Strategies for Shaping of Different Ceramic Foams

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Solid state NMR characterization of phenylphosphonic acid encapsulated in SBA-15 and aminopropyl-modified SBA-15

5th International Conference of theă Federation-of-European-Zeolite-Associations (FEZA), Valencia, SPAIN, JULă 03-07, 2011International audienceWe present in this communication that phenyl phosphonic acid can be efficiently loaded in mesoporous SBA-15 and aminopropyl-modified SBA powdered samples through the incipient wetness impregnation method. High amount of phosphonic acid can be reach up to 380 mg/g of sample. We use multinuclear solid state NMR as a method of choice for the indeep characterization of the samples. Thus we demonstrate that phosphonic acid molecules do not crystallize inside the pores. The molecules are highly mobile in SBA-15 because they are submitted to a confinement effect due to the mesoscopic size of the pores and consequently they exhibit a weak interaction with the silica walls. In the case of aminopropyl-modified SBA material, we show that the molecules are rigid and that they are in strong interaction with the aminopropyl groups. Moreover, a 2D double quantum 1H NMR experiment recorded at high field and high spinning speed permit to propose a model of the phosphonate-aminopropyl interaction. The increase in spectral resolution due to the combination of high magnetic field and fast MAS rate allows also the assignment of 1H resonances in aminopropyl-modified SBA matrix and notably allows the assignment of the protons resonance of the amino group

Silica-based mesoporous materials as drug delivery system for methotrexate release.

Antineoplastic methotrexate has been loaded through different soaking procedures on silica-based mesoporous materials and, successively, released mimicking an oral administration. The materials were prepared using a self-assembly mechanism in the presence of cationic surfactants with alkyl chain of 16, 12, and 10 carbon atoms in the synthesis mixture to obtain different pore diameter in the porous structure. Mesoporous materials were prepared as pure silica sample and in the presence of Al(OH)(3) in the synthesis mixture. Only alumina-silica samples were able to load methotrexate. The amounts of drug loaded and the in vitro release kinetics are a function of the pore size of the materials

Materiali mesoporosi ibridi per il recupero di cationi di metalli pesanti o di metalli preziosi dalle acque

Dottorato di Ricerca in Ingegneria Chimica e dei Materiali, Ciclo XVIII,a.a. 2005-2006Università della Calabri

Preparation and characterization of mesostructured functional materials with different morphologies

Course in Chemical and Materials Engineering, Ciclo XXI, a.a. 2007-2008Mesoporous materials with their good surface and structural properties and versatility can be synthesized in different morphologies (thin films, fibers, membranes, etc.) and represent excellent host matrices, highly functional and with great potentials for advanced applications. In this research work, mesoporous powders and thin films have been successfully achieved and then functionalized with special guest molecules such as organic molecules, organometallic complexes, fluorescent dyes, all having specific and interesting properties. Mesoporous matrices have been prepared by sol-gel chemistry with different mesostructures and high order degree. Chemical modifications approaches (post-synthesis grafting and one-pot synthesis) applied to porous supports highly organized have allowed to product a new class of functional materials, particularly interesting for various applications (opto-electronic, photovoltaic materials, etc.). Surface and structural characterization techniques (FTIR, UV-Vis, fluorescence, ellipsometry spectroscopies, electron transmission microscopy, XRD diffraction and porosimetry analysis) have allowed to investigate the effects of the introduction of guest species inside mesoporous matrices and to identify noteworthy changes about organization and mesostructures. Results show that mesoporous materials, both as powders and thin films, do not suffer significant reductions of surface (surface area, pore volume and diameter) and structural properties (order degree, mesostructure organization, stability) after functionalization process, representing confined environment well adapted to various guest species, with the advantage to increase their activity and physic-chemical properties. In particular, guest species are well trapped into rigid porous matrices with an increase of their functional properties and inorganic network stability. All results have demonstrated that the high structural homogeneity, the control over surface and morphological properties and also the possibility to host different molecules permit to project and engineer high potential technological materials for applications in optic and electro-optic fields.Università della Calabri

Adsorption of CO2 on Amine-Modified Silica Particles in a Confined-Fluidized Bed

To reduce the anthropogenic CO2 emissions produced from fossil fuel burning plants, the application of carbon capture and storage (CCS) is necessary and development of a more efficient and economically feasible CO2 capture process is essential as an alternative to the conventional amine scrubbing process which uses aqueous amine solutions. CO2 capture can be enhanced by improving both the gas–solid contact efficiency and by tuning a specific high-performance sorbent. The aim of this research is to investigate the adsorption of CO2 using impregnated mesoporous silica in a “confined-fluidized bed”. This non-conventional fluidized bed (sometimes also termed the “packed-fluidized bed”) seems suitable for improving the efficiency of gas–solid processes for which the bypass effect of the gas–solid contact caused by bubbling represents a major drawback. Results, expressed as grams of CO2 adsorbed per kilogram of material, are discussed in terms of amine load in the sorbent, breakthrough time and fraction of bed utilized. The stability of the materials after regeneration cycles is also discussed. The results obtained confirm that the confinement of the bed allows exploiting fluidization technology in adsorption operations. The operating velocity can be fixed at a value at which the thermal effects also connected to the operation are kept under control

Amine-Functionalized Mesoporous Silica Adsorbent for CO2 Capture in Confined-Fluidized Bed: Study of the Breakthrough Adsorption Curves as a Function of Several Operating Variables

Carbon capture, utilization, and storage (CCUS) is one of the key promising technologies that can reduce GHG emissions from those industries that generate CO2 as part of their production processes. Compared to other effective CO2 capture methods, the adsorption technique offers the possibility of reducing the costs of the process by setting solid sorbent with a high capacity of adsorption and easy regeneration and, also, controlling the performance of gas-solid contactor. In this work, an amine-functionalized mesoporous sorbent was used to capture CO2 emissions in a confined-fluidized bed. The adoption of a confined environment allows the establishment of a homogeneous expansion regime for the sorbent and allows to improve the exchange of matter and heat between gas and solid phase. The results illustrate how the different concentration of the solution adopted during the functionalization affects the adsorption capacity. That, measured as mg of CO2 per g of sorbent, was determined by breakthrough curves from continuous adsorption tests using different concentrations of CO2 in air. Mesoporous silica functionalized with a concentration of 20% of APTES proves to be the best viable option in terms of cost and ease of preparation, low temperature of regeneration, and effective use for CO2 capture

Evaluation of CO₂ Adsorption Parameters in Fluidised Zeolite 13X Beds Using Non-Linear Multivariate Optimisation

This work is part of a research project aimed at studying potential sorbents for CO2 capture. The main parameters characterising the adsorption process of zeolite 13X were derived with the aim of overcoming the limits of experimental analysis and thus predicting the performances of the materials of interest. In particular, the main parameters that control the adsorption process of CO2 in zeolite 13X were evaluated through parametric optimisation. This systematic procedure allows for the prediction of the performances of the materials at different operating conditions, identifying the most suitable ones for the case under consideration. Another important application lies in the possibility of a preliminary study of a potential process scale-up for future industrial use. The captured carbon dioxide can be stored or used as a reagent in the production of products with higher economic values, such as methanol, DME and others