Peroxide Oxidation Research Articles

Visualizing hydrogen peroxide and nitric oxide dynamics in endothelial cells using multispectral imaging under controlled oxygen conditions

The complex interplay between hydrogen peroxide (H2O2) and nitric oxide (NO) in endothelial cells presents challenges due to technical limitations in simultaneous measurement, hindering the elucidation of their direct relationship. Previous studies have yielded conflicting findings regarding the impact of H2O2 on NO production. To address this problem, we employed genetically encoded biosensors, HyPer7 for H2O2 and geNOps for NO, allowing simultaneous imaging in single endothelial cells. Optimization strategies were implemented to enhance biosensor performance, including camera binning, temperature regulation, and environmental adjustments to mimic physiological normoxia. Our results demonstrate that under ambient oxygen conditions, H2O2 exhibited no significant influence on NO production. Subsequent exploration under physiological normoxia (5 kPa O2) revealed distinct oxidative stress levels characterized by reduced basal HyPer7 signals, enhanced H2O2 scavenging kinetics, and altered responses to pharmacological treatment. Investigation of the relationship between H2O2 and NO under varying oxygen conditions revealed a lack of NO response to H2O2 under hyperoxia (18 kPa O2) but a modest NO response under physiological normoxia (5 kPa O2). Importantly, the NO response was attenuated by l-NAME, suggesting activation of eNOS by endogenous H2O2 generation upon auranofin treatment. Our study highlights the intricate interplay between H2O2 and NO within the endothelial EA.hy926 cell line, emphasizing the necessity for additional research within physiological contexts due to differential response observed under physiological normoxia (5 kPa O2). This further investigation is essential for a comprehensive understanding of the H2O2 and NO signaling considering the physiological effects of ambient O2 levels involved.

Analysis of Maternal and Fetal Oxidative Stress During Delivery with Epidural Analgesia

Childbirth is a stressful event for mothers, and labor epidural analgesia (LEA) may reduce mental stress. Mental stressors include labor pain, fear, and anxiety, which induce oxidative stress. In this study, we focused on oxidative stress during delivery and conducted a cross-sectional analysis of maternal and fetal oxidative stress. The participants included 15 women who received LEA (LEA group) and 15 who did not (No LEA group). Participants with a gestational age of < 37 weeks, BMI of ≥ 35 kg/m2, cerebrovascular or cardiovascular complications, multiple pregnancies, gestational hypertension, gestational diabetes, chronic hypertension, thyroid disease, birth weight of < 2,500 g, emergency cesarean section, or cases in which epidural anesthesia was re-administered during delivery were excluded from the study. Maternal blood was collected on admission, and immediately after delivery, and umbilical artery blood was collected from the fetus. The oxidative stress status was assessed by measuring diacron-reactive oxygen metabolite (an index of the degree of lipid peroxide oxidation), biological antioxidant potential (an index of antioxidant capacity) and calculating the ratio of BAP/d-ROMs (an index of the oxidative stress). The results showed that maternal oxidative stress immediately after delivery was lower in the LEA group than in the No LEA group. Moreover, the fetuses experienced less oxidative stress in the LEA group than in the No LEA group. Taken together, these results suggest that LEA may reduce maternal and fetal oxidative stress associated with childbirth.

Surface-Assisted Selective Air Oxidation of Phosphines Adsorbed on Activated Carbon.

Trialkyl- and triarylphosphines readily adsorb onto the surface of porous activated carbon (AC) even in the absence of solvents through van der Waals interactions between the lone electron pair and the AC surface. This process has been proven by solid-state NMR techniques. Subsequently, it is demonstrated that the AC enables the fast and selective oxidation of adsorbed phosphines to phosphine oxides at ambient temperature in air. In solution, trialkylphosphines are oxidized to a variety of P(V) species when exposed to the atmosphere, while neat or dissolved triarylphosphines cannot be oxidized with air. When the trialkyl- and triarylphosphines PnBu3 (1), PEt3, (2), PnOct3 (3), PMetBu2 (4), PCy3 (5), and PPh3 (6) are adsorbed in a mono- or submonolayer on the surface of AC, in the absence of a solvent and at ambient temperature, they are quantitatively oxidized to the adsorbed phosphine oxides, 1ox-6ox, once air is admitted. No formation of any unwanted P(V) side products or water adducts is observed. The phosphine oxides can then be recovered in good yields by washing them off of the AC. The oxidation is likely facilitated by a radical activation of molecular oxygen due to delocalized electrons on the aromatic surface coating of AC, as proven by ESR. This easy and inexpensive oxidation method renders hydrogen peroxide or other oxidizers unnecessary and is broadly applicable to sterically hindered and even to air-stable triarylphosphines. Phosphines adsorbed at lower surface coverages on AC oxidize at a faster rate. All oxidation reactions were monitored by solution- and solid-state NMR spectroscopy.

Analysis of the Effect of Crystal form on Precipitated Calcium Carbonate (PCC) of Dead Coral Reefs with the Addition of HNO3 Concentration

Many dead coral reefs found on the coast have not been treated optimally and currently their use is still limited as decoration in aquariums. Coral reefs contain calcium carbonate, silicon dioxide, sodium oxide, magnesium peroxide, and Iron (III) oxide, with a calcium carbonate content of around 73.76%. Because of its high calcium carbonate content, it can be used as a raw material for making PCC (Precipitated Calcium Carbonate) which is widely used in the industrial, health and food sectors. The aim of this research is to obtain the optimal temperature and time for CaO levels, as well as the effect of nitric acid solution concentration on the yield with a high level of purity in PCC products using the carbonization method. The fixed variables are: coral reef mass, independent variables: temperature, calcination time and nitric acid concentration and dependent variables: CaO yield and CaCO3 levels. The calcination temperature used was 700℃, 750℃, 800℃, 850℃, 900℃ and HNO3 concentration 1.50M, 2.00M, 2.50 M, 3.00M, 3.50M with Ca analysis using AAS and PCC morphology and content using SEM-EDX. Optimal conditions are the results of calcination at a temperature of 900℃ with an HNO3 concentration of 3.50 M resulting in a yield of 76% with a purity of 98.58%, pH 8, white with a Ca concentration (ppm) of 1,962,630 and the crystal form obtained at 3.00 M HNO3 is calcite and 3.50 M HNO3 is vaterite.

Endogenous advanced oxidation process with peracetic acid for recycling spent LiFePO4 batteries

LiFePO4 batteries are becoming more widely used due to their low cost and high stability advantages, which means that many spent batteries are generated. Designing green and efficient recycling methods for used batteries is strategically significant for the sustainable development of the new energy industry. This study innovatively proposes a self-activated advanced oxidation process with peroxyacetic acid for recycling spent LiFePO4, selectively releasing Li+ while converting LiFePO4 to FePO4. Quenching tests show that the de-embedding of Li+ is mainly caused by the rapid attack from HO• and R-O• radicals. Furthermore, the recycled products Li2CO3 and FePO4 are employed to regenerate LiFePO4 cathode materials, forming a closed-loop recycling process. Compared with traditional hydrometallurgy and hydrogen peroxide oxidation methods, this technology has obvious advantages in terms of process complexity, energy consumption, reagent consumption, recovery profit, and environmental friendliness. This work opens up a new way for the recycling of spent lithium-ion batteries.

Deep dewatering of municipal sludge by combining alternating electric field electro-osmosis and nano-CaO2 oxidation

To improve the effect of traditional electroosmotic sludge dewatering, combining alternating electric field electro-osmosis and nano-calcium peroxide (CaO2) oxidation, a homemade vertical electro-osmosis dewatering device was employed in this work to study the effects of different parameter on the dewatering of primary dewatered sludge from municipal sewage treatment facilities with a moisture content of around 85%. The sludge water content (Wr) was used as an indicator, and concentration of extracellular polymeric substances (EPS) in the dewatered sludge was measured, and its structure was analyzed to investigate the effect of EPS changes on sludge dewatering.The response surface method was used to optimize the parameters. Wr decreased to 36.23 % at a CaO2 amount of 14.79 mg·g−1 dry sludge, a time ratio of 7.98:1, and a voltage gradient of 19.71 V·cm−1. Analysis of zeta potential and infrared characterization indicates that under acidic circumstances, CaO2 reacts more positively with water to produce hydrogen peroxide, and EPS is more easily destabilized and degraded, due to this, the problem of unequal water content in the cathode and anode sludge cakes is also solved. During the sludge dewatering process, the synergistic effect of alternating electric field and calcium peroxide together destroys the cell structure and EPS of sludge, especially the tightly bound EPS (TB-EPS), enabling the migration of substances and the formation of loosely bound EPS (LB-EPS), slime EPS (S-EPS), or filtrate, which can improve the sludge dewaterability.

The Intensity of Lipid Peroxide Oxidation Processes and the System State of Antioxidant Protection of Broiler Chicken Due to the Action of the Synbiotic Preparation in Complex with the Disinfectant

Developing methods for increasing the immune reactivity and antioxidant potential of the bird's body during critical periods of growth is an urgent task today. The purpose of the research was to find out the influence of the synbiotic "Biomagn" in combination with the disinfectant "Diolide" on the intensity of the processes of peroxide oxidation of lipids and the activity of the system of antioxidant protection in the organism of chickens. The research was carried out on 2 groups of chickens, 100 in each, starting from 1 to 41 days of age: the control group was fed with standard compound feed (SCF); the chickens of the experimental group were fed with SCF, and the synbiotic preparation "Biomagn" based on 0.5 kg per ton of compound feed. The experimental group received a solution of the preparation "Diolide" with water. For conducting immunological research, blood was taken from chickens at different age periods: from 10-, 27-, 31-, and 41-day-old chickens. The use of the synbiotic preparation "Biomagn" in combination with the disinfectant "Diolide" in the chickens of the experimental group normalized the intensity of the processes of lipid peroxidation and oxidative modification of proteins in the poultry's organism - a decrease was established (p &amp;lt;0.05–0.001) in GPO content and TBK-active products and aldehyde derivatives oxidative modification of proteins in the blood compared to the control. The detected event was determined by increased activity of the enzyme link of the antioxidant protection system of the organism of chickens.

Moringa oleifera-based feed supplement protects against renal ischaemia/reperfusion injury via downregulation of Bax/caspase 3 signaling.

Ischaemia/reperfusion (I/R) may lead to acute kidney injury via the induction of oxidative stress. On the other hand, Moringa oleifera has been reported to exert antioxidant activities. This study was designed to assess whether or not Moringa oleifera-based feed supplement could prevent I/R-induced renal injury. Renal I/R was induced by occluding the right renal artery for 30 min followed by a 2-h reperfusion. Renal I/R led to increased absolute renal weight and renal organo-somatic weight index. Renal I/R also caused distortion of renal histoarchitecture and impaired renal function evidenced by elevated serum creatinine and blood urea nitrogen. In addition, renal I/R significantly elevated renal levels of hydrogen peroxide, MDA, and advanced oxidation protein products, but suppressed the levels of reduced glutathione, protein thiol, and non-protein thiol, and the activities of superoxide dismutase and glutathione peroxidase. In addition, renal I/R up-regulated myeloperoxidase activity and the renal levels of NO, TNF-α, and IL-6. Renal I/R also up-regulated Bax and caspase 3 expression in the kidney. Furthermore, I/R-driven structural and biochemical alterations were markedly inhibited by Moringa oleifera-based feed supplement. These results suggest that Moringa oleifera-based feed supplement may preserve the gross and histoarchitectural integrity of the kidney as well as renal function via downregulation of Bax/caspase 3 signaling by targeting oxidative stress, inflammation and apoptosis in the kidney of I/R rat.

Comparative study of the degradation of meta-chloronitrobenzene by UV/hydrogen peroxide and UV/persulfate oxidation: Degradation pathways and toxicity

Advanced oxidation processes (AOPs) offer effective means to degrade recalcitrant contaminants, yet concerns about the formation of toxic products may hinder their practical application. This study compared the degradation of meta-chloronitrobenzene (mCNB) by UV-activated hydrogen peroxide (UV/H2O2) and persulfate (UV/PDS) oxidation. Both methods demonstrated efficient mCNB removal, with 73 % and 64 % removal observed, respectively, in 30 min at an oxidant dose of 1.0 mM. However, the products formed in the UV/PDS process exhibited higher toxicity compared to those formed in the UV/H2O2 process. This difference in toxicity arose from the distinct rection behavior of hydroxyl radical (HO•) and sulfate radical (SO4•−), the principal reactive species in UV/H2O2 and UV/PDS processes, respectively. HO• mainly attacked mCNB via an addition mechanism, forming hydroxylated products in UV/H2O2. In contrast, SO4•− reacted with mCNB via single-electron transfer, forming a radical cation (mCNB•+). This radical cation underwent rapid dissociation or hydrolysis to 3-chrolophenol (3CP) and 2-chloro-4-nitrophenol (2C4NP), respectively. Subsequent oxidation of 2C4NP by SO4•− generated a phenoxyl radical. The coupling of mCNB•+ or phenoxyl radical with a nitrogen dioxide radical (NO2•) derived from mCNB denitration, leading to the generation of more toxic dinitro-products. We assume these findings can be extrapolated to the treatment of other nitroaromatic compounds. SO4•−-based oxidation technologies tend to generate more polynitrated byproducts than HO•-based oxidation technologies, thus posing a greater potential risk. This consideration should guide the selection of appropriate treatment technologies for these contaminates.

Stormwater runoff microplastics: Polymer types, particle size, and factors controlling loading rates

Stormwater runoff is a pathway of entry for microplastics (MPs, plastics <5 mm) into aquatic ecosystems. The objectives of this study were to determine MP size, morphology, chemical composition, and loading across urban storm events. Particles were extracted from stormwater samples collected at outfall locations using wet peroxide oxidation and cellulose digestion followed by analysis via attenuated total reflectance (ATR) FTIR. Concentrations observed were 0.99 ± 1.10 MP/L for 500–1000 μm and 0.41 ± 0.30 MP/L for the 1000–5000 μm size ranges. Seventeen different polymer types were observed. MP particle sizes measured using a FTIR-microscope camera indicated non-target size particles based on sieve-size classification, highlighting a potential source of error in studies reporting concentration by size class. A maximum MP load of 38.3 MP/m2 of upstream catchment was calculated. MP loadings had moderate correlations with both rainfall accumulation and intensity (Kendall τ = 0.54 and 0.42, respectively, both p ≤ 0.005). First flush (i.e. rapid wash-off of pollutants from watershed surfaces during rainfall early stages) was not always observed, and antecedent dry days were not correlated with MP abundance, likely due to the short dry periods between sampling events. Overall, the results presented provide data for risk assessment and mitigation strategies.

Biomimetic Vesicles with Designer Phospholipids Can Sense Environmental Redox Cues.

Cell-like materials that sense environmental cues can serve as next-generation biosensors and help advance the understanding of intercellular communication. Currently, bottom-up engineering of protocell models from molecular building blocks remains a grand challenge chemists face. Herein, we describe giant unilamellar vesicles (GUVs) with biomimetic lipid membranes capable of sensing environmental redox cues. The GUVs employ activity-based sensing through designer phospholipids that are fluorescently activated in response to specific reductive (hydrogen sulfide) or oxidative (hydrogen peroxide) conditions. These synthetic phospholipids are derived from 1,2-dipalmitoyl-rac-glycero-3-phosphocholine and they possess a headgroup with heterocyclic aromatic motifs. Despite their structural deviation from the phosphocholine headgroup, the designer phospholipids (0.5-1.0 mol %) mixed with natural lipids can vesiculate, and the resulting GUVs (7-20 μm in diameter) remain intact over the course of redox sensing. All-atom molecular dynamics simulations gave insight into how these lipids are positioned within the hydrophobic core of the membrane bilayer and at the membrane-water interface. This work provides a purely chemical method to investigate potential redox signaling and opens up new design opportunities for soft materials that mimic protocells.

Microbacterium azadirachtae CNUC13 Enhances Salt Tolerance in Maize by Modulating Osmotic and Oxidative Stress.

Soil salinization is one of the leading threats to global ecosystems, food security, and crop production. Plant growth-promoting rhizobacteria (PGPRs) are potential bioinoculants that offer an alternative eco-friendly agricultural approach to enhance crop productivity from salt-deteriorating lands. The current work presents bacterial strain CNUC13 from maize rhizosphere soil that exerted several PGPR traits and abiotic stress tolerance. The strain tolerated up to 1000 mM NaCl and 30% polyethylene glycol (PEG) 6000 and showed plant growth-promoting (PGP) traits, including the production of indole-3-acetic acid (IAA) and siderophore as well as phosphate solubilization. Phylogenetic analysis revealed that strain CNUC13 was Microbacterium azadirachtae. Maize plants exposed to high salinity exhibited osmotic and oxidative stresses, inhibition of seed germination, plant growth, and reduction in photosynthetic pigments. However, maize seedlings inoculated with strain CNUC13 resulted in significantly improved germination rates and seedling growth under the salt-stressed condition. Specifically, compared with the untreated control group, CNUC13-treated seedlings exhibited increased biomass, including fresh weight and root system proliferation. CNUC13 treatment also enhanced photosynthetic pigments (chlorophyll and carotenoids), reduced the accumulation of osmotic (proline) and oxidative (hydrogen peroxide and malondialdehyde) stress indicators, and positively influenced the activities of antioxidant enzymes (catalase, superoxide dismutase, and peroxidase). As a result, CNUC13 treatment alleviated oxidative stress and promoted salt tolerance in maize. Overall, this study demonstrates that M. azadirachtae CNUC13 significantly enhances the growth of salt-stressed maize seedlings by improving photosynthetic efficiency, osmotic regulators, oxidative stress resilience, and antioxidant enzyme activity. These findings emphasize the potential of utilizing M. azadirachtae CNUC13 as a bioinoculant to enhance salt stress tolerance in maize, providing an environmentally friendly approach to mitigate the negative effects of salinity and promote sustainable agriculture.

UV-A assisted catalytic wet peroxide oxidation: Activity of iron minerals in the degradation of DEET

The widespread use of insect repellent N,N’-diethyltoluamide (DEET), along with its low biodegradability, has made this an ubiquitous contaminant in waterbodies. This work explores the elimination of DEET (10 mg/L) in aqueous matrices employing natural iron minerals ilmenite (FeTiO3), hematite (Fe2O3), goethite (Fe(OOH)) and magnetite (Fe3O4) as low-cost catalysts in UV-assisted Catalytic Wet Peroxide Oxidation, using UV-A LEDs (λ: 395 nm) as radiation source in a 500 mL useful-volume reactor. Under the studied conditions, magnetite presented a higher activity, significantly superior to that of the other minerals. A parametric study evaluating the effect of the catalyst load, initial pH, H2O2 dose, UV irradiance and water matrix was performed. Magnetite is able to carry out DEET degradation working at circumneutral pH (pH: 5) with outstanding results in terms of DEET removal even in complex matrices such as river water and WWTP effluent. Furthermore, the catalyst presented an excellent stability. Still, under the optimal operating conditions of this study ([Fe3O4]: 500 mg/L, [H2O2]0: 61.1 mg/L, pH0: 5, T: 25ºC, t: 120 min), only 27.8% mineralization was reached in ultrapure water. Nonetheless, the remaining organic compounds are mainly short-chain organic acids (malonic, oxalic, acetic and formic acids), which account for 98.7% of the residual organic carbon. These compounds, which are readily biodegradable, present a lower phytotoxicity than that of DEET, demonstrating the potential of UV-CWPO for the elimination of this emerging contaminant.

Identifying Electrocatalytic Activity Sequence of Metal Phthalocyanines for the Hydrogen Peroxide Oxidation Reaction

The hydrogen peroxide oxidation reaction (HPOR) plays a vital role in the emerging H2-H2O2 cycle energy storage system, in which the rational design of HPOR electrocatalyst is essential for achieving high system efficiency. Herein, we establish the HPOR activity trends using structurally well-defined metal phthalocyanines (MPc) as model catalysts via a combined experimental and computational approach. The measured activity sequence follows the order of CoPc > FePc > MnPc > ZnPc > H2Pc > NiPc > CuPc based on their site-normalized exchange current (i 0-s). Theoretical calculations indicate that the binding free energy of hydroperoxyl intermediate, HOO*, on MPc (ΔG HOO*) is the activity descriptor for HPOR. A volcano-type activity trend is observed by correlating the logarithm of i 0-s (logi 0-s) with the ΔG HOO* values and agrees with the theoretical predictions. This HPOR activity trend provides insights into the design of highly active electrocatalysts for HPOR and related energy applications.

Natural magnetite as an effective and long-lasting catalyst for CWPO of azole pesticides in a continuous up-flow fixed-bed reactor

The global occurrence of micropollutants in water bodies has raised concerns about potential negative effects on aquatic ecosystems and human health. EU regulations to mitigate such widespread pollution have already been implemented and are expected to become increasingly stringent in the next few years. Catalytic wet peroxide oxidation (CWPO) has proved to be a promising alternative for micropollutant removal from water, but most studies were performed in batch mode, often involving complex, expensive, and hardly recoverable catalysts, that are prone to deactivation. This work aims to demonstrate the feasibility of a fixed-bed reactor (FBR) packed with natural magnetite powder for the removal of a representative mixture of azole pesticides, recently listed in the EU Watch Lists. The performance of the system was evaluated by analyzing the impact of H2O2 dose (3.6–13.4 mg L−1), magnetite load (2–8 g), inlet flow rate (0.25–1 mL min−1), and initial micropollutant concentration (100–1000 µg L−1) over 300 h of continuous operation. Azole pesticide conversion values above 80% were achieved under selected operating conditions (WFe3O4 = 8 g, [H2O2]0 = 6.7 mg L−1, flow rate = 0.5 mL min−1, pH0 = 5, T = 25 °C). Notably, the catalytic system showed a high stability upon 500 h in operation, with limited iron leaching (< 0.1 mg L−1). As a proof of concept, the feasibility of the system was confirmed using a real wastewater treatment plant (WWTP) effluent spiked with the mixture of azole pesticides. These results represent a clear advance for the application of CWPO as a tertiary treatment in WWTPs and open the door for the scale-up of FBR packed with natural magnetite.

Microplastic contamination in rivers: a survey from the Nan River, Thailand

BackgroundSince the 1970s, microplastic contamination has been discovered in various environments. These emerging pollutants threaten water quality and freshwater ecosystems. We aimed to assess microplastic contamination in the Nan River by quantifying their presence, characterising their morphology, and identifying their polymer composition. MethodsThe survey was conducted along the Nan River in northern Thailand, which is divided into three distinct zones based on land use (ie, community areas, agricultural areas, and natural areas). A wide array of samples, including surface water, sediment, and specimens from five aquatic species—Barbonymus altus, Laides hexanema, Kryptopterus cryptopterus, Pomacea canaliculata, and Pseudodon cambodjensis cambodjensis—were collected. The presence of microplastics was analysed via the wet peroxide oxidation process for sample digestion, morphological characteristics were assessed through microscopic examination, and Fourier transform infrared spectrophotometry was used to identify the polymer composition of the microplastics. FindingsNatural areas had the highest mean concentration of microplastics in surface water (23·67 pcs/L, SD 14·22), whereas community areas had the highest mean concentration in soil sediment (24·67 pcs/g, 15·04). No statistically significant differences in the amounts of microplastics were observed among the various land-use zones. Microplastics were predominantly found in the gastrointestinal tracts of fish specimens, with varying quantities observed among different aquatic species; B altus had the highest concentration (11·80 pcs/g, 8·98). The primary microplastic shapes identified were filaments (53·99%), fragments (35·58%), and cylindrical forms (10·43%). We identified ten different polymer types, with polypropylene, nylons, and polymethyl methacrylate being the most prevalent among them. InterpretationAnalysing microplastic pollution in this area brings attention to the issues affecting the rivers of Thailand and emphasises ecological risks, particularly microplastic presence in aquatic species. Because of the Nan River's ecological importance, we call for increased research and collaboration to address the increasing threat of microplastic pollution. FundingNaresuan University.

Sweet cherry tree (Prunus avium) exudate gum-based film modification in a photoreactor: Effects of hydrogen peroxide oxidation, UV irradiation, and TiO2 nanoparticles

The fabrication possibility of nanocomposite film from sweet cherry tree exudate gum (SCG) was studied. To improve SCG film properties, oxidation with hydrogen peroxide, ultraviolet irradiation (UV-A and UV-C), and TiO2 nanoparticles (T-NPs) were used. Hydrogen peroxide oxidation at higher amounts decreased the water vapor permeability (WVP) and thickness and increased the mechanical properties and transparency. In comparison with the UV-A, UV irradiation of the C-type increased permeability, and elongation at break (EAB) and thickness, but reduced the tensile strength (TS), solubility, and transparency. The permeability and tensile strength were increased and elongation at break was decreased at a longer time of irradiation. The transparency values of fabricated films ranged from 65.3 to 79.5 % and WVP were in the range of 2.32–4.72 (×10−10 g/m.s.Pa). The measured TS of the SCG films were between 2.2 and 5 MPa and the EAB of the SCG films was between 35 and 68.7 %. The FTIR spectrum and SEM images revealed that the treatments could affect the bonds and the smoothness of the film surface, respectively. Images provided by AFM showed that the roughness of the films was increased by the addition of T-NPs. The incorporation of T-NPs increased the TS and decreased EAB and WVP. These results indicated that oxidation, UV irradiation and nanomaterials incorporation could be used to improve SCG film properties that are related to food packaging material.

Solar Oxidative Hydrogen Peroxide Production: Is the Oxygen Vacancy Always a Promoter in Solar Water Oxidation?

Solar Oxidative Hydrogen Peroxide Production: Is the Oxygen Vacancy Always a Promoter in Solar Water Oxidation?

Tuning a green carboxymethyl cellulose-based pre-tanning agent via peroxide oxidation for high chrome exhaustion in leather industry

The low chrome uptake by collagen in the conventional tanning process leads to the pollution of the wastewater. Due to environmental concerns, leather scientists are already searching for innovative ways to produce pre-tanning agents as a high exhaustion chrome tanning auxiliary. Herein, a novel kind of pre-tanning agent is engineered by converting carboxymethyl cellulose (CMC) to oxidized carboxymethyl cellulose (OCMC) via the hydrogen peroxide process. FT-IR and carboxyl content analysis demonstrated the increase in carboxyl content after oxidation. After that, the obtained OCMC was utilized as a pre-tanning agent, resulting in a high exhaustion of chrome (92.76 %) which is 27.76 % more than conventional chrome tanning (65 %), and the amount of chrome in wastewater reduced to 7.24 %. The hydrothermal stability of wet-blue increased by increasing the uptake of chrome (Ts = 118 °C). The obtained crust leather represented excellent mechanical properties (Tensile strength: 305.68 kg/cm2; tear strength: 50 kg/cm) and desirable organoleptic properties. The environmental analysis signifies a significant step towards a cleaner and sustainable tanning process (COD = 1600, BOD5 = 560 mg/L) compared to the conventional chrome tanning process. Consequently, the obtained results offer a green pre-tanning agent to meet the requirements of the sustainable development of the leather industry.

Preparation and Application of Zwitterion Modified Starch Catalyzed by HRP‐ACAC Binary System

AbstractEnzymatic modification, compared with traditional starch (St) chemical modification methods, avoids using toxic solvents and toxic catalysts. The horseradish peroxidase (HRP), being the most commonly employed natural green initiator, has found extensive application in starch grafting modification as a substitute for chemical initiators. HRP‐catalyzed grafting of starch with vinyl zwitterionic monomers has not been reported. Here, modified starch (St‐PSBMA) is first synthesized by grafting zwitterionic sulfobetaine [2‐(Methacryloyloxy)ethyl]dimethyl‐(3‐sulfopropyl) (SBMA) onto starch by HRP/Acetylacetone(ACAC) binary initiation system catalyzed. The modified starch‐based hydrogel is then prepared by the repeated freeze‐thaw method. Compared with native starch‐based hydrogels, which bind water molecules only through hydrogen bonding, the ability of modified starch‐based hydrogels to bind water molecules is enhanced by ionic solvation. The modified starch hydrogels also have excellent antiprotein adsorption and antibacterial properties due to the presence of a strong hydration layer. The modified starch‐based hydrogel also has excellent sensitivity and stability when used as a sensor for detecting joint motion. The binary HRP initiating system, employed in this study instead of the traditional three‐component HRP initiating system, offers a novel and promising approach for grafting modification of starch without the need for strong oxidant hydrogen peroxide.