MgO Particles Research Articles

Design and Experimental Evaluation of Composite Magnesium Phosphate Cement-Based Coating with High Cooling Effect

The application of surface heat reflective coatings is one of the effective measures to solve the temperature disease of concrete structures in sunlit environments. To achieve strong bonding, high durability, and good cooling characteristics, a novel inorganic reflective thermal insulation coating was prepared using magnesium phosphate cement (MPC) as the binder and reflective matrix, and titanium dioxide and glass beads as the reflective thermal insulation reinforcement functional additives. The optimum ratio of the new reflective thermal insulation coating was preferred through laboratory irradiation test, thermal conductivity test, and spectral reflectance test. The results show that MPC itself was a good reflection cooling material, and the surface and internal temperatures of concrete blocks were reduced by 7.6 °C and 6.6 °C, respectively, after using MPC as the cooling coating. When 2% titanium dioxide was added to MPC, the surface and internal temperatures were further reduced by 6.0 °C and 4.9 °C, respectively. On top of this, the surface and internal temperatures of the concrete were reduced by a further 3.9 °C and 2.2 °C when 8% glass beads were added. The bond strength of the MPCTG coating to the concrete matrix reached 2.1 MPa. Finally, the microscopic characteristics and the reflective thermal insulation mechanism of the MPCTG coating were investigated with the aid of SEM, thermo gravimetric analysis, and XRD analysis. The results show that the MPC in the MPCTG coating was well hydrated, and a large number of hydration products encapsulated the unreacted MgO particles, titanium dioxide, and glass beads, forming a dense whole with high reflection and low thermal conductivity, and the coating effectively prevented the entry of radiant heat. At the same time, the MPCTG coating was thermally stable below 70 °C. The magnesium phosphate cement-based reflective thermal insulation coating developed in this study has potential application prospects in concrete structure cooling coatings.

Effect of nanoprepared levofloxacin in inhibiting of Klebsilla pneumoniae Isolated from respiratory tract infections

Objective: Global statistics revealed that respiratory tract infections (ARTIs) are one of the main causes of mortality. Klebsiella pneumonia is considered one of the main causes of ARTIs. Levofloxacin has a wide spectrum effect against gram negative and gram positive bacteria, and its inhibitory activity can by improved through nanobiotechnology. Method: A nanohybrid antibiotic was synthesized by intercalating levofloxacin between magnesium oxide layers. The prepared antibiotic was characterized by fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM) and atomic force microscope (AFM). Results: FT-IR spectrum showed the appearance of new groups in the Lev-MgO spectrum, which indicate the creation of a new compound. XRD spectrum revealed the presence of new diffraction planes which support the results obtained from FT-IR technique. SEM images demonstrated that MgO particles were converted to structure similar to coins arranged in irregular mode. AFM images showed the formation of spherical nanoparticle that indicates the formation of a new compound. Conclusion: The nanohybrid antibiotic was efficient in inhibiting twelve Klebsiella pneumonia isolated from respiratory tract infections.

In situ X‐ray Scattering of the Crystallisation of Basic Magnesium Chlorides using a Laboratory Instrument

AbstractWe demonstrate a method for in situ monitoring of the crystallisation of basic magnesium chlorides using a laboratory‐based SAXS (small angle X‐ray scattering)/ WAXS (wide angle X‐ray scattering) instrument. By simultaneous acquisition of SAXS/WAXS, time‐resolved particle size and phase evolution information was obtained from room temperature to 120 °C. The WAXS data were analysed using two‐phase Rietveld refinements, to produce crystallisation curves. From Avrami‐type kinetic analysis two competing mechanistic processes were proposed for the formation of Mg3Cl(OH)5 ⋅ 4 H2O with a nucleation‐type mechanism extending further into the reaction with increased temperature. When comparing SAXS and WAXS, an offset between the consumption of MgO and the reduction of the sphere contribution to the SAXS scattering is observed. This is rationalised by the formation of an amorphous Mg(OH)2 layer on the MgO particle surface. Although laboratory‐based SAXS/WAXS instruments have limitations compared to synchrotron‐based sources, we have demonstrated how they can provide new insights into the formation of materials.

Fabrication and thermal shock behaviour of BaZrO3–MgO composites

This study introduces BaZrO3 with a perovskite structure as a second phase combined with MgO to prepare composites and apply these magnesium matrix composites in high-temperature fields. The prepared composites have good dimensional stability (linear change rate <1%) and better cold compression strength (50–110 MPa) compared to fused magnesite. Sintered samples containing 5 wt % BaZrO3 possessed a better elastic modulus and flexural strength at 1600 °C compared to fused magnesite. BaZrO3 formed a glass phase with CaO and SiO2 in the fused magnesite sand at high temperatures, which was distributed between the particles of MgO. The BaZrO3 inhibited grain growth, promoted the exclusion of pores, and significantly reduced the thermal conductivity of the sintered samples. Scanning electron microscopy images indicated that compared to single-phase MgO, the composite sample produced a glass phase after a thermal shock, filling its pores, resulting in enhanced retention of the sample mechanical properties and better thermal shock stability. This study demonstrates that magnesium matrix composites with BaZrO3 have promising applications in high-temperature materials.

Excellent hydration and thermal shock resistance in MgAlON–MgO ceramics synthesized from spent MgO–C brick: Microstructural characteristics, hydration mechanism and thermal shock behaviour

Hydration and thermal shock resistance of MgAlON–MgO ceramics synthesized from spent MgO–C bricks were investigated by hydration experiment and water/air quenching method. It was observed that MgAlON does not undergo hydration reaction and hydrated MgO only accounts for about 0.2 wt% of total amount of MgAlON–MgO ceramics. Thermal shock tests indicated that MgAlON–MgO quenching in water show different fracture mechanism at different temperature. The retained strength of MgAlON–MgO ceramics quenched at 1398 K is only affected by thermal shock. However, the retained strength of the ceramics quenched at 698 K and 1098 K are affected by synergistic effect of hydration reaction of MgO and thermal shock. The retained strength of MgAlON–MgO ceramics quenching in air and water at 1398 K still reached about 55 MPa and 6 MPa, respectively. Furthermore, thermal shock resistance of MgAlON–MgO improve with the increase of MgO content and MgAlON with 15.7 wt%MgO shows the best thermal shock resistance. The reason for the improvement is that the microcracks between MgAlON and MgO particles increase with the increase of MgO content, and the dispersed microcracks could release the thermoelastic strain energy and thus inhibit crack propagation. The results showed that the MgAlON–MgO ceramics synthesized with spent MgO–C bricks possess excellent hydration and thermal shock resistance hence have potential application in the metallurgical industry.

Evaluation of Bookkeeper mass deacidification based on historical book papers

Bookkeeper, the most widely used deacidification process based on MgO particles, was systematically evaluated on two sets of nonvaluable historical paper samples. Established analytical methods, such as pH and alkaline reserve determination, were used, as well as SEM EDS analyses to evaluate the distribution of Mg-rich particles on the paper surface and in the cross-section of the paper. The degradation rate constants of untreated and deacidified paper samples after accelerated thermal degradation were calculated based on weight average molecular mass determination to evaluate the lifetime extension of paper. The efficiency factors determined after accelerated thermal degradation of untreated and treated paper showed that paper lifetime prolongation after Bookkeeper deacidification treatment is highly limited for most of the investigated paper samples. No correlation was found between the alkaline reserve content or the pH and the degradation rate constants of the deacidified paper samples, but the paper degradation rate correlated with the paper samples pH before deacidification treatment. SEM EDS analysis showed that Mg-rich particles remained on the paper surface, which explains the limited effectiveness of the treatment.Graphical abstract

Effect of MgO on electrochemical properties of silicon-based anode composite material

A silicon (Si)/magnesia (MgO)/graphite composite (denoted as SMG@C) was synthesized by high-energy ball milling (HEBM) via the reduction of silica (SiO) by magnesium (Mg) and subsequent addition of graphite, followed by pitch pyrolysis for carbon coating. The particles of MgO in the SMG@C were removed by hydrogen chloride (HCl) leaching to form the Si/graphite composite (denoted as SG@C). The microstructural characteristics of the two composite materials were analyzed by X-ray diffraction and transmission electron microscopy and their electrochemical properties were evaluated by cyclic voltammetry, electrochemical impedance spectroscopy, and capacity cycling tests. Results indicated that the a homogeneous mixture of nanoscale Si and MgO was fabricated by HEBM, and some of the Si and MgO formed a specific crystallographically coherent interface which was determined as Si(220)//MgO(200). The values of Warburg coefficient for SMG@C and SG@C were determined to be 1.84 Ω/S1/2 and 203.42 Ω/S1/2, respectively. When the SMG@C anode composite material was cycled for 440 cycles at a current density of 200 mA/g, its reversible capacity retention rate was 87.8%, showing excellent long-cycle performance compared to the SG@C. The presence of MgO in the anode composite material greatly improved the electrochemical properties.

Seesaw-type modulation of secondary electron emission characteristics of polytetrafluoroethylene-MgO composite coating

The electrostatic discharge (ESD) from polymer insulators is one of the environment-related anomalies on spacecraft. Theoretically, to mitigate the ESD effects, we could modulate the secondary electron yield (SEY, σ) close to 1 in the entire energy range, suppressing surface charges. However, no single polymer insulator has been reported to achieve this seesaw-type modulation of SEY. Here, we exploringly designed and prepared MgO particles doped polytetrafluoroethylene (PTFE) composite coating to achieve this goal, which exhibits not only the reduced SEY characteristic of the microstructured PTFE coating at low energy but also the enhanced SEY characteristic of the double-layer structure of PTFE and MgO at high energy. The simulation and experiment results demonstrate that MgO particles doped PTFE coating achieves this seesaw-type modulation of SEY. The optimal MgO concentration is 20%, where the maximum SEY (σmax) changes from 2.0 to 1.1; the SEY at 10 keV (σ10k) changes from 0.6 to 0.8, and the higher energy of the SEY equal to 1 (Ep2) increases from 4.5 to 6.5 keV. The discharge test of the microstrip antennas with PTFE-MgO composite coating in a scanning electron microscope verifies the role of the seesaw-type SEY modulation in surface charge suppression. This study supplies an essential reference for suppressing surface charges on vacuum electronics based on modulation of secondary electron emission characteristics.

Research on novel battery thermal management system coupling with shape memory PCM and molecular dynamics analysis

• A novel SCPCM with shape memory and shape stability is proposed. • The interaction of PA/SEBS was analyzed at the molecular level. • SCPCM shows good thermal stability at a temperature range higher than PA phase transition. • Under discharge conditions of 3C, the temperature difference in the PCM module is kept within 3℃. Traditional battery thermal management using phase change materials (PCM) is restricted by PCM’s leakage, low thermal conductivity and incompatibility. In this work, a shape memory composite PCM (SCPCM) composed of styrene-b-(ethylene-co-butylene)-b-styrene triblock copolymer (SEBS), paraffin (PA), expanded graphite (EG) and Fe 3 O 4 -modified graphene oxide (Fe 3 O 4 -MGO) was prepared. The thermal properties and shape stability of the composite material were studied. The compatibility between the phase change matrix and the support material was investigated. The results show that reducing the size of EG particles can effectively reduce the thermal conduction “percolation point”. The Fe 3 O 4 -MGO particles loaded on EG can effectively reduce the interfacial thermal resistance between EG and PA then further strengthen the heat transfer capability of CPCM. SCPCM shows good thermal stability in the range of phase transition temperature higher than PA (49–85 °C). The simulation results show that PA and SEBS molecules exhibit good interfacial compatibility, hydrogen bonds are formed between the molecules where there is a strong interaction. Therefore, PA/SEBS show good thermal stability in the macro system. SCPCM exhibits excellent performance in heat dissipation. Under discharge conditions of 3C, the temperature difference in the SCPCM module is kept within 3 °C.

Novel microstructures inducing an excellent combination of strength and elongation in in-situ MgO/AZ31 composites

Herein, in-situ MgO particles with novel spatial arrangements were introduced into AZ31 using ball milling and hot extrusion. The MgO particles assemble into a honeycomb-like structure in the three-dimensional (3D) space, and exhibit an adequate interfacial integrity with the magnesium matrix. The grains in MgO-rich zones are refined to approximately 1 μm, and the MgO/AZ31 composites exhibit a bimodal structure consisting of fine-grain and coarse-grain zones. The fine grains exhibit a honeycomb-like arrangement and are filled with the coarse grains, just like a bee pupa-infilled honeycomb. Compared to AZ31, the fabricated MgO/AZ31 composites have an greatly enhanced strength and a slightly improved ductility, displaying an adequate combination of strength and ductility. In particular, the ultimate tensile strength and elongation of 0.75 wt% MgO/AZ31 composites were up to 343 MPa and 18.5%, respectively. The outstanding mechanical properties could be attributed to the novel honeycomb-like structure and in-situ MgO.

Study on the Influence of Organic–Inorganic Interface Properties on Breakdown Strength and Thermal Properties of MgO/PLA Composites

Polylactic acid (PLA) is expected to be widely used in green power equipment manufacturing due to its good mechanical properties and biodegradability. In this paper, the effects of MgO with different particle sizes and mass fractions on the thermal and electrical properties of PLA composites were studied. The experiment found that with the increase in MgO particle sizes and mass fractions, the thermal conductivity of MgO/PLA composites showed a rising trend, which was up to 165.4% higher than that of pure PLA. However, the heat resistance first increases and then decreases. For the electrical properties of MgO/PLA composites, the breakdown strength and volume resistivity decrease with an increase in MgO particle size and mass fraction. In order to further study the influence mechanism of the introduction of MgO with different particle sizes and mass fractions on the thermal and electrical properties of MgO/PLA composites, molecular dynamics simulation was used to simulate the glass transition temperature (Tg) of PLA composites doped with MgO of different particle sizes, and it was found that MgO doping weakened the movement of the PLA molecular chain segment. Using density functional theory (DFT) calculations, it was found that in the MgO and PLA system, electrons have a tendency to migrate from the PLA matrix to MgO, which causes the formation of electron traps at the inorganic–organic interface and affects its electrical properties. The purpose of this study is to provide a theoretical reference for PLA composites in the manufacture of power equipment.

Reaching near-theoretical strength by achieving quasi-homogenous surface dislocation nucleation in MgO particles

The structural stability of the ceramic nanoparticle (NP) is essential for its versatile applications in broad fields. Due to inevitable imperfections on the surfaces, the NP usually yields at a stress that is far below its theoretical strength. Here we propose an effective way to approach the theoretical strength of the NPs by simply homogenizing the primary imperfections. Electron beam irradiation is utilized to modify the original uneven surface and achieve surface nano-crystallization in MgO NPs, which leads to more homogeneous stress distribution intrinsically as proved by numerical simulations. As a result, quasi-homogeneous surface nucleation of dislocations occurs and raises the compressive strength to be three times higher than the as-received particles with the original surface. The near-theoretical strength gained here indicates that the imperfection in materials can be homogenized to optimize the properties to approach that of perfect crystals.

Synthesis and Characterization of ZnO and MgO Nanoparticles through Green Approach and Their Antioxidant Properties

The present work focus on the synthesis and structural characterization of ZnO and MgO Nanoparticles using geranium leaves extract as reducing agent through green approach. The prepared ZnO and MgO Nanoparticles were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM).The elemental composition of ZnO and MgO Nanoparticles were investigated using Energy Dispersive X-ray analysis (EDAX). Based on the XRD data, the ZnO and MgO particles were measured to be 64 and 42 nanometers in size, respectively. The DPPH method was used to further test the antioxidant property of the synthesized Nanoparticles. MgO and ZnO were both found to be excellent free radical scavengers, as measured by their DPPH scavenging activities. The antioxidant property of MgO is enhanced when compared to ZnO nanoparticles.

Drying shrinkage characteristics and mechanism primary exploration of MgO-slag mortars

In this work, seven groups of MgO-slag mortars and pastes were prepared with different MgO types and MgO contents. The setting time, compressive strength and drying shrinkage were characterized. The mechanism of drying shrinkage was discussed by means of microscopic test XRD, FT-IR, MIP and SEM-EDS. The results show that the setting time decrease with the increase of MgO activities and contents. The high-activity MgO only shows a higher compressive strength advantage in the early stage, and the higher content of S-MgO, the higher the compressive strength advantage in the later stage. The 120d drying shrinkage first increases and then decreases with the increase of S-MgO contents, and the maximum drying shrinkage is obtained when the S-MgO content is 15%. The drying shrinkage of the mortar mixed with M-MgO is about half of the mortar mixed with S-MgO; the mortar mixed with R-MgO shows expansion change. Intraparticle porosity, interparticle porosity, and MgO particle size are important factors that affect the drying shrinkage of MgO-slag mortars. This study will provide the theoretical basis for the preparation of cementing materials with no length change by using a MgO activator.

NOx emissions in a swirled-stabilized magnesium flame

Alternative sources of clean energy with reduced greenhouse gas emissions have to be considered. Among them, the combustion of metal fuels such as aluminum or magnesium is promising. Nitrogen oxides (NOx) are the only undesirable gases produced during such metal combustion. The present study analyzes the amounts of NOx (NO and NO2) produced by a swirled stabilized magnesium flame. Two geometric swirl numbers are considered: 0.7 (low swirl number) and 7.3 (high swirl number). Different air–fuel ratios – equivalence ratio ranging from 0.17 to 1 – are considered, being obtained by changing the mass flow rate of the injected fuel which is a pulverized fuel of pure magnesium particles with a size fraction 50–70 µm. Thermocouples and a bichromatic pyrometer are implemented to monitor the gas temperature and the flame temperature, respectively. Oxygen (O2) is measured using an in-line paramagnetic analyzers and NOx are measured using an IR-UV analyzer.Whatever the swirl conditions and the air–fuel ratio tested, a stabilized flame of Mg is obtained. The metal combustion exhibits very stable performances. NOx emissions versus equivalent ratio follow a bell-shape curve. Under the tested experimental conditions, the amount of NOx never exceeds 7 gNOx/kWh, which is lower than the maximal value of NOx emission from a gasoline engine. The NOx mole fraction increases when the air–fuel ratio increases, as the power dissipated by the flame increases. The temperature of MgO particles in the flame reaches 2250 °C and the gas temperature never exceeds 1400 °C. The thermal NOx formation is estimated applying Zeldovich’s model. The model indicates that NOx can be produced in the gas surrounding the hot MgO particles. For the highest equivalence ratio, even if the gas temperature is still increasing, the NOx production is disfavored in the rich mixture. Based on these results, a global scheme for NOx formation is proposed which includes four successive steps.

Influence of the residual oxygen amount in reduced graphene nanoplatelets on microstructure and mechanical properties of ZK60 matrix composites

Graphene nanoplatelets (GNPs) are commonly regarded as an ideal reinforcement for metal matrix composites because of their excellent mechanical properties. However, these excellent properties cannot be fully exploited due to GNPs aggregation and poor bonding interface. In the present investigation, GNPs with different residual oxygen amount were prepared by adjusting the amount of KMnO4 oxidant using the modified Hummers method as well as thermal reduction. The GNPs-reinforced ZK60 matrix composites (GNPs/ZK60) were prepared through stir casting. Structure characterization indicates there are C–O, C–O–C and C–CO oxygen-containing functional groups on the synthesized GNPs, among which all C–CO and parts of C–O groups are broken and react with Mg to form MgO particles. The formed interfaces in terms of MgO in the GNPs/ZK60 composites are MgO/Mg, having a semi-coherent interface structure, and MgO/GNPs, having an incoherent interface structure. The sandwich interface structure of Mg/MgO/GNPs improves the interface bonding, in which the ultimate tensile strength and elongation of the 0.05 wt.%GNPs-4/ZK60 composite reached 261 MPa and 12.1%, increasing 37.4% and 128.3%, respectively, compared with those of the monolithic matrix. It is suggested the present work might offer a design guideline for graphene reinforced metal matrix composites.

Investigation of the Densification Behavior of Alumina during Spark Plasma Sintering.

The article presents the results of the investigation of the mechanism of the densification behavior of alumina-based ceramics during spark plasma sintering. The role of the heating rates and additives were investigated. The first (initial) stage of sintering was investigated by the Young–Cutler model. The second (intermediate) stage of sintering was investigated as a process of plastic deformation of a porous body under external pressure. It was shown that, at the initial stage, the formation of necks between the particles is controlled by grain boundary diffusion (the activation energy is Qb ≈ 20 kTm). At this stage, accommodation of the shape of the alumina particles is also occurring (an increase in the packing density). The accommodation process facilitates the shrinkage of the powder, which is reflected in a decrease in the effective activation energy of shrinkage at low heating rates (10 °C/min) to Qb ≈ 17 kTm. At heating rates exceeding 10 °C/min, the intensity of the processes of accommodation of alumina particles turns out to be much slower than the existing diffusion processes of growth of necks between the alumina particles. It was shown that the grain boundary sliding mechanism that occurs in the second stage of sintering can play a decisive role under conditions of spark plasma sintering with a high heating rate. The found value of the activation energy at the second stage of sintering is also close to the activation energy of grain–boundary diffusion of alumina (Qb ≈ 20 kTm). The influences of the second phase particles of MgO, TiO2, and ZrO2 on densification behavior of alumina-based ceramics were investigated. Since at the first stage of sintering the densification relates with the formation of necks between the particles of alumina, the additives (0.5% vol) have no noticeable effect on this process. It was also shown that the second phase particles which are located at the grain boundaries of alumina are not involved in the slip process during the second sintering stage. Analysis shows that additives act only in the final (third) stage of spark plasma sintering of alumina.

Insight into the role and mechanism of polysaccharide in polymorphous magnesium oxide nanoparticle synthesis for arsenate removal

The low cost and non-toxic of magnesium oxides make it a potential eco-friendly material for arsenic removal. Polysaccharide is a kind of green modifier to obtain nanoscale MgO particles with a higher adsorption affinity. In this study, the impact of chain structures of polysaccharides on the morphology features and arsenate removal efficiency of MgO-NPs were investigated. Pullulan and starch facilitated the synthesis of flower-like MgO-NPs, and pectin facilitated the synthesis of plate-like ones. Although the two kinds of flower-like MgO-NPs undergone similar time to reach equilibrium, the one obtained from the starch-synthesis route showed a higher arsenate adsorption capacity (98 mg g−1), due to that their bushy and smaller petals on the surface provide more active sites for arsenic adsorption. The pectin-synthesis route also produced MgO-NPs with higher arsenate adsorption capacity (101 mg g−1), ascribed to stacking of nano-plates on their surfaces facilitated to form defect surfaces. However, due to their lower BET area, the plate-like MgO-NPs took twice times to reach equilibrium for arsenic adsorption compared with the others. In the stage for the hydrolysis of MgO, hydroxyl groups on the polymer chain provide active sites to physically trap or bond with MgO particles and then to produce hydrolyzed precursors. The poly chain containing inter- and intra-hydroxyl groups directed MgO molecular growing into hydroxide crystals with 3D frameworks during their nucleation and growth. However, pectin only provides inter-hydroxyl groups and directs to form hydroxides with 2D frameworks. Furthermore, the rapid-nucleation vs. slow-growth model in the stage of pyrolysis of hydroxide crystals successfully interprets the thinner petals and complex chemical phases of the final nanoparticles obtained from the pullulan-synthesis route. This work may provide direction and perspectives for the rational design of well-performing MgO materials for arsenate removal.

In-situ MgO generation method: A new strategy for mitigating the corrosivity of molten chloride salt

Molten chloride salts are excellent heat transfer fluids (HTFs) and thermal energy storage (TES) media, and they have potential applications in concentrating solar power (CSP) plants. However, they have strong corrosivity to metal pipes or vessels in actual working conditions, which is an urgent problem that needs to be solved. In this paper, a new strategy for mitigating the corrosivity of molten NaCl-CaCl2-MgCl2 salt is proposed. The results showed that the formation of MgO particles in molten salt using the in-situ generation method is an effective method for mitigating the corrosivity of molten chloride salt.

Physicochemical properties of MgO-silica fume cementitious materials exposed to high temperatures

In this paper, MgO and silica fume (SF) are used to prepare MgO-SF cementitious materials, physicochemical properties of MgO-SF materials at room temperature (RT), 100 °C, 200 °C, 300 °C, 400 °C, 600 °C and 800 °C are studied. By means of X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (29Si MAS-NMR), mercury intrusion porosimetry (MIP) and scanning electron microscopy-energy spectrometer (SEM-EDS), the changes of cementitious phase are explored to support the strength change results. The research results show that after a high temperature of 800 °C, the residual compressive strength of MgO-SF mortars is between 43.19% and 66.18%, showing excellent high-temperature resistance. XRD, FT-IR and SEM-EDS test results show that M-S-H gel has stronger thermal stability than brucite. The 29Si MAS-NMR results show that the M-S-H gels at the Q1 and Q2 sites turned to the Q3 site under the action of high-temperature, showing stronger stability. Under the action of high temperature, the presence of MgO-SF undergoes rehydration and M-S-H gel partially decomposes. When the temperature exceeds 400 °C, the brucite loses water and decomposes, the M-S-H gel dehydration and reorganization, and the unhydrated SF particles appear. The gel-like structure, SiO2 and MgO particles are loosely arranged, forming rough and uneven cluster morphology. This study provides an experimental and theoretical basis for the spreading and using MgO-SF materials under high-temperature conditions.