In this study, pure hydroxyapatite (HAp) was successfully produced by using eggshells. The eggshells were collected locally and calcined to get CaO from them. The CaO powder was reacted with diammonium hydrogen phosphate in a mechanochemical method using attritor milling. A portion of the synthesized samples was subjected to a second calcination process at 900 °C to investigate the thermal effects on the material. The structures of the samples were investigated by scanning electron microscopy, X-ray diffraction, and infrared spectroscopy. The as-prepared HAp appeared to be nanocrystalline with low-intensity reflections, which transformed into a highly crystalline hexagonal phase after heat treatment, as revealed by XRD analysis. Quantitative analysis revealed the thermal evolution of the secondary Ca(OH)2 phase, due to the thermal decomposition into CaO without causing HAp decomposition into tricalcium phosphates. FTIR analysis showed characteristic phosphate bands for both samples, but the calcined sample displayed sharper peaks and a clear loss of residual water and carbonates. SEM observations also highlighted the major morphological transformation. The highly aggregated as-prepared nanoparticles formed larger, well-defined grains. Notably, the calcined sample also exhibited a rough, textured surface with a macroporous network with interconnected channels. EDS analysis confirmed a Ca-P-O-rich composition, where the elevated Ca/P ratio (Ca/P = 2.28) suggested the presence of secondary calcium-rich phases. These structural, chemical, and morphological characteristics suggest that eggshell-derived HAp, with or without a second heat treatment, has high potential and may be optimized for different applications in bone tissue engineering. However, biological performance was not evaluated in this study.
Nanoscale liquid film boiling is a key heat transfer mechanism in high-heat-flux thermal management, but the coupled effects of wall vibration and surface wettability remain unclear. In this study, molecular dynamics simulations were performed to investigate water film boiling on platinum surfaces under different wettability conditions, vibration amplitudes, and vibration frequencies. The results show that surface wettability strongly regulates the balance between early nucleation and later heat transfer deterioration. Under wall vibration, the neutral-wettability case (β = 0.02) shows the most favorable overall behavior, with bubble nucleation occurring at 0.35 ns, 46.2% earlier than that for β = 0.013, while the Leidenfrost onset is delayed to 1.65 ns, 153.8% later than that for β = 0.1. For vibration amplitude, increasing the amplitude from 0.5 to 2 Å advances bubble nucleation by 70.8%, whereas further increasing the amplitude to 3-4 Å accelerates Leidenfrost onset by 51.5-75.8%. For vibration frequency, compared with the non-vibrating case, nucleation is advanced by 36.4%, 54.5%, and 81.8% at 100, 150, and 200 GHz, respectively. These results indicate that moderate vibration enhances interfacial energy exchange, whereas excessive vibration promotes premature vapor-layer formation and heat transfer deterioration.
The sustainable bio-activated carbon platelets were synthesized from tamarind (tamarind indicia) fruit seed shells (TFSs) by a pyrolysis approach with an inert gas atmosphere. The carbonization process was carried out at 800 °C under an inert argon atmosphere, yielding both pure TFS-AC and chemically activated TFS-AC (KOH) carbon materials. Microscopic surface morphological analysis confirmed the formation of thin, interconnected porous carbon platelet nanosheets with enhanced surface structural uniformity. Raman spectroscopy revealed characteristic D- and G-bands, signifying the presence of graphitic domains and partial structural disorder. BET surface area analysis indicated a significant improvement from 48.54 m2/g in TFS-AC to 124.72 m2/g in TFS-AC (KOH), suggesting enhanced pore development and surface accessibility due to KOH activation. Electrochemical two-electrode performance was evaluated in symmetric device configurations using 3M KOH aqueous electrolyte. The TFS-AC (KOH) device exhibited a remarkable specific capacitance, which delivered 129.03 F/g at 0.5A/g, compared to the pure TFS-AC device. Electrochemical impedance spectroscopy (EIS) further confirmed low internal resistance and favorable ion transport. These findings confirm that KOH-activated TFS-derived carbon nanosheets have higher electrochemical stability, retaining 98.2% capacitance over 10,000 cycles. These results are promising electrode materials for high-performance supercapacitor applications, owing to their superior electrochemical symmetric device performance of bio-mass carbon Tamarind seed shell platelet nanosheets for future energy storage symmetric device applications.
One of the main issues in oncology is tumor recurrence following resection, which is responsible for a large number of patient deaths and treatment failures in a variety of malignancies. Despite advancements in adjuvant chemotherapy and radiation, residual disease that remains inside or close to the resection cavity and is difficult for systemic therapies to eradicate is the cause of further local recurrence. Hydrogel-nanoparticle (HNP) composites are a new class of therapeutic platforms that emerged from the recent convergence of biomaterial science and nanomedicine. Their specific goals are to fill the surgical gap, provide long-term localized drug release, and energetically remodel the post-surgical tumor microenvironment (TME). This paper includes the biological foundations of localized post-surgical therapy, important physicochemical considerations of the hydrogel matrix and nanoparticle carrier design, and a compilation of mechanistic and preclinical evidence for HNP hybrid platforms. Immunomodulatory strategies, stimuli-responsive release mechanism engineering, and novel techniques, including combination immunotherapy and 3D-printed customized scaffolds, are all given special attention. Examples of translational challenges are also addressed, such as manufacturing repeatability, biocompatibility, and regulatory classification. When considered collectively, the data demonstrate that HNP platforms are a convincing, practically feasible approach to reducing post-surgical recurrence rates and enhancing patient outcomes.
