Search Results (55)

Natural polymer materials are increasingly utilized in drilling fluid additives. Starch has come to be applied extensively due to its low cost and favorable fluid loss reduction properties. However, its poor temperature resistance and high viscosity limit its application in high-temperature wells. This study innovatively introduces for the first time diatomite as an inorganic material in the modification process of starch-based fluid loss additives. Through synergistic modification with acrylamide and acrylic acid, we successfully resolved the longstanding challenge of balancing temperature resistance with viscosity control in existing modification methods. The newly developed fluid loss additive demonstrates remarkable performance: It remains effective at 160 °C when used independently. When added to a 4% sodium bentonite base mud, it achieves an 80% fluid loss reduction rate—significantly higher than the 18.95% observed in conventional starch-based products. The resultant filter cake exhibits thin and compact characteristics. Moreover, this additive shows superior contamination resistance, tolerating 30% NaCl and 0.6% calcium contamination, outperforming other starch-based treatments. With starch content exceeding 75%, the product not only demonstrates enhanced performance but also achieves significant cost reduction compared to conventional starch products (typically containing < 50% starch content). Full article

During the operation of structures, the components and materials from which they are made are exposed to various environmental, technological, and operational impacts. In this context, the use of a modified water-dispersion composition containing finely dispersed fillers with enhanced protective and performance characteristics proves to be effective. This article examines the development of a paint-and-coating composition using hollow glass microspheres and modified diatomite as finely dispersed fillers. The influence of technological factors on the properties of coating materials based on a synthesized acrylic dispersion and fillers—such as modified diatomite and hollow glass microspheres ranging from 20 to 100 μm in size with a bulk density of 0.107–0.252 g/cm³—is analyzed. The optimal formulation of the coating materials was determined to ensure the required coating quality. Experimental results demonstrate the improved strength and hardness of the coating due to the use of acrylic dispersion obtained through an emulsifier-free method and modifiers in the form of finely dispersed fillers. It has been established that the resulting samples also exhibit high adhesion to mineral and metallic substrates, along with excellent corrosion resistance. Moreover, the incorporation of acrylic dispersion contributes to increased elasticity of the coating, resulting in improved resistance to washing and abrasion. The developed protective material can be applied to a variety of surfaces, including walls, ceilings, and roofs of buildings and structures, pipelines, and many other applications. Thus, modified water-dispersion compositions based on synthesized acrylic dispersion showed the following results: resistance to sticking—5, which is the best; chemical resistance and gloss level with standard single-phase acrylic dispersion—no destruction or change in gloss. The adhesion of coatings cured under natural conditions and under the influence of UV radiation was 1 point. The developed formulations for obtaining water-dispersion paint and varnish compositions based on synthesized polymer dispersions, activated diatomite, and hollow glass microspheres, meet all the regulatory requirements for paint and varnish materials in terms of performance, and in terms of economic indicators, the cost of 1 kg of paint is 30% lower than the standard. Full article

In the context of intensified construction and stricter requirements for the energy efficiency of buildings, the use of thermal insulation materials and technologies is becoming particularly important. One promising area in this field is the use of thermal insulation mixtures, which are versatile, adaptable, and highly reliable in operation. Mixtures based on fillers with a porous structure and materials that impart thermal insulation properties, which provide higher thermal insulation properties, are of great interest. However, the development of dry thermal insulation mixtures is hampered by insufficient study of their physical, mechanical, and operational characteristics. This article presents the results of research work on the development and study of dry building thermal insulation mixtures. A distinctive feature of the work is the creation of a composition of dry building thermal insulation mixtures based on local raw materials, such as diatomite, its thermal modification at a temperature of 900 °C, the use of expanded perlite sand, lime, and Portland cement. Research into the properties of modified diatomite has shown that its surface after thermal treatment differs from the surface of unburned diatomite in that it becomes more active and has a 3–4 times higher increase in strength. Modified diatomite and expanded perlite sand have low thermal conductivity, and this property was used in the creation of building thermal insulation mixtures, which was confirmed by research, as the thermal conductivity coefficient ranged from 0.128 to 0.152 W/m °C. The developed dry thermal insulation lime–cement mixture is intended for both interior and exterior finishing works, which is confirmed by the results obtained for determining the frost resistance of the solution and the frost resistance of the contact zone, and corresponds to the F35 grade and has a strength of up to 3.59 MPa. Full article

To address the challenges of cotton cellulose materials being susceptible to environmental humidity and pollutant erosion, a strategy for constructing superhydrophobic functional coatings with biomimetic micro–nano composite structures was proposed. Through surface silanization modification, diatomite (DEM) and Fe₃O₄ nanoparticles were functionalized with octyltriethoxysilane (OTS) to prepare superhydrophobic diatomite flakes (ODEM) and OFe₃O₄ nanoparticles. Following the multi-scale composite principle, ODEM and OFe₃O₄ nanoparticles were blended and crosslinked via the hydroxyl-initiated ring-opening polymerization of epoxy resin (EP), resulting in an EP/ODEM@OFe₃O₄ composite coating with hierarchical roughness. Microstructural characterization revealed that the micrometer-scale porous structure of ODEM and the nanoscale protrusions of OFe₃O₄ form a hierarchical micro–nano topography. The special topography combined with the low surface energy property leads to a contact angle of 158°. Additionally, the narrow bandgap semiconductor characteristic of OFe₃O₄ induces the localized surface plasmon resonance effect. This enables the coating to attain 80% light absorption across the 350–2500 nm spectrum, and rapidly heat to 45.8 °C within 60 s under 0.5 sun, thereby demonstrating excellent deicing performance. This work provides a theoretical foundation for developing environmentally tolerant superhydrophobic photothermal coatings, which exhibit significant application potential in the field of anti-icing and anti-fouling. Full article

Hexavalent chromium Cr (VI) compounds present in ilmenite concentrate not only pose significant environmental hazards due to their toxicity but also complicate further processing, interfering with technological operations in industrial production. The high chromium content in ilmenite concentrates hinders their conversion into titanium-containing slag, necessitating the removal of chromium ions to permissible residual levels to produce titanium dioxide. In this study, various sorbents were investigated for the removal of chromate ions from the industrial effluents generated during ilmenite concentrate processing. The sorbents examined included natural and modified diatomite, activated carbon, taurite (shungite), and the ion-exchange resin Lewatit M500. The structures of both natural and modified diatomite were analyzed using scanning electron microscopy (SEM). It was determined that natural diatomite samples consist of diatom frustules of various shapes and their fragments, with structural element sizes ranging from submicron dimensions to 50 µm. A mathematical analysis of the sorption data for hexavalent chromium ion removal from solutions was performed. The results demonstrated high sorption efficiencies for Lewatit M500 (98.34%) and diatomite modified with iron compounds (98.95%). The findings suggest that diatomite is a promising sorbent for chromate ion removal from wastewater due to its availability and potential for chemical modification. Full article

This research investigates the impact of compost particle size, compost additives, and application rate on the physical properties of loamy sand soil, particularly focusing on water retention characteristics. Compost, enriched with additives like zeolite, biochar, and diatomite, was applied to soil in different rates: 1%, 2%, and 4%. Compost particles were divided into three particle size classes: 0–500 µm, 500–1000 µm, and 1000–2000 µm. The study revealed significant effects of compost on soil physical quality, including bulk density, porosity, and water retention. Zeolite-enriched compost showed the most pronounced improvements in soil water retention by modifying pore diameter. However, the effectiveness of compost additives varied depending on the type and rate of application. Compost with zeolite resulted in a decrease in the volume of large soil pores with diameters of 50–500 µm and above 500 µm. This resulted in higher water retention related to mesopores. Larger compost particles (1.0–2.0 mm) exhibited superior effects on soil physical quality compared to smaller particles (<1.0 mm), although finer particles (0.5–1.0 mm) were associated with higher water repellency. Compost with diatomite resulted in higher water repellency than other compost types. The findings underscore the importance of considering compost particle size, component type, and application rate to optimize soil hydraulic characteristics, particularly in agricultural practices where water management is crucial. Full article

In this paper, the results of the technological combustion of SHS heat insulators based on mineral origins are presented. It is shown that after mechanochemical treatment of minerals—diatomite—the kinetic characteristics of the combustion process change, providing targeted formation of the phase composition, structure, and properties of the SHS composite. A positive effect of using various modifiers during the MCT of diatomite—the activation of the combustion process—was established. The selection of modifiers provides an increase in the strength of the synthesized SHS composites as a result of the formation of aluminate compounds in the synthesis products, and a decrease in thermal conductivity to 0.157 W/m*K due to the formation of the ultraporous structure of the samples. Full article

Transition metal oxides have been widely used in microwave-absorbing materials, but how to improve impedance matching is still an urgent problem. Therefore, we introduced urea as a polymer carbon source into a three-dimensional porous structure modified by Co₃O₄ nanoparticles and explored the influence of different heat treatment temperatures on the wave absorption properties of the composite. The nanomaterials, when calcined at a temperature of 450 °C, exhibited excellent microwave absorption capabilities. Specifically, at an optimized thickness of 9 mm, they achieved a minimum reflection loss (RL_min) of −97.3 dB, accompanied by an effective absorption bandwidth (EAB) of 9.83 GHz that comprehensively covered both the S and Ku frequency bands. On the other hand, with a thickness of 3 mm, the RL_min was recorded as −17.9 dB, with an EAB of 5.53 GHz. This excellent performance is attributed to the multi-facial polarization and multiple reflections induced by the magnetic loss capability of Co₃O₄ nanoparticles, the electrical conductivity of C, and the unique three-dimensional structure of diatomite. For the future development of bio-based microwave absorption, this work provides a methodology and strategy. Full article

This article presents the results of research work devoted to improving the characteristics of paint and varnish coatings based on aqueous dispersions of polyacrylates; it is proposed to modify them by introducing mineral raw materials as fillers and hydrated lime, with subsequent processing in a vortex layer apparatus. The introduction of activated diatomite does not cause the deterioration of covering power, adhesion or an increase in the porosity of the paint material. The modification of coatings contributes to an increase in their operational properties, which can be associated with a reduction in the free volume in the composite and the formation of polymer boundary layers with modified physical and chemical properties. The aim of this study is to obtain a water-dispersion paint and varnish composition containing modified diatomite on a polyacrylate basis and, subsequently, study its main physical and mechanical parameters. The work has been carried out by the following method: determination of porosity, adhesion, elasticity and covering power of the control composition; determination of porosity, adhesion, elasticity and covering power of the obtained composites using modified filler; investigation of the influence of radiation on the infrared spectrum of the paint coating surface using a FLIRB620 thermal imager. As a result of this research work, it was noticed that the modification of water dispersions with silica-activated diatomite helps to eliminate the main disadvantages of materials and coatings based on acrylate binders—low water resistance and low physical and mechanical characteristics. The introduction of modified diatomite into water-emulsion paint on an acrylate base does not lead to the deterioration of the main performance characteristics of paint coatings—porosity, adhesion, elasticity and covering. Full article

A diatomite-modified Fe₂O₃ (Fe₂O₃/Dia) catalyst was prepared to catalyze the ozonation degradation of sulfachloropyridazine sodium (SPDZ). The chemical oxygen demand (COD) was used as the index of pollutant degradation. The catalytic ozonation experiment showed that the COD removal rate of SPDZ was 87% under Fe₂O₃/Dia catalysis, which was much higher than that obtained when using Fe₂O₃ as the catalyst. The characteristics of the Fe₂O₃/Dia catalyst were investigated, and the successful synthesis of the Fe₂O₃/Dia composite catalyst was proved by XRD, XPS, SEM, FTIR, BET and other characterization methods. The catalytic mechanism of degradation by ozone with Fe₂O₃/Dia was analyzed. According to free-radical trapping experiments and an in situ electron paramagnetic spectrometer characterization analysis, the main oxidizing species in the catalytic Fe₂O₃/Dia ozone system is ·OH. The intermediates in the degradation process of SPDZ were detected and analyzed in detail by liquid chromatography-coupled mass spectrometry. The degradation mechanism and three degradation paths of SPDZ were proposed. Full article

Ceramsites are extensively employed as substrates for adsorbents in studies focused on phosphorus adsorption, leaving ceramsites crafted from diatomite less explored. Diatomite-based ceramsite, with its distinct porous architecture and surface silanol functionalities, is adept at supporting a variety of metal oxides, presenting a distinct advantage over other ceramsite variants. In light of this, the present study embarked on producing diatomite-based ceramsite using diatomite as the foundational material, subsequently enhancing it through the incorporation of Fe, thus yielding an Fe-modified diatomite-based ceramsite. Through adsorption testing, the modified ceramsite demonstrated a significantly improved adsorption capacity of 4.06 mg P/g, marking a substantial enhancement from the initial capacity of 0.9 mg P/g. The process of phosphorus adsorption exhibited a strong alignment with the Langmuir isotherm model and the pseudo-second-order kinetic model. In-depth analyses employing XRD, FTIR, zeta potential, and XPS techniques have revealed that the principal mechanisms driving the adsorption process are centered on interactions involving electrostatic forces, the formation of chemical precipitates, and the exchange of ligands. This investigation not only opens new avenues for the application of diatomite-based ceramsite but also lays down a theoretical foundation for its modification, thereby enriching the spectrum of its utility. Full article

A review of the application of matrix solid-phase dispersion (MSPD) in the extraction of biologically active compounds and impurities from plants and food samples with a particular emphasis on conventional and new types of sorbents has been provided. An overview of MSPD applications for the isolation of organic residues from biological samples, determined using chromatographic and spectroscopic techniques, has been presented. In this study, procedural solutions that may extend MSDP applicability for the extraction such as vortex-assisted, ultrasound-assisted, microwave-assisted, and extraction with a magnetic sorbent have been discussed. Special attention has been paid to MSPD sorbents including modified silica, diatomite, magnesium silicate, alumina, carbon materials (carbon nanotubes, graphene oxide, graphene, or graphite), molecularly imprinted polymers, and cyclodextrin. An important aspect of the MSPD procedure is the use of high-purity and environmentally friendly solvents for extraction (e.g., deep eutectic solvents), with such criteria being the most important for modern analytical chemistry. Many advantages of MSPD are presented, such as high recoveries, the requirement for a smaller volume of solvent, and shorter procedure times than classical methods. Full article

This study aimed to create new composite materials based on diatomite—a non-organic porous compound—through its surface modification with bioactive organic compounds, both synthetic and natural. Chloramphenicol, tetrahydroxymethylglycoluril and betulin were used as modifying substances. Composite materials were obtained by covering the diatomite surface with bioactive substance compounds as a solution and material dispersion in it. The materials were characterized by IR spectroscopy, SEM and X-ray photoelectron spectroscopy. For the biocomposites, the hemolytic effect, plasma proteins’ adsorption on the surface and the antibacterial activity of the obtained materials were studied. Results show that the obtained materials are promising for medicine and agriculture. Full article

Cationic polyacrylamide (CPAM) solid particle is one of the most commonly used organic polymer flocculants in oilfield wastewater treatment, but it poses some problems, such as a slow dissolution rate and an easy formation into a “fish-eye” in the process of diluting into aqueous solution. However, the current liquid CPAM products also have some problems, such as low effective content, poor storage stability, degradation in a short time, and high preparation costs. In this paper, a CPAM suspension was successfully prepared with 50.00% CPAM fine powder, 46.87% oil phase solvent, 0.63% separating agent, 1.56% emulsifying and dispersing agent, and 0.94% rheology modifier. This suspension has an effective content of 50.00%. It also showed no separation in 7 days of storage at room temperature, no separation in 30 min of centrifugation at a speed of 2000 rpm, and diluted to a 0.40% solution in just 16.00 min. For 1000 NTU of diatomite-simulated wastewater, the optimal turbidity removal rate of the suspension was 99.50%, which was higher than the optimal turbidity removal rate of 98.40% for the inorganic flocculant polymeric aluminum chloride (PAC). For oilfield wastewater, the optimal turbidity removal rate of the CPAM suspension was 35.60%, which was higher than the optimal turbidity removal rate of 28.40% for solid particle CPAM. In a scale-up test, the CPAM suspension achieved a good application effect. Full article

The purpose of this study is to synthesize geopolymer binders as an environmentally friendly alternative to conventional cement using available local raw materials. Waste materials such as chalcedonite (Ch), amphibolite (A), fly ash from lignite combustion (PB), and diatomite dust (D) calcined at 900 °C were used to produce geopolymer binders. Metakaolin (M) was used as an additional modifier for binders based on waste materials. The base materials were subjected to fluorescence X-ray fluorescence (XRF) analysis and X-ray diffractometry (XRD) to determine chemical and phase composition. A laser particle size analysis was also performed. The various mixtures of raw materials were activated with a 10 M solution of NaOH and sodium water glass and then annealed for 24 h at 60 °C. The produced geopolymer binders were conditioned for 28 days under laboratory conditions and then subjected to microstructural analysis (SEM) and flexural and compressive strength tests. The best compressive strength results were obtained by the Ch + PB samples—more than 57 MPa, while the lowest results were obtained by the Ch + D+A + M samples—more than 20 MPa. On the other hand, as a result of the flexural strength tests, the highest flexural results were obtained by D + A + M + PB binders—more than 12 MPa, and the lowest values were obtained by binders based on Ch + D+A + M—about 4.8 MPa. Full article