CaSO4 Research Articles

Unlocking the Value of Phosphogypsum Waste: Steam Calcination for Efficient Decomposition and Resource Recovery

ABSTRACT Phosphogypsum is a waste by-product of phosphate fertilizer production. It contains calcium sulfate (CaSO4.xH2O), which can be decomposed to produce calcium oxide (CaO) and sulfur dioxide (SO2). Steam calcination is a process that uses steam to decompose CaSO4. This study represents the first comprehensive investigation of steam calcination applied to phosphogypsum, comparing its performance to pure CaSO4 at various temperatures (1050–1200 °C) and steam molar ratios (0, 4%, and 30%). The results showed that steam calcination can significantly lower the calcination temperature of both CaSO4 and phosphogypsum. The presence of steam can significantly accelerate the decomposition reaction of pure CaSO4 and phosphogypsum when compared to decomposition in nitrogen or air. It was found that the decomposition reaction in steam follows the contracting cylinder reaction model in the case of CaSO4 and the first-order reaction model for the phosphogypsum. Additionally, the activation energy for the steam calcination of CaSO4 and phosphogypsum were found to be 421.2 kJ/mol and 418.6 kJ/mol, respectively, which are lower than the activation energy for the calcination in oxyfuel combustion products (O2, CO2, SO2, and H2O gases) 531.4 kJ/mol demonstrating its potential for enhanced energy efficiency. As a result, steam calcination emerges as a promising sustainable solution for valorizing phosphogypsum while reducing energy consumption and greenhouse gas emissions.

3D‐Printed Bioceramic Scaffolds Reinforced by the In Situ Oriented Growth of Grains for Supercritical Bone Defect Reconstruction

AbstractPorous calcium phosphate ceramics have attracted widespread attention owing to their excellent bioactivity. However, their poor mechanical properties severely limit their clinical applications. Significantly improving the mechanical strength of porous CaP ceramics while maintaining their bioactivity remains a major challenge. To address this issue, calcium sulfate is used to regulate the directional growth of hydroxyapatite grains during ceramic sintering. The in situ oriented grains can not only alleviate the stress concentration but also strengthen the bonding force between the ceramic grain boundaries. Calcium sulfate improves the release of active calcium ions from calcium phosphate ceramics, further enhancing their bioactivity and osteoinductivity in vivo. Transcriptome and proteome sequencing reveals that the in situ whisker‐reinforced ceramics increase the expression of proteins related to calcium ion binding and promote the expression of osteogenesis‐related proteins. In the supercritical bone defect repair model, repair of the defect is achieved within 3 months, with mechanical recovery reaching more than 70% of the autologous bone.

The Efficacy of Calcium Sulfate/Hydroxyapatite (CaS/HA) Gentamicin in Osteomyelitis Treatment: A Case Series

Background: Osteomyelitis is a challenging condition caused by infection and inflammation of the bone, presenting a significant economic burden to healthcare systems. Calcium sulfate/hydroxyapatite (CaS/HA) is a bone void filler composed of 60% calcium sulfate and 40% hydroxyapatite. This case series aimed to report the efficacy and infection-related outcomes of CaS/HA combined with Gentamicin (CaS/HA-G) in treating osteomyelitis. Methods: Patients aged 18 and older diagnosed with osteomyelitis requiring surgical intervention and treated with CaS/HA-G during their procedure were included in the study, with a median (Q1–Q3) = 10 (7–16)-month follow-up period of time. Data collected included demographic, surgical, and outcome information. Infection eradication was determined by the normalization of the C-reactive protein, erythrocyte sedimentation rate levels, or the absence of clinical infection symptoms. Results: The case series involved 21 patients (twelve male, nine female) with a mean (SD) age of 54.8 (16.6) years. Vancomycin or/and Tobramycin were used as an additional antibiotic in 17 patients. At the last follow-up, 20 out of 21 patients (95.2%) had eradicated the infection, with a median (Q1–Q3) eradication time of 128 (71.8–233.5) days. Conclusions: In conclusion, this study demonstrates that CaS/HA-G is effective in controlling osseous infection in osteomyelitis while acting as an absorbable bone void filler.

The Use of Phosphonates to Inhibit Salt Crystallization: A Laboratory Study for the Sustainable Conservation of Mural Paintings in the Hypogea Context

This research is focused on the laboratory study of salt crystallization inhibitor products as new materials for conservation treatments which can be applied to mortars and painted plasters; as is well known, salt crystallization is one of the most frequent causes of decay processes on decorated architectural surfaces in a wide range of environments. Specifically, the study targets the field of the preventive conservation of mural paintings within rupestrian heritage sites. For the first time, systematic investigations were performed on mock-ups made of plaster painted with two different pigments: yellow ochre and carbon black. Two types of phosphonate inhibitors, PBTC (2-phosphonobutane-1,2,4-tricarboxylic acid) and ATMP (aminotris (methylene phosphonic acid)), were chosen and applied at two different concentrations. Given the limited literature available, and the presence of pigments potentially sensitive to treatment with salt inhibitors, preliminary tests were required. Their effects on the chromatic features of the pigments were evaluated visually and using colorimetry. The changes in the behaviour of water circulation in the mortar resulting from the treatments were evaluated through water vapour permeability and absorption tests. Accelerated crystallization experiments were carried out to assess how inhibitors could influence the growth of salts and the resulting material damage. The latter was carried out by employing sodium sulphate and calcium sulphate solutions, quantifying the damage to the specimens through material loss in weight and the percentage of painted surface loss. Based on the overall results, the product with the best performance was identified was ATMP 0.1% (by volume) in deionized water. The obtained results show that salt inhibitor treatments are promising for in situ application and could represent an innovative approach to promote the sustainable conservation of mural painting, particularly those located in hypogeal contexts, where the salt supply cannot be removed and slowing the growth of salts and/or changing their crystalline habitus may be effective in limiting their damage.

Effect of alkali metal sulfates on hydration properties of alpha-calcium sulfate hemihydrate for 3D printing

Three-dimensional printing (3DP) technology is an important means of achieving decorative convenience, personalization, and functional integration for future building construction. However, the setting time and hydration process of calcium sulfate hemihydrate (HH) present chanllenges for the 3DP application. This study aims to investigate the accelerating effect of alkali metal sulfates accelerators on the hydration transformation of HH into calcium sulfate dihydrate (DH). The setting time, conductivity, Ca2+ ion concentration, size distribution, and zeta (ζ) potential of gypsum slurries with different accelerators were measured. The results demonstrated that the accelerators significantly enhanced the hydration process of αlpha-calcium sulfate hemihydrate (α-HH). On the effect of accelerators, the setting times of gypsum slurries containing 30 wt% lithium sulfate (LS), sodium sulfate (NS) and potassium sulfate (KS) were accelerated by 82.56 %, 86.06 % and 97.13 %, respectively, compared to the control sample. The crystal particle sizes of hydration products decreased, and the absolute values of ζ potential increased to 1.85 mV, 3.1 mV, and 5.3 mV, respectively. The X-ray photoelectron spectroscopy (XPS) analysis revealed a shift in the peak values of the hardened specimens towards higher electric fields. This was accompanied by improved ion dispersion within the slurry, resulting in enhanced supersaturation of calcium sulfate dihydrate and crystallization of the crystal nuclei. Thus, the suitable accelerators can effectively achieve rapid solidification and hardening of high-fluidity gypsum slurries.

Evaluation of the Effect of pH and Concentration of Calcium and Sulfate Ions on Coal Flotation

The presence of calcium sulfate in the process water during the coal flotation greatly influences the recovery and selectivity of the separation. The concentrations of calcium and sulfate ions modify mineral hydrophobicity by altering surface properties resulting in depression or activation of the mineral species. An investigation to evaluate the statistical significance of the effect of the pH and concentration of calcium and sulfate ions on coal flotation was carried out; for this purpose, a 23 factorial design was implemented. A p-value < 0.05 was determined for the effect of calcium and sulfate ion concentrations, indicating that it is statistically significant. The interactions between factors (pH × calcium, pH × sulfate, calcium × sulfate and pH × calcium × sulfate) are also statistically significant, but the interaction between the concentration of calcium and sulfate ions has a notable influence according to the F statistic value. Employing 800 and 1920 mg/L of calcium and sulfate ions as experimental conditions yields a recovery of 90.4% with a concentrate containing 13% ash.

Strength analysis and microstructural characterization of calcined red mud based-geopolymer concrete modified with slag and phosphogypsum

This research aims to comprehensively investigate the combined use of calcined red mud (RM), calcium sulfate dihydrate (CSD), and ground granulated blast furnace slag (GGBFS) in geopolymer concrete (GC), demonstrating how their optimized proportions improve GC's fresh, mechanical, durability, and microstructural properties. This study investigated the influence of partially replacing calcined red mud (RM) with GGBFS and Phosphogypsum or CSD in GC. The test program included tests on the fresh, mechanical, and durability properties of these blends, including slump value, compressive strength, ultrasonic pulse velocity, water absorption and porosity, rapid chloride penetration, electrical resistivity, mass loss due to freeze-thaw cycles, and resistance to sulfate attack. Material characterization of the GC blends was conducted using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential thermogravimetric analysis (DTG). One-way ANOVA analysis was also used to examine the significance of variation between the results due to the replacement of calcined RM with GGBFS and CSD. The results showed that the mix R40-G45-C15, with 40% calcined red mud, 45% GGBFS, and 15% CSD, demonstrated the highest density at 2401 kg/m³, 15.93% greater than the R70-G15-C15 mix, and achieved a compressive strength 73.40% higher at 28 days. Additionally, R40-G45-C15 showed superior durability, with water absorption and porosity reductions of 87.42% and 83.86%, an 85.78% reduction in charge passed at 7 days, and a 40.94% lower mass loss from freeze-thaw cycles compared to R70-G15-C15. SEM analysis confirmed the formation of N–A–S–H and C–A–S–H gels in the blends, contributing to improved density and strength. XRD tests indicated the nominated peaks of calcite, quartz, and portlandite in the blends, with increased portlandite intensity due to higher RM content. These results indicate that partially substituting the calcined RM with CSD and GGBFS in GC could be a viable alternative option, offering potential contributions to sustainable construction with improved structural performances.

Effect of different calcium sulfate aspect ratios and chitosan addition methods on the interface properties of calcium sulfate/chitosan composite bone cement

AbstractIt is a great challenge to improve the properties of pure calcium sulfate bone cement. Here, two calcium sulfate hemihydrate powders with different aspect ratios were prepared, and three chitosan addition methods were adopted to investigate the effect on the surface and interface properties of calcium sulfate/chitosan composite bone cement. The results showed that it lacked chemical bond between chitosan and calcium sulfate, and the short rod calcium sulfate displayed better interface adhesion with chitosan owing to its smaller size, so it possessed shorter setting time, better compressive strength and slower degradation than the long rod calcium sulfate, while the biocompatibility had no remarkable difference. Moreover, chitosan solution as liquid phase was a better solidification mode than citric acid, and calcium sulfate/chitosan composite as solid phase was the worst mode because of poor interface compatibility. Conclusively, it was a simple, low‐cost, and effective preparation process to choose short rod calcium sulfate powder as solid phase and 1 wt% chitosan solution as liquid phase, which could achieve calcium sulfate/chitosan composite bone cement with the best properties, including setting time, compressive strength, degradation rate, and biocompatibility, displaying a promising application in bone defect repair.

Discovery of calcium sulfate at different hydration states on Mars - based on perseverance SHERLOC analysis

Organic matter on planets is often co-deposited with evaporites, and evaporation of lakes in the Jezero region of Mars may have led to the deposition of abundant organic matter and minerals such as sulfates, making sulfates important minerals for preserving the remains of potential life on Mars, especially in different hydration states, will help to invert the variability of the Martian environment and provide guidance for the exploration of life on Mars. Raman spectroscopy can detect the molecular composition of organic matter and acid anion information of the target of interest, thus enabling in situ analysis of life information and its living environment. In order to realize the detection of life remains on Mars, The Perseverance rover is equipped with SHERLOC in situ material detection payload, which adopts a 248.6 nm deep ultraviolet (DUV) laser to simultaneously excite Raman and fluorescence signals of the target. In this paper, five scans in three modes (survey scan, HDR scan and detail scan) from two sites on Mars (Quartier and Bellegarde) were selected for preliminary analysis, and the presence of sulfate minerals at these two sites was confirmed. The detail scans at Quartier were analyzed in depth, and the presence of four calcium sulfate minerals, gypsum (CaSO4∙2 H2O), bassanite (CaSO4∙0.5 H2O), anhydrite (β-CaSO4) and gamma-calcium sulfate (γ-CaSO4)was inferred from the states of ν1 (SO4), ν3 (SO4) and hydrated peaks. The differences in the degree of hydration of calcium sulfate minerals suggest that there may have been active water activity on Mars. By comparing data collected by SHERLOC with spectra from spectral libraries, the composition of small-scale structures on Mars may be assessable. However, due to the complexity of the Martian geology, more accurate water activity will need to be combined with more detailed ions, temperatures, humidity, and other conditions for a more precise analysis.

A Newly Bio-Based Material for the Construction Industry Using Gypsum Binder and Rice Straw Waste (Oryza sativa)

Construction is one of the economic sectors with the greatest influence on climate change. In addition to working procedures, the primary carbon footprint is attributed to the choice of materials and the energy required for their manufacturing. The underlying idea of this study is to minimize the effects and offer new solutions to emerging problems in the quest for materials that can be deemed as natural, such as gypsum (calcium sulphate dihydrate) and rice straw (Oryza sativa). The acquisition of these materials involves a lower carbon footprint compared to the conventional materials. It is well known since ancient times that gypsum and cereal straw can be used in construction, with numerous examples still available. Cereal straw is one of the oldest construction materials, traditionally combined with earth and occasionally with certain binders, with it continuing to be employed in construction in many countries to this day. This work showcases the feasibility of producing stable prefabricated elements from straw waste with construction gypsum, addressing a significant environmental concern posed by the alternative of having to burn such materials. In this study, for the proposed bio-based material, specific tests, such as thermal conductivity, flexural and compressive strength, and fire resistance, were carried out to evaluate the principal physical and mechanical characteristics for different compositions of water, gypsum, and straw fiber samples. The results highlighted the good performance of the proposed materials in order to spread their use in the green building industry. The addition of straw fibers improved, in different ways, some important physical characteristics of these components so as to diminish environmental pollution and to obtain better material performance. The tests highlighted the different behaviors of the proposed material with respect to the different cuts of the straw and as well as the water/gypsum ratio; this is not very well understood and probably depends on the micro structure of the straw fibers. The blocks with raw straw showed a significant improvement in the breaking mechanism (1775.42 N) compared to the blocks with cut straw (712.26 N) when subjected to bending tests, and their performance in compression tests was also acceptable. Additionally, a very interesting reduction in thermal conductivity was achieved by incorporating rice straw (0.233 W/mK), and high fire exposure times were obtained, with gypsum preventing the spread of ignition in any type of fiber.

Gypsum Crystals Formed by the Anhydrite–Gypsum Transformation at Low Temperatures: Implications for the Formation of the Geode of Pulpí

Determining the mechanisms of the formation of giant crystals is a challenging subject. Gypsum, calcium sulfate dihydrate (CaSO4·2H2O), is known to form crystals larger than one meter in several locations worldwide. These selenite crystals grow at different temperatures, either in sedimentary or hydrothermal systems. The famous selenite crystals of the geode of Pulpí (Almería, Spain) are known to have grown at a temperature T = 20 ± 5 °C and have been proposed to form in a subaqueous environment by a self-feeding mechanism triggered by anhydrite dissolution and the ripening of microcrystalline gypsum, enhanced by oscillations in temperature. This paper reports the monitored crystallization of gypsum crystals, from anhydrite powder dissolution, inside airtight evaporation-free reactors under oscillating low temperatures (15 °C < T < 25 °C). These crystals are clearly smaller than the ones in the Pulpí mine but exhibit similar habits (i.e., single blocky crystals and twins following the 100 twinning law). The growth rate of gypsum single crystals has been measured to be between 3.8 and 35.3 µm/day. Noteworthy, we document the occurrence of the 100 contact twinning law of gypsum, which is the most widespread twinning law in natural environments but never univocally reported in laboratory experiments. The selection of the 100 contact twinning law has been correlated to the low supersaturation values obtained in the experiment, where the concentration in these long-duration experiments can be safely assumed to be the equilibrium concentration, i.e., 0.3 (at 25 °C) ≤ SI ≤ 0.4 (at 15 °C). We discuss the relevance of our experiment for forming the gypsum crystals of Pulpí in the framework of the geological history of Pulpí mineralization. These laboratory model experiments contribute to a deeper understanding of mineral nucleation and growth processes in natural environments.

Spatial distribution of groundwater quality and risk indices evaluation via consumption

Groundwater is a valuable source for drinking and irrigation use and is the primary concern of developing countries. Therefore, the current study investigated groundwater in the Mirpur District of Azad Jammu and Kashmir, Pakistan, for drinking and irrigation purposes. Groundwater was sampled from the Jatlan, Mirpur, and Dadyal towns of studied district and analyzed for physicochemical parameters. Groundwater results revealed that the WHO's upper limits were not surpassed for physiochemical parameters, except for pH value (11.7% samples). Groundwater was evaluated for various quality and risk indices. Based on the water quality index (WQI), groundwater was categorized as excellent to good for drinking use. For irrigation uses, 11.7% of Mirpur and 5.8% of Dadyal water were unsuitable, and the rest was found in the good category as evaluated by sodium adsorption ratio and sodium hazards. The groundwater was classified as calcium sulfate (CaSO4), and mixed types and hydrogeochemistry were predominantly influenced by surrounding rock weathering. The groundwater showed a maximum level of hazard quotient of 0.20 ± 0.05 via fluoride intake in the Dadyal town. Based on studied parameters and risk indices, groundwater is recommended for drinking, domestic, and agricultural purposes.

Spectral induced polarization measurements to detect different scales in oil and gas production tubing

Different varieties of scales, such as iron sulfide (FeS) scale, and calcium carbonate (CaCO3), commonly precipitate within oil and gas production tubing, posing operational challenges and production losses. It is essential to implement efficient mitigation strategies and preserve production integrity to detect and characterize these scales in an accurate and efficient manner. Prior studies have explored Spectral induced Polarization (SIP) for the early detection of FeS within porous media, mainly for environmental applications or for identifying FeS in carbonate formations from the perspective of reservoir characterization. This study focuses on applying SIP to address production-related issues in production tubing. For this purpose, six actual subsurface scale samples were analyzed using X-ray Diffraction, X-ray Fluorescence, and SIP techniques. These samples were categorized into three primary groups based on their composition: Pyrrhotite, Goethite, and Calcium Sulfate Hydrate or Calcite. The results indicate that combining phase shift and conductivity as frequency functions makes it possible to develop an approach to classify and differentiate between various scale types. This information could be instrumental in developing methods that can be potentially integrated into tubing systems to detect and characterize the different scale types.

Gypsum Binder With Increased Water Resistance Derived From Membrane Water Desalination Waste

ABSTRACTA method has been developed for separating a mixture of calcium, magnesium and sodium sulfates obtained through the interaction of sulfuric acid and waste from the water purification process generated by using membrane filters. The primary goal of this method is to extract gypsum and produce gypsum‐based binders. Patterns were identified regarding how various types, ratio and quantities of additives: blast furnace slag, granite screenings, portland cement, electric steel smelting slag affect the water‐gypsum ratio, strength properties, and water resistance of high‐strength gypsum binders. It was found that adding a single‐component additive specifically to enhance water resistance does not significantly impact these properties. Complex additives have been developed based on Portland cement, granulated blast furnace slag, electric furnace slag, expanded clay dust, and granite screenings of various fractions. These additives are designed to maximize the water resistance of high‐strength gypsum binder based on synthetic calcium sulfate dihydrate. As a result, the water resistance coefficient increased from 0.45 to 0.52. Additionally, a technological block diagram of the process has been proposed.

The Use of Dissolvable Synthetic Calcium Impregnated with Antibiotic in Osteoarticular Infection in Patients with Diabetes

The medical management of osteoarticular infections in patients with diabetes continues to be a considerable clinical dilemma because of inadequate blood supply and weakened immune systems. The objective of this study is to assess the effectiveness of dissolvable synthetic pure calcium sulfate beads with antibiotics in the treatment of osteoarticular infections in individuals diagnosed with diabetes mellitus. A retrospective analysis was conducted on 27 patients with diabetes (19 with type II diabetes and 8 with type I diabetes) who were diagnosed with osteoarticular infections and received treatment with locally delivered antibiotic-loaded calcium sulfate beads. The patients were monitored for a duration ranging from 6 months to 2 years, during which the clearance of infection, bone remodeling, and rates of recurrence were evaluated. The evaluation also included an assessment of glycemic control and its influence on infection treatment. The findings revealed a notable decrease in the recurrence of infections, as patients who were given combinations of two antibiotics showed better results in comparison to those who were exclusively treated with one antibiotic. A 92% eradication rate was achieved within the trial group, and patients who had dual-antibiotic treatment did not have any return of illness. Postoperative bone remodeling was shown to take place between 8 and 16 weeks, with faster recovery in individuals who maintained ideal glycemic control (HbA1c < 7%). Only one instance of soft tissue necrosis was documented, indicating minimal consequences. The results validate the use of dissolvable synthetic calcium sulfate as a secure and efficient local antibiotic administration method for controlling osteoarticular infections in patients with diabetes, providing improved infection management and facilitating bone regeneration.

Silk Composite-Based Multifunctional Pellets for Controlled Release.

Chronic wounds present significant clinical challenges due to the high risk of infections and persistent inflammation. While personalized treatments in point-of-care settings are crucial, they are limited by the complex fabrication techniques of the existing products. The calcium sulfate hemihydrate (CSH)-based drug delivery platform enables rapid fabrication but lacks antioxidant and antibacterial properties, essential to promote healing. To develop a multifunctional platform, a tannic acid (TA)-silk fibroin (SF) complex is engineered and incorporated as an additive in CSH cement. This cement is then cast into pellets to create silk/bioceramic-based composite drug delivery systems, designed for point-of-care use. Compared to neat CSH pellets, the composite pellets exhibit a 7.5-fold increase in antioxidant activity and prolonged antibacterial efficacy (up to 13 d). Moreover, the subcutaneous implantation of the pellets shows no hallmarks of local or systemic toxicity in a rodent model. The pellets are optimized in composition and fabrication to ease market translation. Clinically, the pellets have the potential to be further developed into products to place on wound beds or fill into bone cavities that are designed to deliver the intended therapeutic effect. The developed multifunctional system proves to be a promising solution for personalized treatment in point-of-care settings.

The Effect of Calcium Sulfate on the Hydration and Properties of Red Mud-Based Calcium Ferroaluminate Cement Clinker.

The hydration of high-alkali red mud-based ferroaluminate cement (RCFA) clinker with calcium sulfate needs to be regulated. This study explored the effects of the calcium sulfate type and dosage on the hydration and properties of high-alkali RCFA clinker. The research results show that when 4% gypsum was added, the 3 d compressive strength of cement was 39.1 MPa, and the 28 d compressive strength was 63.2 MPa. The 28 d strength increased by 61.6% compared with the 3 d strength. The properties of cement paste can be adversely affected by excessive anhydrite content. The exothermic hydration of clinker was accelerated by calcium sulfate at the beginning, but the rate declined as the process progressed. Sufficient sulfur supply can enhance the hydration of ye'elimite, thereby increasing the AFt content in the hydration product. The mass loss of the hydration product is mainly caused by the dehydration of ettringite, monosulfoaluminate, and AH3. In addition, the Na element in the RCFA hydration product is mainly present in monosulfoaluminate and unhydrated cement particles.

MicroED: Unveiling the Structural Chemistry of Plant Biomineralisation.

Plants are able to produce various types of crystals through metabolic processes, serving functions ranging from herbivore deterrence to photosynthetic efficiency. However, the structural analysis of these crystals has remained challenging due to their small and often imperfect nature, which renders traditional X-ray diffraction techniques unsuitable. This study explores the use of Microcrystal Electron Diffraction (microED) as a novel method for the structural analysis of plant-derived microcrystals, focusing on Armeria maritima (Milld.), a halophytic plant known for its biomineralisation capabilities. In this study, A. maritima plants were cultivated under controlled laboratory conditions with exposure to cadmium and thallium to induce the formation of crystalline deposits on their leaf surfaces. These deposits were analysed using microED, revealing the presence of sodium chloride (halite), sodium sulphate (thénardite), and calcium sulphate dihydrate (gypsum). Our findings highlight the potential of microED as a versatile tool in plant science, capable of providing detailed structural insights into biomineralisation processes, even from minimal and imperfect crystalline samples. The application of microED in this context not only advances the present understanding of A. maritima's adaptation to saline environments but also opens new avenues for exploring the structural chemistry of biomineralisation in other plant species. Our study advocates for the broader adoption of microED in botanical research, especially when dealing with challenging crystallographic problems.

Crystal Patterning from Aqueous Solutions via Solutal Instabilities.

Fluid instabilities can be harnessed for facile self-assembly of patterned structures on the nano- and microscale. Evaporative self-assembly from drops is one simple technique that enables a range of patterning behaviors due to the multitude of fluid instabilities that arise due to the simultaneous existence of temperature and solutal gradients. However, the method suffers from limited controllability over patterns that can arise and their morphology. Here, we demonstrate that a range of distinct crystalline patterns including hexagonal arrays, branches, and sawtooth structures emerge from evaporation of water drops containing calcium sulfate on hydrophilic and superhydrophilic substrates. Different pattern regimes emerge as a function of contact line dynamics and evaporation rates, which dictate which fluid instabilities are most likely to emerge. The underlying physical mechanisms behind instability for controlled self-assembly involve Marangoni flows and forced wetting/dewetting. We also demonstrate that these patterns composed of water-soluble inorganic crystals can serve as sustainable and easily removable masks for applications in microscale fabrication.

Potential role of calcium sulfate/β-tricalcium phosphate/graphene oxide nanocomposite for bone graft application_mechanical and biological analyses

BackgroundBone grafts are extensively used for repairing bone defects and voids in orthopedics and dentistry. Moldable bone grafts offer a promising solution for treating irregular bone defects, which are often difficult to fill with traditional rigid grafts. However, practical applications have been limited by insufficient mechanical strength and rapid degradation.MethodsThis study developed a ceramic composite bone graft composed of calcium sulfate (CS), β-tricalcium phosphate (β-TCP) with/without graphene oxide (GO) nano-particles. The biomechanical properties, degradation rate, and in-vitro cellular responses were investigated. In addition, the graft was implanted in-vivo in a critical-sized calvarial defect model.ResultsThe results showed that the compressive strength significantly improved by 135% and the degradation rate slowed by 25.5% in comparison to the control model. The addition of GO nanoparticles also improved cell compatibility and promoted osteogenic differentiation in the in-vitro cell culture study and was found to be effective at promoting bone repair in the in-vivo animal model.ConclusionsThe mixed ceramic composites presented in this study can be considered as a promising alternative for bone graft applications.