The effect of temperature on crystallinity of carbonate apatite (CAp) foam prepared from alpha-tricalcium phosphate (alpha-TCP) foam by hydrothermal treatment was investigated in the present study. The alpha-TCP foams were prepared through a conventional sintering method using polyurethane foam as template. Then, the resultant alpha-TCP foams were hydrothermally treated with Na2CO3 aqueous solution at 100 degrees C, 150 degrees C and 200 degrees C for 72 h. After hydrothermal treatment, the cancellous bone-like macroporous structure of the alpha-TCP foams was maintained. However, microscopic morphology of the foams' frame significantly changed after the 72 h treatment period. The smooth surface of alpha-TCP foam disappeared and the whole surface was covered with plate-like deposits. The plate-like deposits treated at 150 degrees C and 200 degrees C had smooth surface while those treated at 100 degrees C were constructed from spherical particles of approximately 200 nm in diameter. The results of X-ray diffraction and Fourier transform infrared analysis showed that alpha-TCP was completely converted to CAp and the crystallinity of CAp prepared at 100 degrees C was significantly lower than those prepared at 150 degrees C and 200 degrees C. Hydrothermal treatment of alpha-TCP foam at 100 degrees C allowed the formation of low-crystalline CAp foam but complete conversion needs a longer treatment period.
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http://dx.doi.org/10.3233/BME-2009-0581 | DOI Listing |
ACS Appl Mater Interfaces
December 2024
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, No. 2, Nengyuan Rd., Tianhe DistrictGuangzhou 510640, China.
MCM-41, a mesoporous material with a high surface area and tunable pore size, shows great potential for water vapor adsorption. However, due to its large pore size, the effective adsorption capacity at medium to low relative partial pressures is limited in adsorption chiller applications. In this work, MCM-41 was successfully synthesized at room temperature using cetyltrimethylammonium bromide (CTAB) as a templating agent.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
Global concern over per- and polyfluoroalkyl substances (PFASs), especially perfluorooctane sulfonate (PFOS), disposal prompts the search for effective degradation methods. Subcritical water hydrothermal treatment shows promise but suffers from unclear degradation pathways, hindering engineering application design due to unknown intermediate products. This study introduces Fe-based amorphous alloy to enhance the subcritical water hydrothermal degradation of PFOS, achieving a degradation rate of approximately 85 % under optimized conditions of 325 °C and 1 M sodium bicarbonate (NaHCO₃), compared to 56 % without the alloy.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei 112, Taiwan.
Oral squamous-cell carcinoma (OSCC) poses significant treatment challenges due to its high recurrence rates and the limitations of current therapies. Titanium dioxide (TiO) nanoparticles are promising radiosensitizers, while bacterial outer membrane vesicles (OMVs) are known for their immunomodulatory properties. This study investigates the potential of OMV-encapsulated TiO nanoparticles (TiO@OMV) to combine these effects for improved OSCC treatment.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Institute of Physical Chemistry-Ilie Murgulescu of the Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest, Romania.
Bimetallic (Ta/Ti, V, Co, Nb) mesoporous MCM-41 nanoparticles were obtained by direct synthesis and hydrothermal treatment. The obtained mesoporous materials were characterized by XRD, XRF, N adsorption/desorption, SEM, TEM, XPS, Raman, UV-Vis, and PL spectroscopy. A more significant effect was observed on the mesoporous structure, typically for MCM-41, and on optic properties if the second metal (Ti, Co) did not belong to the same Vb group with Ta as V and Nb.
View Article and Find Full Text PDFGels
December 2024
Chemistry Department, Faculty of Science, Taibah University, Medina Munwarah 42353, Saudi Arabia.
This work presents a novel hydrothermally aided sol-gel method for preparation of mesoporous silica nanoparticles (MSNs) with a narrow particle size distribution and varied pore sizes. The method was carried out in alkaline media in presence of polyethylene glycol (PEG) and cetyltrimethylammonium chloride (CTAC) as dual templates and permitted the synthesis of spherical mesoporous silica with a high surface area (1011.42 m/g).
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