electric-field-induced catalysis in O3/H2O2 process: A reactive molecular dynamics perspective

O3/H2O2 process, as a well-used ozone advanced oxidation technology, has been considered to be suitable for treating a variety of organic wastewater. However, the low solubility of ozone in hydrogen peroxide aqueous solution makes the catalytic effect to ozone reaction unsatisfactory. In this study, a novel method of external electric field (EEF) catalyzing O3/H2O2 process was proposed. The chemical reaction in O3/H2O2 process under EEF were investigated by reaction molecular dynamics simulation. The mechanism of the catalytic effect of EEF on chemical reactions in the O3/H2O2 system was revealed by analyzing the system energy, hydrogen bond energy, reaction rate and degree of reaction of the reactants, and the amount of reaction products under EEF with different strength. The results show that EEF can significantly promote the ionization reaction of H2O2 to produce more HO– 2, which further promote the reaction of O3, thus ultimately leads to the increase of •OH production and generation rate. In addition, the catalytic effect of EEF is proportional to the field strength. When the amount of ozone is constant, the concentration of hydrogen peroxide will affect the catalytic effect of EEF.