Surface Modification Of Particles Research Articles

Extraction and Characterization of Cellulose from Coffee Husk and Brewery’s Spent Grain Fibers Using Alkali-Hydrogen Peroxide Treatment Method

Coffee husk (CH) and brewery spent grain (BSG) fibers are sustainable industrial residues that consist of cellulose. The present study aimed at the extraction of cellulose from CH and BSG fibers and to study the effect of alkali-hydrogen peroxide (5% NaOH–7% H2O2) treatment during the extraction by characterizing the extracted cellulose. Characterization of cellulose particles, such as crystallinity, functional groups, thermal properties, and morphology, was conducted by performing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyzer (TGA), and scanning electron microscopy (SEM), respectively. The finding shows that the maximum cellulose yields obtained from CH and BSG fibers are 37.3% and 26.5%, respectively. From the XRD results, the cellulose obtained from CH fiber (C-CH) and from BSG fiber (C-BSG) showed diffractive peaks with the highest intensity of approximately 1,003 and 1,236 counted at 2θ = 22°, respectively. A reduction in the absorption of peaks was observed on the FTIR spectrum for both C-BSG and C-CH samples at different wavelengths. SEM demonstrated that the surface roughness of the celluloses was enhanced. TGA showed that the maximum temperature decomposition observed for both C-CH and C-BSG is 360°C and 380°C, respectively. Generally, in this study, alkali-hydrogen peroxide (5% NaOH–7% H2O2) treatment was effectively used for the treatment of BSG and CH fibers for the extraction and surface modification of cellulose particles. The extracted cellulose in the present study can be used as an alternative to conventional cellulose for the manufacturing of biocomposite materials, preparation of particle boards and furniture, and production of food packaging materials.

Nano-ZnO modified hydroxyapatite whiskers with enhanced osteoinductivity for bone defect repair

Abstract Hydroxyapatite (HA) whisker (HAw) represents a distinct form of HA characterized by its high aspect ratio, offering significant potential for enhancing the mechanical properties of bone tissue engineering scaffolds. However, the limited osteoinductivity of HAw hampers its widespread application. In this investigation, we observed HAw punctured osteoblast membranes and infiltrated the cell body, resulting in mechanical damage to cells that adversely impacted osteoblast proliferation and differentiation. To address this challenge, we developed nano-zinc oxide particle-modified HAw (nano-ZnO/HAw). Acting as a reinforcing and toughening agent, nano-ZnO/HAw augmented the compressive strength and ductility of the matrix materials. At the same time, the surface modification with nano-ZnO particles improved osteoblast differentiation by reducing the mechanical damage from HAw to cells and releasing zinc ion, the two aspects collectively promoted the osteoinductivity of HAw. Encouragingly, the osteoinductive potential of 5%nano-ZnO/HAw and 10%nano-ZnO/HAw was validated in relevant rat models, demonstrating the efficacy of this approach in promoting new bone formation in vivo. Our findings underscore the role of nano-ZnO particle surface modification in enhancing the osteoinductivity of HAw from a physical standpoint, offering valuable insights into the development of bone substitutes with favorable osteoinductive properties while simultaneously bolstering matrix material strength and toughness.

Effects of surface modification of sucrose particles on chocolate morphology and fat bloom during storage

In this study, a new bloom-reducing approach, modifying the surface of crystalline sugar was introduced and confirmed through two methods (circularity and Casson viscosity). Targeting the effects of sucrose shape on bloom, model chocolates were formulated with 2 sucrose surfaces (before and after modification) at 3 sucrose volume fractions (0.15, 0.50, and 0.75) in the nonfat particle phase. Bloom was evaluated by changes in whiteness index (ΔWI) and white area percentage (WA%), accompanied by polymorphic transition evaluations. Surface morphology during storage was also evaluated by scanning electron microscopy (SEM) to quantify surface roughness and porosity. Bloom and SEM results both showed similar trends: smoothing sucrose particle surface as well as reducing sucrose fraction volume significantly reduced bloom and surface morphological (roughness and porosity) change, indicating that sucrose surface modification may have a significant impact on the particulate microstructures in chocolate thus impeding bloom formation during storage.

Preparation and performance of carboxyl modified NdFeB and derived magnetic self-healing PU composites

With the rapid development of today’s society, magnetic self-healing materials are widely used in many fields due to their excellent magnetism and self-healing ability. This article presents a magnetic self-healing composite with good mechanical, self-healing and magnetic properties and magnetic drive performance. Tetraethyl orthosilicate (TEOS), silane coupling agent and succinic anhydride (SA) were used for surface modification of NdFeB magnetic particles (MPs) and NdFeB@SiO2-COOH MPs was synthesized. Iron(III) ions were added to the self-polymerization process of the natural small molecule thioctic acid (TA) to form the PTA-Fe prepolymer. PTA-Fe prepolymer, isophorone diisocyanate (IPDI) and polyether amine (PEA) reacted to synthesis PTA-Fe-PU matrix with good self-healing performance at room temperature. The prepared NdFeB@SiO2-COOH MPs was mixed with the self-healing matrix and cured to obtain the magnetic room-temperature self-healing composite MPTA-Fe-PU. The best tensile strength of the composite was 7.31 MPa and the ultimate elongation was 833 %. After the prepared MPTA-Fe-PU sample strip was completely cut, the incision on the surface almost disapeared and the tensile strength recovered to 6.35 MPa after 12 h self-healing at room temperature. The self-healing efficiency was up to 87 %. The highly efficient self-healing properties were mainly derived from the disulfide bonds exchange reaction and iron(III) ion coordination in the matrix.

Particle-based Photoelectrodes for PEC Water Splitting: Concepts and Perspectives.

This comprehensive review delves into the intricacies of the photoelectrochemical (PEC) water splitting process, specifically focusing on the design, fabrication, and optimization of particle-based photoelectrodes for efficient green hydrogen production. These photoelectrodes, composed of semiconductor materials, potentially harness light energy and generate charge carriers, driving water oxidation and reduction reactions. The versatility of particle-based photoelectrodes as a platform for investigating and enhancing various semiconductor candidates is explored, particularly the emerging complex oxides with compelling charge transfer properties. However, the challenges presented by many factors influencing the performance and stability of these photoelectrodes, including particle size, shape, composition, morphology, surface modification, and electrode configuration, are highlighted. The review introduces the fundamental principles of semiconductor photoelectrodes for PEC water splitting, presents an exhaustive overview of different synthesis methods for semiconductor powders and their assembly into photoelectrodes, and discusses recent advances and challenges in photoelectrode material development. It concludes by offering promising strategies for improving photoelectrode performance and stability, such as the adoption of novel architectures and heterojunctions. This article is protected by copyright. All rights reserved.

Preparation of thermal interface materials with high thermal conductivity through the synergistic effect of Monoalkoxy-Terminated polysiloxane and branched siloxane oligomers

Four mono-alkoxysilyl-terminated asymmetric siloxane oligomers and a dimethylvinylsilyl-terminated branched-chain structure siloxane oligomer were prepared by a series of reactions to improve the filling loads and dispersion of Al2O3 particles in the polysiloxane matrix. Their influence on the surface modification of Al2O3 particles and the viscosity of composite materials was investigated. When the branched-chain siloxane oligomer was not used, mono-trimethoxysilyl-terminated asymmetric siloxane oligomers exhibited the best modification effect on the Al2O3 surface, and the silicone paste prepared by filling 70.8 vol% mixed-size Al2O3 particles had the lowest viscosity. When the branched-chain siloxane oligomer was used, the filling load of the modified Al2O3 particles could be further increased to 84.3 vol% under the synergistic effect of the mono-trimethoxysilyl-terminated asymmetric siloxane oligomers and the branched-chain siloxane oligomer. The viscosity of the silicone paste decreased with the increase in the polymerization degree of the dimethylsiloxane segment in the-mono trimethoxysilyl-terminated asymmetric siloxane oligomers. Meanwhile, the thermal conductivity of these silicone pastes also exhibited an increasing trend with the increase in the polymerization degree of the asymmetric siloxane oligomers. A thermal interface material with a thermal conductivity higher than 8.0 W/(m·K) was successfully prepared by using the asymmetric siloxane oligomers as the surface modification agent for Al2O3 particles and the branched-chain siloxane oligomer as the fluidity modifier for silicone paste.

Seedless and electroless plating of silver on silica particles by using microreactor

Synthesis of silver nanoshells is still a challenge especially in the absence of surface modification of core particles and/or metal seed decoration on core surfaces. In this study, we applied a microrector to seedless and electroless plating of silver on bare silica particles, and investigated the effects of reaction temperatures and silver ion concentrations on the morphology and surface coverage of silver on the core particle surface. Our experiments demonstrated that the use of the microreactor enabled the one-step direct deposition of silver with a morphology close to complete shells and that silver ion concentrations from 0.2 to 0.5 mM at a moderate temperature of 50 °C produced high coverage and yield. Besides, the mixing sequence of NH3 and HCHO in the synthesis procedure was found to be a key factor to achieve the high silver coverage. In addition, we demonstrated that the addition of polyvinylpyrrolidone (PVP) after the silver shell growth reaction increases the stability without decreasing the reaction rate.

Size reduction and water dispersibility improvement of hexagonal boron nitride particles by femtosecond laser irradiation in water

Controlling the size and surface state of inorganic particles, which strongly influence their dispersibility in solvents, is important for diverse applications. Intense femtosecond laser pulses can induce plasma formation in material–dispersed solvents and interact with both materials and solvents. In this study, femtosecond laser pulses are employed to modify hexagonal boron nitride (hBN) particles dispersed in water, with the aim of evaluating the effects of the femtosecond laser process on the size reduction and surface modification of hBN particles. Shadowgraph imaging reveals the formation of the reactive environment in hBN–dispersed water, resulting from the ionization of water molecules which leads to the generation of OH radicals. Evaluation of the hBN particle sizes suggests an overall reduction from 160 to 110 nm after 60 min of irradiation and the generation of nanodots between 5 and 10 nm in size. In addition, it is confirmed that the number of particles with higher zeta potentials increases after the samples are laser-irradiated, suggesting a change in the surface state. Consequently, the duration of hBN particle dispersion in water is significantly increased, with an improvement of at least one order of magnitude, for the laser-irradiated samples. This study presents a demonstration of the formation of a reaction field that affects hBN particles in size and dispersibility in water.

Flow Field Characteristics and Flotation Efficacy in a Pulse Jet Flotation Machine: A Comprehensive Investigation

The design and optimization of flotation machines hold significant importance in enhancing the industrial-grade coal beneficiation process. In this research, the flow field characteristics and flotation performance of a novel pulse jet flotation machine (PJFM) were investigated. The results showed that a PJFM equipped with an innovative pulse cavity can improve the mineralization efficiency of coal due to the coupling of multiple jet shapes. The aeration performance of this PJFM also exceeds the usual desired targets of coal flotation machines, which are characterized by an aeration uniformity coefficient higher than 70% and dominant bubbles of 100~200 μm and 200~300 μm, including a small amount of −100 μm bubbles. The cavitation of the pulse jet achieved the modification of the coal particle surface, and subsequently, the electric potential of the coal largely decreased in absolute value, and the floatability of the coal significantly improved. The concentrate yield of step release flotation increased by 12.42%, while the ash content was only 0.45% higher. Furthermore, in the early stage of flotation, the flotation rate of 0~0.074 mm coal slurry is the fastest and is preferentially floated; in the later stage, the flotation of 0.25–0.5 mm particles dominates. The PJFM demonstrates enhanced particle size selectivity and superior performance in selective flotation.

Role of nonionic natural dispersing agent Acacia Concinna on the slurryability and stability of concentrated iron ore suspension

The present study examines the impacts of saponin, extracted from the fruits of Acacia Concinna, in its effectiveness as a dispersant and stabilizer during the pipeline conveyance of iron ore particles. The basic fundamental characteristics of iron ore, which comprises a majority of hematite and has a size of (≤75 µm), have been examined and characterized. Iron ore water slurry (IWS) rheological behavior has been investigated as a function of saponin doses, pH, particle concentration, and the shear rate-shear stress correlation. The change in zeta potential with pH is used to compute the isoelectric point of IWS. An appropriate mechanism has been presented to explicate the interaction between saponin and particles of Iron ore. The surface-modified particles exhibit improved dispersion characteristics in the aqueous solution due to the modification of electrostatic force that the surface charge on each particle causes. Investigation indicates that the optimal proportion of saponin had a significant favorable effect on the fluidity and stability of the suspension. The analysis of the economic impact of the dispersant has been conducted through the evaluation of slurry head loss and specific energy consumption (SEC) pertaining to the implementation of the IWS pipeline in its intended commercial application.

Magnetic Nanoparticles: Synthesis, Characterization, and Their Use in Biomedical Field

In recent years, the use of magnetic nanoparticles (MNPs) in biomedical applications has gained more and more attention. Their unusual properties make them ideal candidates for the advancement of diagnosis, therapy, and imaging applications. This review addresses the use of MNPs in the field of biomedicine encompassing their synthesis, biofunctionalization, and unique physicochemical properties that make them ideal candidates for such applications. The synthesis of magnetic nanoparticles involves a range of techniques that allow for control over particle size, shape, and surface modifications. The most commonly used synthesis techniques that play a crucial role in tailoring the magnetic properties of nanoparticles are summarized in this review. Nevertheless, the main characterization techniques that can be employed after a successful synthesis procedure are also included together with a short description of their biomedical applications. As the field of magnetic nanoparticles in biomedical applications is rapidly evolving, this review aims to serve as a valuable resource, especially for young researchers and medical professionals, offering basic but very useful insights into recent advancements and future prospects in this highly interdisciplinary research topic.

Physical origin of the peak tailing of monoclonal antibodies in size-exclusion chromatography using bio-compatible systems and columns.

The analysis of mixtures containing monoclonal antibody (mAb) (approximately 150 kDa molecular weight) and sub-unit impurities (approximately 100 kDa) is challenging, even when adopting the latest ultra-high-pressure liquid chromatography (UHPLC) columns (4.6 mm [Formula: see text] 150mm coated hardware, 1.7 [Formula: see text]m 250 BEH[Formula: see text] Surface-modified Particles) and systems (ACQUITY[Formula: see text] UPLC[Formula: see text] I-class Bio Plus). The main issue still encountered is a persistent tail of the mAb peak. Here, the physical origin(s) of such peak tailing in size-exclusion chromatography (SEC) are investigated from both fundamental and practical approaches. Up to five relevant physical origins are analyzed: sample heterogeneity (glycoforms), UHPLC system dispersion, strong residual binding of the mAb to the SEC particles (via hydrophobic and/or electrostatic interactions) and to the stainless steel column/system hardware, slow escape kinetics of the mAb from the SEC particles, and flow heterogeneity caused by the non-ideal slurry packing of SEC columns. Experiments (testing sample heterogeneity, system dispersion, and strong residual interactions) and calculations (predicting the transient absorption/escape kinetics in a single SEC particle and the two-dimensional peak concentration profiles) altogether unambiguously demonstrate that the observed mAb peak tailing is caused primarily by the long-range velocity biases across the SEC column combined with the slow transverse dispersion of mAbs. Therefore, improvement in the resolution between mAb and sub-unit fragment impurities can only be achieved by increasing the column length, e.g., by applying recycling chromatography at acceptable pressures.

Alteration of zeta potential and cell viability in rat-derived L6 skeletal muscle cells and H9c2 cardiomyocytes: A study with submicron polystyrene particles.

Microand nanoplastics pollution can cause substantial damage to ecosystems. Since scientists have focused mainly on their impact on aquatic environments, less attention has been paid to the accumulation of polymer particles in terrestrial organisms. We checked if submicron (<5 mm) polystyrene (PS) particles, which can accumulate in living organisms, lead to changes in the physicochemical properties of mammalian cell membranes. The influence of submicron PS particles on the properties of rat-derived L6 myocytes and H9c2 cardiomyocytes was analyzed. Non-functionalized and amine-functionalized PS particles of 100 nm and 200 nm in diameter were used. The MTT assay was performed to evaluate the viability of the polymers-treated cells. The effect of short (6 h) and prolonged (48 h) incubation with different concentrations of PS particles on the cell's zeta (ζ) potential was examined with the electrophoretic light scattering technique (ELS). Polystyrene particles' physicochemical characteristics (size and stability) were performed using dynamic light scattering (DLS) and electrophoretic light scattering methods. The results show that submicron PS particles affect cell viability and cause changes in the physiochemical parameters of rat cell membranes. Differences were observed depending on the origin of the cells. We observed doseand time-dependent alterations in the studied parameters after submicron PS particle incubation in L6 myotubes and H9c2 cardiomyocytes. The size and modification of PS particle surfaces determine the extent to which they affect the analyzed properties of rat cardiomyocytes and myocytes membranes.

A breakthrough in Coulombic reversibility of dual-ion batteries at quick charge and underlying mechanisms

Dual-ion batteries (DIBs) with renewable graphite as cathode materials have emerged as promising alternatives to Li-ion batteries because of their sustainability and cost-effectiveness. However, DIBs still suffer from the low initial Coulombic efficiency and rapid capacity fading upon long-term cycling due to the intense co-intercalation and oxidative decomposition of electrolytes along with the anions intercalation into graphite at high potentials. To mitigate the electrolyte reactions, the common strategies are mainly focused on the optimization of electrolyte components and surface modification of graphite particles to construct superior cathode/electrolyte interphases (CEI). This work innovatively discovers and reveals that the CEI structure and electrochemical reversibility of Li||graphite DIBs can be optimized through simply adjusting the charge rates. The initial Coulombic efficiency is increased to a very high value of 90.6 % (at the charge rate of 2C), in sharp contrast with the value of 40.8 % (at the charge rate of 0.1C). Besides, the overall electrochemical performances including the reversible capacity, cycling stability and high-rate capability are all improved significantly. These results not only provide an easy strategy for the performance improvement of DIBs but also shed light on the correlation among the charge rates, electrochemical reversibility and CEI of DIBs.

Preventing Agglomeration and Enhancing the Energetic Performance of Fine Ammonium Perchlorate through Surface Modification with Hydrophobic Reduced Graphene Oxide

AbstractThe combustion rate of energetic composite propellants (ECPs) is adversely affected by the agglomeration of fine ammonium perchlorate (AP), which is the most commonly used oxidizer. To address this issue, this study explores the use of hydrophobic reduced graphene oxide (R‐GO) for surface modification of fine AP particles. An intermittent spray coating technique was used to coat the fine AP particles with graphene oxide (GO) dispersion. Hydrophilic GO was transformed into hydrophobic R‐GO by gentle thermal annealing. Fine AP was then scrutinized for changes in hygroscopicity and thermal decomposition behavior before and after coating with R‐GO. The findings demonstrate that surface modification significantly reduces the hygroscopicity of fine AP, reducing the moisture adsorption rate from 0.28 % to 0.11 % after a 10‐day exposure to ambient humidity. Moreover, this surface modification markedly enhances its energetic performance, doubling the energy release from 717.5 to 1413.5 J ⋅ g−1 when incorporating a 0.3 % mass of R‐GO coating. This study suggests that surface modification of fine AP with R‐GO is a promising strategy for addressing its agglomeration issue and improving its performance in ECPs.

Surface modification of particles in a photochemical fluidized bed

Different techniques have been recently studied to promote the surface modification of materials. Surface modifications are used to improve the performance of materials in diverse areas, such as chemical processes, pharmaceutical industry and agriculture. Despite the considerable work in the literature on the subject, the experiments carried out were always conducted with small samples of the materials, and the performance of the treatment on a larger scale has yet to be evaluated. This work aimed to make the surface modification of particles of different materials by UV-assisted treatment in a photochemical fluidized bed. The purpose was to verify the feasibility of treating particles with UV radiation on a larger scale, something not yet found in the literature. The analyzed materials were two polymers and four types of forage seeds. The effect of UV radiation on the surface was checked using the water contact angle (WCA) and FTIR analysis. The treated seeds were also submitted to the Standard Germination Test (SGT) to verify eventual physiological damages and possible beneficial effects of the treatment. The results indicated a significant decrease in the contact angle of the treated particles of all materials because of the incorporation of oxygenated groups on their surface. In turn, the SGT pointed out not only that the seeds were not damaged by radiation but also that there was a significant increase in the agronomic index for two of the species studied. The data obtained in this work showed that the photochemical fluidized bed proved a viable way to carry out the surface treatment of particles with UV radiation, making it possible to conduct the process on a larger scale.

In Ukrainian

The influence of the electronic subsystem of nanographene particles modified with titanium dioxide nanoparticles on the thermal destruction of the polymer matrix is analyzed. The variation in the conductivity of the modifiers made it possible to vary the effect of the metallic electronic system of graphene on thermal destruction by attenuating its effect through the transfer of energy to the electronic subsystem throughout the semiconductor film of anatase and excluding its effect on thermal destruction through a wide-band TiO2 dielectric of rutile form, which is opaque for energy transfer to the electronic subsystem. The application of such films does not affect the thermal processes in which the phonon subsystems of polymer, graphene and crystal modifiers are involved. The method of thermally programmable desorption mass spectrometry investigated the thermal destruction of hybrid composites of epoxy resin with graphene, namely the effect of surface modification of multilayer graphene particles by nanoparticles of pyrogenic titanium dioxide (anatase and rutile forms) on the thermal stability of hybrid epoxy composites in the temperature range of 40 − 800 °C. The activation energies Ed of destruction of atomic fragments of the polymer structure with the value m/z in the range of 16 ‒ 140 D were determined. It has been established that the thermal destruction of fragments of the polymer structure of epoxy resin composites with graphene modified with anatase and rutile forms of titanium dioxide is determined by the peculiarities of thermal transport at the polymer-modifier interfaces. Modification of graphene particles by the anatase form of titanium dioxide leads to increased thermal stability of polymer chains and cross-links in epoxycomposites in the entire range of m/z values of desorbed fragments. Filling the resin with graphene particles coated with the rutile form of TiO2 practically does not affect the intensity of thermal destruction of the composite matrix. The Ed values of different destruction fragments in composites with unmodified and modified graphene are in the range of 50 ‒ 130 kJ/mol. The value of Ed increases by 5 ‒ 10 kJ/mol when the resin is filled with graphene nanoparticles, while the coating of particles with titanium dioxide of the anatase and rutile phases practically does not change the value of Ed of the vast majority of fragments.

An analysis of microstructural morphology, surface topography, surface integrity, recast layer, and machining performance of graphene nanosheets on Inconel 718 superalloy: Investigating the impact on EDM characteristics, surface characterizations, and optimization

Inconel 718 finds extensive applications in the aviation and aerospace industries, particularly in the manufacturing of jet engines and high-speed airframe components like fasteners, bolts, buckets, instrumentation parts, wheels, and spacers. It is also utilised in the production of cryogenic tankage and gas turbine blades. The present study focuses on investigating the machining performance of graphene nanosheets on Inconel 718. Various aspects of Inconel 718's machinability through electrical discharge machining (EDM) have been examined, including material removal rate (MRR), surface roughness, surface morphology, tool rear Rate (TWR), residual stresses on the machined surface, Vickers hardness, and recast layer thickness. The investigation reveals a significant impact of process parameters on these machining characteristics. The effects of graphene nanosheets have been observed using several analytical instruments such as field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), particle size analyzer, and X-ray diffraction (XRD). Furthermore, optimization of the response data with respect to input parameters has been performed in this study. TEM analysis is used to determine the size of individual debris particles in deionised water and mixed graphene nanosheet dielectric mediums. To verify that the debris particles are the same as the parent material, energy dispersive X-ray spectroscopy (EDX) is used. To determine the compounds and crystal structures present in the base metal and machined surfaces, XRD analysis is used. A high-resolution X-ray diffractometer (HRXRD) is used to measure the residual stresses on the machined surface. EDX composition testing is used to analyze surface modification. Due to the rapid heating and quenching that takes place in the dielectric medium, the machined surface becomes harder. Deposited materials, microholes, and surface textures can all be observed through FESEM microstructure observation. Comparing conventional EDM to nanosheets mixed dielectric, the thickness of the recast layer is reduced. To recapitulate, the study explores how various machining parameters and dielectric mediums affect EDM processes. It examines debris particle size, compound formation, residual stresses, surface modification, hardness, microstructure, and recast layer thickness. The addition of graphene nanosheets to the dielectric medium produces promising results, reducing the thickness of the recast layer and improving surface quality. The results offer suggestions for improving Inconel 718 material surface properties and EDM machining effectiveness.

Hydrodynamics intensification and interface control in the flotation conditioning process using fractal impellers

Flotation conditioning, an essential part affecting the function of flotation reagent and flotation performance, has gradually become a key field for the process enhancement of flotation. A fractal impeller device was proposed in this paper for use in pre-flotation pulp conditioning. The flow field characteristics and relevant effects on the liquid–solid mixing performance were investigated by the numerical simulation of computational fluid dynamics. The outcome of particle surface modification was assessed by studying changes in the contact angle and zeta potential of diaspore particles. These results showed that the increase of turbulent kinetic energy induced by the fractal impeller improved the dispersion of mineral particles. Meanwhile, the strong turbulence and high shear induced by the fractal impeller provided favorable conditions for collector adsorption and particle modification, leading to the increase in contact angle under relatively higher energy input. This work introduced a kind of novel fractal impellers used in the flotation conditioning to strengthen the flotation separation of minerals.

Potential and Harmful Effects of Titanium Dioxide Nanoparticle on Health: A Brief Note

Abstract: Titanium dioxide nanoparticles (TiO2 NPs) are formed in vast amounts worldwide for usage in several applications. They possess excellent photocatalytic properties, high chemical stability, and a wide bandgap, making them highly effective in environmental remediation and solar energy conversion. TiO2 nanoparticles exhibit biocompatibility, allowing their utilization in biomedical uses, such as molecular imaging, drug delivery, and tissue engineering. Chemical methods, such as hydrothermal, sol-gel, and chemical vapor deposition, provide versatility in controlling nanoparticle size, morphology, and crystallinity. They offer relatively lower production costs, scalability, and the ability to incorporate dopants or functionalize the nanoparticle surface. Their small size and large surface area-to-volume ratio enable enhanced reactivity and surface functionality, facilitating their incorporation into composite materials and surface coatings for improved performance. Regarding the potential toxicity of TiO2 nanoparticles, the bulk form of TiO2 is considered safe for human consumption, but the reduced size of nanoparticles raises concerns about their potential adverse effects. TiO2 nanoparticles strongly depend on factors, such as particle size, surface modifications, exposure route, and duration. Therefore, continued research is essential to gain a comprehensive understanding of the toxicity mechanisms and develop strategies to mitigate any potential adverse effects, ensuring the safe and responsible utilization of TiO2 nanoparticles in different fields.