Formation and characteristics of novel magnesium silicate hydroxide-derived carbon-based tribofilms under rolling contact

Stabilization of a Magnesium Silicate Scale Providing Corrosion Control in a Potable Water Distribution System

Background: Pleurodesis is a treatment method that aims to create permanent adhesion between the pleural layers to prevent recurrent fluid or air accumulation in the pleural cavity. Talc, one of the most commonly preferred agents in this procedure, is widely used in clinical practice. In this study, a new talc formulation with a modified surface to impart antibacterial and analgesic properties was experimentally evaluated for the first time. The main objective of the study was to comparatively assess the inflammatory and fibrotic responses following standard talc and modified talc applications. Methods: Thirty-six 12-week-old female Wistar albino rats were simply randomly divided into three different groups: control (n = 12), standard talc (n = 12), and modified talc (n = 12). Under anesthesia, 1 mL of physiological saline containing 17 mg of talc was injected intrapleurally into the right hemithorax. The presence of pneumothorax after the procedure was assessed by chest radiography. After a 12-day follow-up period, the animals were euthanized. Bronchoalveolar lavage (BAL) fluid samples, blood samples, and lung and pleural tissue samples were collected for biochemical, histopathological, and immunohistochemical analyses. Results: Modified talc application resulted in a significant increase in both visceral and parietal pleural thickness (p < 0.05). Granulation tissue formation and collagen deposition were significantly higher in the modified talc group. In addition, TGF-β expression and CD68-positive macrophage count increased significantly in the modified talc group (p < 0.05). Inflammatory changes in the lung parenchyma were limited and not statistically significant. Conclusions: The modified talc formulation enriched with lidocaine and antibacterial agents produced a stronger inflammatory and fibrotic response compared to standard talc. These findings indicate that modified talc may increase the effectiveness of pleurodesis. Furthermore, the absence of significant lung parenchymal damage suggests that this treatment is locally effective and feasible. However, further long-term and advanced studies are needed to translate these results into clinical use.

Comparative analysis of regression models for predicting SCC strength using copper slag and magnesium silicate

Talc mineralization in the SW Fodikwan area, Red Sea Hills, NE Sudan: Geological and geochemical constraints

Synergistic reinforcement and flame retardancy in silicone rubber achieved by magnesium silicate nanotubes

This study aims to characterize the minerals in rock samples from Dembek and Wariab Villages, South Manokwari Regency, West Papua, using the X-ray Diffraction (XRD) method. XRD was used to identify crystalline phases and mineral compositions in the rocks, as well as to understand the geological conditions and mineral resource potential in the area. Rock samples were systematically collected from both locations and analyzed using an X-ray diffractometer. The analysis results show that the rocks from Dembek Village are dominated by quartz (SiO 2 ), Sodium Aluminum Silicate (Na 1.45 Al 1.45 Si 0.55 O 4 ), Potassium Aluminum Silicate (KAlSi 2 O 6 and KAlSiO 4 ), Potassium Silicon Fluoride (K 2 SiF 6 ), Albite (Na (Si 3 Al)O 8 ), Magnesium (Mg), Sodium Magnesium Aluminum Silicate (Na 3 MgAlSi 2 O 8 ), and Potassium Magnesium Silicate (K 2 MgSi 5 O 12 ). The rocks from Wariab Village contain a more varied range of minerals from two sampling points, namely, at the WRB-L1 location, consisting of halite (NaCl), quartz (SiO 2 ), Potassium Magnesium Fluoride (KMgF 3 ), Potassium Magnesium Silicate (K 2 MgSi 5 O 12 ), anorthite (CaAl 2 Si 2 O 8 ), and Potassium Aluminum Silicate (KAlSi 2 O 6 ). The WRB-L2 location consisted of fluorite (CaF 2 ), Potassium Silicon Fluoride (K 2 S1F 6 ), sylvite (KCl), sodalite (Na 4 Al 3 Si 3 O 12 Cl), and Sodium Aluminum Silicate (Na 1.65 Al 1.65 Si 0.35 O 4 ). These differences in mineral composition reflect variations in the formation environment and geochemical processes that occur at each location.

ABSTRACT This study has investigated the effects of seawater and cement type on the mineralogical changes resulting from cement-bentonite interactions in the context of geological disposal of transuranic (TRU) waste in Japan. High-pH ordinary Portland cement (OPC) paste and low-pH high content fly ash silica fume cement (HFSC) paste were mixed with bentonite, ultrapure water and seawater, and reaction times of 6 months or 15 years were all investigated at 60°C. The results show a clear cement-type dependence. In the OPC specimens, high-pH plume generation was observed due to extensive cement hydrate dissolution, which resulted in calcium silicate hydrate (C-S-H) formation in the bentonite regions, while in the HFSC specimens, the chemical gradients were small and alkaline alteration was minimal. The solution composition also significantly affected the interactions, with ultrapure water resulting in uniform elemental distribution and artificial seawater causing zonation due to magnesium silicate hydrate (M-S-H) formation. The C-S-H formed in the bentonite regions was inferred to function as a barrier that inhibited the penetration of seawater components, suggesting that high-pH cement may not necessarily be unsuitable as a cementitious material adjacent to bentonite.

Large volumes of dredged sludge (DS) are generated in waterway and port engineering, yet its direct utilization is limited by high water content and poor mechanical properties. Cement stabilization improves strength but fails to ensure long–term stability under cyclic loading, where stiffness degradation and cumulative deformation remain critical issues. This study evaluates the dynamic performance of nano–magnesium oxide (NM) modified cement–stabilized dredged sludge (CDS) through unconfined compressive strength (UCS) and cyclic triaxial tests, supported by X–ray diffraction (XRD) and scanning electron microscopy (SEM). Results show that incorporating 2% NM increases the 28–day UCS by ∼97% compared with cement–only samples, reduces cumulative plastic strain by nearly two–thirds, and delays dynamic modulus degradation by more than 20%. A dual mechanism of “σ 3 enhancement–σd amplification” is proposed to describe the confining pressure effect. Microstructural analyses reveal that NM promotes the formation of magnesium silicate hydrate (M–S–H) and Mg(OH)2 gels while inhibiting AFt, leading to a denser pore structure and improved fatigue resistance. The findings provide mechanistic understanding and practical guidance for the sustainable reuse of dredged sludge in coastal road and railway subgrades subjected to traffic– and wave–induced cyclic loads.

Calcium magnesium phosphate cements (CMPCs) were obtained starting from dolomite (alone or mixed with fly ash) thermally treated at two different temperatures. Dolomite calcination at 750 °C for 3 h determined the formation of a mixture of MgO and CaCO3. The mixing of dolomite with fly ash and the increase in the calcination temperature at 1200 °C determined the formation of new compounds (calcium aluminum silicate and calcium magnesium silicates), which are present along with MgO and small amounts of CaO in the thermally treated material. These two precursors were mixed with KH2PO4 solution and borax (as a retardant admixture) to obtain the CMPCs. The setting time and compressive strengths of these CMPCs were assessed and the XRD analyses provided insights into their mineralogical composition after hardening and thermal treatment. The cements, as so or mixed with perlite, were applied on steel plates, to assess their behavior when put in direct contact with a flame. The compatibility of these materials with the steel substrate was evaluated by scanning electron microscopy (SEM). The direct contact with the flame up to 60 min provided information regarding the CMPCs’ ability to prevent the rapid increase in the substrate (steel plate) temperature. The findings indicate that CMPC pastes and composites containing perlite can offer a degree of protection for steel structures in the event of a fire.

Basic magnesium sulfate cement (BMSC) exhibits rapid setting, early strength development, high ultimate strength, and good durability, making it a promising construction material for the extreme environments of Mars. Following the principle of in situ resource utilization (ISRU), this study employs the Martian regolith simulant NUAA-1M, developed by Nanjing University of Aeronautics and Astronautics, as both a mineral admixture and aggregate to prepare Martian basic magnesium sulfate cement (M-BMSC) and Martian basic magnesium sulfate cement concrete (M-BMSCC). The effects of NUAA-1M fines on the setting time, compressive strength, hydration heat evolution, hydration products, microstructure, and pore structure of M-BMSC were systematically investigated. Moreover, the fundamental physical and mechanical properties of M-BMSCC incorporating NUAA-1M as an aggregate were evaluated, and an empirical correlation model was established between its compressive strength (fcu), flexural strength (ft), and splitting tensile strength (fsp). Results indicate that with increasing NUAA-1M fines content, the setting time of M-BMSC was prolonged, while its compressive strength initially increased and then decreased. The incorporation of NUAA-1M fines modified the hydration process and phase assemblage of M-BMSC, promoting the formation of magnesium (alumino)silicate hydrate (M-(A)-S-H) gels and refining the pore structure. Hydration monitoring within 24 h confirmed the rapid hydration characteristics of M-BMSC, demonstrating its suitability for Martian conditions. M-BMSCC exhibited excellent early- and high-strength performance, achieving a 28-day compressive strength of 59.2 MPa at a binder-to-aggregate ratio of 2:1, corresponding to a total NUAA-1M content of 84.75% in the mixture. This work provides a novel ISRU-based material strategy for the construction of Martian bases and infrastructure.

Abstract The focus of recent research on cement binders has shifted to alternatives such as magnesium silicate hydrate (M‐S‐H) to mitigate the environmental impact of conventional concrete production. However, a detailed understanding of the morphology and growth rate of M‐S‐H, which informs its applicability as a cementing agent, is lacking. These properties are important as they influence cement hydration and consequently the development of macroscopic properties. In this study, the particle size distribution and growth rate of M‐S‐H synthesized by mixing aqueous stock solutions were analyzed using synchrotron‐based small‐angle X‐ray scattering. The reaction solutions contained dissolved magnesium and silicon with concentrations ranging from 2 to 500 mM, corresponding to saturation indices with respect to M‐S‐H endmembers, M 0.75 ‐S‐H and M 1.50 ‐S‐H, between 5.8 and 10.3. The precipitation rates of M‐S‐H align with affinity‐based kinetic models and can be described by the following equations: For M 0.75 ‐S‐H: , and for M 1.50 ‐S‐H: , where is the rate in mol/L/s, and represents the saturation ratio with respect to M‐S‐H. Moreover, we observed that changing the [Mg]/[Si] ratio affects particle size, a trend that cannot be fully explained by changes in the saturation index alone. These insights are critical for improving the predictability and control of cementation in concrete that utilizes M‐S‐H‐based binders.

This study investigates environmentally friendly and efficient protocols for synthesizing two distinct heterocyclic scaffolds: pyranopyrazoles and dihydropyranochromenes. Dihydropyranochromenes were synthesized using talc in refluxing ethanol, while pyranopyrazoles were obtained from solvent-free under mixing conditions. The advantages of these methods include high yields, operability, and the use of an accessible, inexpensive, and non-toxic basic catalyst. The reaction conditions, including reaction time, molar ratios of reactants, and catalyst amount, were optimized for the synthesis of products, resulting in high yields of 97% for pyranopyrazoles and 95% for dihydropyranochromenes. The synthesized products were characterized using analytical techniques, including FTIR and NMR, which confirmed the successful synthesis. In this study, total energy and band gap energy calculations were performed for dihydropyranochromenes and pyranopyrazoles derivatives. This suggests that talc powder a natural catalyst, can enhance organic synthesis and offer a sustainable and environmentally friendly solution for modern organic chemistry.

Can silicate types regulate plant defense and rhizospheric microbiome diversity differently during heat stress conditions?

Chemical Control of Magnesium Silicate Precipitation in Magnesium- and Silica-Loaded Process Waters by Phosphonate-Functionalized and Systematically Elongated Linear Amino Acids

Abstract Magnesium silicate hydroxide (MSH) is valued for its excellent antiwear and self-repairing properties. In this study, vinyl-tri-(2-methoxyethoxy)-silane (VTMOEO) was used to modify MSH via a hydrothermal method, synthesizing VTMOEO-intercalated MSH (VTMOEO@MSH). Characterization confirmed the successful intercalation of VTMOEO into the layers of MSH. Tribological tests showed that VTMOEO@MSH exhibited outstanding antiwear and friction-reducing properties in PAO. The optimal formulation reduced the friction coefficient and wear volume by 41.2% and 32.5%, respectively, compared to the PAO. Scanning electron microscopy (SEM), molecular dynamics simulation, and optical interference experiments demonstrated that VTMOEO modification enhanced the adhesion of MSH on the worn surface and prevented its reaction with the worn surface, forming a removable adsorption film. This suggests that the antiwear and antifriction mechanism of VTMOEO@MSH operates by forming an adsorption film on the friction surface.

Fabrication of waste bread-derived biodegradable mulch film with sustained-release atrazine performance.

Hydrophobic magnesium silicate hydroxide coating for daytime radiative cooling

Zinc-doped calcium magnesium silicate ceramics: A comprehensive study on bioactivity, mechanical strength, and microbial resistance

Regulators specific adsorption mechanism underlying the selective flotation separation of pyrite from magnesium silicate minerals