Fine Powder Research Articles

Fabrication of graphene oxide/ammonium molybdophosphate composite membrane for decontamination of cesium ions from seawater

Efficient separation of radioactive cesium ions (Cs+) from complicated aqueous environmental media has attracted considerable interest, especially seawater. Ammonium molybdophosphate (AMP) is regarded as a promising adsorbent for Cs+, but its fine powder dramatically inhibits the potential for practical applications. Herein, graphene oxide (GO) was utilized as a support for the in-situ growth of AMP, and after vacuum filtration, GO/AMP composite membrane was successfully fabricated. It was found that the GO/AMP membrane exhibited excellent adsorptive filtration performance (47.3 L m−2h−1 bar−1 water flux and 99.2 % rejection for Cs+ with 20 ppm initial concentration, 30 mL feed solution). Influent pH and coexisting metallic ions had scarcely effects on Cs+ rejection. Over five cycles, the water permeability and Cs+ rejection remained essentially unchanged. Moreover, the decontamination of Cs+ from real seawater was demonstrated with the rejection ratio as high as 87.4 % and a relatively inhibitory flux of 14 L m−2h−1 bar−1. Based on FT-IR, XPS, and EXAFS analyzes, the rejection of Cs+ was mainly ascribed to the exchange of NH4+ in AMP with Cs+ in solution, and an inner-sphere coordination of Cs+ rather than a weak outer-sphere interaction between hydrated Cs+ ions and adsorbent occurred.

Sustainable lignin-based powder coatings doped with ZnO displayed excellent UV resistance properties

Sustainable lignin-based powder coatings doped with ZnO displayed excellent UV resistance properties

An experimental and theoretical study on effects of particle size distribution on flowability and film properties of organic powder coatings

An experimental and theoretical study on effects of particle size distribution on flowability and film properties of organic powder coatings

Synthesizing a novel cerium-modified graphene powder to achieve long-term anticorrosion performance of epoxy powder coatings

Synthesizing a novel cerium-modified graphene powder to achieve long-term anticorrosion performance of epoxy powder coatings

Lasers Powder Coatings Quickly and Energy-Efficiently

Lasers Powder Coatings Quickly and Energy-Efficiently

Oil-based drilling cutting pyrolysis residues-recycled fine powder sintered ceramsite: Basic properties, microsintering mechanism, lightweight concrete application and heavy metals solidification

Oil-based Drilling Cutting Pyrolysis Residue (ODPR) is a waste produced during oilfield drilling using oil-based mud. Recycled Fine Powder (RFP) consists of particles less than 0.16 mm, crushed and sieved from waste concrete. China's solid waste is characterized by high production, low utilization rates, and high pollution levels. This study explores the feasibility of preparing ceramsite from ODPR and RFP. By examining the effects of varying temperatures and proportions on the macroscopic and microscopic properties of ODPR-RFP ceramsite (ORC), the optimal process was determined: ODPR: RFP = 7:3, 2 % borax flux, 10 minutes ball milling, 1200℃ sintering temperature, and 30 minutes insulation. The resulting ORC, with a bulk density of 1120 kg/m³, cylinder compression strength of 10.50 MPa, and water absorption rate of 7.8 %, meets the "Lightweight aggregates and its test methods (GT/B17431.2)" standard. Batch production of ORC products of various sizes was conducted to evaluate their practical application in LC30 lightweight aggregate concrete. Replacing the aggregate in lightweight concrete with ORC yielded a concrete with excellent mixing performance, reaching a maximum strength of 31.2 MPa after 7d and 44.8 MPa after 28d. The damage pattern of ORC lightweight concrete is characterized by longitudinal splitting, with varied crack initiation and expansion paths. In the interfacial transition zone of ORC concrete, the ORC form a strong bond with the cement mortar, enhancing the strength of the lightweight concrete. Additionally, the leaching of heavy metals (HMs) from the ORC was examined to assess potential environmental pollution. The results indicated that preparing ORC from these two types of solid waste can effectively immobilize HMs, with a solidification rate of up to 92.10 %. Pb with high content is mainly solidified in the form of solid solution to form (Ba, Pb) SO4. The ecological risk assessment method for HMs shows that using this solid waste and process to prepare ORC does not pose HMs risks and is an environmentally friendly building material.

Increasing particle-size by air-flow modification – An experimental study

Ambient particulate are characterize by submicron particles that may penetrate deep into the lungs, where they become harmful due to their morphology and composition, or due to their role as carriers of harmful chemicals or biological agents. Particle filtration technologies have in general a lower efficiency at diameter size around 0.1–0.3 μm. This study examines the concept of particle grouping as a means to overcome this size-gap, for improving air purification or filtration systems. The grouping manipulation is induced by a controlled rotating valve which creates a sinusoidal flow in the experimental tube, and by modules with varying diameter, forcing a wavy flow. Fine particles with a known size distribution which are introduced into the manipulated flow, exhibit groups of particles in the outflow, hence increase the effective size of the particles. Former successful studies were performed with high flow velocity and particle load of industrial duct and car engine outflow, while in the current study smaller particle loads representing ambient to indoor levels are in operation. Although the low velocity and particle load are challenging, this study shows a promising shift of the particle size distribution from a peak at 0.2–0.3 μm, towards larger particle diameters. Fine powder of dolomite is used in this study and preliminary results of adhesion experiments related to dolomite are also reported.

Graphene oxide with different oxygen content produced from natural and synthetic graphite sources for methylene blue sorption

Graphene oxide (GO) is of great interest due to its unique structure and properties and potential applications, including water purification. In this work, we report the synthesis of GO samples with different oxidation degree from two different sources of graphite using Hummers method. Natural flake graphite with a high degree of crystallinity, and synthetic fine powder graphite were used. All produced materials were characterized by CHNS analysis, X-Ray Diffractive analysis (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). It was shown that the oxidation process for natural and synthetic graphite sources proceeds in different ways. The factors, affecting for the structure and properties of GO are the degree of crystallinity and the lateral size of the graphite flakes. The sorption activity of underoxidized, normally oxidized and overoxidized GO was compared toward the methylene blue (MB) dye in aqueous solution. The most efficient sorption was registered for GO produced from synthetic graphite with the use of 2.0 and 4.5 wt. eq. KMnO4. The sorbents removed 94 % and 100 % of MB from the solution, respectively, in approximately 10 min. Our results reveal that the structure and sorption properties of GO can be tuned by varying the oxidation degree as well as the graphite source, which may open the way to new developments in the GO-based materials applications.

The effects of raw materials particle sizes on the solid-state reaction progress, morphology and magnetic properties of M-type strontium hexaferrites

In this work, the effects of SrCO3 and Fe2O3 particle size on the reaction process, morphology and magnetic properties of M-type strontium hexaferrites (SrM) have been further studied. Pure strontium hexaferrite magnetic sample based on SrCO3 and Fe2O3 molar ratio of 1:6 has been successfully prepared at 1150 °C. The results indicated that Fe2O3 particle size was the main factor of affecting the formation of SrM, a pure SrM phase magnetic sample was able to obtain at lower calcination temperatures by using fine Fe2O3 powder as raw material, and at the same calcination temperature, a sample using fine Fe2O3 powder as raw material was able to obtain pure SrM phase magnetic sample with shorter holding time. When the mean particle size of Fe2O3 was below 60 nm, a pure SrM phase magnetic sample was able to form at 1150 °C at a molar ratio of 1:6 of SrCO3 and Fe2O3. In this case, the magnetic parameters of the sample with the optimum magnetic parameters were saturation magnetization MS = 77.8 emu/g and coercive force HC = 4122 Oe. And the solid-state reaction process of the corresponding samples was slightly faster when the mean particle size ratio of Fe2O3 and SrCO3 was between 0.35 and 0.36. Assuming that a SrCO3 particle is surrounded by Fe2O3 particles, it can be inferred that the corresponding molar ratio of Fe and Sr of the nearest raw material particles is between 3.6 and 3.8.

Investigation of Proximate Composition and Bioactive Components in Banana (Musa acuminata) Peels Using Advanced Analytical Techniques

Background: Banana peels, often considered waste, contain valuable nutrients and bioactive compounds. This study investigates the proximate composition and bioactive components of banana (Musa acuminata) peels using advanced analytical techniques. Materials and Methods: Banana peels were collected from household wastes and processing facilities, washed, dried, and ground into fine powder. Proximate analysis was performed to determine moisture, carbohydrate, ash, crude fiber, protein, and crude fat content using standard methods. Gas Chromatography-Mass Spectrometry (GC-MS) and Fourier Transform Infrared Spectroscopy (FT-IR) were employed to identify and characterize bioactive components and functional groups. Results: The proximate composition revealed moisture (7.36 ± 0.37%), carbohydrate (23.15 ± 0.05%), ash (12.11 ± 0.09%), crude fibre (30.53 ± 0.77%), protein (16.42 ± 0.45%), and crude fat (10.43 ± 0.67%). GC-MS analysis identified various bioactive compounds, including 13-Docosenoic acid methyl ester (12.67%), 1-Docosene (12.63%), and Octadecanal (9.45%). FT-IR analysis indicated the presence of functional groups such as alkane (2746.688 cm^-1), ester (1888.360 cm^-1), and primary amine (3514.793 cm^-1). Conclusion: Banana peels possess significant nutritional and bioactive components, making them a potential resource for various industrial applications. The study highlights the importance of valorizing banana peels for nutritional and therapeutic uses.

Establishment and evaluation of dynamic viscoelasticity constitutive model for asphalt mixtures based on PCA model: Utilizing coal-based synthetic natural gas slag and phosphogypsum whisker as substitute fillers

To promote the secondary utilization of solid waste in asphalt pavement and reduce resource waste and environmental damage, the fine solid waste powder from the secondary treatment of solid waste was used as a substitute filler to prepare asphalt mixtures. To more precisely characterize the effects of filler type and substitution ratio on the dynamic viscoelastic mechanical characteristics of asphalt mixtures, the dynamic modulus test was conducted on asphalt mixtures, while the dynamic modulus master curve of asphalt mixtures was established based on the time-temperature equivalent principle and the Sigmoidal function. The improved generalized Sigmoidal (IGS) model, five-parameter fractional Zener (FFZ) model, six-parameter fractional Zener (SFZ) model and ten-parameter fractional Zener (TFZ) model were used to construct the shrinkage frequency curves of different asphalt mixtures under different constitutive relationships, whereas the applicability of the constitutive models was further evaluated by the principal component analysis (PCA) model. The research results showed that the dynamic modulus and phase angle of the mixture exhibited a similar change rule with the variation of temperature and frequency, and the use of solid waste-based fillers could effectively reduce the effect of frequency variation on the viscoelasticity of the mixture. The dynamic modulus master curve constructed by Sigmoidal function could accurately describe the functional relationship between the dynamic modulus with loading frequency and temperature, and the variation trend of dynamic modulus in a wider frequency range was flattened with the increase in frequency, and this change rule was not affected by the substitution ratio of the filler, while the use of solid waste-based filler could reduce the dependence of the mixture on the temperature. Compared to several fractional constitutive models, the IGS model exhibited a higher fitting accuracy for the dynamic viscoelasticity of several mixtures, and with the use of solid waste-based fillers, the deviation of fitting curves gradually decreased. A comparative study showed that the fractional constitutive model was difficult to accurately describe the dynamic viscoelasticity of the mixture, and the IGS model was preferred to be recommended as a calculation model to investigate the constitutive relationship on the dynamic viscoelasticity of the mixture.

Sintering Properties of ZrO2(MexOy) Fine Powders Produced by Different Methods

Sintering Properties of ZrO2(MexOy) Fine Powders Produced by Different Methods

MODIFICATION OF BUCKWHEAT HUSK POWDER AND CREATION OF COMPOSITE MATERIAL ON ITS BASIS

Abstract Waste of plant origin is becoming increasingly relevant for use as fillers in polymer matrices to create new composite materials. In this study, a composite material based on biodegradable thermoplastic polylactide (PLA) and buckwheat husks (BHS) was prepared. L-PLA IngeoTM Biopolymer 4043D in pellet form (Nature Works LLC, USA) was chosen as the base for the polymer matrix. BHS in the form of fine powder (harvested in 2023) was used as a plant filler. In order to purify the raw material from dust and pathogenic bacteria, as well as to increase the adhesion ability of the material, BHS was treated with 4% alkaline solution (NaOH). Modification of the filler was carried out using organosilicon resin K-9 (manufacturer Khimprodukt LLC, Lyubertsy, Russia). The filler was added to the material in the ratio of 22 %, 32%, 42% by weight of the product. A technology for modification of BHS powder is proposed, which makes it possible to significantly increase the wetting angle from 59.47±1.59° to 95.6±1.35°. The strength properties and water absorption resistance of the developed composites with different weight ratios of PLA/ BHS are investigated. The modification of the filler changes the structure and properties of BHS, as well as contributes to the improvement of strength properties. At the ratio PLA 68 wt.% / modified BHS 32 wt.% the composite material has the following characteristics: density - 1342 kg/m3, bending strength – 21.31 MPa, maximum deformation value – 0.22 mm, Vickers hardness at a load of 200 g – 20.21, water absorption – 1.9%. Research on the utilization of plant components will make it possible to integrate into industry innovative products based on renewable and biodegradable resources that will meet all societal needs and contribute to the preservation of the environment and exhaustible resources.

The Effect of Powder Form and Sample Weight on the Acceptability of Yellow Melinjo (Gnetum gnemon L.) Peel Tea

Tea is one of the nutritious drinks that are popular with the Indonesian people. Recently, researchers have developed various new types of tea beyond the traditional tea plant (Camelia sinensis). One potential ingredient for tea development is melinjo peel, particularly the yellow melinjo peel, due to its strong antioxidant activity and superior α-glucosidase inhibitory activity. This study aims to investigate the influence of the powder form and sample weight on the acceptability of yellow melinjo (Gnetum gnemon L.) peel tea. The research employed an experimental method with a factorial completely randomized design (CRD) involving two factors. The first factor was the powder form of the tea (fine, semi-fine, and coarse), and the second factor was the sample weight (2.5 grams, 3 grams, and 5 grams). A hedonic test was conducted to assess the acceptability of yellow melinjo peel tea, involving 40 semi-trained panelists using a scale from 1 to 7 (strongly dislike to very much like). Data were analized using IBM SPSS 25.0 Statistics for Windows, with Kruskal-Wallis and Mann-Whitney tests at a significance level of P < 0.05. The results showed that both the powder form and sample weight of yellow melinjo peel tea significantly affected (P<0.05) taste, aroma, clarity, intensity, astringency, flavor, and overall acceptability, but did not significantly affect (P > 0.05) color and taste intensity. The most preferred formulation by panelists was yellow melinjo peel tea with a sample weight of 2.5 grams and a fine powder form, with an average score of 4.23 (like slightly).

Enhancement of thermal and mechanical properties of PMMA nanocomposites by adding spark plug ceramic waste

In this research, poly methyl methacrylate (PMMA) resin was used as a base material and spark plug ceramic waste (CW) particles as a support material with different weight ratios (0%, 1%, 2%, 4%, 6%, 10%, 14%, and 20%) to study the thermal and mechanical properties through diffraction examination. FE-SEM surface structure images showed that the fracture surface of the (94% PMMA +6%CW) nanocomposite sample manifests a good distribution of particles at low and high levels. The result showed that the thermal conductivity (K) slightly increased until it reached the maximum value (0.6 watt/m.ºC) at the ratio (86%PMMA +14%CW). For the impact strength, it was noticed that the impact strength of PMMA increases with the increased weight ratios (1, 2, 4, 6, 10, 14, and 20%) of fine powder of ceramic waste compared with pure PMMA to reach the maximum value (6.02 kJ/mm2) at the sample (94% PMMA +6%CW) under L.C. Moreover, after 30 days of submersion in water, the PMMA reinforced with ceramic waste particles had enhanced impact strength. The shore D-number readings for all of the samples showed an increase as a result of the findings of nanocomposite compared with PMMA pure, where the sample (94% PMMA+6%CM) attained the greatest shore D numbers (87 H.NO). The compressive strength at the weight percentage (99% PMMA + 1% CW) was somewhat reduced. Then the compressive strength increased till it reached its maximum value (29.94 MPa) at the weight percentage (94% PMMA + 6% CW).

Phytochemicals Analysis, In vitro Anti-plasmodium Activity of Delonix regia Bark and Carica papaya Leaf Extracts in Combination with Chloroquine

Background: The effectiveness of treating malaria may be jeopardized by artemisinin-resistant parasites. Pharmaceutical companies have been using plants for a very long time to generate the prototype molecules needed to treat Plasmodium infections. Objective: To evaluate anti-plasmodial potency of extracts of Delonix regia and Carica papaya when used in combinations with chloroquine. Methods: The plants were collected from Homa-Bay County in Kenya, dried under shade to a consistent weight, and then milled into a fine powder. Organic solvents were then used for extraction. After phytochemical screening of the extracts was conducted, In vitro tests were done on the extracts against Plasmodium falciparum, with a starting concentration of 100µg/mL. To prepare the test concentration ranges, the extracts were serially diluted 2-fold in growth medium. In a sealed gas chamber, the assay plates were incubated at 370C for 72 hours with 3% O2 and 4% CO2 with N2 as the balance. By comparing each well's absorbance to that of a well that contained the drug-free control, the number of parasites still present at each concentration of the test substance were ascertained. Plotting survival against concentration enabled the determination of the IC50 values by a non-linear dose response curve fitting. Results: In this investigation, the extracts from Delonix regia showed significant synergism (based on IC50 shifts) with CQ for both the ethyl acetate and methanol extracts with the exception of the highest combination dosage. Carica papaya extracts were much improved by the presence of CQ; however, this was not consistently reflected in the corresponding CQ IC50. Conclusion: The results of this study which revealed synergism between the study plants extracts and chloroquine, support the reasons why some traditional healers have started combining medicinal herbs with chloroquine to boost its potency.

Choorna Kalpana: Bridging Ayurvedic Traditions with Modern Size Reduction Techniques for Optimal Therapeutic Outcomes

Choorna Kalpana, a fine powder derived from completely dry drugs, is a fundamental preparation in Ayurveda. Recognized for its stability and ease of absorption, Choorna is used independently to treat various diseases, as an adjuvant with other medicines, and in secondary preparations like Avaleha (medicated semisolid preparation), Vati (tablets), and Sneha Kalpana (oil and ghee preparations). The preparation involves meticulous processes of washing, drying, pounding, and sieving drugs to ensure homogeneity. Modern practices in Choorna Kalpana incorporate size reduction techniques such as cutting, compression, impact, and attrition, which enhance its efficiency and therapeutic potential. Factors influencing size reduction, including hardness, toughness, abrasiveness, stickiness, softening temperature, and moisture content, are critical for achieving desired particle sizes. Size separation and mixing techniques are also essential in ensuring the uniformity and efficacy of Choorna. This paper explores the traditional and modern methodologies of Choorna preparation, highlighting its significance in Ayurvedic medicine.

Effect of foaming conditions and drying temperatures on total polyphenol content and drying rate of foam-mat dried banana powder: Modeling and optimization study

This study aims to optimize the parameters of the foam-mat drying to produce banana powder. Input parameters of the foam drying such as foaming agent (egg albumin) concentration used from 5 to 15 %, the foam stabilizer (maltodextrin) used from 1 to 3 % and the drying temperature varied between 60 and 80 °C. Factors with 3 levels are arranged according to the Box-Behnken design, which further modelled by RSM (response surface methodology) and ANN (artificial neural network), and optimized. The drying rate and total polyphenol content (TPC) of banana powder under the studied conditions were determined as the target output. The moisture, color, total polyphenol, antioxidant activity and some physical parameters of final fine powder were analyzed. Increasing temperature has increased the drying rate. In addition, increasing the concentrations of egg albumin and maltodextrin maintained the highest TPC and maximum drying rate. ANN model showed the higher forecasting capacity than that of RSM. Moreover, simultaneous optimization of two responses (TPC and drying rate) was selected to maximize the desired value at the concentration of albumin, maltodextrin and drying temperature of 11.86 %, 1.92 %, 74.94 °C, respectively, corresponding to the highest TPC value and drying rate of 1.31 mgGAE/g DW and 2.48 g water/g dry matter/min. At this condition, the drying time was recorded as 103 min. Validation of the optimal ratios showed that the experimental values of TPC and drying rate were in good agreement with the model predicted data. The moisture content and water activity of product were found to be 5.87 ± 0.07 % and 0.37 ± 0.01. The product had bright colors with L*, a* and b* values were measured as 86.4 ± 0.5, 1.75 ± 0.08 and 15.2 ± 0.3, respectively. The high DPPH radical scavenging activity was detected (53.5 %) with the water solubility index and water absorption index of banana powder was determined at value of 56.98 % and 5.17 g/g, respectively. Foam mat dried banana powder was well preserved in paper packaging with aluminum foil.

Copper leaching from ultrasonically treated milled waste printed circuit boards: investigation of parameters optimization and kinetics.

Waste printed circuit boards (WPCBs) encompass abundant metals (gold, silver, and copper), along with other harmful materials including brominated epoxy resins, plastics, and heavy metals (lead, mercury, and cadmium). Direct burning and landfilling of WPCBs may cause severe health issues and impair the environment. Therefore, sustainable treatment of WPCBs is necessary to recover valuable metals and remove hazardous materials before disposal. The present work investigates the separation of copper-rich metallic fractions from the WPCBs by the combination of hammer milling and ultrasonic irradiation. Initially, discarded mobile phone PCBs are pre-processed and shortened into 1 × 1 cm2. Downscaled WPCBs are fed into the hammer mill to obtain the fine ground powder. The Powdered WPCBs are further processed through ultrasonic treatment to acquire metal-rich fraction. XRD, SEM-EDS, and ICP/AAS analysis revealed that the current technique can efficiently separate the metal-rich fraction without using toxic solvents. Results show the enhancement of copper fraction from 42.73 to 87 wt. % after ultrasonic treatment of WPCBs ground powder. Further, nitric acid leaching has been implemented to metal-rich fractions, and the parameters have been optimized for copper leaching with the assistance of response surface methodology (RSM) of the design of experiments (DOE). Quantitative dissolution (98.96%) of copper occurred using 3.5M nitric acid within 3h at 30°C with 50 GPL pulp density and 500rpm agitation speed. Finally, the kinetics of the leaching process were studied to conform the kinetics model. Moreover, the activation energy for diffusion (19.075kJ/mole) and reaction kinetics model (13.29kJ/mole) has also been calculated. The low energy consumption due to room temperature pre-treatment and effective leaching ensures the industrial feasibility of the proposed process.

Sustainable lignin-based powder coatings doped with ZnO displayed excellent UV resistance properties

Lignin with increased polyhydroxyl content (LOH) was prepared via a one-pot synthesis using enzymatically hydrolyzed lignin (EHL) as the raw material. The modified structure and hydroxyl content of LOH were analyzed using FT-IR, 1H NMR, and 31P NMR. LOH was blended with zinc oxide (ZnO), polyester resin and hydroxyl alkyl amide (HAA) to prepare polyester powder coatings. The anti-UV properties of the coating were significantly enhanced by the addition of LOH and ZnO. The coating exhibits exceptional adhesion, rating at level 0, and achieves a pencil hardness of 7H. The gel time for the coating is 195 s, and it has a 5-degree Celsius increase in melting temperature, which greatly enhances its storage stability. Considering a range of factors, the formula LOH7.5 % has been identified as the optimal composition. The results of this study demonstrate an easy approach to developing sustainable lignin-based powder coatings with excellent properties.