Acrylic Acid Research Articles

Chemical plant optimization layout based on the domino hazard index considering the fixed hazard unit outside the available area

The layout of chemical plants is a significant step to promote the safe and efficient operation of a chemical factory. In the actual production process, the chemical process plant layout may be affected by immovable hazards outside the available layout area. In this paper, the external hazard unit is arranged as one of the chemical process plants. The domino effect potential of all chemical process plants is quantified by using the classical domino hazard index (DHI). A layout optimization model considering the effects of external hazard units has been proposed to obtain the optimal plant layout from economic and safety aspects. The feasible layout solutions are obtained under the orientation, boundary and non-overlapping constraints by the non-dominated sorting genetic algorithm II (NSGA-Ⅱ). The proposed model is further analyzed through a hypothetical case of three storage tanks outside the acrylic acid (AA) production plant layout area. The results show that the total cost range for the optimal solution is 650348–1365443 $, with corresponding DHI values ranging from 29 to 129. The plant with larger DHI value will be arranged to far away from the external hazard units to obtain a safer layout. This work can provide rational layout solutions for the layout designers to make different decisions according to the actual situation.

Highly transparent inorganic superhydrophilic coatings with sustainable anti-fogging and mechanically robust underwater anti-oil-fouling capabilities

Inorganic coatings with high transparency and superhydrophilicity have attracted tremendous attention because of their potential applications in marine environment monitoring, and oily wastewater treatment. However, the transparency and superhydrophilicity are usually mutually exclusive. Herein, we present a new facile strategy for fabricating highly transparent and mechanically robust superhydrophilic inorganic coatings with outstanding anti-fogging ability and anti-oil-fouling performance for high-viscosity oils. In this strategy, amorphous calcium phosphate (ACP) coatings are mineralized on the surface of polydopamine and polyethylenimine (PDA/PEI) membranes under the synergistic effect of magnesium ions, citric acid, and poly(acrylic acid) at room temperature, forming an organic-inorganic composite structure with a uniform texture on various substrates. Owing to the strong hydration capacity of ACP, these coatings are highly efficient at preventing surface fogging and avoiding underwater crude oil fouling. Meanwhile, the ACP coating without grain boundaries or pores can reduce light scattering, thus maintaining the high transparency of the substrate. Moreover, the organic-inorganic composite structure endows the coatings with robust mechanical properties. This PDA/PEI-ACP mineralized coating can be deposited on various substrates, showing potential applications in underwater optical lenses, oily wastewater treatment, microfluidic devices, and other areas.

New fibrous carboxyl cation exchangers for sorption cations of heavy and non-ferrous metals from water

New fibrous carboxyl cation exchangers FIBAN were synthesized by the method of graft copolymerization to polypropylene staple fibers of acrylic acid and various bifunctional comonomers (divinylbenzene – DVB, ethyleneglycoldimethacrylate – EGDM, methylene-bis-acrylamide – MBAA). Sorption properties of the fibers towards cations of heavy and non-ferrous metals (Cо2+, Ni2+, Zn2+, Cd2+, Cu2+ и Pb2+) were studied on the model solutions in the dynamic regime. The dynamic activity of the crosslinked sorbents towards Cu2+ and Pb2+ ions is higher compared to fibrous analogues FIBAN Х-1, FIBAN Х-2, FIBAN К-6М, FIBAN К-5, VION КN-1. The best sorbent for lead ions between the crosslinked fibers is the fiber with EGDM. The fiber with MBAA has a higher affinity towards the cations of Ni2+, Zn2+, Cd2+ and Cа2+, which increases with the increasing of the degree of crosslinking by MBAA. Studying the fibers by the methods of Fourier-transform IR-spectroscopy, scanning electron microscopy, analyzing of the chemical oxygen demand in water extracts and determination of the equivalent moisture capacity coefficient coefficient demonstrated that the crosslinking by MBAA provides a stable structure of the sorbent. The high stability of the crosslinked structure combined with the high ion exchange capacity near 7 mEq/g and dynamic activity towards the cations of Pb2+, Zn2+, Cd2+ и Cа2+ makes the fibrous carboxyl sorbent with MBAA safe and perspective for drinking water purification.

Magnetic Silver Nanoparticles Stabilized by Superhydrophilic Polymer Brushes with Exceptional Kinetics and Catalysis.

Stimuli-responsive catalysts with exceptional kinetics and complete recoverability for efficient recyclability are essential in, for example, converting pollutants and hazardous organic compounds into less harmful chemicals. Here, we used a novel approach to stabilize silver nanoparticles (NPs) through magneto/hydro-responsive anionic polymer brushes that consist of poly (acrylic acid) (PAA) moieties at the amine functional groups of chitosan. Two types of responsive catalyst systems with variable silver loading (wt.%) of high and low (PAAgCHI/Fe3O4/Ag (H, L)) were prepared. The catalytic activity was evaluated by monitoring the reduction of organic dye compounds, 4-nitrophenol and methyl orange in the presence of NaBH4. The high dispersity and hydrophilic nature of the catalyst provided exceptional kinetics for dye reduction that surpassed previously reported nanocatalysts for organic dye reduction. Dynamic light scattering (DLS) measurements were carried out to study the colloidal stability of the nanocatalysts. The hybrid materials not only showed enhanced colloidal stability due to electrostatic repulsion among adjacent polymer brushes but also offered more rapid kinetics when compared with as-prepared Ag nanoparticles (AgNPs), which results from super-hydrophilicity and easy accumulation/diffusion of dye species within polymer brushes. Such remarkable kinetics, biodegradability, biocompatibility, low cost and facile magnetic recoverability of the Ag nanocatalysts reported here contribute to their ranking among the top catalyst systems reported in the literature. It was observed that the apparent catalytic rate constant for the reduction of methyl orange dye was enhanced, PAAgCHI/Fe3O4/Ag (H) ca. 35-fold and PAAgCHI/Fe3O4/Ag (L) ca. 23-fold, when compared against the as prepared AgNPs. Finally, the regeneration and recyclability of the nanocatalyst systems were studied over 15 consecutive cycles. It was demonstrated that the nanomaterials display excellent recyclability without a notable loss in catalytic activity.

INITIATED CHEMICAL VAPOR DEPOSITION (iCVD) OF POLY(ACRYLIC ACID): A COMPARISON BETWEEN CONTINUOUS AND CLOSED-BATCH iCVD APPROACHES

In this study, poly(acrylic acid) (PAA) thin films were deposited on silicon wafer and glass surfaces by initiated chemical vapor deposition (iCVD) method using di-tert-butyl peroxide (TBPO) as the initiator and acrylic acid (AA) as the monomer. During iCVD, two different precursor feeding approaches, namely continuous and closed-batch, were employed. The effects of substrate temperature and the precursor feeding approaches on the deposition rates and surface morphology of the films were investigated. The highest deposition rates for the continuous and closed-batch iCVD approaches were found as 26.1 nm/min and 18.6 nm/min, respectively, at a substrate temperature of 15 °C. FTIR analysis of the films deposited by both approaches indicated high structural retention of the monomer during the polymerization. AFM results indicated that, PAA thin films possessed low RMS roughness values of 2.76 nm and 1.84 nm using continuous and closed-batch iCVD, respectively. Due to the slightly higher surface roughness of the film deposited under continuous iCVD, that film exhibited a lower water contact angle of 16.1° than the film deposited in closed-batch iCVD. In terms of monomer utilization ratio, closed-batch system was found to be more effective, which may help to minimize the carbon footprint of iCVD process.

Suppression of aerosol dispersion by highly viscoelastic poly(acrylic acid)- and poly(ethylene oxide)-based coolants during bone drilling

Bone drilling in neurosurgical, dental, and orthopedic procedures, combined with the use of coolants, generates a dispersion of bone particles, coolants, and blood aerosols in the air. This poses the threat of airborne transmission of infectious diseases between patients and medical practitioners. Highly viscoelastic polymeric poly(acrylic acid) (PAA) and poly(ethylene oxide) (PEO) solutions of various concentrations were used as coolants during bone drilling at different mass flow rates to suppress aerosol generation, thereby mitigating the threat of cross-infection. The results revealed that the PAA and PEO solutions provide less advection than water and a comparable cooling performance. However, excessive viscoelasticity of PEO causes the fluid to rise along the cutting burr (the Weissenberg effect), thereby reducing the cooling coverage area. In contrast, slightly lower viscoelasticity of PEO results in a high cooling coverage area. The cooling coverage area is smaller for the PAA at 20 ml/min because the corresponding PAA solution easily swirls or splashes away from the drilling location. However, at 80 ml/min, the supplied PAA solution sufficiently cools the drilling area, despite the loss through splashing. The numbers of atomized droplets of water and the PAA and PEO solutions were quantified and compared to investigate the degree of aerosol formation and dispersion. The solution with the strongest viscoelasticity most significantly suppressed aerosolization and produced the fewest dispersed aerosol droplets during bone drilling.

Enhanced uranium extraction using a nanostructured photothermal hydrogel membrane

Uranium is the basic resource in nuclear energy and a sword of two sides. The accidental release of radioactive uranium to the environment may cause serious impact on the environment and living creatures. Herein, a nanostructured hydrogel-based solar evaporator with in-situ formed nanostructures is designed for simultaneous solar evaporation and uranium extraction from polluted water. To be specific, poly(acrylic acid) and gelatin with embedded carbon black nanoparticles coated on a cotton cloth self-assemble into nanostructures via salting-out and acid treatment to reduce the light reflectivity and enhance the specific surface area for uranium adsorption. Numerical simulation confirms that the evaporation-induced flow accelerates the diffusion of uranyl ions towards the adsorbent. Under solar irradiation of 1 kW m−2 a maximum uranium adsorption capacity of 443.2 ± 18.1 mg g−1 is achieved in 20 ppm uranium-spiked water, meanwhile a high solar evaporation rate of 3.75 kg m−2 h−1 is reached, hence, the solar evaporator is ranked among the most powerful adsorbents/evaporators. This work provides a cost-effective and scalable approach for dealing with uranium-polluted water.

Poly(ionic liquids-acrylic acid)-modified MIL-101(Cr) metal−organic frameworks: Preparation and efficient adsorption of europium☆

A novel composite material, Poly(IL-AA)@MIL-101(Cr), combining metal-organic framework, polymeric ionic liquid and acrylic acid, was synthesized for the selective and efficient adsorption of rare earths europium(III) (Eu3+). Characterization of the materials was carried out using techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET). The results demonstrate successful incorporation of the polymeric ionic liquid onto the material surface while preserving the crystal structure and morphology of MIL-101(Cr). Adsorption experiments were conducted to explore parameters including solution pH, initial Eu3+ concentration, and duration, with comprehensive analyses of adsorption kinetics, isotherms, and mechanisms. Findings reveal that Poly(IL1-AA)@MIL-101(Cr), Poly(IL3-AA)@MIL-101(Cr), and Poly(IL5-AA)@MIL-101(Cr) achieve adsorption equilibrium for Eu3+ at approximately 9 h with an equilibrium pH of 6.2. The adsorption of Eu3+ predominantly follows a pseudo-second-order kinetic model and Langmuir isotherm adsorption model. Moreover, the prepared composite material exhibits superior adsorption selectivity for Eu3+ over other metal ions in the mixture (K+, Mg2+, Ni2+, Co2+, Zn2+, La3+, and Nd3+). Even after five adsorption-desorption cycles, the composite material maintains satisfactory adsorption performance.

Evaluation of dental cements derived from mixtures of highly reactive ionomer glasses and bottle glass: Cement manipulation, mechanical, fluoride ion releasing, radiopaque and setting properties

ObjectivesTo evaluate the mechanical properties, fluoride release, radiopacity, and setting characteristics of dental cements derived from highly reactive ionomer glasses and bottle glass mixtures. MethodsTwo highly reactive glass series, LG99 and LG117, were synthesized, milled, sieved, and characterized using XRD and laser particle size analysis. These glasses were mixed with predetermined ratios of ground bottle glass, poly(acrylic acid), and aqueous tartaric acid to form glass ionomer cements. The cements' working time (WT), setting time (ST), fluoride release, radiopacity, compressive strength (CS), and elastic modulus (EM) were evaluated. Mean differences in CS were analyzed using multivariate ANOVA with Tukey’s post hoc test at p = 0.05. ResultsThe WT and ST for both groups ranged from 1.5 to 2.5 min. LG99 series cements showed significantly higher CS (∼65 MPa) and EM (∼2 GPa) than LG117 series (p < 0.05). Both series showed similar fluoride release profiles, peaking at 1.2 mmol/L at 28 days. Radiopacity for LG99 ranged from 0.97 to 1.34, while LG117 ranged from 0.60 to 0.95. Solid state 27Al magic-angle spinning-nuclear magnetic resonance (MAS NMR) confirmed the presence of Al(IV) and Al(VI), indicating setting completion by one day for both series. Bottle glass showed a chemical shift at 55.8 ppm, overlapping with LG99′s Al(IV) signal. The 19F MAS NMR spectra revealed Al-F and F-Sr(n) species in all glasses, with LG117 forming CaF2 after one day in deionized water. ConclusionMixtures of highly reactive ionomer glass and bottle glass produced cements with satisfactory properties for dental applications. Further research is needed to optimize their formulation and properties.

Rapid, Micron-Resolution 3D Printing of Nd:YAG Ceramic with Optical Gain.

Polycrystalline yttrium aluminum garnet (YAG) ceramic doped with neodymium (Nd), referred to as Nd:YAG, is widely used in solid-state lasers. However, conventional powder metallurgy methods suffer from expenses, time consumption, and limitations in customizing structures. This study introduces a novel approach for creating Nd:YAG ceramics with 3D free-form structures from micron (∼70µm) to centimeter scales. Firstly, sol-gel synthesis is employed to form photocurable colloidal solutions. Subsequently, by utilizing a home-built micro-continuous liquid interface printing process, precursors are printed into 3D poly(acrylic acid) hydrogels containing yttrium, aluminum, and neodymium hydroxides, with a resolution of 5.8µm pixel-1 at a speed of 10µm s-1. After the hydrogels undergo thermal dehydration, debinding, and sintering, polycrystalline Nd:YAG ceramics featuring distinguishable grains are successfully produced. By optimizing the concentrations of the sintering aids (tetraethyl orthosilicate) and neodymium trichloride (NdCl3), the resultant samples exhibit satisfactory photoluminescence, emitting light concentrated at 1064nm when stimulated by a 532nm laser. Additionally, Nd:YAG ceramics with various 3D geometries (e.g., cone, spiral, and angled pillar) are printed and characterized, which demonstrates the potential for applications, such as laser and amplifier fibers, couplers, and splitters in optical circuits, as well as gain metamaterials or metasurfaces.

Synthesis of acrylic acid and acrylates from CO&lt;sub&gt;2&lt;/sub&gt; and ethylene — the thorny path from dream to reality

The development of atom-economical and efficient processes for obtaining a variety of chemical products using CO&lt;sub&gt;2&lt;/sub&gt; as C&lt;sub&gt;1&lt;/sub&gt;-synthon plays an increasingly important role in modern scientific and technological research. Due to the inertness of CO2 many extremely attractive routes to valuable chemical products turn out to be impossible to implement, particularly for thermodynamic reasons, leaving one only dreaming about them as something unattainable. This review demonstrates how the catalytic coupling of ethylene and CO&lt;sub&gt;2&lt;/sub&gt; into acrylic acid, once considered a "dream reaction" has not only become a reality, but has also evolved into the category of technological processes. The key stages of the long-term development of this unique reaction from the discovery of metal activation of CO&lt;sub&gt;2&lt;/sub&gt; and stoichiometric preparation of metallalactones to catalytic synthesis using a variety of metal-catalysts (Ni, Pd, Ru, Rh) showcase the ingenuity and skill of researchers as well as an example of consistent development in this field of chemistry. We believe that this remarkably successful example will inspire scientists to tackle any "impossible" problems.&lt;br&gt; The bibliography includes 117 references.

Evaluation of two acrylic acid production processes from renewable crude glycerol: Rigorous process design, techno-economic evaluation, and life cycle assessment

This study aims to propose and evaluate two acrylic acid (AA) production processes that utilize bio-based crude glycerol as a feedstock. Scheme 1 employs acrolein as an intermediate, while Scheme 2 utilizes allyl alcohol as an intermediate. For process intensification, Scheme 1 employs a one-pot reactor configuration that couples the glycerol dehydration and oxidation reactions and uses an additional reactor to suppress the formation of side products. Scheme 2 implements a membrane that helps prevent the multiple azeotropic distillation between water and other substances. Furthermore, both processes were systematically optimized based on varying levels of information available in the process (i.e., three objectives for Scheme 1, single objective for Scheme 2). From a techno-economic evaluation, Scheme 2 (2.136 USD/kg) slightly outperforms Scheme 1 (2.514 USD/kg) in terms of the minimum required selling price (MRSP). Both values are significantly higher than the market price (1.24–1.32 USD/kg) based on the conventional process that uses propene as a feedstock. Subsequently, a cradle-to-gate life cycle assessment was conducted to compare these processes across five impact categories (i.e., global warming potential, fossil source scarcity, human non-carcinogenic toxicity, water consumption, and terrestrial acidification). We have observed that Scheme 1 can be more sustainable than Scheme 2 and the conventional process if the issue associated with the acrolein left in the wastewater can be addressed. In contrast, Scheme 2 is far from environmentally friendly even compared to the conventional process, primarily because of the use of formic acid as a co-reactant.

Biocompatible Quince Seed Mucilage Hydrogel: A Versatile Platform for Efficient Drug Delivery of Ceftriaxone with Enhanced Adsorption Properties

AbstractThe objective of this study was to explore the applicability of biocompatible quince seed mucilage hydrogel as a promising material for drug delivery systems. In this investigation, the hydrogel was synthesized through the graft copolymerization of acrylic acid and allyl polyvinyl alcohol onto quince seed mucilage in an aqueous solution under an argon atmosphere. Characterization of the synthesized hydrogel was performed using Fourier‐transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FE‐SEM), and thermogravimetric analysis (TGA). Subsequently, the developed hydrogel served as a carrier for ceftriaxone antibiotic release in both distilled water and a buffer solution with a pH of 7.4. The results demonstrated an impressive encapsulation efficiency of 96.1% for ceftriaxone within the hydrogel matrix. Additionally, the adsorption properties of ceftriaxone onto the proposed hydrogel structures (I, II, and III) were theoretically investigated in the aqueous phase using Monte Carlo adsorption locator calculations in Materials Studio2017. Our findings revealed strong adsorption on structure (III) compared to structures (I and II), with respective theoretical energies of −2.836 kcal/mol, −2.840 kcal/mol, and −2.127 kcal/mol. Therefore, the proposed hydrogel structure (III) emerges as a promising candidate for drug delivery applications, emphasizing its potential as an efficient carrier system.

Experimental Study for Enhancement of Water Flow in Horizontal Pipelines by Using Nanoparticles of Zinc Oxide and Poly Acrylic Acid

Experimental Study for Enhancement of Water Flow in Horizontal Pipelines by Using Nanoparticles of Zinc Oxide and Poly Acrylic Acid

Incorporation of polyzwitterions in superabsorbent network membranes for enhanced saltwater absorption and retention

BackgroundSuperabsorbent polymers (SAPs) have a remarkable ability to absorb significant quantities of water. However, their absorption capacity is significantly reduced when exposed to saline solutions, such as urine, due to the polyelectrolyte effect and charge screening. MethodsIn this study, we demonstrate a zwitterionic superabsorbent polymer (ZSAP) with excellent salt-water absorption and retention capacities. ZSAP was synthesized by grafting a copolymer of p(sulfobetaine methacrylate-co-2-hydroxyethyl methacrylate) (p(SBMA-co-HEMA)) onto an acrylic acid (AA)-based hydrogel via free-radical polymerization. The introduction of zwitterionic SBMA significantly enhances the hydrophilicity of the polymer, particularly in a saline solution due to the anti-polyelectrolyte effect, thereby accelerating the rate of salt absorption. Additionally, the hydroxyl groups from HEMA facilitate the formation of covalent bonds with the AA network membrane through esterification, effectively mitigating polymer leaching. The hydration/dehydration behaviors of linear polymers were measured using the dynamic vapor sorption (DVS) method. Moreover, the salt-water absorption capacity, centrifuge retention capacity (CRC), and absorbency under load (AUL) of ZSAP with various SBMA moieties and copolymer dosages were comprehensively evaluated in a 0.9 wt% sodium chloride solution. Additionally, the water retention under different temperatures and polymer leaching of ZSAP were investigated. Significant FindingsThe copolymer p(SBMA-co-HEMA) not only demonstrates a high salt-water absorption rate at 90% RH in a 0.9 wt% NaCl solution but also exhibits superior water retention at 0% RH compared to the AA polymer. Moreover, the ZSAP exhibits superior salt-water absorption capacity and AUL in a 0.9 wt% NaCl solution compared to conventional AA-based SAP. Additionally, the introduction of the hydroxyl moiety from the p(SBMA-co-HEMA) copolymer reduces free polymer leaching from ZSAP. This work presents an approach for the development of new SAP with high salt-water absorption and retention.

Unleashing high-volume waste plastic recycling in sustainable cement mortar with synergistic matrix enabled by in-situ polymerization

The substantial energy consumption and CO2 emissions associated with the production and transportation of concrete and its components have necessitated the search for suitable replacements, particularly waste materials such as plastic, to mitigate their environmental impact. The emergent challenge of employing recycled waste plastics (RWP) in concrete centers around their poor interactions with the cement matrix. Here, a synergistic approach with in-situ polymerization by using sodium acrylate (SA) at various doses (0 %, 0.5 %, 1 %, 2 %) was employed to produce environmentally-friendly mortars. Recycled polypropylene (PP) particles were adopted as the aggregate to replace natural sand in cement mortar. Results indicate decreased water contact angel by 46 % and increased pull-off strength by 25 % for SA-polymerized PP. Moreover, mortars with 2 % SA exhibited a 31 % increase in compressive strength, a 64 % increase in flexural strength, a 76 % reduction in water sorptivity, and a 13.6 % decrease in total porosity. The formation of interconnected polymeric networks in the cement matrix and interfacial transition zone (ITZ) contributes to structural densification, highlighting the superior engineering properties. These findings present a promising pathway towards sustainable and resource-efficient building materials, fostering a circular economy for plastics.

Evaluating the operational properties of concrete admixtures containing molecularly modified polycarboxylate superplasticizers

The objective of this study focused on the design and preparation of a molecularly modified polycarboxylate superplasticizer to develop concretes with enhanced engineering features. For this purpose, polyethylene glycol was chemically modified with maleic anhydride to give the mono polyethylene glycol maleate (MPEGM). Then, polycarboxylate superplasticizer comprising of isoprenyl oxy polyethylene glycol (TPEG) and acrylic acid (AA, PCE-1), and the synthesized MPEGM with TPEG and AA (PCE-2) were prepared through solution radical polymerization. Subsequently, concrete mixtures with different dosages (0, 0.1, 0.15, 0.2, 0.25, 0.3 wt%) of PCE-1 and PCE-2 were prepared. Chemical structure of the synthesized MPEGM and superplasticizers together with their copolymer composition were identified by FTIR and 1HNMR analyses. The molecular weights (Mw) and molecular weight distributions (PDI) of PCE-1 (8.74 × 104, 1.36) and PCE-2 (8.74 × 104, 2.19) were studied by GPC analysis, respectively. The zeta potential of cement particles (2.8 mV) becomes negative in the presence of 0.6 g/L of PCE-1 (− 7.8) and PCE-2 (− 9.5). This implies that electrostatic and steric hindrance forces of adsorbed superplasticizers synergistically provide a situation for appropriate dispersion of cement particles. The results of water-reducing percentage, fluidity, air content, bleeding water rate, initial and final setting times, wet density, flexural and compressive properties, and ultrasonic pulse velocity analyses exhibit significant enhancement on the features of concrete mixtures made of polycarboxylate superplasticizer. The superiority of PCE-2 to PCE-1 was connected to its adsorption-dispersibility potent induced by stronger electrostatic and steric repulsion forces, which result in quality and continuity enhancement in concretes.

Integrating self-hygroscopic hydrogel electrolyte and porous electrode for supercapacitor operating in variable humidity environments

The application of supercapacitors (SCs) based on the conventional polyvinyl alcohol‑potassium hydroxide (PVA-KOH) polymer electrolyte is challenged in variable humidity environments, especially in low relative humidity (RH) environments. Herein, taking advantage of the high ionic conductivity and strong hygroscopicity of highly concentrated KOH solutions, we have prepared a hygroscopic hydrogel polymer electrolyte composed of sodium alginate (SA)/PVA/poly(acrylic acid) (PAA)-KOH. The SA/PVA/PAA-KOH gel electrolyte exhibits high ionic conductivity, superior water retention and even water adsorption capability. A three-dimensional CoCu-layered double hydroxide/zeolitic imidazole framework-67 (CuCo-LDH/ZIF-67) porous electrode has also been prepared for the construction of the high-performance SC operating in variable RH environments. The CuCo-LDH/ZIF-67 porous electrode allows deep penetration of the self-hygroscopic electrolyte, facilitating electron/ion diffusion and providing fast water transport channels. As a result, our asymmetric SC show significantly improved electrochemical performance than that of SC based on conventional PVA-KOH electrolyte under different RH environments. This integration strategy can advance the practical application of SC in extreme environments.

Cyclic catalysis of intratumor Fe3+/2+ initiated by a hollow mesoporous iron sesquioxide nanoparticle for ferroptosis therapy of large tumors

Numerous nanoparticles have been utilized to deliver Fe2+ for tumor ferroptosis therapy, which can be readily converted to Fe3+via Fenton reactions to generate hydroxyl radical (•OH). However, the ferroptosis therapeutic efficacy of large tumors is limited due to the slow conversion of Fe3+ to Fe2+via Fenton reactions. Herein, a strategy of intratumor Fe3+/2+ cyclic catalysis is proposed for ferroptosis therapy of large tumors, which was realized based on our newly developed hollow mesoporous iron sesquioxide nanoparticle (HMISN). Cisplatin (CDDP) and Gd-poly(acrylic acid) macrochelates (GP) were loaded into the hollow core of HMISN, whose surface was modified by laccase (LAC). Fe3+, CDDP, GP, and LAC can be gradually released from CDDP@GP@HMISN@LAC in the acidic tumor microenvironment. The intratumor O2 can be catalyzed into superoxide anion (O2•-) by LAC, and the intratumor NADPH oxidases can be activated by CDDP to generate O2•-. The O2•- can react with Fe3+ to generate Fe2+, and raise H2O2 level via the superoxide dismutase. The generated Fe2+ and H2O2 can be fast converted into Fe3+ and •OH via Fenton reactions. The cyclic catalysis of intratumor Fe3+/2+ initiated by CDDP@GP@HMISN@LAC can be used for ferroptosis therapy of large tumors.

Electrodeposited Zn-Mn on three-dimensional electrodes as anodes in liquid and quasi-solid-state zinc-air batteries

Zinc-air batteries (ZABs) are eco-friendly and sustainable energy storage devices. There are different challenges to overcome in ZABs, where anodic issues such as shape changes, passivation, self-corrosion, and dendrite formation require urgent solutions. In this work, Zn and Zn-Mn alloys were electrodeposited on three-dimensional porous carbon electrodes varying the Mn composition (2, 20 and 40 g L−1) and studying its effect during the operation of a 6 M KOH liquid ZAB and a quasi-solid-state ZAB based on poly(vinyl alcohol)/poly(acrylic acid) PVA/PAA gel polymer electrolyte (GPE). Scanning electron microscopy (SEM) images indicated that Zn and Zn-Mn were deposited as platelet-like bi-dimensional structures. Additionally, the use of 20 and 40 g L−1 of the Mn precursor resulted in larger Zn deposition covering the 3D structure of the carbon paper. Elemental analysis indicated that the Mn content in Zn-Mn was 1.3, 2.4 and 6 %. In the aqueous ZAB, the Zn-Mn with 2.4 % Mn enabled to increase the maximum current density achieving the highest power density of 45 mW cm⁻2. In QSS-ZAB, Zn-Mn at 1.3 and 2.4. % Mn displayed higher stability to recovery after demanding different current densities, while the first anode displayed higher cyclability, presenting a similar round trip after 240 charge/discharge cycles This ZAB was maintained functional during 290 cycles vs. 120 cycles for Zn foil. The rechargeability was improved because of the decrease in Zn dendritic growth and passivation.