Ammonium Persulfate Research Articles

Tissue adhesive hyaluronan-quercetin (Ago)@halloysite-fungal carboxymethyl chitosan nanocomposite hydrogels for wound dressing applications

This study investigates nanocomposite hydrogels reinforced with hyaluronan-quercetin‑silver nanoparticles intercalated halloysite clay (HAQ-Hal-Ag) for potential application as wound dressings. HAQ-Hal-Ag (at 1, 3, and 5 wt%) was incorporated into a fungal carboxymethyl chitosan (FC)/polyacrylamide (PAM) network (FC-PAM) using methylene bisacrylamide (MBA) as the crosslinker and ammonium persulfate (APS) as the initiator. Various physicochemical analyses were performed to characterize the resulting hydrogels. The compressive strength of the nanocomposite hydrogels exhibited a proportional increase with increasing HAQ-Hal-Ag content, reaching a remarkable 0.83 MPa for hydrogels containing 5 wt% HAQ-Hal-Ag. Additionally, the hydrogels displayed highly porous structures with excellent swelling capacity. Importantly, they exhibited exceptional antibacterial efficacy against Escherichia coli and Staphylococcus aureus. Furthermore, cytotoxicity assays revealed high cell viability and proliferation rates, confirming the biocompatibility of these hydrogels with human dermal fibroblasts. These findings suggest significant promise for the nanocomposite hydrogels as wound dressing materials due to their outstanding biocompatibility, impressive compressive strength, and potent antibacterial activity.

Extraction and incorporation of cellulose microfibers from textile wastes into MXene-enhanced PVA-borax hydrogel for multifunctional wearable sensors.

Conductive hydrogel has drawn great concern in wearable sensors, human-machine interfaces, artificial intelligence (AI), health monitoring, et al. But it still remains challenge to develop hydrogel through facile and sustainable methods. In this work, a conductive, flexible, bendable, and self-healing hydrogel (PBCM) composed of polyvinyl alcohol (PVA), borax, cellulose microfibers (CMFs), and MXene nanosheet was fabricated by a simple and efficient strategy. The carboxylated CMFs were extracted from waste ramie fibers via a one-pot ammonium persulfate oxidation method. The crystallinity and tensile strength were increased 70 % and 4 times due to the addition of CMFs and MXene compared to the pristine PVA-borax hydrogel. The incorporation of MXene nanosheets acts as multifunctional cross-linkers and energy transfer platform, promoting the electrical conductivity, stretchability, and bendability of hydrogel remarkably. The PBCM-2 hydrogel exhibited the maximum electrical conductivity of 0.81 S/cm. Additionally, the dynamic borate ester linkage imparts self-healing ability to the hydrogel. The resulting PBCM hydrogel demonstrated excellent resistance to fire and pH response properties. Moreover, it showed sensitivity in monitoring various human physiological movements, including finger, wrist, elbow, knee bending, and drinking water, indicating its potential for wearable sensing applications like health care and sports training.

"From Waste to Wonder": Comparative Evaluation of Chinese Cabbage Waste and Banana Peel Derived Hydrogels on Soil Water Retention Performance.

Under the increasing severity of drought issues and the urgent need for the resourceful utilization of agricultural waste, this study aimed to compare the soil water retention properties of hydrogels prepared from Chinese cabbage waste (CW) and banana peel (BP) using grafting techniques with acrylic acid (AA) and acrylamide (AAm). Free radical polymerization was initiated with ammonium persulfate (APS), and N, N'-methylene bisacrylamide (MBA) served as the crosslinking agent to fabricate the grafted polymer hydrogels. The hydrogels were subjected to detailed evaluations of their water absorption, reusability, and water retention capabilities through indoor experiments. The optimal hydrogel was identified and its applicability in wheat seedling growth was assessed. The findings revealed that the CW-gel, with an equilibrium swelling ratio of 551.8 g/g in ultrapure water, demonstrated remarkable performance and sustained a high water retention of 57.6% even after drying, which was markedly superior to that of the BP-gel. The CW-gel with the best comprehensive properties significantly improved water retention in sandy soil by 78.2% and prolonged the retention time by five days, indicating its potential for long-term irrigation management. In contrast, the BP-gel showed better performance in clay soil, with an increased water-holding capacity of 43.3%. The application of a 1.5% CW-gel concentration under drought stress significantly improved wheat seedling growth, highlighting the role of hydrogels in agriculture and providing a new path for sustainable water resource management in dryland farming.

The Design of a Controlled-Release Polymer of a Phytopharmaceutical Agent: A Study on the Release in Different PH Environments Using the Ultrafiltration Technique

A series of hydrophilic copolymers were prepared using 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) from free radical polymerization at different feed monomer ratios using ammonium persulfate (APS) initiators in water at 70 °C. The herbicide 2,4-dichlorophenoxy acetic acid (2,4-D) was grafted to Poly(HEMA-co-IA) by a condensation reaction. The hydrolysis of the polymeric release system, Poly(HEMA-co-IA)-2,4-D, demonstrated that the release of the herbicide in an aqueous phase depends on the polymeric system’s pH value and hydrophilic character. In addition, the swelling behavior (Wt%) was studied at different pH values using Liquid-phase Polymer Retention (LPR) in an ultrafiltration system. The acid hydrolysis of the herbicide from the conjugates follows a first-order kinetic, showing higher kinetic constants as the pH increases. The base-catalyzed hydrolysis reaction of the herbicide follows a zero-order kinetic, where the basic medium acts as a catalyst, accelerating the release rate of the herbicide and showing higher kinetic constants as the pH increases. The differences in the release rates found for the hydrogel herbicide at different pH values can be correlated with the difference in their swelling capacity, where the release rate generally increases with an increase in the swelling capacity from water solution at higher pH values. The study of the release process revealed that all samples in distilled water at a pH of 10 are representative of agricultural systems. It showed first-order swelling kinetics and an absorption capacity that conforms to the parameters for hydrogels for agricultural applications, which supports their potential for these purposes.

Evaluation of adsorption characteristic of GG-g-polyacrylic acid P(AA)/CoFe2O4 for the metamorfin hydrochloride (MF) and diclofenac sodium(DCF)

ABSTRACT The removal of contaminants from the water system is so significant for the better human life. Adsorption method is proven to be best method for the decontamination of waste water. Adsorbent based on biohydrogel is widely used for this purpose so biooriginated adsorbent named GG-g- P(AA)/CoFe2O4 (30 mg)-GGAACF-3 was synthesised and utilised for the combine removal of metformin hydrochloride (MF) and diclofenac sodium (DCF). GG-g- P(AA)/CoFe2O4 (30 mg)-GGAACF-3 prepared using free radical initiator ammonium persulphate(APS), cross-linked using crosslinking agent N, N’- methylenebisacrylamide (MBA) and accelerator using tetramethyl ethylenediamine (TEMED). The GGAACF-3 exhibited high removal efficiency for DCF than MF. The highest removal efficiency for DCF and MF found to 82.17% and 69.26% at adsorbent dose 40 mg, neutral pH, room temperature (20°C) and contact time 24 h, respectively. Adsorption of both drugs followed the Langmuir adsorption isotherm and Pseudo- 2nd-order model kinetic model which indicated about homogeneous adsorption of both drugs on the surface of GGAACF-3 and chemisorption, respectively. The maximum adsorption capacity (qe) for MF and DCF determined to 123.60 mg/g and 120.7729 mg/g, respectively.

The Application of Porous Carbon Derived from Furfural Residue as the Electrode Material in Supercapacitors.

Resource use is crucial for the sustainable growth of energy and green low-carbon applications since the improper handling of biomass waste would have a detrimental effect on the environment. This paper used nano-ZnO and ammonium persulfate ((NH4)2S2O8, APS) as a template agent and heteroatom dopant, respectively. Using a one-step carbonization process in an inert atmosphere, the biomass waste furfural residue (FR) was converted into porous carbon (PC), which was applied to the supercapacitor electrode. The impact of varying APS ratios and carbonization temperatures on the physicochemical properties and electrochemical properties of PC was studied. O, S, and N atoms were evenly distributed in the carbon skeleton, producing abundant heteroatomic functional groups. The sample with the largest specific surface area (SSA, 855.62 m2 g-1) was made at 900 °C without the addition of APS. With the increase in adding the ratio of APS, the SSA and pore volume of the sample were reduced, owing to the combination of APS and ZnO to form ZnS during the carbonization process, which inhibited the pore generation and activation effect of ZnO and damaged the pore structure of PC. At 0.5 A g-1 current density, PC900-1 (FR: ZnO: APS ratio 1:1:1, prepared at 900 °C) exhibited the maximum specific capacitance of 153.03 F g-1, whereas it had limited capacitance retention at high current density. PC900-0.1 displayed high specific capacitance (141.32 F g-1 at 0.5 A g-1), capacitance retention (80.7%), low equivalent series resistance (0.306 Ω), and charge transfer resistance (0.145 Ω) and showed good rate and energy characteristics depending on the synergistic effect of the double layer capacitance and pseudo-capacitance. In conclusion, the prepared FR-derived PC can meet the application of a supercapacitor energy storage field and realize the resource and functional utilization of biomass, which has a good application prospect.

Preparation of Expandable Polymer Plugging Agent and Its Application in Water‐Based Drilling Fluid

ABSTRACTIn order to reduce the economic loss caused by well leakage and the lag of drilling progress, it is very important to use plugging materials reasonably and effectively. Expandable polymer materials can better fill cracks and holes of different sizes by absorbing water expansion and deforming. In this article, an expandable polymer plugging agent (PSMAN) was prepared by soap‐free emulsion polymerization using methyl methacrylate (MMA), styrene (St), 2‐acrylamide‐2‐methylpropanesulfonic acid (AMPS) as reaction monomers, N‐hydroxymethyl acrylamide (NMA) as a cross‐linking agent, and ammonium persulfate (APS) as initiator. The optimal synthesis conditions were determined by designing the orthogonal experiments, and the various properties of the materials were tested and evaluated. The experimental results show that PSMAN has good high temperature resistance, spherical structure, and median particle size of 15.099 μm, and the water absorption rate of room temperature at 24 h reaches 37.8 g/g, and pressure bearing capacity can reach 5 MPa. The addition of polymer to water‐based drilling fluid can increase the viscosity of drilling fluid and improve the rheological properties of drilling fluid by a small amount. Under normal temperature and medium pressure, the polymer can form a dense film on the surface of the mud cake, thereby reducing the filtration of drilling fluid and effectively improving the stability of the wellbore.

Damage mechanism analysis of polymer gel to petroleum reservoirs and development of new protective methods based on NMR technique

Polymer gels are widely used in water control and enhanced oil recovery in oil fields. However, the damage mechanism of polymer gels to layers with remaining oil and not requiring plugging and corresponding protective measures are unclear. In this paper, we investigated polymer gels' damage and protection performance through static gel-breaking experiments and dynamic plugging and oil recovery evaluations on rock cores. Moreover, nuclear magnetic resonance (NMR) technology was combined to analyze the damage performance of polymer gels on cores from the pore scale. In addition, a protective technique based on gel breakers for layers with remaining oil and not requiring plugging was proposed. Results showed that when polymer gels were injected into heterogeneous cores, they plugged high-permeability layers while also penetrating low-permeability layers. When the damage to the low-permeability layers was not alleviated, the conformance and oil displacement efficiency were significantly reduced. When the concentration of ammonium persulfate was 2%–5%, the gel-breaking time was shortest and the residue was very minimal. Ammonium persulfate could be used as a gel breaker and reservoir protective material. Furthermore, after injecting ammonium persulfate into heterogeneous reservoir cores, the gel damage on the face of low-permeability layers was relieved. Consequently, the improvement in sweep efficiency was achieved, showing the re-activation of the remaining oil in medium-low permeability layers. Therefore, the low-permeability layer protection process and core experiment study based on gel-breaking agents proposed in this study were suggested to provide a new technique for the field application of conformance modification agents, aiming to achieve higher recovery degrees.

Extraction of manganese and ammonia nitrogen from electrolytic manganese residue by enhanced leaching with ammonium persulfate

Electrolytic manganese residue (EMR) represents a solid waste generated during the production of electrolytic manganese. Under the leaching and dissolution by rainwater, manganese, ammonia nitrogen, and heavy metal ions in EMR can infiltrate into the surrounding environment, thereby disrupting ecological balance and posing threats to human health. This study optimized the leaching conditions for manganese from EMR using ammonium persulfate(APS) through single-factor and orthogonal experiments. It was found that temperature, APS concentration, and reaction time significantly influenced the manganese leaching efficiency. Under leaching temperature of 80°C, leaching time of 3hours, APS concentration of 30g/L, and a liquid-to-solid mass ratio of 6mL/g, a high manganese leaching rate of 88.91% was achieved in a single process, and significant removal of ammonia nitrogen was observed. After enhanced leaching, the content of organic matter and the total amount of water-soluble salt were 4.10wt.% and 3.11wt.%, respectively. And it meets the requirements of the standard GB 18599-2020 for solid waste entering the class II site in China. Kinetic analysis revealed that the manganese leaching process was controlled by intraparticle diffusion within the solid phase. Mineralogical phase analysis indicated that the primary mineral structures were oxidatively decoupled and disrupted, leading to the dissociation of aggregates, which facilitated the leaching of manganese and ammonia nitrogen. This study provides a practical, green, and economical technological route for the harmless treatment of EMR.

Efficient Synthesis and Characterization of Antibacterial Xanthan Gum–Based Self‐Healing Hydrogels: Conventional Versus Microwave Treated

ABSTRACTThe development of self‐healing hydrogels with mechanical integrity is vital for biomedical applications. This study synthesizes multi‐network (MN) self‐healing hydrogels using xanthan gum (XG) through conventional and microwave‐assisted methods via free‐radical polymerization. The synthesis materials included XG, acrylamide, acrylonitrile, sodium dodecyl sulfate, ferric chloride hexahydrate, and ammonium persulfate. Conventional synthesis took 60 min at 70°C, while microwave synthesis was completed in 4.5 min at 540 W, enhancing energy and material efficiency. Structural tests like FTIR and SEM confirmed the results. Microwave synthesis produced a layered structure with smaller pores, leading to slower swelling kinetics, and EDX mapping showed higher Fe3+ ion concentrations, indicating better crosslinking. Thermal gravimetric analysis demonstrated that degradation onset temperatures were 184°C for microwave‐assisted synthesis XG hydrogel (MHXG) and 163°C for the water bath XG hydrogel method (HXG), indicating a 20°C enhancement due to the coherent structure induced by microwave treatment. Evaluation of self‐healing capabilities through visual and rheological tests showed significant enhancements in MHXG, which exhibited a self‐healing time of 2 h compared to 1 day required by HXG, attributed to increased crosslink density and hydrogen bonding facilitated by microwave treatment. Rheological assessments confirmed that both hydrogel types maintained their structural integrity and viscoelastic properties after healing. MHXG exhibited a mechanical strength of 21.12 kPa and elasticity of 10 kPa, whereas HXG showed 11.59 kPa and 1 kPa, respectively. Microwave‐treated hydrogel showed enhanced antibacterial effectiveness against Staphylococcus aureus due to better distribution of agents in the matrix. This method for synthesizing XG‐based self‐healing hydrogels is promising for advanced biomedical applications.

Synthesis of polyaniline nanomaterials for an effective supercapacitor applications

Abstract Polyaniline-based materials have been widely used for supercapacitors due to their outstanding properties, such as high specific capacitance, excellent electrochemical properties, and ease of synthesis methods; however, the short-cycle stability of PANI-based supercapacitors limits their commercialization. Herein, we synthesized polyaniline (PANI) nanomaterials, which meet high specific capacitance through the chemical oxidative polymerization of aniline with ammonium persulfate (APS) in aqueous salicylic acid. The electrode materials were characterized using

The Inhibitory Effect of Low Phosphorus and Low Molecular Weight Terpolymer Scale Inhibitor on Calcium Scale in Oilfields

ABSTRACTThe study utilized itaconic acid (IA), N‐hydroxyethyl acrylamide (HEAA), and sodium hypophosphite (SHP) as starting materials for a free radical polymerization process. This process resulted in creating a new type of low‐phosphorus terpolymer scale inhibitor called P(IA‐HEAA‐SHP). Its primary application was as an effective scale inhibitor to block CaCO3 and CaSO4. FTIR, 1H‐NMR, and 13C‐NMR were used to characterize the synthesized copolymer structures, and it was confirmed that the synthesized products had the desired structures. The synthesis conditions have been optimized using the static scale inhibition approach, which involved adjusting the monomer ratio, initiator dosage, and reaction time. This resulted in the synthesis of polymeric scale inhibitors with outstanding scale inhibition properties. Additionally, GPC was employed to examine the correlation of the molecular weight of the polymers with their scale inhibition properties at various reaction times. The results showed that when the monomer ratio n(IA):n(HEAA) = 1.5:1, the SHP dosage mass fraction was 15%, the ammonium persulfate initiator dosage was 10%, the reaction temperature was 90°C, and the reaction time was 4 h. At a measured dose of 30 mg L−1, the scale inhibition impact on CaCO3 is 86.63%, while the scale inhibition impact on CaSO4 is 96.83%. The thermal properties of the copolymers, the crystal structure, and the micro‐morphology of the scale samples were analyzed by TGA, XRD, and SEM, and the scale inhibition mechanism was discussed in conjunction with the zeta potential analysis.

Establishment and Validation of Sandell-Kolthoff Method for Saliva Iodine Determination.

Saliva iodine is a useful biochemical marker for evaluating iodine status and controlling iodine-related diseases. This study aims to establish and validate a simple, reliable, and low-cost Sandell-Kolthoff (S-K) method for the determination of iodine in saliva. The method was established by considering the digestion solution type, concentration, dosage, digestion time and temperature, the volume of saliva samples, glass tube size, dosage of arsenious acid solution and ammonium ceric sulfate solution, and warm bath time. Then, the effectiveness of the method was examined by the linearity of the standard curve, detection limit, precision, and accuracy. The 1.5mL 1 Mol/L ammonium persulfate solution at 100°C for 90min, the 200 μL saliva sample, glass tubes of 15mm × 120mm, 2.5mL arsenious acid solution, 0.3mL ammonium ceric sulfate solution, and 15min for warm bath was selected to determine saliva iodine. In terms of validation of the S-K method, the linearity method has the linear range of the standard curve from 0 to 300μg/L and the coefficient of determination ≥ 0.999; the detection limit, when the volume of saliva samples was 0.2mL, was 4.6μg/L; for precision, the relative standard deviation was from 0.3 to 2.8%; and for accuracy, the total recovery rate ranged from 92.8 to 107.0%. This S-K method is easy to operate, has good precision and accuracy, and can be used as a method to determine saliva iodine. It has great potential practical value in disease prevention, clinical auxiliary diagnosis, and experimental research.

Aryl Radicals Generated from Aryl Pinacol Boronates Modify Peptides and Proteins

AbstractWe report here a distinct reaction, which generates aryl radicals from aryl pinacol boronates under mild aqueous conditions and can be used for peptide and protein modifications. The strategy leverages the versatile reactivity of aryl pinacol boronates to form aryl radicals in presence of ammonium persulfate (APS). The formed aryl radicals insert readily into peptide disulfide bonds while tolerating other functionalities. On the protein level, the reactivity extends beyond the disulfide bonds. The methodology benefits from the accessibility of starting aryl pinacol boronates, as well as biocompatible conditions. In contrast to conventional methods used for aryl radical generation, the strategy is metal‐free, does not require photoinduction and can be readily performed under aqueous conditions. The mechanism of the reactions was investigated by radical‐trapping experiments, spectroscopic analysis and oxygen scavenging. The presented approach broadens the application of aryl pinacol boronate esters in radical reactions.

Self-adhesive, stretchable, anti-freezing conductive organohydrogels with fast gelation from catechol-metal ion self-catalytic system for flexible strain sensors

Conductive hydrogels have attracted tremendous attention in flexible sensors due to their flexibility, durability, and multifunctionality. However, time and energy-consumption fabrication process and intrinsic instability in extreme environments severely limit their practical implementations. Herein, a universal and facile synergetic self-catalytic system based on catechol-based molecules and metal ions has been developed to the fast gelation (≈3s) of conductive organohydrogels in water–ethylene glycol (EG) binary solvent, which exhibits excellent stretchability (up to 630 % elongation), satisfactory self-adhesion (up to 16.3 kPa), and extreme environment applicability (−80 °C to 45 °C). This dual self-catalytic system consists of tannic acid (TA) and ferric ions (Fe3+), which form stable redox pairs to activate ammonium persulfate to generate free radicals, rapidly initiating the polymerization of monomers. Furthermore, the introduction of H2O/EG binary solvent not only facilitates the dispersion of components to improve the mechanical performance of organohydrogels, but also the generation of abundant hydrogen bonds between EG and water molecules endows extreme freezing drying resistance, and enhances self-adhesion for organohydrogels. The organohydrogels showing high sensitivity toward tensile deformation are assembled into flexible strain sensors to detect human motions with high sensitivity, exceptional stability, and excellent durability, which holds great promise in flexible electronics.

(Digital Presentation) 2D Transition Metal Borides: Different Etchants for Al Removal from MAB and Application in Cd2+, Pb2+, Cu2+ and Hg2+ Sensing

Despite significant progress in MBene research, achieving perfect layered structures and high purity under different etching conditions remains challenging. Additionally, their potential for heavy metal ion detection in electrochemical applications is underexplored. The synthesis of MBenes, particularly MoB, involves removing Al precursor MoAlB. Recent advancements focus on high-temperature solid-state etching using Lewis bases or chemical wet etching, with wet etching proving more economical, milder, and higher purity products. This study compares various non-fluoride etchants' effects. Ammonium persulfate (APS) achieved a significant etching rate of ~71% for Al, resulting in restacked accordion-like multilayered MBene. However, high temperatures led to stable, insoluble AlxO, reducing product purity. CuCl₂ etching yielded a lower rate of ~54%, producing flake structures with copper impurities. Acid etching resulted in a perfect layered structure but lower purity, while alkali etching provided similar etching rates to APS with the highest purity. Complete Al removal at elevated temperatures caused the loss of the layered structure. Maintaining a small amount of Al during hydrothermal etching supports the layered structure, and subsequent room-temperature etching produces fluffy open-layered MBene MoB (OL-MBene).Electrochemical studies revealed that OL-MBene-modified GCE exhibited excellent performance in detecting Cd²⁺, Pb²⁺, Cu²⁺, and Hg²⁺ ions individually and simultaneously, with high sensitivity and selectivity. Notably, the sensor exhibited superior performance for Cu²⁺ and Pb²⁺ ions. The varying adsorption energies of these ions explain the differences in sensitivity and selectivity, and Pb²⁺ demonstrated the highest sensitivity due to its lowest adsorption energy on the MBene surface. Competitive adsorption studies indicated that Pb²⁺ competes with Hg²⁺ for adsorption sites while having minimal impact on Cd²⁺ and Cu²⁺ adsorption. This research advances our understanding of MBene synthesis and characterization, introducing a new avenue for leveraging MBenes in sensitive and selective electrochemical sensors for environmental monitoring. Figure 1

Fabrication and Characterization of Electrochromic Devices Utilizing CVD Graphene

Electrochromism is a function whereby the optical properties of materials change reversibly and persistently through electrochemical redox reactions driven by small electrical energy. Electrochromic devices are used in a wide range of applications including smart windows for buildings and aircraft, displays, electronic paper, and so on. The advantages of electrochromic devices include the ability to be manufactured at low cost and compatibility with non-planar and flexible surfaces. Electrochromic devices typically have a multilayer structure comprising transparent conductive electrodes, electrochromic film, ion-conducting layer, and ion-storage film. Since electrochromic devices in their uncolored state need to be transparent, the fabrication of flexible electrochromic devices requires flexible transparent conductive films as well as flexible and transparent ion-conducting layers.In this study, we aim to fabricate flexible film-type electrochromic devices using graphene films as transparent conductive electrodes. Fig. 1 illustrates the schematic images of the fabricated electrochromic devices. The electrochromic devices consist of two graphene films grown using chemical vapor deposition. Prussian blue (PB), the electrochromic material, and silver nanoparticles, which act as the ion-storage material, were electrodeposited onto each graphene film, respectively. A PVDF (polyvinylidene fluoride) porous membrane, soaked in a KCl solution as an electrolyte, was sandwiched between the two graphene electrodes to serve as a separator and ion-conducting layer. The PVDF membrane exhibits a white color due to its porous structure. Therefore, by adjusting the refractive index of the KCl solution to match that of PVDF, a transparent and flexible ion-conducting layer was formed.The graphene films were grown on copper foils by the CVD method and were then transferred onto a PET substrate using thermal press bonding with PMMA (polymethyl methacrylate) as the adhesive layer. Subsequently, copper was etched using an ammonium persulfate aqueous solution. A gold contact electrode was formed on the edge of the graphene surface by vacuum evaporation. PB was electrodeposited on one of the graphene electrode surfaces by applying a constant current of −20 μA/cm2 for 5 min in an electrolyte solution containing K3[Fe(CN)6] (5 mM), FeCl3 (5 mM), KCl (0.1 M), and HCl (0.1 M). Silver was electrodeposited on other graphene electrode surfaces by applying a constant current of −100 μA/cm2 for 5 min in an electrolyte solution containing NaNO3 (0.1 M) and AgNO3 (1 mM). The mixture of water (nd=1.333) and glycerol (nd=1.473) solution containing 0.1 M KCl was utilized to make PVDF films transparent by matching the refractive index of the electrolyte solution with that of the PVDF. By preparing the electrolyte with a water-to-glycerol ratio of 4:6, resulting in a refractive index of 1.42 for PVDF, the transmittance of PVDF immersed in this electrolyte reached almost 100%. Using this electrolyte, the EC characteristics of the film-type EC device were evaluated by Cyclic voltammetry (CV). CV curves obtained using PB/graphene as a working electrode vs Ag/graphene as a counter electrode are presented in Fig. 2, showing oxidation peaks at 0.5 V and reduction peaks at −0.2 V. It was confirmed that Prussian blue undergoes decolorization during reduction and coloration during oxidation, enabling reversible color changes between blue and transparent. Therefore, this demonstrates that the transparent and flexible PVDF layer functions as the ion-conductive layer even in the presence of 60% glycerol in the electrolyte and that the conductivity of graphene films is maintained even with a stacking structure, indicating their potential as flexible light-dimming devices.These results reveal that it was possible to fabricate flexible electrochromic devices using graphene. We believe that this work will promote further efforts to develop new multifunctional electrochromic devices that can be attached to existing glass materials such as window glass and eyeglasses to add a dimming function afterward. Figure 1

Hydrophilic Polyacrylamide Gels Modified with Poly-N-vinylpyrrolidone

In modern medicine, there is a need to create biologically active polymer materials for the controlled release of drugs with improved characteristics compared to existing materials. Hydrogels are an ideal basis for creating such materials due to their high water content, excellent biocompatibility, and soft consistency, which is similar to that of body tissues. Therefore, this study aimed to develop and investigate hydrogels modified with poly-N-vinylpyrrolidone (PVP) for their potential use as drug carriers. A series of polyacrylamide gels (PAAGs) were synthesized, modified with PVP at concentrations of 0.3 wt.%, 0.5 wt.% and 1.0 wt.% relative to the weight of acrylamide. The synthesis was performed through free radical polymerization of acrylamide, N,N'-methylene-bis-acrylamide, and PVP in a sodium phosphate buffer solution (pH 8.0–8.5) in the presence of an oxidation-reduction initiation system (ammonium persulfate and N,N,N′,N′-tetramethylethylenediamine). The structural characteristics, water absorption, rheological, and sorption properties of these hydrogels were analyzed. IR spectroscopic analysis revealed that the incorporation of PVP into the PAAG structure leads to alterations in the hydrogen bonding of NH groups within the polymer matrix and changes in the skeletal chain, associated with varying contents of CH, CH<sub>2</sub>, CH<sub>3</sub> groups. Rheological studies demonstrated that PVP-modified hydrogels exhibit a reduction in viscosity by 22.4-35.3% compared to unmodified PAAGs, depending on the PVP content. Despite this decrease in viscosity, the structural stability remained sufficient for the hydrophilic matrix to function effectively in drug immobilization. The water absorption studies indicated absorption values ranging from 761.9 to 1059.8%. Sorption properties were assessed using the drug dacarbazine, revealing that increasing the PVP content in the hydrogel to 0.5 wt.% and 1.0 wt.% enhanced the sorption capacity of PAAGs by 21.1% and 27.1%, respectively. Thus, the synthesized hydrogel materials exhibit sorption capacity for dacarbazine and demonstrate high water absorption values, indicating that they are promising materials for use as drug carriers in medical practice; thus, they require further medical and biological research.

Magnetic carrageenan gum-grafted-polyacrylamide nanocomposite for uptake of cationic dyes from the aquatic systems

Using an ex-situ growth approach, this research fabricated k Carrageenan/Polyacrylamide@magnetite nanocomposites (NCs), (k-Car/PAM@Magnetite NCs). The k-Carrageenan (k-Car) backbone was modified through graft polymerization of acrylamide (PAm) via radical polymerization using ammonium persulfate (APS) as the initiator. N'-N' methylenebisacrylamide (MBAA) was used as the cross-linking agent, and magnetic nanoparticles (MNPs) were incorporated to impart magnetic properties. The successful synthesis of the k-Car/PAM@Magnetite NCs was confirmed through various analyses, including FT-IR, FESEM, EDS, XRD, VSM, BET, TGA, and Zeta. The adsorption effectiveness of the NCs for removing methylene blue (MB) and rhodamine B (RhB) from wastewater was evaluated by optimizing experimental parameters such as pH, adsorbent dosage, agitation time, and initial dye concentration. The NCs demonstrated a maximum adsorption capacity according to the Langmuir Isotherm (Qmax) of 204.082 mg. g−1 for MB and 200 mg.g−1 for RhB using 0.004 g of NCs.The adsorption data fit the Freundlich non-linear isotherm model well, and the kinetic data followed a pseudo-second-order (PSO) model. It is evident from the thermodynamic parameters that adsorption is an endothermic process that is spontaneous and favourable. The k-Car/PAM@Magnetite NCs also exhibited excellent regeneration capabilities, maintaining high adsorption efficiency after three consecutive adsorption-desorption cycles.

Study of the gut transcriptomic response in <i>Drosophila melanogaster</i> with knockdown of the <i>Gagr</i>, domesticated <i>gag/i> gene of errantiviruses

As a result of molecular domestication of the gag gene of errantiviruses, the Gagr gene was formed in the genome of Drosophila melanogaster. It has previously been shown that the Gagr gene is transcribed at the highest level in gut tissues relative to other tissues, and its transcription is most effectively induced in females in response to ammonium persulfate added to the diet. In the present work, the gut transcriptome of females with knockdown of the Gagr gene was studied in all tissues under standard conditions and under stress conditions caused by ammonium persulfate. It was revealed that in females with knockdown of the Gagr gene, the genes of animicrobial peptides controlled by the Toll and Imd signaling pathways are activated in the gut. Induction of a stress response by ammonium persulfate revealed disruption of the JAK/STAT and JNK/MAPK signaling pathways and an almost complete absence of activation of the ER-stress and UPR-stress pathways in the Gagr gene mutant. The data obtained confirm the important role of the Gagr gene in maintaining the homeostasis and the immune response.