Papers by Keyword: Mesoporous Material

Abstract: Development of covalent organic polymer (COP) is a potential new class of adsorbent for gas separation due to their good hydrothermal stability, chemical tuning flexibility and low cost. COP-1 was prepared via one-step polycondensation of cyanuric chloride and piperazine under catalyst free and N₂ atmosphere condition. The properties of COP-1 were characterized using several analytical methods such as Fourier Transform Infra-Red (FTIR), solid Nuclear Magnetic Resonance (s-NMR), Thermal gravimetric analysis (TGA) and N₂ adsorption and desorption measurement. The C-N bond of COP-1 which has non-rigid framework was successfully linked in this study. It is found that COP-1 has low thermal degradation temperature i.e. 483 K. As compared to literature, lower surface area (75.5 m²/g) and slightly large pore size (8 nm) are noticed. The difference of physical properties of COP-1 synthesized between in this study and literature revealed the challenge of reproducibility for COP-1.

Abstract: Novel silica-based bioactive glasses were successfully prepared by the sol-gel method. The optimized glass composition for fabrication of the scaffolds was (in mol.%) 60% SiO₂ – 30% CaO - 5% Na₂O - 5% P₂O₅ (60S30C5N5P). This composition was confirmed to develop a thick hydroxycarbonate apatite (HCA) layer in Simulated Body Fluid (SBF) after 7 days, as revealed by Fourier Transform Infrared Spectroscopy (FTIR), indicating the bioactive character of the scaffolds. The mesoporous nature of the glass structure allows the load of tetracycline and a sustained release of the drug in PBS during 7 days was measured.

Abstract: Highly active titanium modified 3D mesoporous material Ti-TUD-1 with different Si/Ti molar ratios (10, 25, 50 and 100) were synthesized using TEA as a template and TEAOH as an auxiliary template. The Ti-TUD-1 materials were characterized by means of XRD, TEM and UV-vis DRS. The results showed that Ti was successfully incorporated in the framework of TUD-1 by forming Ti-O-Si bonds. The catalytic activities were tested in a high pressure micro reactor using FCC diesel and the results showed that the HDS efficiency of Ti modified TUD-1(Si/Ti=50) was better than TUD-1, as high as 98.15%.

Abstract: In the present study, organic-inorganic hybrid mesoporous material (HMC) were used to optimize the removal rate for Cr (VI) by applying Response Surface Methodological approach. Batch mode experiments were also carried out to assess the adsorption equilibrium in aqueous solution. The effect of three parameters, that is pH of the solution (1.52.5), initial concentration (100500 mg/L) and adsorbent dose (0.050.15 g/ 50 mL) was studied for the removal of Cr (VI) by HMC. BoxBehnken model was used as an experimental design. The optimum pH, adsorbent dose and initial Cr (VI) concentration were found to be 2.0, 0.05 g/L and 500 mg/L, respectively. Under these conditions removal adsorption capacity of Cr (VI) was found to be 337..

Abstract: The development of nanostructured silica thin films encapsulated with organic functionalities has been an area of active research. The functionalization of films can be done by post doping, covalent or non-covalent methodology. The materials researchers were interested to study and understand the nature of interactions existing in the host silica network and associated physicochemical properties of the derived films. The photofunction imparted films have been explored for chemical and biological sensing applications. In the presented work, an optical filter application based on dye encapsulated nanostructured silica films is reported. To the best of our knowledge, we report for the first time cresol red- a sulfonephthalein dye based nanostructured silica film acting as optical filter. These supported films were found to resemble optical notch filter with center wavelength (CWL) at 432 nm and optical density of 0.05. The films were formed on glass slides by spin coating technique. The coating solution was prepared by template assisted sol-gel method. The films were studied for their physical and chemical characteristics using an array of instrumental techniques.

Abstract: Al and S co-doped TiO2 (S-Al-TiO2) mesoporous materials as a kind of visible light photo- catalysts are prepared using pyridine as a template through a solid state reaction route. The materials features are characterized by the advanced instruments. The photodegradation kinetic of paclobutra- zol is investigated. It is shown that the doping of S and Al could effectively inhibit the growth of anatase TiO2, both S and Al have entered into the lattice of TiO2. Surface area of 81.3m2/g and narrow pore size distribution (~2.1nm) are presented, it not only enables the visible-light absorption but also promotes photocatalytic property of paclobutrazol. Moreover, within 150 min of visible-light irradiation, the photocatalytic degradation of paclobutrazol approximately follows an order kinetics, and the photodegradation rate in 46.7% and reaction rate constant of 0.00414 min-1 are obtained.

Abstract: A series of mesoporous materials Sn-SBA-16 was prepared by one-step hydrothermal synthesis with F127, TEOS and SnCl4•5H2O as template, silica source and tin source, respectively, without mineral acid added. The samples were characterized by XRD, N2 sorption, TEM and UV–Vis. The acidity property of acidic sites in the surface of the samples was investigated by pyridine-absorbed FT-IR. The results indicate that the materials exhibit high surface area and uniform pore distribution. The samples contain both Lewis and Brönsted acid sites, moreover, the total concentration of both Lewis and Brönsted acid sites increases with the decrease of the ratio of Si to Sn. And Lewis acid site plays the dominate role.

Abstract: kinds of Al2O3 were synthesized by using aluminum nitrate as the aluminum source, glucose, lactic acid and citric acid as templates respectively. It is showed that all Al2O3 were mesoporous materials due to their BET surface area results. The Al2O3-glu, synthesized by using glucose as a template, demonstrated fine pore shape, larger surface area and pore volume. The Ce0.1Cu0.9O1.1/Al2O3-glu catalyst exhibited good performance for dimethyl ether(DME) Combustion. La-doping can promote its catalytic activity. Over La0.4-Ce0.1Cu0.9O1.1/ Al2O3-glu catalyst, the DME combustion temperature(T10) was 493 K and the complete combustion temperature(T90) was 498 K. The life test result indicated its catalytic activity without any reduce even after 100 h reaction.

Abstract: Multifunctional behaviour viz., ferroelectric, ferromagnetic and magnetodielectric coupling has been reported in a number of nanocomposites. The latter were synthesized by growing nanoparticles of different kinds within a suitable matrix. Different morphologies of the particles were introduced. Both natural as well as synthetic mesoporous materials were used to prepare nanocomposite systems. Mesoporous structures with large surface areas and pore volumes were found to be effective in developing most efficient drug delivery systems. For identical reasons such structures were suitable as catalysts in various industrially important reaction processes, as humidity and gas sensors, as magnetic sensors. Mesoporous carbon based nanocomposites used as electrodes were found to improve the efficiency of lithium-ion batteries. Nanocomposites using mesoporous carbon and carbon nanotubes were shown to improve the performance of dye sensitized solar cells. In this article, the above mentioned developments are reviewed and discussed.

Abstract: Cr(VI) has a highly toxic effect on the organism and has caused serious harm to the environment. Due to quantum size effects and interface coupling effects, mesoporous materials have novel physical, chemical and many other excellent performances, especially for the promising application in the adsorption of heavy metals. This article includes a survey of removal mesoporous materials for Cr(VI)-contaminated wastewater. It also presents the challenges and prospects in using the mesoporous adsorbents for Cr(VI) removal in wastewater treatment.