Hydroxide Research Articles

Phase-separated cationic giant unilamellar vesicles as templates for the polymerization of tetraethyl orthosilicate (TEOS)

Unlike homogeneous liposomes, phase-separated liposomes have the potential to be attractive soft materials because they exhibit different properties for each phase. In this study, phase separation was observed when liposomes were prepared using 1,2-dioleoyloxy-3-trimethylammonium propane chloride (DOTAP), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), and cholesterol. The pH of the DOTAP-rich phase was evaluated using a coumarin derivative, and measurements showed that DOTAP molecules accumulated hydroxyl ions (OH−) in the DOTAP-rich phase. Such accumulation of OH− was not observed when homogeneous DSPC liposomes were used. The difference in local concentration of OH− in each phase was applied to prepare hollow silica particles with large pores. The OH− promotes the polymerization of tetraethyl orthosilicate (TEOS). Therefore, TEOS polymerized preferentially in the DOTAP-rich phase, whereas a silica membrane barely formed in the DSPC-rich phase.

Remediation of antimony and arsenic in co-contaminated soil by electrolytic manganese residue-biochar composite: Effects, mechanisms, and microbial response

Antimony (Sb) mining and smelting activities caused Sb and arsenic (As) pollution in the soil, posing a threat to the ecosystem and human health. To remediate Sb and As in co-contaminated soil and realize the resource utilization of typical industrial solid waste, electrolytic manganese residue (EMR)-biochar composite (EB) was prepared from EMR and distillers grains by a facile one-step pyrolysis method. The immobilization effect of EB on Sb and As in soil was studied using a column leaching experiment. Pot and soil incubation experiments were conducted to investigate the effects of EB on the bioavailability of Sb/As and microbial communities. The results showed that 4 wt% EB treatment reduced the accumulated contents of Sb and As in leachates by 29.21%-55.65% and 53.51%-68.95%, respectively, compared with the control. EB treatment (1 wt%) improved plant height, root length, phytomass, and chlorophyll content of Brassica campestris L. Compared to the untreated soils, 4 wt% EB treatment increased the well-crystallized hydrous oxides and residual fractions of Sb and As by 4.29%-6.23% and 4.09%-7.03%, respectively. The concentrations of bioavailable Sb and As in soil were reduced by 48.01%-71.92% and 52.31%-53.81%, respectively. EB interacted with As/Sb-resistant dominant microorganisms such as Proteobacteria in the soil, promoted their growth, and enhanced the immobilization of Sb/As. EB increased the relative abundance of redox-related bacteria of Sb and As (Thiobacillus and Sulfuriferula) by affecting soil EC and bioavailable Sb/As. The immobilization of As and Sb by EB include complexation, hydrogen bonding, and pore filling. These findings provide novel insights into the remediation of Sb and As co-contaminated soils.

Self‐Photocatalysis Boosted Electrochemiluminescence System of Pyrene Based Hydrogen‐Bonded Organic Framework: Oxygen‐Vacancy Mediated Adsorption and Peroxydisulfate Radical Activation

AbstractRational design and optimization of the electrochemiluminescence (ECL) system undoubtedly underpins critical future advances in the field of sensing. Herein, an efficient ECL system is prepared by the integration of pyrene self‐assembled hydrogen‐bonded organic frameworks (PSA‐HOF) and defective hydrated tungsten oxide nanosheets (dWO3•H2O), displaying a self‐cycling photocatalytic activation mechanism to boost ECL performances. PSA‐HOF was exploited as the ECL luminophor to produce a light source with sufficient intensity due to the unique structure and aggregation‐induced emission‐enhanced emission. Meanwhile, dWO3•H2O exhibited dual functionality: 1) serving as highly efficient adsorbents for capturing peroxydisulfate (PDS), 2) acting as photoactive materials, which can be activated by the light emitted from PSA‐HOF. Notably, the presence of oxygen vacancies within dWO3•H2O can not only lowered adsorption energy and increase exposure of active sites, but also enhance the photocatalytic performance, thus activating PDS through a radical‐mediated mechanism, which can further stimulate the photocatalytic materials in turn to achieve self‐circulation within the system. As a proof of concept, an ECL biosensor for detecting microcystin‐RR (MC‐RR) is successfully established, which displays a wide detection range and a low detection limit. This work offers a new perspective on the development of ECL technology with high efficiency and stability.

Reconstruction Effects of Layered Vanadium Oxides by Nanoengineering and Preintercalation for High Zinc-Ion Storage Performance.

Layered vanadium oxides with preintercalated cations have been recognized to be among the most promising cathode materials for aqueous zinc-ion batteries (AZIBs). However, their underlying structure-property relationships are still poorly understood owing to the lack of systematic comparison. Herein, a series of layered V2O5 nanobelts including single-layer α-V2O5 and bilayer hydrated δ-V2O5 with preintercalation (MxV2O5·nH2O, M = Mg2+, Ca2+, or Ba2+) with similar morphology are fabricated through a controllable synthesis protocol as models. The side-by-side comparisons of the energy storage performances and related kinetics in these samples decouple the reconstruction effects of nanostructuring and preintercalation. Results demonstrate that nanostructuring tends to improve the capacity and rate retention of α-V2O5 but leaves the rapid capacity decay unsettled, whereas preintercalation can convert α-V2O5 into δ-V2O5 with simultaneously enhanced discharge capacity, rate retention, and cycling stability. Regulation of the cations' species/content and their associated structural water appears to accelerate the electron/ion transport in V2O5 and stabilize the framework of V2O5, thereby boosting the energy storage properties. The optimized sample with a stoichiometric formula of Mg0.255V2O5·0.809H2O exhibits outstanding comprehensive energy storage performance that is comparable to the most advanced vanadium oxide hydrate cathodes reported in the literature. The quantification and understanding of the reconstruction effects of nanostructuring and preintercalation in this work offer insights into the structural engineering of advanced cathodes for AZIBs and beyond.

Synergistic effect of rice husk-derived activated carbon modified by Ni/Al-layered double hydroxides for lead removal from industrial wastewater

To enhance the adsorption efficiency of activated carbon for heavy metals, herein we synthesized a novel composite adsorbent by loading of nickel/aluminum layered double hydroxides (Ni/Al-LDH) onto a chemically modified Egyptian rice husk-derived activated carbon. The characterization techniques used for determining the chemical and surface structure of the prepared composite were including FTIR, XRD, SEM, and BET which confirmed the successful loading of LDH onto the prepared activated carbon surface. The modified activated carbon established significantly upgraded performance in eliminating lead ions from wastewater. Adsorption studies revealed that the process follows Freundlich isotherm and pseudo-second-order kinetics, indicating chemisorption as the rate-determining step. The maximum lead ions removal (using 50 ppm concentration solution) was 82% after 210 min at pH 7. The improved lead ions removal efficiency was attributed to the synergistic effect of the activated carbon’s surface chemistry and the LDH’s ion exchange properties. The presence of chelating groups like hydroxyl (–OH), amide (–CO–NH–), carboxylate (–COOH), and nitrogen-containing functional groups on the activated carbon surface, along with the hydroxide groups of the LDH, facilitates the complexation and adsorption of lead ions.

Comparative study of zirconium-zinc oxide thin films on ceramic and glass substrates: Structural, optical, and photocatalytic properties

This study investigates the structural, optical, and photocatalytic properties of zirconium-doped zinc oxide (Zr) thin films deposited on ceramic and glass substrates. X-ray diffraction (XRD) analysis revealed that all samples exhibited a polycrystalline wurtzite structure, with grain sizes ranging from 25 to 43 nm for ceramic substrates and 19 to 32 nm for glass substrates. UV–visible absorbance measurements indicated that Zr films absorbed visible light around 410 nm, with the band gap widening to 2.93 eV on ceramic substrates. Scanning electron microscopy (SEM) showed that Zr doping significantly affected the morphology of thin films, resulting in rougher surfaces and larger grains on ceramic substrates. Photocatalytic tests demonstrated that the 5 wt% Zr on DD1Z ceramic achieved a degradation efficiency of 61.44 % for orange II dye after 5 h of UV irradiation. In contrast, Zr on ceramic substrates achieved only 18.56 %, and the bare DD1Z substrate reached just 4.02 %. These findings highlight the superior photocatalytic performance of Zr on ceramic substrates, indicating their potential for advanced water purification technologies. The mechanism of photolysis was investigated using hole/radical scavengers, revealing that Zr-ZnO networks enhance the adsorption of hydroxyl ions on the surface. This acts as a trap site, reducing hole/electron pair recombination and thus increasing activity and photodegradation efficiency.

Enhanced oxygen evolution reaction in flexoelectric thin-film heterostructures

Recently, the flexoelectric effect has triggered considerable interest in energy-related applications, such as flexo-actuation, flexo-photovoltaic, and flexo-catalysis, because of its ubiquitous feature allowing the creation of electric polarity, i.e., the flexoelectric polarization (Pflexo), in non-polar materials by strain gradient. Here, we show a flexoelectric strategy in electrocatalytic water splitting. Remarkably enhanced oxygen evolution reaction (OER) properties are achieved in strain-gradient LaFeO3 (LFO) thin-film heterostructures owing to the promotion of kinetic processes by Pflexo. The improved OER is demonstrated by increased current density of ∼300% in linear sweep voltammetry and lowered charge transfer resistance by two orders of magnitude in electrochemical impedance spectroscopy. These are ascribed to the flexoelectric-induced downward bending of the LFO band, as revealed by density functional theory calculations and band structure measurements. With Pflexo in the thin-film heterostructure catalysts, the adsorption of hydroxyl ions is strengthened on the polar LFO surface, and the transfer of electrons is accelerated from the reactants/key intermediates to the catalyst across the band-tilted LFO layer. These findings indicate the significance of flexoelectric effect in OER kinetics and open a new perspective for exploiting catalytic mechanisms and performances in water splitting.

A new approach to overcome cytotoxic effects of Cu by delivering dual therapeutic ions (Sr, Cu)

IntroductionThe incorporation of trace elements such as strontium (Sr) and copper (Cu) in the composition of mesoporous bioactive glass (MBG) is widely known to enhance its biological functionality for bone tissue regeneration MethodsTwo MBG powders with the composition 80SiO2-11CaO-5P2O5-XCuO/SrO, one doped with 4mol.% of CuO, the second with 4mol.% of SrO were blended in the weight ratios of Cu-MBG: Sr-MBG; 100:0, 70: 30, 50: 50, 30: 70 and 0:100 aiming at minimizing Cu to minimize the cytotoxicity of Cu while preserving its antimicrobial activity. The synergistic effects of Sr and Cu ions on bioactivity, cytotoxicity, and antimicrobial activity were studied. ResultsTransmission electron microscopy (TEM) examination of Cu-MBG and Sr-MBG showed fringes related to the development of a mesoporous structure. The specific surface area values of the Cu-MBG and Sr-MBG powders were 287 and 349 m2/g, respectively. A characteristic compact layer consisting of particles with platelet-like morphology commonly associated with HAp crystals was confirmed after 7 days soaking in simulated body fluid (SBF). Mouse preosteoblast cells (MC3T3-E1) exhibited higher cell viability when exposed to a 1% w/v eluate from blended Cu-MBG powders compared to pure Cu-MBG. Notably, the Cu-MBG: Sr-MBG ratio of 30:70 exhibited cell viability of around 85% at this concentration. A higher cell viability (above 100%) towards MC3T3-E1 cells was observed for all powders when tested with the 0.1% w/v eluate. With progressive increase in the amount of Cu-MBG in the blended system the bacterial inhibitory effects were more pronounced. The Cu ions releases from Cu-MBG generate hydroxyl ions and increase the pH leading to disruption of the cellular membrane of microbes, resulting in enhanced antimicrobial activity. ConclusionThis newly developed blended system composed of Cu and Sr doped MBGs is expected to be more effective as bioactive filler in comparison to single ion doped MBGs for bone tissue engineering applications.

Enhancement of reactive oxygen species production by ultra-short electron pulses.

The development of laser-driven accelerators-on-chip has provided an opportunity to miniaturize devices for electron radiotherapy delivery. Laser-driven accelerators produce highly time-compressed electron pulses, on the 100 fs to 1 ps scale. This delivers electrons at high peak power yet low average beam current compared with conventional delivery devices, which generate pulses of approximately 3 µs. The biophysical effects of this time structure, however, are unclear. Here, we use a Monte Carlo simulation approach to explore the effects of the electron beam time structure on the production of reactive oxygen species (ROS) in water. Our results show a power law increase in the generation of hydroxyl ions per deposited electron with decreasing pulse length over the pulse length range of 10 µs to 100 fs. Similar trends were observed for hydrogen peroxide, superoxide, hydroperoxyl, hydronium and solvated electrons. In practical terms, this indicates a fourfold increase in the efficiency of free radical production for sub-picosecond pulses, relative to that of conventional microsecond pulses, for the same number of deposited electrons.

Comparative evaluation of removal of oil-based calcium hydroxide intracanal medicaments with two calcium chelators: An in vitro cone-beam computed tomography volumetric analysis

Background: Intracanal medicament (ICM) eliminates remaining bacteria and their toxins that were not removed by chemomechanical preparation during endodontic treatment. Aim: The aim of this study was to compare and evaluate the removal of ozonated oil-based, silicone oil-based, and distilled water-based ICM with two calcium chelators, i.e., 0.2% chitosan and 17% ethylenediaminetetraacetic acid (EDTA). Materials and Methods: A total of 54 mandibular permanent premolars were included and randomly allocated into 3 groups after cleaning and shaping along with thorough irrigation. Group 1 - ozonized calcium hydroxide group; Group 2 - Metapex group; Group 3 - Ca(OH)2 with distilled water group. Using an irrigant for removal, the teeth in each group were distributed at random to two subgroups – (A) 0.2% chitosan solution; (B) 17% EDTA solution. All the samples were ultrasonically agitated and the volume remaining in each tooth after retrieval was estimated using additional cone-beam computed tomography scans. The result was analyzed using one-way analysis of variance, following post hoc Tukey test. Results: The mean percentage of ozonized Ca(OH)2, aqueous calcium hydroxide, and Metapex removed by 0.2% chitosan had greater values in comparison to 17% EDTA. When eliminating aqueous-based calcium hydroxide, both chelators showed similar effectiveness (P > 0.05). In contrast, 0.2% chitosan outperformed 17% EDTA in retrieving oil-based Ca(OH)2 (P < 0.05). Conclusion: The aqueous-based form of Ca(OH)2 was removed more easily compared to the oil-based form. A combination of 0.2% chitosan and ultrasonics proved to be more effective than 17% EDTA in eliminating oil-based calcium hydroxide.

Detection of lunar water, hydroxyl ion and their diurnal changes from CHACE-2 orbiter observation

This work reports the spatial and diurnal variations of the number densities of lunar molecular water (H2O), atomic mass unit (amu) 18 and hydroxyl (OH), amu 17 over low (0° to 30°), middle (31° to 60°) and high (61° to 80°) latitudinal regions of the lunar exosphere during the pre-sunrise, noon, sunset and midnight periods using the mass spectrometric data of CHandra's Atmospheric Composition Explorer-2 (CHACE-2) on board Chandrayaan-2, the second lunar mission developed in India. Both H2O and OH exhibit, particularly in the low latitude regions, a trend of increasing number density after the sunrise and up to noon, followed by a decrease till sunset. An overall higher density of H2O is obtained compared to the previous reports. The findings are justified in terms of the polar orbital height of the instrument and the duration of data procurement. The maximum number density for the low, middle and high latitudes reaches 5225 cm−3, 5135 cm−3 and 3747 cm−3, respectively. The corresponding OH abundances are found to be 5079 cm−3, 5565 cm−3 and 5720 cm−3. The diurnal variations of H2O and OH and their comparisons, similar to those of the present report may provide suitable means for tracing the lunar water cycle. The CHACE-2 observations imply that the influence of magnetotail passage on volatiles like water is to be further quantified in future missions with other sensors.

Antimony resistant bacteria isolated from Budúcnosť adit (Pezinok-Kolársky vrch deposit) in western Slovakia

Potentially toxic elements (PTE), such as antimony (Sb), are dangerous putative contaminants for ground and surface waters around abandoned mines and ore deposits in Slovakia. Nearby mines antimony is commonly coprecipitated in ochre sediments precipitated from Fe-rich drainage waters and, therefore, these sites function as natural scavengers of this metalloid. Bacteria are well known to contribute to the process of redox state maintenance, biosorption and bioaccumulation of antimony and, consequently, to antimony precipitation or release from iron oxides complexes. Here we isolated 48 bacterial strains from circumneutral hydrous ferric oxides (HFO) rich iron ochres accumulated in the waters running from tailing pounds nearby Budúcnosť mine, Pezinok, Slovakia and polluted with high, but fluctuating, concentrations of antimony (130 μg/l Sb in water and 2317 mg/kg Sb in iron ochre in average). The isolated strains were V1-V9 16S rRNA sequenced and the resulting taxonomic affiliations of isolated strains were compared with taxonomy assignments obtained by V4 16S rRNA next generation sequencing approach, including two independent NGS analysis pipelines and different taxonomy classifiers ((IDTAXA (RDP, GTDB, SILVA, CONTAX), MEGAN (NCBI), RDP a SILVAngs). A Sb resistant subgroup of isolated strains (Pseudomonas A60B, Pseudomonas A59, Pseudomonas A28, Aeromonas A21, Aeromonas A13, Aeromonas A60A, Acinetobacter A14, Buttiauxella A58, Shewanella A20A a Yersinia A68), well growing at high Sb concentration (300 mg/l Sb), was tested for an ability of the strains to retain Sb from cultivation media. Based on ICP-MS measurements of the dried biomasses we concluded that all the strains can retain antimony from growth media to some extent, with strains Shewanella A20A, Buttiauxella A58, Yersinia A68 and Aeromonas A60A being the most effective.

Investigating the in vitro Anticancer Potential and Phytochemical Constituents of Cheilanthes hirta Swartz Plant Extracts

Cancer, a complex group of diseases characterized by uncontrolled cell growth, remains a leading cause of death worldwide, accounting for approximately 10 million deaths in 2020. Despite advancements in chemotherapy and targeted therapies, survival rates have not significantly improved, necessitating the exploration of novel anticancer agents. This study investigates the in vitro anticancer potential and phytochemical constituents of Cheilanthes hirta Swartz, a fern known for its medicinal properties. The plant was collected from KwaZulu Natal, South Africa and extracts were prepared using water, ethanol and methanol. The phytochemical and FTIR screening were carried out using standard procedure and anticancer activities of the extracts were assessed against prostate (PC-3 and DU-145), human T-lymphocytes (SKU-T) and gastric (AGS) cancer cell lines using the MTT assay. The phytochemical screening revealed the presence of tannins, terpenoids, saponins, flavonoids, cardiac glycosides, anthraquinones, phlobatannins, alkaloids and steroids. FTIR spectroscopy identified the functional groups such as hydroxyl, carboxylic acid, terminal alkynes, ketones, phenols and phosphate ions. The cytotoxicity results showed that the ethanol extract exhibited the most potent antiproliferative effects on prostate cancer cell lines, while the aqueous extract had the strongest effect on the gastric cancer cells. This study highlights the potential of C. hirta as a source of bioactive compounds for anticancer drug development, however, further investigation into its mechanisms of action and therapeutic efficacy is needed.

A Wide‐Temperature Adaptive Electrochromic Device Based on a Poly(vinyl alcohol)/Poly(acrylic acid) Gel Electrolyte

AbstractAs a promising energy‐saving technology, electrochromic technology has been widely investigated for practical applications. However, there is relatively few research about the applications under certain extreme climatic conditions since gel electrolytes often occur freezing and volatilizing. In this work, a poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) gel electrolyte with good anti‐freezing and heat‐resistance performance is developed. Utilizing hydrated tungsten oxide (WO3·xH2O) and polyaniline (PANI) as electrochromic materials and the PVA/PAA gel as electrolyte, a WO3·xH2O/PVA/PAA‐ethylene glycol (EG)‐H2O/PANI electrochromic device (WO3·xH2O/PAEH/PANI ECD) is obtained, which can work efficiently at wide operating temperatures from −20 to 60 °C. The device has multiple reversible color changes, a large optical modulation of 66.2% at 600 nm, high coloration efficiency of 386.0 cm2 C−1, fast responses (with coloration/bleaching times of 1.3/1.1 s), as well as excellent cyclic stability (82.0% of the initial optical modulation is still retained after 2100 cycles). This work reveals the potential application prospects of PAEH gel electrolyte in practical extreme operating conditions.

Effective purification of Fe/V as spherical phosphosiderite and porous vanadium oxyhydroxide from waste vanadium-bearing slag

Recovery of valuable vanadium (V) from V-rich waste was of economic and environmental and commonly treated by calcination and/or extraction. Herein, a novel route was developed to stepwise separate Fe and V from grayish slag via a coupled dissolution and hydrothermal route. After dissolving the V-rich slag in acid, the generated leachate was hydrothermally treated with the addition of phosphate and ethanol. 99.1 % Fe was effectively removed, whilst the loss of V and Mg were only 5.2 % and <2 %. The optimal parameters were 160 °C, 20 g/L phosphate and 0.1-ml ethanol. Fe reacted with phosphate and crystallized as phosphosiderite particles at 160 °C. With the Fe removal, free H+ was released and then consumed in the redox reaction of nitrate and ethanol. The thermodynamic analysis showed that phosphate accelerated the Fe hydrolysis/crystallization, resulting in the removal of Fe prior to V at the pH < 0.5 and the co-removal of Fe/V at the pH > 1. 98.7 % V was recycled as vanadium oxide hydrate particles by adjusting the leachate to pH 0.2 at 90 °C by adding urea. This provided as a promising strategy to separate Fe and V from leachate and posed potential application in the resource utilization of V-rich waste.

Structure–reactivity relationships in the removal efficiency of catechol and hydroquinone by structurally diverse Mn-oxides

Catechol and hydroquinone are widely present hydroxybenzene isomers in the natural environment that induce environmental toxicities. These hydroxybenzene compounds can be effectively removed by manganese (Mn)-oxides via sorption and oxidative degradation processes. In the present study, we investigated the structure–reactivity relationships in the sorption and oxidation of catechol and hydroquinone on Mn-oxide surfaces. Two widely present Mn-oxides, including hydrous Mn oxide (HMO) and cryptomelane, comprised of layer and tunnel structures, respectively, are specifically studied. Effects of Mn-oxide structures and environmental pH conditions on the removal efficiency of these hydroxybenzene compounds, via sorption and oxidative degradation, are investigated. Cryptomelane, which has a higher specific surface area than HMO, possesses a higher sorption and oxidation capacity. The complexation mechanisms of catechol and hydroquinone vary due to their structure-induced difference in reactivity. Catechol reduced and dissolved more Mn from Mn-oxides than hydroquinone, accompanied by a higher C loss of catechol-C, suggesting a higher reactivity of catechol. Structural changes occurred in the Mn-oxides resulting from reaction with catechol and hydroquinone: reduction of Mn(IV), corresponding formation of Mn(III) and Mn(II) in the mineral, and free Mn2+ ions released into the suspension. These insights could help us better understand and predict the fate of hydroxybenzene compounds in Mn-oxide-rich soils and wastewater treatment systems that generate Mn-oxides via Mn removal and the associated environmental toxicity.

Microplastics–biofilm in aquatic ecosystem: Formation, pollutants complexation, greenhouse gas emission and ecotoxicology

The omnipresent microplastics (MPs) have gradually become a significant environmental problem due to its adverse consequences for ecological systems. MPs serve as substrates for biofilms colonization, which enhances adsorption of harmful contaminants on MPs surface in the aquatic ecosystem. The present study provides a critical discussion on the mechanism involved in MPs–biofilm formation, microbial colonization and the robust factors influencing the process in the aquatic ecosystem. Subsequently, the impact of MPs–biofilm on adsorption of inorganic and organic contaminants is explored. The ecological significance of MPs–biofilm associated pollutant complex for promoting greenhouse gases (GHGs) emissions from aquatic ecosystem is extensively discussed for understanding the climatic risk. Furthermore, the discussion is extended over ecotoxicological impact of MPs–biofilm on aquatic biodiversity and humans. The protective extracellular polymeric substances secreted by colonised bacteria over MPs during biofilm formation creates sticky MPs surface for heteroaggregates formation with swift adsorption of chemical compounds and microorganisms. MPs with functional aromatic groups facilitate the bacterial adhesion on the surface, but affect formation of biofilm. Alternatively, MPs–biofilm promotes the Mn and Fe hydrous oxides formation that can co–precipitate with heavy metal ions and facilitate in remediation measures. However, MPs biodegradation generates GHGs emission per unit mass, comparably more from freshwater than marine ecosystem. Considering the toxicity, MPs–biofilm induces the oxidative response in fishes, causing painful death and thus, destroys aquatic biodiversity. This study will be useful to address MPs–biofilm associated pollution scenario via trace, test and treat strategy involving future engineering research framework for ecological restoration.

Synthesis and characterization of chloroquine-modified albumin-binding siRNA-lipid conjugates for improved intracellular delivery and gene silencing in cancer cells.

siRNA therapeutics have considerable potential as molecularly-targeted therapeutics in malignant disease, but identification of effective delivery strategies that mediate rapid intracellular delivery while minimizing toxicity has been challenging. Our group recently developed and optimized an siRNA conjugate platform termed "siRNA-L 2 ," which harnesses non-covalent association with endogenous circulating albumin to extend circulation half-life and achieve tumor-selective delivery without the use of traditional cationic lipids or polymers for transfection. To improve intracellular delivery and particularly the endosomal escape properties of siRNA-L 2 towards more efficient gene silencing, we report synthesis of siRNA-CQ-L 2 conjugates, in which chloroquine (CQ), an endosomolytic quinoline alkaloid, is covalently incorporated into the branching lipid tail structure. We accomplished this via synthesis of a novel CQ phosphoramidite, which can be incorporated into a modular siRNA-L 2 backbone using on-column solid-phase synthesis through use of asymmetric branchers with levulinyl-protected hydroxide groups that allow covalent addition of pendant CQ repeats. We demonstrate that siRNA-CQ-L 2 maintains the ability to non-covalently bind albumin, and with multiple copies of CQ, siRNA-CQ-L 2 mediates higher endosomal disruption, cellular uptake/retention, and reporter gene knockdown in cancer cells. Further, in mice, the addition of CQ did not significantly affect circulation kinetics nor organ biodistribution and did not produce hematologic or organ-level toxicity. Thus, controlled, multivalent conjugation of albumin-binding siRNA-L 2 to endosomolytic small molecule compounds holds promise in improving siRNA-L 2 knockdown potency while maintaining albumin-binding properties and overall safety.

Tailoring the Heterointerfaces of Earth-Abundant Transition-Metal Nanoclusters on Nickel Oxide Nanosheets for Enhanced Overall Water Splitting through Electronic Structure Optimization.

Evolving highly competent and economical electrocatalysts for alkaline water electrolysis is crucial in renewable hydrogen energy technologies. The slow hydrogen evolution reaction (HER)/oxygen evolution reaction (OER) kinetics under alkaline electrolytes, still, has troubled developments in high-performance green hydrogen production systems. Herein, we demonstrate the tailoring of the interface of earth-abundant transition-metal nanoclusters (MNCs), including iron (Fe), cobalt (Co), nickel (Ni), and copper (Cu) nanoclusters on nickel oxide nanosheets (M NCs|NiO NS) through metal-support interaction for enriched overall water splitting under an alkaline electrolyte. The strong metal-metal oxide interaction allows alteration of the binding capabilities of hydrogen ions (*H) and hydroxyl ions (*OH) on Ni electrodes. Specifically, the robust interaction between Fe and NiO reveals optimized binding of H* and OH* energies, facilitating the water-splitting reaction under an alkaline electrolyte. In addition, the improved HER/OER catalytic activity is attained with the Fe NCs|NiO NS with small overpotentials of ∼62.0 and ∼380.0 mV for the HER and OER, respectively, a high mass activity of ∼90.0 A g-1, a turnover frequency of ∼5.94 s-1, and long-lasting stability via offering abundant electrochemical active sites, three-dimensional (3D) morphologies, and high dispersion of nanoclusters that provide effective charge and mass transport processes. This study provides a promising strategy for the effective design of efficient bifunctional electrocatalysts based on earth-abundant materials for alkaline water electrolyzers.

Titanium oxide hydrates as versatile polymer crosslinkers and molecular‐hybrid formers

AbstractMolecular hybrid materials based on widely available polymers crosslinked with an inorganic species have received increasing interest for their unique property sets outside of the usual range of commodity plastics and/or nanocomposites. Here, we provide a mini‐review on molecular hybrids based on metal oxide hydrates—compounds that readily react with, for example, hydroxylated polymers to form inorganic:organic materials systems with many desirable features and properties. Focusing on titanium oxide hydrates, we discuss here that such molecular hybrids can exhibit a broad refractive index range in addition to an increased glass transition temperature, mechanical stiffness and swelling resistance in comparison to the neat polymer, which illustrates that such hybrid systems offer a new, low‐cost, robust and versatile functional materials platform with great promise for, for example, solution‐processed photonics, catalysts and antimicrobial coatings. Generally, our mini‐review seeks to provide a concise and accessible overview of titanium oxide hydrate:polymer hybrid systems, focusing on their unique properties and processability as well as their broad and largely untapped potential as functional materials. © 2024 The Author(s). Polymer International published by John Wiley &amp; Sons Ltd on behalf of Society of Chemical Industry.