Dispersed Structure Research Articles

Adsorption Properties of Natural Zeolite Supported by Chitosan on Cd(II) in Micropolluted Irrigation Water.

This study utilized a 1% chitosan solution (dissolved in 2% acetic acid), with a chitosan-to-zeolite mass ratio of 0.005, to successfully prepare chitosan-loaded natural zeolite. The performance of chitosan-modified natural zeolite in the removal of low-concentration cadmium ions in the presence of micropollutants was investigated. The adsorbent was characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM)/energy-dispersive spectroscopy (EDS) techniques. The impact of modified adsorbent dosage, pH value, contact time, temperature, and initial concentration on adsorption performance was discussed. Additionally, the adsorption kinetics, isotherms, and thermodynamics of cadmium on chitosan-modified zeolites were analyzed. The results indicated that the modified zeolite exhibited a dispersed and porous structure with increased surface area, average pore size, and total pore volume. Under the conditions of 25 °C, pH 6, a dosage of 8 g/L, and a 60 min adsorption reaction time, chitosan-loaded natural zeolite (CNZ) achieved a removal efficiency of over 94.51% for a 100 μg/L cadmium solution (in a 100 mL volume). The adsorption process followed the Langmuir model, suggesting monolayer adsorption. The adsorption kinetics followed a pseudo-second-order equation, indicating an exothermic process with an increase in entropy. Chitosan-loaded natural zeolite demonstrated improved adsorption capacity and effectively removed cadmium from water contaminated with micropollutants.

Occurrence of the pugnose pipefish Bryx dunckeri in the Sargasso Sea.

Juvenile specimens of the pugnose pipefish, Bryx dunckeri, were collected during a multipurpose research survey conducted within the Sargasso Sea Subtropical Convergence Zone, extending the known distribution range of this species to include open ocean areas of the Western North Atlantic. Novel spatial data are of scientific interest as information on the distribution, population structure, and population size of this species is limited. Additionally, we present detailed photographs and morphological data on the collected specimens. The results are discussed in relation to the dispersal abilities and population structure in syngnathids.

Influence of Ethanol Decomposition on Dispersion of PEFC Catalyst Ink

To achieve high power density operation of polymer electrolyte fuel cells (PEFCs), it is required to realize high-performance catalyst layer with low oxygen transport resistance, high proton and electron conductivities, and high electrochemical surface area (ECSA) with low Platinum loading. Because dispersion structure of catalyst ink strongly affects porous structure of the catalyst layer, it is crucial for realization of high-performance catalyst layer to understand the dispersion mechanism of the catalyst ink. Our group has reported that decomposition of ethanol, as a solvent, by platinum catalyst significantly affects aggregation of the catalyst ink. [1, 2] But, the mechanism of the catalyst ink aggregation was not fully understood. In this study, effect of ethanol decomposition on the aggregation of the catalyst ink was investigated.The catalyst ink was fabricated by mixing platinum-supported carbon (TEC10V30E, Tanaka Kikinzoku), ionomer (DE1021, Sigma-Aldrich), and water/ethanol solvent (water/ethanol: 60/40 wt%). Decomposition product of ethanol within the catalyst ink solvent was analyzed by GC/MS (GCMS-QP2020NX, SHIMADZU), and presence of acetaldehyde (C2H4O) and acetic acid (CH3COOH) was detected. In order to investigate the influence of these products on aggregation of the catalyst ink, acetaldehyde or acetic acid was added to the catalyst ink. The particle size distribution was evaluated by using laser diffraction type particle size distribution meter (LA-960V2, HORIBA) without dilution, and it was confirmed that the acetaldehyde-added catalyst ink showed larger particle size and the acetaldehyde caused the aggregation of the catalyst ink (Figure 1). In addition, dispersion of the catalyst ink was observed by using an optical microscopy, and aggregation of the catalyst ink by adding the acetaldehyde was clearly observed (Figure 2). To understand the aggregation mechanism by adding acetaldehyde, ionomer adsorption fraction on the platinum-supported carbon was measured by using centrifugation method, and the decrease in ionomer adsorption fraction by adding acetaldehyde was confirmed. From these results, it was confirmed that acetaldehyde generated by the decomposition of ethanol in the catalyst ink leads to a decrease in the ionomer adsorption fraction. It is reported that the ionomer promotes the dispersion of platinum-supported carbon due to electrostatic repulsion forces, and it is suggested that the decrease in ionomer adsorption fraction results in the aggregation of the catalyst ink. Therefore, to realize high-performance catalyst layer, influence of acetaldehyde should be minimized and further research is requested to understand it. Acknowledgement This presentation is based on results obtained from a project commissioned by the New Energy and Industrial Technology Development Organization (NEDO).

Structured polymer dispersant for efficient phthalocyanine blue dispersion and color paste preparation

AbstractTo overcome challenges in pigment dispersion, especially for difficult‐to‐disperse pigments like phthalocyanine blue, the structure of dispersants has been studied in recent years. Herein, we present the development and performance evaluation of a structured polymer dispersant for efficient dispersion of phthalocyanine blue and color paste preparation. The dispersant was synthesized using a two‐step free radical polymerization process, allowing precise control over its structure. The study investigates the impact of key factors on dispersion, including the molecular weight of the hydrophilic long‐chain poly(ethylene glycol) monomethyl ether (MPEG), the ratio of anchoring groups styrene (St) and dimethylaminoethyl methacrylate (DMAEMA), and the dispersant dosage. Optimal stability was achieved with MPEG‐400 as the hydrophilic long chain and a St:DMAEMA ratio of 1:1, along with a MPEG‐400AA:AA ratio of 0.5:1 at 2000 r min−1. At a dispersant dosage of 25%, the particle size of the color paste measured 340 nm, with viscosity reaching 600 mPa·s. The structured dispersant effectively synergized spatial potential resistance and electrostatic effects to achieve stable pigment dispersion. These findings offer promising prospects for advancing dispersant technologies, with implications for improving color‐based applications across various industries, such as paints, coatings, and inks.

Corporate name change: the effect of the firm’s shareholder distribution

ABSTRACT This study explores the effect of corporate ownership structure on firm performance resulting from a firm’s strategic decision of corporate name change. First, the study uses the separation of ownership and control to capture the corporate ownership structure using a new shareholder distribution metric. Second, the study empirically estimates the main and interaction effects of shareholder distribution on a firm’s performance resulting from its corporate name change using data from the Australian Securities Exchange from 2017 to 2022, during which 457 unique firms changed their corporate names. The study finds shareholding distribution has contrasting effects on firm performance due to the corporate name change. The positive impact of shareholder distribution on a firm’s abnormal returns is attenuated due to the corporate name change. Thus, while a manager-controlled firm, characterized by its larger shareholder distribution, reaps more benefits, such benefits are reduced when it makes strategic decisions, such as corporate name change. The study attributes such reduction in firm benefit to owner-manager conflict emanating from a firm’s dispersed corporate ownership structure.

Specific Hydrogen Spillover Pathways Generated on Graphene Oxide Enabling the Formation of Non-Equilibrium Alloy Nanoparticles.

The phenomenon of hydrogen spillover is investigated as a means of realizing a hydrogen-based society for over half a century. Herein, a graphene oxide having a precisely tuned architecture via calcination in air to introduce ether groups onto basal planes along with carbon defects is reported. This material provides specific pathways for the spillover of atomic hydrogen and has practical applications with regard to the synthesis of non-equilibrium solid-solution alloy nanoparticles. A combination of experimental work and simulations confirmed that the presence of ether groups associated with carbon defects facilitated hydrogen spillover within the basal planes of this graphene oxide. This enhanced hydrogen spillover ability, in turn, enables the simultaneous reduction of Ru3+ and Ni2+ ions to form RuNi alloy nanoparticles under hydrogen reduction conditions. Energy dispersive X-ray and X-ray absorption near edge structure simulations establish that this strategy forms unique alloy nanoparticles each comprising a Ru core with a RuNi solid-solution shell having a hexagonal close-packed structure. These non-equilibrium RuNi alloy nanoparticles exhibit greater catalytic activity than monometallic Ru nanoparticles during the hydrolysis of ammonia borane.

The Role of Carbides in Forming the Steels Structure and Properties under Pulsed Laser Irradiation

Introduction. At present, in scientific publications, there is no unambiguous understanding and reasoned metal physical justification of the role of the carbide phase of irradiated materials in forming the required structure and achieving a given degree of hardening of surface layers of steels during pulsed laser treatment, especially in the zone of laser hardening from a solid (austenitic) state. The solution to this issue is of great importance, since it allows us to reasonably and purposefully design the required structure of surface layers of products of various functional purposes with high performance properties. The complexity and insufficiently detailed study of the process of structure formation in the surface layers of steels under extreme thermal effects of pulsed laser radiation required a series of metal physical experiments to study the fine structure of steels after high-speed high-temperature hardening. The aim of this article was to obtain, quantify and critically analyze the array of results of metal physical studies and to assess the degree of influence of the carbide phase on the formation of structure and properties of surface layers of steels in the process of pulsed laser hardening in different modes, that is, with and without melting the surface of the samples. Materials and Methods. In the work, carbon and alloyed tool steels were subjected to surface laser irradiation at a Kvant 16 installation. The radiation power density was 70–200 MW/m2. Optical, scanning probe and electron microscopy were used in conducting metal physical studies, as well as methods of diffractometric, spectral and durometric analysis of steels before and after laser treatment. Results. It was shown that laser treatment of steels with a radiation power density of 130–200 MW/m2 led to a local change in the chemical composition in the laser-fused areas of the spot, partial or complete dissolution of carbides present in the irradiated metal and an increase in the amount of residual austenite in the fused areas up to 40–60 %. It was found that on P6M5 steel, the maximum possible hardness of the irradiated zones was achieved by dissolving 30 % of carbides, on 9XC, HVG steels — 60–70 %. It was shown that under pulsed laser irradiation with q=70–125 MW/m2, that is, without melting the steel surface, "white zones" formed around carbide inclusions under the influence of thermo-deformation stresses at the boundaries of the "carbide – steel matrix" composition. They had irretrievability, dispersion of the structure and increased hardness (10–12 GPa). It was determined that the maximum hardness of laser-hardened metal in the zones of laser hardening from a solid state was achieved if the "white zones" occupied 40 % of the irradiated area of steel. It was found that the dispersion of carbides in this case was 0.5–1.5 microns. Discussion and Conclusion. The results of the conducted studies indicate that in order to obtain the best combination of hardness and viscosity of the irradiated zones during laser treatment with melting of the surface of steels of different chemical composition, it is necessary to dissolve different amounts of carbides. The dispersed structure of laser-fused steel zones, along with a sufficiently high content of residual austenite, predetermine the possibility of improving the operational characteristics of irradiated materials, especially under conditions of external shock loads. The analysis of the conducted metal physical studies irradiated without melting the surface of steels allows us to conclude that in order to obtain a high degree of hardening, it is necessary and expedient to ensure the presence of a certain volume of dispersed carbides in the structure of the irradiated steel. The structural composition of "white zones" formed during laser treatment without melting the steel surface contributes to obtaining a unique level of operational properties. The results of the performed studies contribute to the theory of steel structure formation under conditions of extreme heat exposure and allow for a rational choice of modes of surface laser processing of products and their operability.

Inverse design of polymorphic Dirac-like cone dispersion relationship in photonic crystals

Dirac-like cone linear dispersion relations in photonic crystals (PhCs) often endow them with unique properties, yet searching for such relations can be challenging. We introduce a generalized inverse design system that, given the dielectric constants and lattice of two-dimensional PhCs, can efficiently determine its structural parameters to obtain its Dirac-like cone dispersion. Employing this inverse design strategy, we design three types of Dirac cone PhCs, including triple degenerate, quadruple degenerate, and triple degenerate under dual polarization with the same frequency. Further investigations reveal a systematic relationship between the radius of the dielectric rods in these PhCs and their corresponding Dirac frequencies across varying dielectric constants. The zero refractive index characteristic is validated in two of the three PhCs studied, as confirmed through numerical simulations. Additionally, by leveraging our proposed inverse design method, we introduce an innovative shell dielectric rod model, which encapsulates a dielectric material, achieving a quadruple degenerate dispersion structure with dual Dirac cones. This research provides a potent tool for the inverse design of PhCs and expands its application in Dirac cone dispersion design.

Enhanced strength-ductility synergy of Al/Zn/Al laminated composite with unique interface and multi-modal heterogeneous microstructure

Laminated bimetal composites have become an important strategy for designing and manufacturing desirable metallic components. Here, Al/Zn/Al laminated composite was fabricated by porthole die co-extrusion (PDCE) process, offering excellent mechanical performance. An obvious transition zone with a dispersed duplex structure (α and η phases) instead of intermetallic compounds was formed in Al/Zn interface due to element inter-diffusion and eutectoid transformation. The α/η phase interface showed a 3D characteristic with compositional and structural gradients. Moreover, Al/Zn/Al composite displayed a multi-modal heterogenous structure including the typical macroscopic hierarchical structure by alternately stacking Al and Zn layers with different microstructures, the gradient structure from Al/Zn interface to the center of Al or Zn layer, and the bimodal structure formed either near Al/Zn interface or in the layer center. As a result, Al/Zn/Al composite exhibits superior mechanical performance compared with the individual component (Al or Zn) and a satisfactory balance between strength and ductility.

A Study of the Structure and Thermodynamic Properties of Polyvinyl Acetate Dispersion after Microwave Electromagnetic Treatment

A Study of the Structure and Thermodynamic Properties of Polyvinyl Acetate Dispersion after Microwave Electromagnetic Treatment

NiCo2S4 Nanoflowers for Exceptional Electrochemical Supercapacitor Energy Storage Performances

The increasing demand for efficient and high-performance energy storage systems has prompted extensive research into advanced materials for electrochemical supercapacitors. Among these materials, NiCo2S4 nanoflowers have emerged as promising candidates, demonstrating remarkable electrochemical properties. A simple solvothermal method was employed to prepare NiCo2S4 nanoflowers with excellent morphology, showcasing a well-organized, dispersed, and well-developed structure. Purity, high crystal structure, and oxidation state were confirmed through XRD and XPS analyses, respectively. SEM analysis validated the morphology of both nanoflowers and nanoarrays, revealing a uniform and well-developed structure. The unique morphology plays a vital role in achieving excellent capacitance by providing a high surface area, maximizing the involvement of active metals, and reducing diffusion kinetics. The nanoflowers exhibited an outstanding capacitance of 877 F g−1, at a current density of 2 A g−1. Leveraging the synergistic chemistry of Ni and Co, the material not only demonstrated outstanding capacitance but also exhibited excellent stability of more than 91%, even after 5000 cycles. NiCo2S4 nanoflowers demonstrated an excellent energy density of 22 WhKg−1 and power density of 158 WKg−1. The excellent performances of NCS nanoflowers recommend it as a favorable pseudocapacitive nanomaterials for excellent energy storage applications.

Preparation of Pt/CNT catalyst with high dispersion structure via plasma jet

A plasma jet (a high temperature jet formed by blowing a free arc through high pressure air) method based on free arc was carried out to disperse carbon nanotubes (CNTs) in gas phase while generating Pt nanoparticles (Pt-NPs) on them at the same time. The plasma jet is generated through the discharge between the cathode composed of CNTs, PtCl4 and DI water and the anode with a hole. Plasma jet prepares the Pt/CNT catalyst by directly spraying. The CNT carrier in the catalyst have good dispersion by SEM images. The mean size of Pt-NPs estimated by TEM images is 3.41 nm with the plasma jet method and about 4.77 nm with the commercial Pt/C respectively. It was showed that the bulk of Pt-NPs produced by plasma jet is in metal state in the analysis of XPS measurements. Compared with Pt/C, Pt/CNT have roughly equal catalytic activity and higher durability by cyclic voltammetry measurements. Based on these properties, the plasma injection method solves the problems of carrier dispersion and metal particle preparation at the same time, which greatly simplifies the catalyst preparation process.

Genetic Connectivity of Roundjaw Bonefish Albula glossodonta (Elopomorpha, Albulidae) in the Central Pacific Ocean Resolved through ddRAD-Based Population Genomics

Bonefishes are a nearshore species targeted by non-commercial anglers and subsistence fishers in the Central and South Pacific islands. Among the bonefish species in the Indo-Pacific region, Albula glossodonta are known to have one of the widest geographic ranges, from the Red Sea to the Central Pacific, but it is unknown how dispersive A. glossodonta are between geographically isolated islands. Volunteer anglers collected A. glossodonta fin clips from the main Hawaiian Islands in the North Pacific, Anaa Atoll in the South Pacific, and intermediate Kiritimati Island (Line Islands) to assess the scale of dispersal and population structure within the Pacific Ocean. Population genomics was conducted based on 208 individuals and 7225 SNPs. Although adult A. glossodonta exhibit strong site fidelity, genomic results show no population differentiation between Oahu and Maui in Hawai‘i. Bonefishes exhibit significant population structure between Anaa and Hawai‘i (FST = 0.096), with intermediate Kiritimati comprising admixed fishes. A lengthy larval duration likely promotes connectivity between Pacific islands. Regional management regimes may be most appropriate for a species with this level of dispersal.

Scientific approaches to the creation of technology structured milk desserts with a combined composition of raw materials

One of the promising areas of the dairy industry is the production of combined products. Its essence consists in the directed regulation of the constituent components of products in order to improve their composition and properties. Today, dairy desserts are one of the most popular products on the domestic market. In order to expand the range of dairy desserts, improve their structure and quality, increase the nutritional value and reduce the calorie content, it is rational to use non-traditional raw materials that contain the necessary functional ingredients. To obtain dairy desserts with a certain structure, it is necessary to use the appropriate components of animal and plant origin. For example, milk powder, milk and whey concentrates, condensed milk products, hydrocolloids (food fibers, starch, gelatin, cellulose derivatives, gums, etc.). Justification of the use of the above-mentioned components during the development of the technology of dairy desserts with a combined composition of raw materials is an actual direction of scientific research. The purpose of the work was to develop a scientifically based model for combining protein and carbohydrate components in the composition of dairy desserts with gel-like and complex dispersed structures and to create pudding and cream technology. The article presents a developed model of combining protein and carbohydrate components in structured dairy desserts. Based on the model of combining carbohydrate and protein components in dairy desserts, we have developed cream and pudding technologies based on buttermilk or retentate. In order to obtain dairy desserts with aggregative stability, it is necessary to carry out thermomechanical processing at a temperature of 80–85 °C with constant mixing and agitator revolutions of 2800 rpm, followed by packaging without cooling. The organoleptic and physico-chemical parameters of the produced samples of dairy desserts were studied. It was established that dairy desserts have the maximum moisture retention capacity – 100%, their sugar and fat content is 43–52% and 33–47% lower, respectively, and the protein content is 3–5 times higher than in traditional types of desserts. It has been proven that on the basis of the developed and scientifically based model of combining protein and carbohydrate components, low-calorie structured dairy desserts with high protein content, low fat and sugar content and appropriate quality indicators were obtained. Key words: dairy desserts, creams, puddings, combined composition of raw materials, technology, structure, secondary dairy raw materials, whey proteins, hydrocolloids.

Modeling the structure and thermodynamics of multicomponent and polydisperse hard-sphere dispersions with continuous potentials.

A model system of identical particles interacting via a hard-sphere potential is essential in condensed matter physics; it helps to understand in and out of equilibrium phenomena in complex fluids, such as colloidal dispersions. Yet, most of the fixed time-step algorithms to study the transport properties of those systems have drawbacks due to the mathematical nature of the interparticle potential. Because of this, mapping a hard-sphere potential onto a soft potential has been recently proposed [Báez et al., J. Chem. Phys. 149, 164907 (2018)]. More specifically, using the second virial coefficient criterion, one can set a route to estimate the parameters of the soft potential that accurately reproduces the thermodynamic properties of a monocomponent hard-sphere system. However, real colloidal dispersions are multicomponent or polydisperse, making it important to find an efficient way to extend the potential model for dealing with such kind of many-body systems. In this paper, we report on the extension and applicability of the second virial coefficient criterion to build a description that correctly captures the phenomenology of both multicomponent and polydisperse hard-sphere dispersions. To assess the accuracy of the continuous potentials, we compare the structure of soft polydisperse systems with their hard-core counterpart. We also contrast the structural and thermodynamic properties of soft binary mixtures with those obtained through mean-field approximations and the Ornstein-Zernike equation for the two-component hard-sphere dispersion.

Evidence of residual micellar structures in a lipid nanocapsule dispersion. A multi-technique approach

Nanoemulsions are metastable emulsions in the nanometric range which can be obtained using low-energy processes. A decade ago, it was demonstrated that a non-negligible amount of residual surfactant micelles may coexist with the oil nanodroplets in a model oil/surfactant system. Those micelles were called “wasted” micelles as they did not participate in the formation of the nanodroplets. Little attention has been focused on the potential presence or effect of such secondary structures in nanoemulsions used as drug delivery systems. Here, we present an extensive characterization of lipid nanocapsules, a nanoemulsion obtained from a medium-chain triglyceride mixed with a pegylated surfactant by a process comprising a temperature-dependent phase inversion followed by a cold-water quench. Lipid nanocapsules demonstrate a very good shelf stability. First, for clarity and academic purposes, we briefly present the pros and the cons of the various diffusion-based characterization techniques used i.e., multi-angle and single-angle dynamic light scattering, nanoparticle tracking analysis, fluorescence recovery after photobleaching, and diffusometry nuclear magnetic resonance. Then, combining all these techniques, we show that up to 40 wt% of the surfactant is not involved in the lipid nanocapsule construction but forms residual micellar structures. Those micelles also contain a small quantity of medium-chain triglyceride (2 wt% of the initial amount) and encapsulate around 40 wt% of a fluorescent dye originally dispersed in the oily phase.

Influence of organic and inorganic fillers on the photoaging behavior of polyolefins

The use of fillers has become a common approach of improving the performance of polymer composites. In this study, the photooxidation activity and radiation absorption phenomena of silica, cellulose and carbon black, which differ in morphology (shape, particle size), structure, coloration and degree of dispersion, were investigated. Ethylene-norbornene copolymer was selected as the polymer matrix because it is an ideal transparent medium for studying aging processes. Samples were subjected to accelerated UV (340 nm) and solar (315–1400 nm) aging tests in special chambers for 300, 500, 700 and 900 h. The obtained results demonstrated that composite filled with carbon black exhibited the highest photostability and retained its functional properties; after 900 h of exposure to radiation, its aging factor value was still close to 1. It was observed that carbon black limits the penetration of radiation by absorbing it. Moreover, its role against photooxidation can be considered in terms of antioxidant activity, probably through the catalytic decomposition of peroxides and reaction with free radicals. Completely different aging behavior was noted for composites containing silica and cellulose, which lost their performance properties. This could be related to their weaker dispersion in the polymer matrix and greater susceptibility to the oxidation process, which was confirmed by FTIR analysis.

Desynchrony induced by higher-order interactions in triplex metapopulations.

In a predator-prey metapopulation, two traits are adversely related: synchronization and persistence. A decrease in synchrony apparently leads to an increase in persistence and, therefore, necessitates the study of desynchrony in a metapopulation. In this article, we study predator-prey patches that communicate with one another while being interconnected through distinct dispersal structures in the layers of a three-layer multiplex network. We investigate the synchronization phenomenon among the patches of the outer layers by introducing higher-order interactions (specifically three-body interactions) in the middle layer. We observe a decrease in the synchronous behavior or, alternatively, an increase in desynchrony due to the inclusion of group interactions among the patches of the middle layer. The advancement of desynchrony becomes more prominent with increasing strength and numbers of three-way interactions in the middle layer. We analytically validate our numerical results by performing a stability analysis of the referred synchronous solution using the master stability function approach. Additionally, we verify our findings by taking into account two distinct predator-prey models and dispersal topologies, which ultimately supports that the findings are generalizable across various models and dispersal structures.

A simplified and efficient preparation process of pineapple leaf fibers via in-situ retting and degumming by Bacillus subtilis XW-18

Pineapple leaves are agricultural waste but rich in the pineapple leaf fiber (PALF) with superior mechanical properties. The conventional PALF preparation usually include two steps of manual/mechanical extraction and chemical degumming, resulting in adverse issues such as fiber loss, inferior fiber quality, and environmental pollution. In the present study, a simplified and efficient preparation process of PALF, without any pretreatment and subsequent bleaching, was successfully achieved through in-situ inoculation of Bacillus subtilis XW-18 to fresh pineapple leaves. Results showed that B. subtilis XW-18 was rich in the diversified degumming-related enzymes, which could exert an direct retting and degumming action on the fresh pineapple leaves by simultaneously secreting high-activity pectinase, mannanase, and xylanase but low-activity cellulase. Due to the ideal combination of degumming-related enzymes in B. subtilis XW-18, the prepared PALF reached 2.29% of fiber yield and 3.50% of residual gum content, displaying a dispersed fibrous structure and white appearance. Structural characterizations and chemical compositions of PALF further confirmed that B. subtilis XW-18 had an effective action on removal of the non-cellulosic macromolecules such as gummy substances, hemicelluloses, and lignin, thus acquiring a high cellulose content up to 79.36 wt%. Furthermore, the method using in-situ inoculation of B. subtilis XW-18 achieved the prepared PALF with ideal physical and mechanical properties. In summary, B. subtilis XW-18 offered a promising alternative option for the green and efficient preparation of PALF, not only due to its one-step process for PALF preparation, but also due to its ideal combination of the degumming-related enzymes.

Mesoporous Layered Double Hydroxides: Synthesis for High Effective Uranium Ions Sorption from Seawater and Salt Solutions on Nanocomposite Functional Materials

A series of sorption materials based on layered double hydroxides (Co-Fe LDH, Ni-Fe LDH, and Zn-Ti LDH) were obtained by a facile and environmentally friendly method of coprecipitation. A low particle size of no more than 10 µm was achieved. The use of transition metals makes it possible to obtain compounds that are mechanically and chemically stable in aggressive environments. XRD analysis revealed that the compounds have a highly organized crystalline structure. Using SEM, it was determined that Co-Fe LDH and Ni-Fe LDH had a loose, highly dispersed surface structure, while Zn-Ti LDH had a monolithic surface structure. U(VI) adsorption on the obtained materials in solutions containing Na2CO3, Na2SO4, KNO3, NaCl, K3PO4, and NaHCO3, was studied in batch mode. The degree of purification in the presence of these salts reached 99.9%, while the distribution coefficient Kd reached 105 mL/g. Sorption capacity qmax and equilibrium adsorption constants Kf and KL for U(VI) adsorption in batch mode (for 24 h) from distilled and seawater were determined using the Freundlich and Langmuir equations. The highest sorption capacity of 101.6 mg/g in seawater and 114.1 mg/g in distilled water was registered for Co-Fe-LDH. The presence of competing ions in seawater can reduce sorption efficiency by up to 40%. The provided research allowed us to conclude that the obtained materials, Co-Fe LDH, Ni-Fe LDH, and Zn-Ti LDH are promising for the sorption removal of U(VI) from aqueous media of medium salinity.