Structure and Properties of Functionalized Porous Silica Hybrid Materials

Abstract

Functionalized silica hybrid materials are extensively studied and applied materials in the field of science and technology. Functionalization is an approach, which allows for the application of organic components in the improvement of the design, properties and potential application of silicate materials. Silica hybrid materials, functionalized via incorporation of organic components (chitosan and methacrylic acid) were synthesized by the sol-gel method. The base silica structure of the hybrids was obtained via hydrolysis and condensation of the silicate precursor, tetraethyl orthosilicate. The investigations of synthesized hybrids are focused on the influence of the nature and quantity of functional organic components on their final structures and properties. The structural characteristics of obtained hybrid materials were investigated using XRD, FTIR, SEM and DTA/TG analysis. The obtained results presented the formation of amorphous porous structure and the organic components are evenly distributed into the silica network. The functional radicals of chitosan and methacrylic acid (amine, hydroxyl groups) exist in the hybrid structure as free reactive centers, as their quantity increases with increasing the organic amount. The swelling behavior in acidic and neutral solutions of the synthesized materials is investigated and the results presented, that the silicate materials exhibit hydrophilic character.

The Synthesis and Characterization of Low-Cost Mesoporous Silica SiO2 from Local Pumice Rock

“…As shown in Figure 7, a DTA thermogram of silica powder showed an intensive endothermic reaction in the range of 30-150°C and a shoulder at temperatures beyond 200°C. These peaks are correlated to the loss of physically adsorbed water from the surface (5.2%) and chemically adsorbed water bonded to Si-OH (1.3%) through the hydrogen bond, which corresponds well with the previous results [16]. The total weight loss of pure silica material established from TG analysis is 6.5%.…”

“…The first form is aggregated particles of colloidal dimensions and the second is fine-powder amorphous silica with a large surface area, obtained by coagulation of particles from an aqueous solution [10]. Both materials have many potential applications, such as catalyst supports [11,12], in pharmaceuticals [13], in vegetable-oil refining [14] and in thin films or coatings for electronic and optical materials [15,16].…”

Synthesis and Pore Structure Characterisation of Novel Mesoporous MgO-CeO₂/SBA-15 as a Potential Catalyst Support

“…The two isotherms as seen in figure 3, exhibit typical H1 type hysteresis. This confirms mesoporous characteristics of the catalyst and that the composite MgO-CeO 2 /SBA-15 has open ended cylindrical mesopores ideal for a number of industrial application [18]. The isotherm also shows that the pore width of S4 is narrower than S3.…”

“…The peak at 2300 cm −1 is attributed to the presence of dissolved or atmospheric CO 2 in the sample. The absorption range 3500-3800 cm -1 corresponds to stretching vibrations of O-H groups in ceria [18].…”

Preparation and Characterization of New Sol–Gel Hybrid Inulin–TEOS Adsorbent

“…The phase composition of the synthesized inulin–TEOS hybrid adsorbent was analyzed by XRD ( Figure 6 ). The most significant peak was observed at 22° in the 2θ angle, which shows the amorphous state of the silica network [ 30 , 31 ]. According to Ronkart et al, inulin could form a semi-crystalline structure in the presence of water, which was represented at peaks around 12°, 16.4°, 17.7°, 21.4°, 23.8°, and 37.37° [ 32 ].…”