Eggshell Particles Research Articles

Eggshell-derived particle composites with epoxy resin for enhanced radiation shielding applications.

This study explores the development and efficacy of eggshell-derived particle composites with epoxy resin for enhanced radiation shielding applications. Eggshells, primarily composed of calcium carbonate, were processed into particles of three sizes: small, medium, and large. These particles were incorporated into epoxy resin at a 50% weight ratio and characterized using a Laser Particle Size Distribution Analyzer. Radiation shielding properties were determined using diagnostic X-ray equipment and a Radcal Accu-Gold detector, evaluating attenuation parameters such as the Half-Value Layer (HVL) and Linear Attenuation Coefficient (LAC). Mechanical testing revealed that composites with large particles exhibited the weakest performance, with a maximum force of 5674 N and stress of 52MPa. In contrast, small particle composites demonstrated superior mechanical properties, achieving a maximum force of 9125 N and stress of 97MPa. Additionally, small particle composites (S50%) displayed the highest LAC and lowest HVL, confirming their superior radiation shielding efficiency due to better dispersion and increased surface area. These findings highlight the potential of using finely ground eggshell particles to create cost-effective, environmentally friendly materials for radiation protection, underscoring the importance of particle size optimization in the development of advanced composite materials.

Enhancing thermo-mechanical properties of additively manufactured PLA using eggshell microparticle fillers

Polylactic acid (PLA) is a widely studied polymer for potential biomedical applications and is one of the most commonly used polymers for additive manufacturing or 3D printing. Additive manufacturing (AM) technology is a fast-rising method of fabrication of polymer parts compared to other traditional fabrication techniques. In recent years, natural plant-based and animal-based fibers have shown immense potential to be used as fillers or reinforcements for polymer composites. In this study, chicken eggshell particles (ESP) have been used as inorganic calcium carbonate fillers to enhance PLA's mechanical properties. Four different concentrations (0 wt%, 1 wt%, 3 wt%, and 5 wt%) of PLA/ESP composite filaments have been extruded using a single screw extruder. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analyses were used to determine the chemical composition of eggshell powder, showing peaks matching with that of calcium carbonate (CaCO3). Thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis show the effect of the filler on the PLA composite's thermal stability, indicating that pristine PLA has the highest melting temperature of 152 °C while the 5 wt% has the lowest melting temperature of 147 °C. The addition of eggshell particles slightly enhanced the compressive strength and dynamical mechanical properties of the PLA/ESP composites. The eggshell powders enhanced the dynamic mechanical property of PLA, with the 3 wt% concentration having the highest storage modulus at room temperature, with 5.2 % and 3.6 % increase for the filament and 3D printed samples respectively. Finally, the eggshell particles did not have much effect on the tensile and flexural strength of the composite, however, it enhanced the compressive strength of PLA with the 5 wt% sample having an average strength of 66.50 MPa and modulus of 2.27 GPa, respectively.

Synergistic effects of boron carbide and eggshell particles on mechanical and tribological properties of ultrasonic-assisted stir cast aluminium alloy based composites

Aluminium matrix composites are in high demand for their lightweight nature and favourable properties, yet issues like high thermal expansion, low microhardness or high cost often challenge them. To address these limitations, the integration of sustainable, cost-effective reinforcing agents that can enhance hardness and wear resistance can be explored, as this can broaden the application scope of these composites across various industries. The present study fabricates aluminium matrix composites with aluminium alloy (AA6063-T6) as a matrix and different wt.% (0%, 2% and 4%) of micro-sized eggshell (ES) and boron carbide (B4C) particles as reinforcements through ultrasonic-assisted stir-casting. Analysis of microstructure, mechanical and tribological properties of the fabricated composites are done and compared to those of the as-cast base alloy. Results from optical and scanning electron microscopy (SEM), together with energy-dispersive X-ray spectroscopy (EDS) analysis, revealed the uniform distribution of reinforcements in all three composites. X-ray diffraction (XRD) indicated the formation of several compounds in each composite. Among all, the as-cast base alloy exhibited the lowest porosity at 0.48%. The AA6063-T6/B4C composite demonstrated the highest hardness, with an increase of 46.08%, while the AA6063-T6/ES/B4C composite achieved the highest tensile strength, showing a 62.28% improvement compared to the as-cast base alloy. As the load increased from 20N to 60N, the wear rate of the reinforced composites rises while the coefficient of friction decreased, with the AA6063-T6/B4C composite showing the highest wear resistance.

OPTIMIZATION OF WEAR RESISTANCE OF ALUMINUM MATRIX COMPOSITE (AL-7050/10WT% EGGSHELL) BY STUDY OF EFFECT STIRRING SPEED AND STIRRING TIME

This study investigates the impact of stirring speed (X1) and stirring time (X2) composite materials (Al-7050/10 wt. %eggshell) renforcemented by eggshell particles of the on wear resistance by using the MINITAB 16 program. A composite material was produced by the stir casting method; the ingot was melted, and a molten metal vortex was produced by varying the stirring speed (200, 300, 400, 500, 600 rpm) and stirring duration (10, 20, 30, 40, and 50 minutes). Eggshell particles with a fixed weight fraction of (10% wt.) and sizes (21–30 μm) were used. It was concluded if the variables (X1 = 543.4343 rpm) and (X2 = 48.1818 min.) wear loss of (0.0061 g) could be achieved. In practice, wear loss (0.0063 g) was obtained using the values of X1 and X2, which were obtained using the programs. Was wear loss is almost identical to the value obtained by the program. Additionally, the results manifested that the stirring time (X2) and stirring speed (X1) have a significant impact on the wear loss, where increase in stirring speed and time leading to an increase in wear strength. Furthermore, the effect of stirring speed (X1) on the wear loss is larger than that of stirring time (X2).

Eggshell Particulate Reinforced Polymer Composite – A Review

Due to their low loading bearing, high thermal stability, renewability, and cost-effectiveness, natural filler reinforced polymer composite plays a significant role in the production of biodegradable materials. In spite of the fact that eggshells are discarded as waste, eggs are a highly produced food all over the world. Due to its high calcium carbonate content, eggshell is a potential resource for the polymer industry. This research aims to advance our understanding of eggshell and eggshell particulate reinforced polymer composites. Both fabrication techniques and methods for treating eggshell particles are discussed. Then, the physical and mechanical properties of eggshell-polymer composites are review and presented.

Wear Prediction of Functionally Graded Composites Using Machine Learning.

This study focuses on the production of functionally graded composites by utilizing magnesium matrix waste chips and cost-effective eggshell reinforcements through centrifugal casting. The wear behavior of the produced samples was thoroughly examined, considering a range of loads (5 N to 35 N), sliding speeds (0.5 m/s to 3.5 m/s), and sliding distances (500 m to 3500 m). The worn surfaces were carefully analyzed to gain insights into the underlying wear mechanisms. The results indicated successful eggshell particle integration in graded levels within the composite, enhancing hardness and wear resistance. In the outer zone, there was a 25.26% increase in hardness over the inner zone due to the particle gradient, with wear resistance improving by 19.8% compared to the inner zone. To predict the wear behavior, four distinct machine learning algorithms were employed, and their performance was compared using a limited dataset obtained from various test operations. The tree-based machine learning model surpassed the deep neural-based models in predicting the wear rate among the developed models. These models provide a fast and effective way to evaluate functionally graded magnesium composites reinforced with eggshell particles for specific applications, potentially decreasing the need for extensive additional tests. Notably, the LightGBM model exhibited the highest accuracy in predicting the testing set across the three zones. Finally, the study findings highlighted the viability of employing magnesium waste chips and eggshell particles in crafting functionally graded composites. This approach not only minimizes environmental impact through material repurposing but also offers a cost-effective means of utilizing these resources in creating functionally graded composites for automotive components that demand varying hardness and wear resistance properties across their surfaces, from outer to inner regions.

Tribological Performance of Polymer Composite Modified with Calcined Eggshell Particles Post High-Temperature Exposure

During operation, brake lining material rubs against the disc to generate heat. This heat could decrease the brake lining performance, such as the friction coefficient, specific wear rate, and interface temperature of the rubbing surfaces. The resulting wear debris is environmentally harmful and poses risks to human health. Therefore, this study aimed to replace the harmful material using eggshell particles as a filler in brake lining composite and enhance tribological properties. The brake lining samples were manufactured through three stages: cold compaction, hot compaction, and post-curing. The next step is the samples were subjected to a one-hour high-temperature exposure at 200°C, 300°C, 400°C, and 500°C. The results showed that the high-temperature exposure significantly affected the specific wear rate, friction coefficient, and interface temperature between the brake lining and disc. An interesting finding was that adding calcined eggshell particles in composite could improve the tribological properties up to 400°C. However, the best material’s performance resulted when the samples got an exposure temperature of 200°C. Doi: 10.28991/ESJ-2024-08-04-03 Full Text: PDF

Osteoproductivity of Injectable Bone Grafts with and without Ostrich Eggshell Membrane Protein in Rabbit Femur.

The aim of this study was to evaluate the biocompatibility and effectiveness in terms of osseointegration of dental implants composed of novel injectable bone grafts with and without ostrich eggshell particles and membrane protein in rabbit femur. Sixteen adult male New Zealand rabbits were used in this study. A bone defect was created in each animal's right and left femur, and a dental implant was placed adjacent to the defect. Two graft materials were prepared, one containing the membrane protein and the other not. In two groups, the defects were filled with these materials. In the negative control group (NC, (n:8)), the defects were left empty. A commercial product of biphasic calcium sulfate was used as a positive control material (PC, n = 8). The graft groups were defined as the group with the membrane protein (MP+, (n:8)), and without the membrane protein (MP-, n:8). The animals were euthanized at the 12th week after surgery. The samples were investigated using histology, histomorphometry, and micro-computed tomography. Data were statistically analyzed using one-way ANOVA and Tukey's tests (p = 0.05). Both the PC and MP+ groups had similar newly formed bone areas, and the mean values of these groups were significantly (p < 0.05) higher than those of the MP- and NC groups. The PC group had the highest amount of unresorbed material, while the MP- group had the lowest amount of unresorbed material. The bone-implant contact (BIC) scores of the PC and MP+ groups were significantly higher (p < 0.05) than that of the NC group. The connective tissue area of the PC group was the lowest, which was significantly lower than the other groups (p < 0.05). The grafts produced are highly biocompatible and also showed osteoproductivity. Their cost-effectiveness and osteoproductive activity require further investigation.

Development of polymer/carbon nanotubes incorporated sustainable materials for manufacturing of autobrake pad

AbstractAlthough asbestos fiber is used for autobrake pad production due to its heat resistance capacity, it is associated with a challenge of health risk (cancerogenic in nature). This health risk associated with asbestos-based autobrake pads has presented polymeric materials as a better candidate for the application due to their eco-friendliness, lightweight, chemical inertness, easy of processing, etc. However, polymers are associated with low wear and low mechanical properties, which are vital properties for autobrake pads. Therefore, this study developed EP nanocomposites reinforced with a low content of carbon nanotubes (CNTs) and eggshell (ES) attached cow bone (CB) particles denoted as (ES@CB) as agro-waste/sustainable materials for the manufacturing of autobrake pads. The hybrid ternary nanocomposites were developed via solution mixing and casting. Scanning electron microscope (SEM) revealed the 1-D structure of the CNTs, and relatively spherical shapes of ES and CB particles, and microstructures of the developed nanocomposites. The nanocomposite showed a low coefficient of friction and a reduction in wear rate in the range of 1.14 × 10−4 mm3/Nm for pure EP to 5.45 × 10−6 mm3/Nm for EP/0.4wt%CNTs-10wt%ES@CB nanocomposite, while the elastic modulus and hardness increased from 1.84 GPa and 128.64 MPa for pure EP to 4.41 GPa and 252.88 MPa for EP/0.2wt%CNTs-20wt%ES@CB nanocomposite, respectively. The comparison of the wear response of the developed nanocomposites with the current asbestos-based brake pads show that the developed epoxy nanocomposites from agro-waste materials are potential option for the manufacturing of autobrake pads, which will ensure sustainability, health risk-free, and environmentally friendly.

Superhydrophobic eggshell for fabrication of hydrophobic barrier of paper-based analytical device for colorimetric determination of ammonium ion in water

This work demonstrates the first application of the superhydrophobic eggshell as an environmental-friendly material for fabricating the hydrophobic barrier of a paper-based analytical device (PAD). The eggshell surface was modified by mixing the pulverized chicken eggshell biowaste with stearic acid and a polystyrene binder to accomplish superhydrophobicity. The PAD (10 × 10 mm2) is comprised of the circular-shaped hydrophilic reservoir (Ø 5 mm). The liquid barrier was fabricated by painting both the topside and the underside of the filter paper with the dispersed superhydrophobic eggshell solution. The SEM images revealed that the microsized superhydrophobic eggshell particles absorbed onto the porous surface of the cellulose fibril. A coated surface with a water contact angle of 155.39° ± 1.02° (n = 10) on the paper substrate was achieved, and this indicated superhydrophobicity. The eggshell barrier enabled excellent water and chemical resistance. The fabricated PAD was applied for the colorimetric determination of ammonium cations (NH4+), based on the modified Berthelot reaction. Samples and chromogenic solutions were aliquoted onto the hydrophilic reservoir, with subsequent capture of the optical image of the stable, green-colored product by a smart phone under a light-controlled studio. The green color intensities were evaluated by ImageJ™ and plotted against the standard NH4+ concentrations. A wide linear calibration range 5.0 to 100 mg N/L was achieved with good linearity (r2 > 0.99). The PAD confirmed satisfied analytical recovery (Mean ± SD: 100.6 % ± 0.97, n = 11 samples) and high precision (RSD = 0.85 %: 10-PAD replicate measurements of 1.0 mg N/L). The limit of detection (3 SD of blank/slope) of 1.05 mg N/L was found sensitive enough to monitor the NH4+ contents in freshwater. The results, determined by the developed PAD and ion chromatography, showed no significant difference under the statistical paired t-test at 95 % confidence (tstat = -1.80, tcri = 2.57, n = 6 samples).

Sustainable application of waste eggshell as fillers in alkali-activated solid waste-based materials: Varying treated methods and particle sizes

The incorporation of waste eggshells as fillers in construction materials is currently constrained by factors such as shell-membrane separation, particle size, and proportion of incorporation. This study aims to assess the feasibility of utilizing non-calcined eggshell particles (EPs) in alkali-activated solid waste-based materials. Initially, the micro characteristics of water-treated and alkali-treated eggshells were evaluated. Subsequently, nine groups of alkali-activated slag-based paste samples were prepared by using EPs as fillers, and the influence of the particles on the physical and mechanical properties of the materials was assessed based on flowability, density, and compressive strength. Furthermore, the impact of shell-membrane separation and particle size on the microstructure and composition of the alkali-activated materials (AAMs) was characterized by using a combination of SEM-EDS, XRD, FTIR, and TG-DSC techniques. Finally, six groups of alkali-activated slag-red mud-fly ash-based mortar samples were prepared with EPs as fillers, which demonstrates the feasibility of EPs in multi-waste-based materials and expands the application range of non-calcined eggshells. The results show that water treatment and alkali treatment of EPs provide viable methods for shell-membrane separation, albeit with some loss of fine particles. The physical filling of membranes in AAMs does not affect the chemical composition. The EPs (with a particle size less than 0.5 mm) can be used as fillers in AAMs without shell-membrane separation. Moreover, when the EPs content is increased to 33%, the 90-d flexural strength of the AAMs increases by 60% compared to the control group (without EPs), while the compressive strength remains unchanged. Thus, it is feasible to directly crush and sieve non-calcined eggshells for use as fillers in alkali-activated waste-based cementitious materials without the need for shell-membrane separation, and this method does not produce any negative impact. The findings of this research provide an effective technical approach for the application of waste eggshells in eco-friendly construction materials.

Toward the production of biopolyethylene‐based ecocomposites with improved performance: The potential of eggshell particles as an ecological additive

AbstractLow‐density biopolyethylene (BioLDPE) ecocomposites added with particles of eggshell (ES) residue were produced using linear low‐density polyethylene grafted with maleic anhydride (LDPE‐g‐MA) as a compatibilizing agent. BioLDPE/ES and BioLDPE/ES/LDPE‐g‐MA compounds were processed in a twin‐screw extruder, and the specimens were injection molded. Torque rheometry increased and melt flow index reduced more prominently for the BioLDPE/LDPE‐g‐MA biocomposite with 20 phr ES, suggesting higher viscosity. Consequently, there was a higher level of ES particles breakdown, generating greater distribution and dispersion, as verified in optical microscopy and scanning electron microscopy images. This finding was supported by Fourier transform infrared spectroscopy, considering the intense absorption band at 871 cm−1 for BioLDPE/ES (20 phr)/LDPE‐g‐MA biocomposite, indicating a higher level of ES particles dispersion in BioLDPE matrix. Therefore, BioLDPE/ES (20 phr)/LDPE‐g‐MA biocomposite increased the elastic modulus, tensile strength, Shore D hardness, and heat deflection temperature by 51.4%, 16.9%, 16.4%, and 14, 6%, respectively, related to BioLDPE. Additionally, the flexibility was kept as seen in the elongation at break and impact strength, including not fractured during the impact test. Reported results for the biocomposites are valuable mainly for the polymer additive sector, since the ES has the potential to improve BioLDPE properties, expanding the range of applications.

DYNAMIC MECHANICAL AND STATIC ANALYSIS OF KEVLAR FIBER REINFORCED EPOXY COMPOSITES INCORPORATED WITH EGG SHELL PARTICLE

Research on composite material has been carried out stringently by using various reinforcing elements in the matrix with an intend to replace traditional monolithic materials eventually. In this regard, the Calcium-rich egg shell, which is abundantly available as a solid waste, can be used as a possible filler material for reducing material cost, improving processability, and refining the requisite properties of composite for specific applications with simultaneous reduction of the waste. In this study, the static and dynamic mechanical characteristics of eggshell particle-filled Kevlar/epoxy composites have been investigated. Through stirring with the aid of an Ultrasonicator, different weight percent of NaOH-treated eggshell particles (0, 10, 20 wt. %) of 90 micron sizes are mixed with epoxy to fabricate the composite using the traditional hand-layup method. In comparison to the hybrid composites, the mechanical properties of Kevlar/epoxy (0 wt. % filler) composite demonstrate superior tensile and flexural strength and modulus. However, when the Thermogravimetric analysis (TGA) and the Dynamic mechanical analysis (DMA) are accomplished for evaluating the thermal deterioration and viscoelastic characteristics, the hybrid composites demonstrated improvement in overall damping properties including storage modulus and loss modulus along with the thermal stability characteristics. Also, the elongation before failure is more for composite with 10 wt. % (71%) as well as 20 wt.% (18%) filler content with substantial improvement in Inter Laminar Shear Strength. Thus, the presently prepared composite is recommended for weight-sensitive and high-performance engineering applications under elevated temperatures and intense dynamic loading.

Fabrication and Sliding Wear Characterization of Eggshell Particulate Reinforced AA6061 Alloy Metal Matrix Composites

In this work, AA6061 aluminum alloy composites reinforced with industrial wastes, i.e., eggshell particles are fabricated. The stir casting technique was used to fabricate the Al6061 metal matrix composites. The AA6061 matrix contains 3, 5, and 7 wt.% eggshell particles as reinforcement. Mechanical characterization i.e., hardness, toughness, and tensile strength was examined of the eggshell particle-reinforced composites. According to the experimental findings, adding eggshell particles significantly increased the material's hardness, tensile strength, and toughness. Moreover, the sliding wear resistance improved by adding eggshell particles as reinforcement. ANNOVA results predict that sliding velocity and load are the dominant factors for the sliding wear of composites.

EXPLORING THE MECHANICAL PROPERTIES OF LEAF SPRINGS REINFORCED WITH FIBRE COMPOSITES

To determine whether eggshell particles can be used as a filler material to improve mechanical properties, this study examines the mechanical characteristics of a hybrid material made of eggshell particles and glass-fiber-reinforced polymer (GFRP). To obtain the appropriate particle size, the eggshells are cleaned, crushed, and sieved as part of the experimental approach. The eggshell fragments are then mixed with resin and glass fibres using a vacuum-assisted resin-transfer moulding process to create GFRP composites. The produced GFRP composites’ flexural strength, stiffness, fatigue stability, and other pertinent characteristics are evaluated with practical tests. Notably, certain qualities are enhanced with the inclusion of eggshell particles containing 110 % of the weight of fibroin. In comparison to conventional GFRP composites, which only consider fatigue life during the exhaustion testing phase, the results reveal a 15% increase in the enhancement rate. The findings imply that adding eggshell particles to GFRP composites has tremendous opportunities for progress, notably in automotive applications, and more specifically in the use of leaf springs. The hybrid material’s better mechanical characteristics suggest that it may be possible to improve the performance and longevity of leaf-spring applications. This study advances the investigation of low-cost, environmentally friendly materials for improving composite materials’ mechanical properties in the automobile sector. The application of eco-friendly and effective solutions in the production of automobiles may result from more study and development in this field.

Unlocking the optimization of electrical properties of epoxy-carbon nanotube composites modified with waste eggshell particles via the Taguchi-Grey method

Abstract Advanced electronics demand materials that combine high thermal conductivity with enhanced electrical properties, yet achieving these improvements simultaneously poses significant challenges. This research employs the Taguchi-Grey methodology to explore the synergistic effects of dielectric elements and the high thermal conductivity of epoxy-based composites reinforced with carbon nanotubes (CNTs) and repurposed eggshell particles (ESp). Composite production involved solution blending, followed by evaluations of dielectric constant, thermal conductivity, and sample morphology. Under optimal conditions—1 wt% ESp, 2.5 wt% CNTs, curing at 90°C for 6 h—substantial increases in electrical and thermal conductivity of 19.130% and 94.27%, respectively, were achieved. These enhancements are attributed to the synergistic interaction between dielectric materials and CNTs, as well as the uniform CNT dispersion facilitated by the repurposed eggshells. The 95% confidence level confirmed a strong alignment between the predicted and experimental grey relational grades (GRG), validating the identified optimal parameters. This study demonstrates the potential of using repurposed eggshells to produce conductive polymers with uniformly dispersed CNTs, significantly enhancing thermal conductivity. These findings suggest a promising approach for sustainable, high-performance dielectric materials for electronic applications.

Dimensional stability of brake pads reinforced with calcined eggshell particles under exposed to engine lubricating oil

Exposure to a humid environment can affect the behavior of brake lining composites. Considering the vital function of brake linings in controlling vehicle speed, environmental influences must receive serious attention. Exposure to lubricating oil that sticks to the brake lining can cause changes in performance during work. This study will investigate the dimensional stability of brake pad composites when exposed to engine oil and understand the physical behavior of material to facilitate appropriate handling. The brake pads in this study comprised 35% phenolic resin, 10% graphite, 10% bamboo fiber, 10% alumina powder, 5% zinc powder, 5% bamboo particles, and 25% eggshell particles. The manufacturing of brake linings involves three process stages: cold compaction, hot compaction, and post-curing. The samples were soaked in Federal Ultratec API SJ JASO MA engine lubricating oil for 12, 24, 36, and 48 hours. The results showed that the immersion time of the composite in lubricating oil did not significantly affect the dimensional stability of the composite. This result shows that the addition of calcined eggshell particles can improve the material's resistance to engine lubricating oil.

Effect of Calcined Eggshell Particles on Some Properties and Microstructure of Al-Si-Mg Alloy

In this study, different sizes (25, 50, and 75 µm) and volume fractions (1, 2, and 3 wt%) of calcined eggshell particles were utilized to strengthen the Al-Si-Mg alloy. Several experimental runs were conducted to assess the impact of particle size and concentration on both physical properties (density, corrosion, and thermal conductivity) and mechanical properties (hardness, yield strength, impact energy, and modulus of elasticity). The findings revealed significant enhancements in hardness (21 %), yield strength (61 %), modulus of elasticity (43 %), and thermal conductivity (34 %). Conversely, a reduction of 62 % in impact strength and 8 % in density was observed. The corrosion rate displayed an increase from 0 to 16.67 mpy. Analysis using XRD and XRF techniques identified CaO and Al2O3 as the primary constituents of the eggshell. Optical micrographs consistently showed cored (segregated) dendritic structures typical of castings cooled under normal conditions in the Al-Si-Mg composite. SEM micrographs, EDS spectra, and area analyses confirmed a uniform distribution of Calcined Eggshell Particles (CEP) within the composite films. Additionally, an optimal calcination condition for the eggshell particles was determined to be 900 °C for 2.5 h, resulting in a CaO yield of 99.62 %.

Effect of adding micronized eggshell waste particles on the properties of biodegradable pectin/starch films

Upcycling agroindustry residues into new valuable products is a strategy for mitigating environmental impacts while increasing material circularity. In this study, two sizes of eggshell particles (D90 = 7.1 μm (ESAJ) and D90 = 16.3 μm (ESBU)) were obtained and their incorporation as fillers into biodegradable pectin/starch film was evaluated. The effect of the presence of eggshell particles (2–8 w/w%) on the structural and morphological aspects, water barrier, and mechanical, optical, and thermal properties of the biocomposites was evaluated and then the reinforced film was applied on the surface of kraft paper. The release of calcium in an acidic solution was inverse to the size and concentration of particles and the released íon may contribute to the crosslinking of pectin. The incorporation of only 2 % eggshell resulted in 42% lower solubility of the film. The eggshell-reinforced films proved to be more opaque and rigid. The addition of 6% ESAJ significantly improved the tensile strength (an increase of 32%), modulus of elasticity (an increase of 29.7%), and water vapor barrier (59% of improvement). DSC analysis suggests that the calcium from the eggshell interacts with the pectin polymeric structure, reducing the sites available for water molecules, which may have caused more mobility of the chains through the matrix. The reinforced pectin/starch film was very well adhered to the kraft paper in the application test by continuous casting, but the coated paper showed no improvement in oil and water resistance, which means that other coating processes need to be explored.

Osteoproductivity in Experimentally Induced Cranial Bone Defects in Rabbits.

Autogenous bone grafts are the gold standard for being used as graft materials in maxillofacial surgery. However, a limited amount of these materials is available from the donor site, and there is also more need for a larger operating area and a second surgery, which frequently leads to unreliable graft incorporation, tooth ankylosis, and root resorption. Therefore, newer bone graft substitutes have been developed as alternatives, among which eggshell powder has been introduced as a bone substitute. This study aimed to evaluate the biocompatibility, resorption kinetics, and osteoproductivity of the unprocessed, CMC-coated, and gelatin-coated ostrich eggshell particles. Four half-thickness calvarial defects were created in each animal. At the end of the 1st and 3rd months, the defected sites were investigated by clinical, histological, radiological and histomorphometrical methods. Coating the eggshell particles with CMC and gelatin facilitated their surgical application and contributed to new bone formation. However, their newly formed bone rate at the 3rd month was lower than those of the unprocessed eggshell particles. The CMC coating was more effective than gelatin coating in the bone modeling process. Ostrich eggshell particles either in native form or coated with CMC could be used as a bone filler for supporting new bone formation and healing in treatment of osseous defects.