Addition Of Acetic Acid Research Articles

Synthesis of fulgidic acid and the two possible stereoisomers of chaenomic acid D.

We synthesized fulgidic acid and the proposed structure for chaenomic acid D. The core part of the two natural products was constructed stereoselectively by the addition of acetic acid to the α,β-unsaturated epoxy alcohol in the presence of a palladium catalyst. Subsequently, the two natural products were synthesized from the intermediate in a few steps. The data for the synthesized fulgidic acid were in good agreement with the reported data. Chaenomic acid was in good agreement with the natural product in the 1H and 13C NMR data, but not in the optical rotation. The 15R-isomer of chaenomic acid was also synthesized, but the 1H and 13C NMR data did not agree with the natural product.

In Vitro Shoot Culture Growth of Pontianak Orange (Citrus nobilis var. microcarpa) with the Addition of Naphthalene Acetic Acid and 6-Benzyl Amino Purine

Pontianak siam orange (Citrus nobilis var. microcarpa) is an important agricultural commodity unique to Sambas Regency, West Kalimantan. The demand for Pontianak siam oranges has been steadily increasing over the years, yet the production of Pontianak oranges has not been able to meet the domestic demand. The limited availability of superior seedlings is one of the reasons for this situation. Therefore, efforts are needed to fulfill the demand for Pontianak siam oranges by producing a large quantity of superior seedlings in a short period. One of the strategies that can be employed is in vitro propagation. This research aims to observe the growth of Pontianak Siamese orange shoot explants after administration of NAA (Naphthalene Acetic Acid) and BAP (6-Benzyl Amino Purine). This research was conducted from January to June 2023 at the Tissue Culture Laboratory of the Department of Biology, Faculty of Mathematics and Natural Sciences, Tanjungpura University. The study employed a Completely Randomized Design (CRD) with two treatment factors namely NAA concentrations with 4 levels (0; 0.25; 0.5; 0.75 mg/L), and BAP concentrations with 5 levels (0; 0.5; 1; 1.5; 2 mg/L). Parameters observed were the emergence time of shoot, shoot number, height of shoot, and the number of leaves. The results showed that single NAA, single BAP, and combination treatment of NAA and BAP significantly affected all growth parameters. Treatment with the addition of 0.25 mg/L NAA and 1 mg/L BAP (A1B2) was the treatment with the fastest shoot emergence time (2.80 days after planting), the largest number of shoots (2.60 shoots)the tallest shoots (1.50 cm), , and the greatest number of leaves (2.60 leaves).

Discovery and In Situ Crystallization Studies of Cerium-Based Metal-Organic Frameworks with V-Shaped Linker Molecules.

We report the discovery and characterization of two porous Ce(III)-based metal-organic frameworks (MOFs) with the V-shaped linker molecules 4,4'-sulfonyldibenzoate (SDB2-) and 4,4'-(hexafluoroisopropylidene)bis(benzoate) (hfipbb2-). The compounds of framework composition [Ce2(H2O)(SDB)3] (1) and [Ce2(hfipbb)3] (2) were obtained by using a synthetic approach in acetonitrile that we recently established. Structure determination of 1 was accomplished from 3D electron diffraction (3D ED) data, while 2 could be refined against powder X-ray diffraction (PXRD) data using the crystal structure of an isostructural La-MOF as the starting model. Their framework structures consist of chain-like inorganic building units (IBUs) or hybrid-BUs that are interconnected by the V-shaped linker molecules to form framework structures with channel-type pores. The composition of both compounds was confirmed by PXRD, elemental analysis, as well as NMR and IR spectroscopy. Interestingly, despite the use of (NH4)2[CeIV(NO3)6] in the synthesis, cerium ions in both MOFs occur exclusively in the + III oxidation state as determined by X-ray absorption near edge structure (XANES) and X-ray photoelectron spectroscopy (XPS). Thermal analyses reveal remarkably high thermal stabilities of ≥400 °C for the MOFs. Initial N2 sorption measurements revealed the peculiar sorption behavior of 2 which prompted a deeper investigation by Ar and CO2 sorption experiments. The combination with nonlocal density functional theory (NL-DFT) calculations adds to the understanding of the nature of the different pore diameters in 2. An extensive quasi-simultaneous in situ XANES/XRD investigation was carried out to unveil the formation of Ce-MOFs during the solvothermal syntheses in acetonitrile. The crystallization of the two Ce(III)-MOFs presented herein as well as two previously reported Ce(IV)-MOFs, all obtained by a similar synthetic approach, were studied. While the XRD patterns show time-dependent MOF crystallization, the XANES data reveal the presence of Ce(III) intermediates and their subsequent conversion to the MOFs. The addition of acetic acid in combination with the V-shaped linker molecule was identified as the crucial factor for the formation of the crystalline Ce(III/IV)-MOFs.

Impact of potato trimming acidification on protein characteristics and bacterial community during long-term storage

Potato trimmings are a valuable by-product from potato processing containing both nutritional and functional potato protein. However, to allow delayed processing of trimmings, stabilisation methods should be implemented ensuring food safety and protein quality. In this study, acidification strategies by addition of different concentrations of organic acids i.e. acetic-, lactic- and citric acid were investigated as novel stabilisation methods for potato trimming and compared to natural acidification. Stabilisation was analysed and assessed by a variety of microbial, biochemical and protein characteristics.After 56 days of storage in acidified conditions, no decreases in true protein contents were observed despite changes in the protein molecular weight profile. In terms of food safety, yeast and mould inhibition during storage could solely be achieved by acetic acid addition, while lactic and citric acid could even result in increased unwanted growth. Therefore, acetic acid addition has been proven to be a successful stabilisation strategy.

Mitigation of ammonia emissions during food waste composting through acetic acid addition: A promising strategy for sustainable waste management

This research investigates using acetic acid to reduce ammonia emissions during composting while also evaluating its impact on microbial activity, compost quality, and nitrogen content. Composting is essential for recycling food waste and achieving renewable resource targets, but ammonia emissions pose environmental and health concerns. Addressing these issues is crucial for advancing composting technology and promoting sustainable waste management practices. The study reveals that adjusting the pH of compost piles to pH5, pH6, and pH7 reduced ammonia odor production by 65%, 40%, and 20%, respectively, compared to the control pile without acetic acid. The dominant bacteria, including Lactobacillus, Bacillus, and Aneurinibacillus species, played a crucial role in nitrification, leading to significant ammonia reduction during thermophilic and mesophilic phases. Additionally, nitrogen assimilation during composting enriches the nutrient content of the mature compost, as evidenced by seed germination indexes more significant than 80% in the treated piles. These findings contribute to optimizing composting processes and promoting sustainable agricultural circular economies.

Effect of the addition of acetic acid on spinning sol and mullite fibers properties

The preparation of mullite fibers by sol-gel method is the preferred method in industrial production, where the stability, rheological properties and microstructure of spinning sols are essential for the preparation of continuous, low-defect fibers. In this study, aluminum carboxylate solutions (ACs) were prepared using aluminum powder, formic acid and acetic acid as raw materials, silica sol was added, and spinnable sol was obtained by concentration and aging. After dry spinning and calcination at 1200 °C, continuous mullite fibers with mullite as the main crystal phases were obtained. The effect of acetic acid addition on the stability of Al-Si mixed sol was studied, and the polymerization process of spinning sol was studied on its rheological properties and microstructure. The cross-section of mullite fibers obtained after calcination at 1200 °C was “dumbbell” type, and the cause of this cross-section was discussed, which laid a foundation for subsequent optimization research.

Making of Biodegradable Plastic Based on Corn Starch (Amylum Maydis) with Addition of Acid (CH3 COOh) and Gliserol Plasticizer

Almost all countries face the problem of plastic waste due to the large production of conventional plastics and the long degradation process. Therefore, to protect nature from the accumulation of plastic waste, research on biodegradable plastics needs to be done. Biodegradable plastics are made from starch, cellulose, chitosan, and proteins extracted from renewable biomass. Starch for making biodegradable plastics can be obtained from plants, one of which is corn. This study aims to determine the effect of the composition of acetic acid, glycerol and corn starch on the quality of biodegradable plastics which include tensile strength, elongation and biodegradation. The independent variables were variations of acetic acid and glycerol. Control variables are plastic mold size, corn starch mass of 5 grams, other compounds outside the independent variables. The dependent variable is tensile strength, elongation and biodegradation. To test the tensile strength and elongation of biodegradable plastic, Ultimate Testing Machine Mini was used. The results showed that the addition of acetic acid and glycerol to the corn starch and glycerol blending material had an effect on increasing the tensile strength value and reducing the elongation and biodegradation values of biodegradable plastics. The highest tensile strength value is 50.04 Mpa, obtained from the addition of 1.44% acetic acid and 35.71% glycerol from a volume of distilled water of 70 ml. The highest length gain or elongation of 90% was obtained from the addition of 0.48% acetic acid and glycerol as much as 21.43% of the 70 ml volume of distilled water. Percent weight loss of the largest plastic obtained from the addition of acetic acid as much as 0.48% and glycerol as much as 21.43% of the volume of distilled water as much as 70 ml, which amounted to 93.33%.

Structure of 2-nitro-2’-hydroxy-5’-methylazobenzene: Theoretical and spectroscopic study

Objectives. 2-Hydroxy-nitroazobenzenes comprise reagents for the synthesis of heteroaromatic compounds, in the molecules of which the benzene and azole cycles are annulated. These reagents are widely used in the production of chemical products for various industries. In particular, 2-2’-hydroxy-5’-methylphenylbenzotriazole is used as an effective photo stabilizer for polystyrene and polyethylene. A promising method for its preparation is the liquid-phase catalytic hydrogenation of 2-nitro-2'-hydroxy-5'-methylazobenzene (2NAB). The aim of the present study was to establish the structure of 2NAB in solutions of different composition.Methods. Theoretical calculations were carried out within the framework of the density functional theory at a temperature of 298.15 K for the gas phase at B3LYP/6-311++G(d, p) and M06-2X/6-311++G(d, p) levels; for hexane, 2-propanol, toluene at B3LYP/6-311++G(d, p) level using the conductor-like polarizable continuum model. An experimental study to determine the probable isomeric structure of 2NAB in various solvents, including sodium hydroxide (NaOH) and acetic acid (CH3COOH) additives, was carried out using infrared (IR) and ultraviolet (UV) spectroscopy.Results. The most probable structure of 2NAB isomers for the gas phase and a number of solvents was determined. Experimental and theoretical IR and UV spectra were obtained. The thermodynamic characteristics of the reaction of intramolecular proton transfer from –OH to –N=N– group in the gas phase were calculated.Conclusions. A comparison of the experimental and calculated results supports the conclusion that the cis-isomer should be considered most probable for the gas phase. For the studied solutions, a trans-isomer of 2NAB with hydrogen bonds formed between the hydroxyl group hydrogen and the β-nitrogen atom of the azo group of dye molecule should be considered as the most likely structure. In the studied individual and binary solvents, prototropic equilibrium is shifted towards the azo form of the dye, while intramolecular proton transfer is possible only in aqueous diethylamine and dimethylformamide solutions with additions of NaOH.

Structure of 2-nitro-2’-hydroxy-5’-methylazobenzene: Theoretical and spectroscopic study

Objectives. 2-Hydroxy-nitroazobenzenes comprise reagents for the synthesis of heteroaromatic compounds, in the molecules of which the benzene and azole cycles are annulated. These reagents are widely used in the production of chemical products for various industries. In particular, 2-2’-hydroxy-5’-methylphenylbenzotriazole is used as an effective photo stabilizer for polystyrene and polyethylene. A promising method for its preparation is the liquid-phase catalytic hydrogenation of 2-nitro-2'-hydroxy-5'-methylazobenzene (2NAB). The aim of the present study was to establish the structure of 2NAB in solutions of different composition.Methods. Theoretical calculations were carried out within the framework of the density functional theory at a temperature of 298.15 K for the gas phase at B3LYP/6-311++G(d, p) and M06-2X/6-311++G(d, p) levels; for hexane, 2-propanol, toluene at B3LYP/6-311++G(d, p) level using the conductor-like polarizable continuum model. An experimental study to determine the probable isomeric structure of 2NAB in various solvents, including sodium hydroxide (NaOH) and acetic acid (CH3COOH) additives, was carried out using infrared (IR) and ultraviolet (UV) spectroscopy.Results. The most probable structure of 2NAB isomers for the gas phase and a number of solvents was determined. Experimental and theoretical IR and UV spectra were obtained. The thermodynamic characteristics of the reaction of intramolecular proton transfer from –OH to –N=N– group in the gas phase were calculated.Conclusions. A comparison of the experimental and calculated results supports the conclusion that the cis-isomer should be considered most probable for the gas phase. For the studied solutions, a trans-isomer of 2NAB with hydrogen bonds formed between the hydroxyl group hydrogen and the β-nitrogen atom of the azo group of dye molecule should be considered as the most likely structure. In the studied individual and binary solvents, prototropic equilibrium is shifted towards the azo form of the dye, while intramolecular proton transfer is possible only in aqueous diethylamine and dimethylformamide solutions with additions of NaOH.

Effect of Formic and Acetic Acid Additives on the Photocatalytic Reduction of Water by Cadmium Sulfide Particles

Effect of Formic and Acetic Acid Additives on the Photocatalytic Reduction of Water by Cadmium Sulfide Particles

Effect of acetic acid addition to rice straw pre-treated with urea on performance of dairy ewes.

This experiment was carried out to study the effect of acetic acid addition to rice straws that had been already treated with urea on chemical composition, digestibility, nutritive value, and productive performance of ewes. Thirty ewes with an initial body weight of 44 ± 0.41 kg were chosen 7 days after parturition and divided into 3 groups (10 of each) for 3 months. Each group was assigned randomly to receive one of the three experimental rations composed of concentrate feed mixture and untreated rice straw as a control group (G1), urea-treated rice straw (G2), and urea-acetic acid-treated rice straw (G3). Digestibility coefficients and nutritive value were determined using fifteen mature rams andblood samples were obtained at the end of the collecting period. Findings indicated that the crude protein of rice straw was increased, and crude fiber content was decreased by either urea or urea-acetic acid rations(i.e., G2 and G3). Digestibility of most nutrients was increased (P < 0.05) for animals fed either G2 or G3 rations. There were no significant differences in nutritive value astotal digestible nutrients (TDN) among tested groups; however, digestible crude protein(DCP) increased (P < 0.05) for G2 and G3 rations. Plasma total protein, AST, creatinine, and urea were increased (P < 0.05) by feeding on G2 or G3 ration; however, plasma ALT was not affected. The average daily intake ofdry matter (DM), TDN, and DCP was higher for G2 and G3 rations. Actual milk yield, fat-corrected milk(FCM), percentages of fat, and total solids and constituents yield were increased (P < 0.05) by feeding on treated rice straw rations (i.e.,G2 and G3); however, the percentages of protein, lactose, solids not fat, and ash were not affected. In the 1st month after parturition, the changes in ewes body weight were less (P < 0.05) when they fed on G2 and G3 rations than the control one(G1)). Dams' production and offspring performance were improved (P < 0.05) by feeding on G2 and G3 rations. Feed conversion as kg DMI/kg FCM, kg TDN/kg FCM, and economic efficiency was improved for G2 and G3. Inconcluded, adding acetic acid to urea-treated rice straw may improve the performance of ewes fed on it and increase their milk production and profitability. The same trend was observed with (G2) which received urea-treated rice straw ration.

Hydrolysis of MgH2 enhanced by acetic acid for stable hydrogen generation

Magnesium hydride (MgH2) is known for its high hydrogen yield, reaching up to 1703 mL/g through hydrolysis. However, the formation of a passive Mg(OH)2 layer impedes the reaction. To address this, acetic acid was used to enhance the hydrolysis. The experimental system achieved a nearly 98% hydrogen yield by injecting acetic acid, and a possible mechanism involving the neutralization reaction with the passivation layer was proposed. By optimizing the molar ratios of CH3COOH to MgH2 and H2O to MgH2, the hydrogen storage density of the hydrolysis reactants reached 1.43 wt%. Using these optimized parameters, a hydrogen generation setup was designed, achieving an average rate of 8.4 L/min. Controlled addition of acetic acid enabled continuous and regulated hydrogen production. This study offers a novel strategy for designing hydrogen supply systems.

Production of Biodegradable Polymeric Composites with the Addition of Waste.

Several solutions have been presented to minimize the environmental impact generated by polymers produced from petroleum resources. This work produced a biopolymer using glycerol, starch (<5) and macaúba epicarp fiber (10-15-20-25-30%) as reinforcement. The interaction of glycerol with starch was favored by the addition of acetic acid (CH3COOH). The pH was adjusted with sodium hydroxide (NaOH) at a concentration of 0.1 mol·L-1. The characterization was carried out through scanning electron microscopy (SEM), infrared reflectance-FTIR, water solubility, biodegradability and technological properties. Through the results obtained in this work, it is observed that the tensile strength and modulus of elasticity are influenced by the addition of the fiber concentration; the sample that received a 30% addition presented 19.17 MPa and 348.12 MPa, respectively. All samples showed low solubility in water and low density, in addition to a high rate of degradability in soil with mass loss corresponding to 59% over a period of three months. The results of this investigation are satisfactory for the production of materials that can be used in everyday life, replacing conventional plastic.

Effect of fatty acids on intracellular pneumocandin B0 storage in the fermentation of Glarea lozoyensis

The natural product pneumocandin B0 is the precursor of the antifungal drug caspofungin. To explore the relationship between pneumocandin B0 and oil. We found that the addition of 1 g/L of oil to the fermentation medium is more conducive to the production of pneumocandin B0. The metabolic reaction mechanism was explored using different fatty acids and the results showed that stearic acid and acetic acid increased the total production of pneumocandin B0 by 22.98% and 9.08%, respectively, as well as increasing the content of intracellular lipid droplets. We also analyzed gene expression and pathway differences between the two different fatty acids using transcriptome analyses. The addition of both acetic acid and stearic acid promoted an active pentose phosphate pathway, providing cells with higher intracellular reducing power. We found that the addition of fatty acids can lead to lipid accumulation, and lipid droplets can sequester lipophilic secondary metabolites such as pneumocandin B0 to reduce cell damage. These results provide novel insights into the relationship between pneumocandin B0 biosynthesis and fatty acids in G. lozoyensis. In addition, this study provides important genetic information for improving the yield of pneumocandin B0 through a strategy of metabolic engineering in the future.Graphical

Solution-processed transparent PVP:HfO2 hybrid dielectric films with low leakage current density and high k

Organicinorganic hybrid dielectric materials have attracted significant attention owing to their capacity to integrate the mechanical and electrical characteristics of organic and inorganic components. This paper presents the deposition of high-performance polyvinylpyrrolidone (PVP): hafnium oxide (HfO2) hybrid dielectric films at low temperature using the sol-gel method. Initially, the influence of precursor components on the surface morphology of single-component dielectric films was investigated. It is observed that the addition of FSO and acetic acid can result in smoother and more uniform surfaces for PVP and HfO2, respectively. Furthermore, based on these findings, we successfully prepared PVP:HfO2 hybrid dielectric films with surface roughness below 1 nm, high transmittance above 95% in the visible range (400–760 nm), and wide optical bandgaps exceeding 5.3 eV. The formation of PVP:HfO2 cross-linked network was identified through FTIR analysis, and a mechanism was proposed. Moreover, MIM devices were fabricated to determine the insulating performance of dielectric films. We found that the PVP:HfO2 hybrid dielectric films exhibit a significant reduction in leakage current density and a substantial increase in relative dielectric constant compared to the single-component dielectric films. In addition, with the increase in PVP concentration, the leakage current density first decreases and then increases, while the relative dielectric constant first increases and then decreases. After optimization, 0.5 wt% PVP:HfO2 hybrid dielectric film exhibits a low leakage current density of 5.89×10−8 A/cm2 @1 MV/cm and a high relative dielectric constant of 32.54. PVP:HfO2 hybrid dielectric films exhibit tremendous potential for applications in the realm of high-performance transparent electronic devices.

Melamine Acetate Preparation as a Urea-Formaldehyde Resin Additive for Particleboard Production

Urea-formaldehyde (UF) resin binders for wood-based panel production often use melamine as an additive to improve both mechanical properties and environmental compliance. Direct fortification for efficient use of melamine remains a problem due to low solubility. Pizzi &amp; coworkers suggested the use of more soluble melamine salts and demonstrated success in terms of product performance. However, their preparation method showed low productivity and inefficient use of material and energy. In their scheme, a batch reactor fed with 1 kg of water and 75 g of a stoichiometric amount of melamine and acetic acid produced only around 25 g of solid melamine acetate crystal. In contrast, the remaining 50 g remained dissolved in 991 g of water, which requires high of energy to evaporate. This paper reports an attempt to increase batch productivity and work towards the more efficient use of material and energy. The experiment showed that the successive addition of melamine and acetic acid to the batch up to the solubility limit of melamine at the same reaction condition increased melamine and acetic acid fed from 75 g to 165 g. This was followed by a significant increase in dry crystal yield from 25 g to 117 - 132 g. Feeding the mother liquor to the next batch decreased the water use to only 8% of the original requirement. This resulted in a highly efficient process, eliminating the need for energy-intensive melamine acetate recovery from the mother liquor. The addition of 2% - 4% wt. of the product to UF resin resulted in particleboard with significantly lower thickness swelling, an increase in MOR &amp; IB strength, and lower formaldehyde emission.

The effects of dietary addition of acetic acid on milk yield and composition in Awassi ewes at an early stage of lactation

This study was conducted to evaluate the effect of dietary supplementation of acetic acid at different levels on milk yield and composition. A total of eighteen Awassi ewes in the early stage of lactation were used in this study, with average body weight (37.631.84) and ages (3–4 years). Animals were allocated to three treatments; the first treatment was control fed with a basal diet without additives (T1). Acetic acid (98%) was added to the concentrate feed daily before feeding by 5 mL/ewe daily in T2 and 10 mL/ewe in T3 after dilution 1:10 with tab water. Results indicate an insignificant increase in ewes' body weight in T2 and T3, which were 40.41 and 41.11 kg compared to T1 at 37.93 kg. Actual milk yield was not affected while fat corrected milk Increased in T3 was 390 g/day compared to T2 with 323 g/day. Milk fat percentage increased (p ≤ 0.05) in T3 at 6.26% as compared to T1 and T2 at 5.65% and 5.43%, respectively, while fat yield was higher (p ≤ 0.05) in T3 at 23.85 g/day than in T2 17.58 g/day. This was reflected in increased milk energy (p ≤ 0.05) in the T3 at 953 kcal/kg compared to T2 at 858 kcal/kg. From the results, it can be concluded that acetic acid can be used as an additive to the ewes diet, and effect positively in ewes’ weight and milk fat.

A Comparative Study of the Effects of Whole Cereals and Refined Cereals on Intestinal Microbiota.

Cereals are one of the most important foods on which human beings rely to sustain basic life activities and are closely related to human health. This study investigated the effects of different steamed buns on intestinal microbiota. Three steamed buns were prepared using refined flour (RF), 1:1 mixed flour (MF), and whole wheat flour (WF). In vitro digestion simulations were conducted using a bionic gastrointestinal reactor (BGR) to examine their influence on intestinal microbiota. The results showed that at 0.5% addition, butyric acid and short-chain fatty acids in WF were significantly different from those in RF and MF (p < 0.05). WF also promoted the proliferation of beneficial microbiota, such as Megamonas and Subdoligranulum. At 0.5%, 1.0%, and 1.5% additions of WF, acetic acid and short-chain fatty acids at 1.5% WF increased by 1167.5% and 11.4% from 0.5% WF, respectively, and by 20.2% and 7.6% from 1.0% WF, respectively. WF also promoted the proliferation of Bifidobacterium, Lactobacillus, and Bacteroides and inhibited the growth of pathogenic microbiota, such as Streptococcus, Enterococcus, and Klebsiella. These findings support the consumption of whole cereals and offer insights into the development of new functional foods derived from wheat.

Co-partial oxidation of acetic acid, methanol, and ethanol in an integrated porous media with efficient heat recirculation: Green hydrogen production and its expansion method

Green energy from biomass contributed to substituting the traditional fossil fuels and environmental protection. To explore the hydrogen production from bioethanol with the industrial by-products, a porous media burner integrated with a heat-recirculating tube was designed to realize the efficient vaporization of ethanol. Then the partial oxidation characteristics of ethanol were investigated with the acetic acid and methanol addition at different operating conditions. The results indicated that the acetic acid and methanol addition inhibited hydrogen production but promoted methane production. Compared with pure ethanol, the heating values of syngas were decreased by 3.41 and 0.64 MJ/Nm3 with the acetic acid or methanol content of 20%. The highest yields of hydrogen and carbon monoxide were achieved at 43.94% and 66.45% respectively when the ratio of acetic acid content to methanol was 5:15. Nevertheless, blended fuels achieved more syngas production at higher equivalence ratios and velocities. The hydrogen concentration of the blended fuel reached the maximum of 21%, exceeding that of pure ethanol by 1.6% when the velocity was 22 cm/s. The corresponding results provided a theoretical reference for the industrial application of bioethanol.

ZIF‐8 Based Active Wound Dressing for pH Modulation and pH‐Responsive Delivery of Curcumin and Zn2+: Effect of Acidity on the Drug Release for Antibacterial and Antioxidant Efficacy

AbstractA wound evolves with variable pHs depending on the healing stage, and the maintenance of mild acidic condition can help healing by deterring the formation of a biofilm. Herein, a dual‐layer wound dressing with an acid‐responsive zeolitic imidazolate framework–8 (ZIF‐8) layer and an acid‐modulating layer is designed to control the acid‐dependent release of therapeutic agents for the improved healing process. The outer dressing layer is coated with curcumin‐incorporated ZIF‐8, where curcumin and zinc ions are released upon dissociation of ZIF‐8 in an acidic condition. The inner layer, a pH modulator, is fabricated by electrospinning polyvinylpyrrolidone with addition of acetic acid. In vitro release test shows that the outer layer dressing attains a considerably higher release of curcumin and Zn2+ under an acidic condition. Combined with the inner acidic layer, the dual layer dressing exhibits facilitated release of effective agents regardless of environmental pHs, attributed to the proper pH modulation to about 6.5. The anti‐oxidant activity of curcumin and antibacterial activity of Zn2+ are confirmed. The study highlights the novel proof‐of‐concept design of active wound dressing demonstrating the dual functions of pH regulation and the stimulus‐responsive drug delivery.