Water Tolerance Research Articles

Porous membrane with highly stable liquid-filled surface based on aerogel structure for oil-water separation

Liquid-filled porous membranes have been developed for oil-water separation with antifouling properties. However, the degradation of fouling resistance and reduction of separation efficiency may occur due to the poor stability of the liquid layer. Prompted by the mesoporous structure and high porosity characteristics of aerogel, the membrane with aerogel-network-stabilized slippery surfaces was fabricated by in situ growth of silica aerogel coating on the polyethylene terephthalate (PET) fiber membrane and silicone oil filling. Owing to the oil-locking ability of the aerogel coating, the liquid layer of the membrane showed excellent stability against chemical corrosion and high-temperature, improved stability against shear and mechanical abrasion, and good hot water tolerance and self-healing performance. The prepared liquid-filled membrane can efficiently separate water-in-oil emulsion. In filtrating-cleaning cycles, the membrane showed antifouling property and durability with high separation efficiency and flux recovery. The membranes with highly stable liquid-filled surface provide promising prospects in industrial oil treatment and oil spill recovery.

WO3 boosted water tolerance of Pt nanoparticle on SO42--ZrO2 for propane oxidation

H2O poisoning of platinum-based catalysts for VOCs oxidation is a long-standing problem due to H2O strongly competitive adsorption on active sites. In this work, it is found that the H2O competitive adsorption on Pt active sites is effectively weakened by enhancing strong metal-support interaction (SMSI) in Pt-based catalyst. SMSI between WO3 and Pt species occurs in the WO3 supported Pt catalyst (Pt/WO3) but disappears in Pt-3W/ZrO2 due to monolayer dispersed WO3 on ZrO2. The formation of aggregated WO3 species in Pt-3W/SO42--ZrO2 leads to the SMSI which is further enhanced by SO42--ZrO2. The enhanced SMSI plays critical role on weakening water vapor adsorption on active sites, thus Pt-3W/SO42--ZrO2 exhibits both highest activity (T90 = 200 °C) and water tolerance which is much superior than Pt/ZrO2, Pt/WO3, Pt-3W/ZrO2 and Pt/SO42--ZrO2 under wet condition (5% H2O). Our primary results provide a promising strategy for designing superior platinum catalysts for VOCs complete oxidation.

Lincomycin HCl-Loaded Borneol-Based In Situ Gel for Periodontitis Treatment.

Solvent exchange-induced in situ forming gel (ISG) has emerged as a versatile drug delivery system, particularly for periodontal pocket applications. In this study, we developed lincomycin HCl-loaded ISGs using a 40% borneol-based matrix and N-methyl pyrrolidone (NMP) as a solvent. The physicochemical properties and antimicrobial activities of the ISGs were evaluated. The prepared ISGs exhibited low viscosity and reduced surface tension, allowing for easy injection and spreadability. Gel formation increased the contact angle on agarose gel, while higher lincomycin HCl content decreased water tolerance and facilitated phase separation. The drug-loading influenced solvent exchange and matrix formation, resulting in thinner and inhomogeneous borneol matrices with slower gel formation and lower gel hardness. The lincomycin HCl-loaded borneol-based ISGs demonstrated sustained drug release above the minimum inhibitory concentration (MIC) for 8 days, following Fickian diffusion and fitting well with Higuchi's equation. These formulations exhibited dose-dependent inhibition of Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 8739, and Prophyromonas gingivalis ATCC 33277, and the release of NMP effectively inhibited Candida albicans ATCC 10231. Overall, the 7.5% lincomycin HCl-loaded 40% borneol-based ISGs hold promise as localized drug delivery systems for periodontitis treatment.

Rationally designed of lanthanum decorated NiCo2O4 nanoboxs supported palladium for enhanced low temperature wet methane combustion

The development of high-efficiency Pd-based catalysts with excellent water tolerance at low temperatures remains a major challenge. Here, an atomic layer deposition (ALD) process is developed for depositing lanthanum on the surface of hollow NiCo2O4 nanoboxes (NiCo2O4 NBs), and then acts as a structural template to incorporate PdOx species by in-situ reduction method (Pd/La-NiCo2O4 NBs). The hollow structure of NiCo2O4 NBs is beneficial for exposing more active sites. The ALD-modification of La on the surface of NiCo2O4 NBs can inhibit the accumulation of inactive hydroxyl groups/water and improve water vapor tolerance of Pd/La-NiCo2O4 NBs at low temperature. The Pd embedded into NiCo2O4 lattice significant enhance the catalyst activity of Pd/La-NiCo2O4 NBs for methane combustion at low temperatures. This strategy of surface control of spinel by ALD technology provides a new route for rational design high-efficiency catalysts.

Sugarcane inspired polydopamine @ attapulgite-based aerogels with vertical pore structure for solar-driven steam generation

Desalination using solar-driven photothermal evaporators (SPEs) is of great significance for solving mankind's current shortage of fresh water. Herein, inspired by the vascular bundles for the directed and rapid transport of water and organic pollution such as inorganic salts in the vascular system of sugarcane, a polydopamine (PDA) @ attapulgite (ATP) based biomimetic aerogel (named as PAS aerogels) was prepared for efficient desalination. In PAS aerogels, the ATP gives the aerogel excellent mechanical properties, whereas the PDA gives the aerogel excellent light absorption properties. In the wet state, PAS aerogels have low thermal conductivity (0.24 W ∙ m−1∙ K−1) and low apparent density (0.13 g ∙ cm−3). Indicating that the photothermal evaporation rate of PAS-1.5 aerogel is 1.71 kg ∙ m−2∙ h−1 in pure water under 1 sun irradiation. Meanwhile, it can maintain excellent evaporation performance even in high salt solution with 20% concentration (about 1.50 kg ∙ m−2∙ h−1). Owing to the vertical pore structure of the aerogel, which is similar to that of sugarcane transport tissues, the aerogel has both an adequate supply of water and excellent salt tolerance. Furthermore, outdoor experiment of Yellow Sea water evaporation demonstrates its feasibility in the actual production of desalination.

Force Regulation by Sequence-Defined Polyelectrolytes

In order to achieve multifunctional adhesive materials with water and salt tolerance, it is crucial to understand the electrostatic mechanism of nanoconfined polyelectrolytes (PEs) with specific monomer sequences. Here, using density functional theory (DFT), self-consistent field theory (SCFT), and molecular dynamics (MD) simulation, we analyzed the microstructures of sequence-defined PEs confined in a nanoscale slit and the relationship between sequences and the attractive forces induced by the nanoconfined PEs. Among three sequence-defined (alternating [A], tapered [T], and reversely tapered [R] sequence) PEs, due to the formation of stable multibridge conformations, [A]-sequence PEs induce the strongest attractive forces even in the case with high salt concentrations, i.e., the best salt tolerance. It is worth emphasizing that salt enhancement of attractive forces occurs in systems with [A]-sequence PEs due to the screening of repulsive interactions between PE chains. In contrast, in systems with [T]-sequence PEs, the shielding of the attractive interactions between surfaces and charged monomers significantly attenuates the attractive forces between surfaces at high salt concentrations. In addition, the strength of attractive forces can be regulated by block number Nb. At high charge fractions such as fc = 0.5, the attractive forces induced by [A]-sequence PEs become stronger with Nb, while at low charge fractions such as fc = 0.2, the attractive forces vary nonmonotonically with Nb due to the electrostatic correlations.

A novel triple-conductive cathode with high efficiency and stability for protonic ceramic fuel cells

The sluggish kinetics of cathodic oxygen reduction reaction is one of the key barriers to the development of protonic ceramic fuel cells (PCFCs), while the appearance of triple-conductive material reported in recent years has brought a new dawn for the commercialization of PCFCs. These materials need to have excellent hydration ability and water tolerance to expand the active sites and prolong the operation lifespan. Herein, a highly efficient and stable cathode material, BaCo0.4Fe0.4Zr0.1Sc0.1O3-δ (BCFZSc) with cubic perovskite structure, is proposed for PCFCs. Electrical conductivity relaxation measurements reveal that the oxygen surface exchange coefficient of BCFZSc can reach the value of 1.8 × 10−3 cm s−1 at 700 °C, almost an order of magnitude larger than those of most reported cathodes. Applying BCFZSc as cathode, single cell exhibits an excellent peak power density of 1.334 W cm−2 with a small polarization resistance of 0.044 Ω cm2 at 700 °C, and a decent durability over 150 h at 600 °C is demonstrated. This research highlights that BCFZSc is a promising candidate for PCFCs cathode.

Clotrimazole-Loaded Borneol-Based In Situ Forming Gel as Oral Sprays for Oropharyngeal Candidiasis Therapy.

Oral candidiasis encompasses fungal infections of the tongue and other oral mucosal sites with fungal overgrowth and its invasion of superficial oral tissues. Borneol was assessed in this research as the matrix-forming agent of clotrimazole-loaded in situ forming gel (ISG) comprising clove oil as the co-active agent and N-methyl pyrrolidone (NMP) as a solvent. Their physicochemical properties, including pH, density, viscosity, surface tension, contact angle, water tolerance, gel formation, and drug release/permeation, were determined. Their antimicrobial activities were tested using agar cup diffusion. The pH values of clotrimazole-loaded borneol-based ISGs were in the range of 5.59-6.61, which are close to the pH of 6.8 of saliva. Increasing the borneol content in the formulation slightly decreased the density, surface tension, water tolerance, and spray angle but increased the viscosity and gel formation. The borneol matrix formation from NMP removal promoted a significantly (p < 0.05) higher contact angle of the borneol-loaded ISGs on agarose gel and porcine buccal mucosa than those of all borneol-free solutions. Clotrimazole-loaded ISG containing 40% borneol demonstrated appropriate physicochemical properties and rapid gel formation at microscopic and macroscopic levels. In addition, it prolonged drug release with a maximum flux of 370 µg·cm-2 at 2 days. The borneol matrix generated from this ISG obsentively controlled the drug penetration through the porcine buccal membrane. Most clotrimazole amounts still remained in formulation at the donor part and then the buccal membrane and receiving medium, repectively. Therefore, the borneol matrix extended the drug release and penetration through the buccal membrane efficiently. Some accumulated clotrimazole in tissue should exhibit its potential antifugal activity against microbes invading the host tissue. The other predominant drug release into the saliva of the oral cavity should influence the pathogen of oropharyngeal candidiasis. Clotrimazole-loaded ISG demonstrated efficacious inhibition of growth against S. aureus, E. coli, C. albicans, C. krusei, C. Lusitaniae, and C. tropicalis. Consequently, the clotrimazole-loaded ISG exhibited great potential as a drug delivery system for oropharyngeal candidiasis treatment by localized spraying.

The construction of MnOx with rich oxygen vacancy for robust low-temperature denitration

In the present study, manganese oxide (MnOx) with attractive feature of rich oxygen vacancy was constructed by a surfactant-assisted method and explored for NH3-SCR. The obtained MnOx-OV showed distinct performance, with full conversion of NO achieved at the low temperature window of 100–200 °C under a high space velocity of 120,000 mL·g−1·h-1. Besides, good water tolerance was exhibited, as evidenced by the minor drop (13%) of NO conversion under typical low temperature of 125 °C with 10% H2O. Through comprehensive characterization, it was found that the MnOx-OV with rich oxygen vacancy could promote oxygen diffusion and thus induce enhanced oxidative dehydrogenation capacity to NH3, which played a crucial role in facilitating the reaction between NOx and NH3. Regarding the reaction mechanism, Langmuir-Hinshelwood (L-H) pathway was proposed based on the results from in situ DRIFTS and reaction order measurement. The result of present study is expected to provide useful guidance for designing well performed catalysts for low-temperature NH3-SCR.

CuCeOx/CuO Catalyst Derived from the Layered Double Hydroxide Precursor: Catalytic Performance in NO Reduction with CO in the Presence of Water and Oxygen.

Valencies of metal species and lattice defects, such as oxygen vacancies, play a pivotal role in metal oxide-catalyzed reactions. Herein, we report a promising synthetic strategy for preparing CuO-supported CuCeOx catalysts (CuCeOx/CuO) by calcination of a hydrotalcite precursor [Cu6Ce2(OH)16]CO3·nH2O. The structural and chemical properties of catalysts were characterized by XRD, ICP-AES, TEM, TPR, NH3-TPD, XPS, Raman spectroscopy, and N2 adsorption, which revealed that the thermal pretreatment in an oxidative atmosphere caused segregation and reconstitution processes of the precursor, resulting in a mesoporous catalyst consisting of well-dispersed CuO-supported CuCeOx clusters of 1.8-3.2 nm in size with a high population of oxygen vacancies. The as-prepared catalyst shows excellent catalytic performance in the reduction of NO by CO in the absence as well as in the presence of water and oxygen. This behavior is attributed to its high oxygen defect concentration facilitating the interplay of the redox equilibria between Cu2+ and reduced copper species (Cu+/Cu0) and (Ce4+/Ce3+). The high surface population of oxygen vacancies and in situ-generated metallic copper species have been evidenced by Raman spectroscopy and X-ray photoelectron spectroscopy. The layered double hydroxide-derived CuCeOx/CuO also showed good water tolerance and long-term stability. In situ infrared spectroscopy investigations indicated that adsorbed hyponitrite species are the main reaction intermediates of the NO conversion as also corroborated by theoretical simulations.

Selective catalytic reduction of nitric oxide with a novel Mn–Ti–Ce oxide core-shell catalyst having improved low-temperature activity and water tolerance

A novel core-shell-shell Mn–Ti–Ce oxide catalyst (MnOx@TiO2@CeO2) was synthesized by a three-step method and applied for the selective catalytic reduction of NOx with ammonia (NH3-SCR). The catalyst exhibited an excellent low-temperature activity with NOx conversion >80% in a broad temperature range under both dry (120–260 °C) and wet (180–255 °C) conditions with a weight hourly space velocity (WHSV) of 240,000 mL/(g·h). Nitrogen physisorption and X-ray photoelectron spectroscopy (XPS) results showed that the formation of the inner TiO2 shell significantly increased the specific surface area, surface Mn4+/Mn ratio and chemisorbed oxygen, which could provide more active sites and promote the oxidation of NO to NO2. Ammonia temperature-programmed desorption (NH3-TPD) results indicated that the formation of the outer CeO2 shell not only extensively increased the surface acid sites but also enhanced the acid strength, beneficial for the ammonia adsorption and resulting in a good water tolerance.

Effects of saline immersion on the physiological alterations of grass goldfish (Carassius auratus) during subsequent recovery in freshwater

The present work aims to evaluate the tolerance, osmoregulation, metabolism, and antioxidant ability of saline water immersed grass goldfish (Carassius auratus) during the recovery in freshwater. Grass goldfish (38.15 ± 5.48g) acclimated in freshwater were immersed by salinities (0‰, 20‰ and 30‰) for different time durations (10, 20, 30 and 60 min); and the physiological responses were measured during freshwater recovery. The blood osmolalities were not significantly different at any group fish, while whereas the decline of Na+ concentration and the ratio of Na+/Cl- as well as the rise of Cl- concentration was observed in saline treated fish. Soon after freshwater recovery, the transcription of NKA-α and NKA-β mRNA in gills of salinity 20 immersed fish elevated significantly and then decreased, whereas no obvious changes were detected in salinity 30 treated fish. Till 24h post freshwater recovery, gill Na+/K+-ATPase activities in saline treated fish were lower than control group except for the fish immersed by salinity 20 for 10-30 min. At 24h of recovery, cortisol levels in salinity 20 immersed fish were lower than salinity 30 treated fish, but remained higher than control. As for serum lactic acid, fish treated by salinity 20 for 10 or 20 min did not show any fluctuation. However, higher lactic acid contents were detected in all other five salinity treated groups during recovery. Generally, at 24 h of recovery, salinity 20 treated fish exhibited higher SOD and CAT activities than fish immersed by salinity 30. In summary, grass goldfish could survive by immersion in salinity 20 less than 60 min or salinity 30 less than 30min, even though immersion by salinity 20 could minimize the negative effects.

Facile casting preparation of hydrophilic coordinated PVA–Zn ion coatings with strong adhesion and high water tolerance

Fogging on transparent surfaces may severely influence vision. Thus, antifogging coatings are in high demand. Poly vinyl alcohol (PVA) and zinc chloride were mixed to prepare hydrophilic coatings (denoted as PVA/Zn2+ coatings) on glass substrates using the casting method with contact angles <59°. The polymer-metal complex was formed by the coordination of ZnCl2 with the hydroxyl groups of PVA. The adhesion and water resistance of the coating were improved by adjusting the mole ratio of PVA to Zn2+. A 5B adhesion grade of the optimal mole ratio of PVA to Zn2+ was determined according to the standard of the American Society of Testing Materials D3359, and the lap shear strength was 2.39 ± 0.42 MPa. The coordination between OH and Zn2+ was evidenced by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. UV–vis spectra show that the coating has a high optical transmittance (>90 %). In addition, the coating was applied on four common hydrophobic substrate surfaces to obtain hydrophilic surfaces. The antifogging performance of the coating indicates its potential application to many materials such as in transparent optical devices.

Superior Selective CO2 Adsorption and Separation over N2 and CH4 of Porous Carbon Nitride Nanosheets: Insights from GCMC and DFT Simulations.

Development of high-performance materials for the capture and separation of CO2 from the gas mixture is significant to alleviate carbon emission and mitigate the greenhouse effect. In this work, a novel structure of C9N7 slit was developed to explore its CO2 adsorption capacity and selectivity using Grand Canonical Monte Carlo (GCMC) and Density Functional Theory (DFT) calculations. Among varying slit widths, C9N7 with the slit width of 0.7 nm exhibited remarkable CO2 uptake with superior CO2/N2 and CO2/CH4 selectivity. At 1 bar and 298 K, a maximum CO2 adsorption capacity can be obtained as high as 7.06 mmol/g, and the selectivity of CO2/N2 and CO2/CH4 was 41.43 and 18.67, respectively. In the presence of H2O, the CO2 uptake of C9N7 slit decreased slightly as the water content increased, showing better water tolerance. Furthermore, the underlying mechanism of highly selective CO2 adsorption and separation on the C9N7 surface was revealed. The closer the adsorption distance, the stronger the interaction energy between the gas molecule and the C9N7 surface. The strong interaction between the C9N7 nanosheet and the CO2 molecule contributes to its impressive CO2 uptake and selectivity performance, suggesting that the C9N7 slit could be a promising candidate for CO2 capture and separation.

Heat Treatment Improves the Activity and Water Tolerance of Pt/Al2O3 Catalysts in Ammonia Catalytic Oxidation.

Ammonia selective catalytic oxidation (NH3-SCO) is a commercial technology applied to diesel vehicles to eliminate ammonia leakage. In this study, a series of Pt/Al2O3 catalysts were synthesized by an impregnation method, and the state of Pt species was carefully adjusted by heat treatment. These Pt/Al2O3 catalysts were further systematically characterized by Brunauer-Emmett-Teller, X-ray diffraction, X-ray photoelectron spectroscopy, X-ray absorption fine structure, UV-vis, H2-tempertaure-programmed reduction, and NH3-temperature-programmed desorption. The characterization results showed that dispersed oxidized Pt species were present on conventional Pt/Al2O3 samples, while high-temperature treatment induced the aggregation of platinum species to form metallic Pt nanoparticles. The Pt/Al2O3 catalysts treated at high temperatures showed superior activity and water tolerance in the NH3-SCO reaction. Diffuse reflectance infrared Fourier-transform spectroscopy combined with mass spectrometry experiments revealed that the Lewis acid sites were more reactive than the Brønsted acid sites. Moreover, compared to oxidized Pt species, metallic Pt nanoparticles were beneficial for oxygen activation and were less affected by water vapor, thus contributing to the superior activity and water tolerance of Pt/Al-800.

Gossypium purpurascens genome provides insight into the origin and domestication of upland cotton

IntroductionAllotetraploid upland cotton (Gossypium hirsutum L.) is native to the Mesoamerican and Caribbean regions, had been improved in the southern United States by the mid-eighteenth century, was then dispersed worldwide. However, a Hainan Island Native Cotton (HIC) has long been grown extensively on Hainan Island, China. ObjectivesExplore HIC’s evolutionary relationship and genomic diversity with other tetraploid cottons, its origin and whether it was used for YAZHOUBU (Yazhou cloth, World Intangible Cultural Heritage) weaving, and the role of structural variations (SVs) in upland cotton domestication. MethodsWe assembled a high-quality genome of one HIC plant. We performed phylogenetic analysis, divergence time estimation, principal component analysis and population differentiation estimation using cotton assemblies and/or resequencing data. SVs were detected by whole-genome comparison. A F2 population was used for linkage analysis and to study effects of SVs. Buoyancy and salt water tolerance tests for seeds were conducted. ResultsWe found that the HIC belongs to G. purpurascens. G. purpurascens is best classified as a primitive race of G. hirsutum. The potential for long range transoceanic dispersal of G. purpurascens seeds was proved. A set of SVs, selective sweep regions between G. hirsutum races and cultivars, and quantitative trait loci (QTLs) of eleven agronomic traits were obtained. SVs, especially large-scale SVs, were found to have important effects on cotton domestication and improvement. Of them, eight large-scale inversions strongly associated with yield and fiber quality have probably undergone artificial selection in domestication. ConclusionG. purpurascens including HIC is a primitive race of G. hirsutum, probably disperse to Hainan from Central America by floating on ocean currents, may have been partly domesticated, planted and was likely used for YAZHOUBU weaving in Hainan much earlier than the Pre-Columbian period. SV plays an important role in cotton domestication and improvement.

Phosphaphenanthrene-modified zirconium phosphate nanosheets for improving fire resistance, smoke suppression and water tolerance of intumescent coatings

Phosphaphenanthrene-modified zirconium phosphate nanosheets for improving fire resistance, smoke suppression and water tolerance of intumescent coatings

Synthesis, Structure and Light‐Driven H2 Production of a {Ti21} Titanium‐Oxo Cluster Featuring Pentagonal {Ti(Ti5)} Motifs

AbstractPentagonal {Ti(Ti5)} motifs play a crucial role during the assembly of novel titanium‐oxide clusters (TOCs), whose development is still in its infancy. In this work, an unprecedented TOC [(CH3)2NH2]2[Ti21O29(OiPr)12(DMF)6(SO4)8] ({Ti21}) based on {Ti(Ti5)} motifs had been obtained under hydrothermal conditions. It possesses ‘fused’ dimeric {Ti11} as well as trimeric {Ti12} subunits featuring unexpected bonding modes based on pentagonal {Ti(Ti5)} motifs. Furthermore, {Ti21} exhibits good water and solvent tolerance. As an atomically precise TOCs‐based semiconductor photocatalyst, {Ti21} exhibits appreciable photocatalytic hydrogen evolution activity with an optimal hydrogen generation rate of 191.94 μmol/g/h under UV/Vis light. This work provides significant advances and favorable models for the further synthesis of TOCs with unique structure and functionality.

Unveiling geometric and electronic effects of Pt species on water-tolerant Pt/ZSM-5 catalyst for propane oxidation

Si/Al ratio of ZSM-5 affecting Pt/ZSM-5 catalyst water-tolerance has been investigated for propane oxidation. Under wet condition (5 % H2O), it is found that Pt/ZSM-5 (18) catalyst contains both irreversible and reversible deactivation Pt active sites; Pt/ZSM-5 (130) and Pt/ZSM-5 (500) catalysts have only reversible deactivation Pt active sites; all the Pt active sites in the Pt/ZSM-5 (1200) catalyst are water tolerant. It is further found that the Si/Al ratio of ZSM-5 determines the geometrical and electronic states of Pt particles, and amount of surface acid sites on catalysts, thereby affecting the water tolerance of Pt/ZSM-5 catalyst. Low Si/Al ratio of ZSM-5 benefits to anchor the Pt species and form small Pt particles, but Pt particle with small size and more oxidized state Pt species (Ptδ+) on Pt/ZSM-5 (18) is easily poisoned by H2O. More Pt0 species generating on large Pt particle during propane oxidation reaction and low surface acid sites on Pt/ZSM-5 (1200) catalyst are responsible for its high water tolerance.

Morphology effects in MnCeOx solid solution-catalyzed NO reduction with CO: Active sites, water tolerance, and reaction pathway

Morphology effects in MnCeOx solid solution-catalyzed NO reduction with CO: Active sites, water tolerance, and reaction pathway