Tuning Textural Properties by Changing the Morphology of SBA-15 Mesoporous Materials
Ontology highlight
ABSTRACT:
SUBMITTER:
PROVIDER: S-EPMC11204648 | biostudies-literature | 2024 Jun
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Ce-modified mesoporous silica materials MCM-41 and SBA-15, namely 32 wt % Ce-Si-MCM-41, 16 wt % Ce-H-MCM-41 and 20 wt % Ce-Si-SBA-15, were prepared, characterized and studied in the selective preparation of trans-carveol by α-pinene oxide isomerization. The characterizations of these catalysts were performed using scanning electron microscopy, X-ray photoelectron spectroscopy, nitrogen adsorption and FTIR pyridine adsorption. Selective preparation of trans-carveol was carried out in the liquid phase in a batch reactor. The activity and the selectivity of catalyst were observed to be influenced by their acidity, basicity and morphology of the mesoporous materials. The formation of trans-carveol is moreover strongly influenced by the basicity of the used solvent and in order to achieve high yields of this desired alcohol it is necessary to use polar basic solvent.
| S-EPMC5452500 | biostudies-other
Project description:Surface polarity plays a key role in controlling molecular adsorption at solid-liquid interfaces, with major implications for reactions and separations. In this study, the chemical composition of periodic mesoporous organosilicas (PMOs) was varied by co-condensing Si(OEt)4 with organodisilanes, to create a homologous series of materials with similar surface areas, pore volumes, and hydroxyl contents. Their relative surface polarities, obtained by measuring the fluorescence of a solvatochromic dye, cover a wide range. In this series of PMO materials, EPR spectra of tethered nitroxide radicals show monotonically decreasing mobility as larger fractions of the radicals interact strongly with increasingly non-polar surfaces. The surface properties of the materials also correlate with their affinities for organic molecules dissolved in various solvents. The most polar PMO has negligible affinity for phenol, p-cresol, or furfural when these molecules are dissolved in water. However, stronger solute-surface interactions and favor adsorption as the surface polarity decreases. The trend is reversed for furfural in benzene, where weaker solvent-surface interactions result in higher adsorption on polar surfaces. In DMSO, furfural adsorption is suppressed due to the similar strengths of solute-surface and solvent-surface interactions. Thus, the polarity of the surface relative to the solvent is critical for molecular adsorption. These findings show how adsorption/desorption can be precisely and systematically tuned by appropriate choice of both solvent and surface, and contribute to a predictive strategy for the design of catalytic and separations processes.
| S-EPMC7643544 | biostudies-literature
Project description:Various cosmetics having a single function are increasingly being used, but cosmetics having multifunctional activities remain limited. We aimed to develop a multifunctional cosmetic cream having antioxidant, anti-tyrosinase, anti-aging and antimicrobial activities. Antimicrobial activities were performed by disc-diffusion method. Cell toxicity and cell proliferations were evaluated in a 96-well plate with different cell lines such as HaCaT, RAW264.7, CCD-986Sk, B16F1, and B16F10. Mushroom tyrosinase inhibition, elastase inhibition, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities were evaluated and IC50 was calculated. Mesoporous silica particle was synthesized using Pluronic P123 and tetraethyl ortho-silicate (TEOS). Facial pictures were captured by VISIA-CR (Facial Imaging System for Clinical Research). Roughness of image was analysed by PRIMOS software and brightness of image was analyzed by Chromameter CR-400. The crude product of strain T65 inhibited the different human pathogenic bacteria such as Bacillus subtilis, Escherichia coli, Propionibacterium acnes, Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus epidermidis. The IC50 of T65 crude product for mushroom tyrosinase, elastase, and DPPH radical scavenging activities were 58.73, 14.68, and 6.31 µg/mL, respectively. T65 crude product proliferated collagen type I in CCD-986Sk cell up to 145.91% ± 9.11% (mean ± SD; mean of 24, 48, and 72 h) at 250 pg/mL. Synthesized mesoporous particles (SBA-15) confirmed the sustainable performance by control-release for three days. Formulated functional cosmetic cream containing T65 embedded SBA-15, significantly decreased the skin roughness by 4.670% and increased the skin brightness by 0.472% after application of 4 weeks. T65 crude product inhibited both Gram-positive and Gram-negative pathogens. Synthesized mesoporous particle, SBA-15, confirmed the physiologically active substance was released in sustainable release condition. T65 crude product showed impeccable antimicrobial, antioxidant, anti-aging, and whitening activities with non-cytotoxic effects to different cell lines related to the human skin.
| S-EPMC7222176 | biostudies-literature
Project description:SBA-15 is an interesting mesoporous silica material having highly ordered nanopores and a large surface area, which is widely employed as catalyst supports, absorbents, drug delivery materials, etc. Since it has a lack of functionality, heteroatoms and organic functional groups have been incorporated by direct or post-synthesis methods in order to modify their functionality. The aim of this article is to review the state-of-the-art related to the use of SBA-15-based mesoporous systems as supports for hydrodesulfurization (HDS) catalysts.
| S-EPMC5452652 | biostudies-other
Project description:In this study mesoporous silica SBA-15 was evaluated as a vehicle for the transport of cytotoxic natural product emodin (EO). SBA-15 was loaded with different quantities of EO (SBA-15|EO1⁻SBA-15|EO5: 8⁻36%) and characterized by traditional methods. Several parameters (stabilities) and the in vitro behavior on tumor cell lines (melanoma A375, B16 and B16F10) were investigated. SBA-15 suppresses EO release in extremely acidic milieu, pointing out that EO will not be discharged in the stomach. Furthermore, SBA-15 protects EO from photodecomposition. In vitro studies showed a dose dependent decrease of cellular viability which is directly correlated with an increasing amount of EO in SBA-15 for up to 27% of EO, while a constant activity for 32% and 36% of EO in SBA-15 was observed. Additionally, SBA-15 loaded with EO (SBA-15|EO3) does not disturb viability of peritoneal macrophages. SBA-15|EO3 causes inhibition of tumor cell proliferation and triggers apoptosis, connected with caspase activation, upregulation of Bax, as well as Bcl-2 and Bim downregulation along with amplification of poly-(ADP-ribose)-polymerase (PARP) cleavage fragment. Thus, the mesoporous SBA-15 is a promising carrier of the water-insoluble drug emodin.
| S-EPMC5977336 | biostudies-literature
Project description:The active combustion catalyst that is based on 30 wt % cobalt oxide on mesoporous SBA-15 has been tested in 1,2-dichloropropane oxidation and is characterized by means of FT-IR (Fourier transform infrared spectroscopy) and ammonia-TPD (temperature-programmed desorption). In this work, we report the spectroscopic evidence for the role of surface acidity in chloroalkane conversion. Both Lewis acidity and weakly acidic silanol groups from SBA support are involved in the adsorption and initial conversion steps. Moreover, total oxidation reaction results in the formation of new Bronsted acidic sites, which are likely associated with the generation of HCl at high temperature and its adsorption at the catalyst surface. Highly dispersed Co oxide on the mesoporous support and Co-chloride or oxychloride particles, together with the presence of several families of acidic sites originated from the conditioning effect of reaction products may explain the good activity of this catalyst in the oxidation of Chlorinated Volatile Organic Compounds.
| S-EPMC6025381 | biostudies-literature
Project description:Transition metals as catalysts for total VOC oxidation at low temperatures (150-280 °C) are a big challenge nowadays. Therefore, iron-modified SBA-15, AlSBA-15, and ZrSBA-15 materials with 0.5 to 5.0 wt.% Fe loading were prepared and tested for toluene oxidation. It was found that increasing Fe loading significantly improved the rate of oxidation and lowered the temperature of achieving 100% removal of toluene from above 500 °C for the supports (AlSBA-15 and ZrSBA-15) to below 400 °C for 5FeZrSBA-15. The formation of finely dispersed iron oxide active sites with a particle size less than 5 nm was observed on all the SBA-15, AlSBA-15, and ZrSBA-15 supports. It was found that the surface properties of the mesoporous support due to the addition of Al or Zr predetermined the type of formed iron oxide species and their localization on the support surface. Fe-containing SBA-15 and AlSBA-15 showed activity in total toluene oxidation at higher temperatures (280-450 °C). However, 5 wt. % Fe-containing ZrSBA-15 showed excellent activity in the total oxidation of toluene as a model VOC at lower temperatures (150-380 °C) due to the synergistic effect of Fe-Zr and the presence of accessible and stable Fe2+/Fe3+ active sites.
| S-EPMC9821885 | biostudies-literature
Project description:Gallic acid has been covalently conjugated to SBA-15 mesoporous silica surface through different linkers. Cytotoxic activity of the hybrid organic-inorganic systems against HeLa and KB cell lines has been analyzed. Up to 67% of HeLa or KB tumor cells growth inhibition has been achieved at low silica concentration used (10 ?g mL(-1)).
| S-EPMC4495030 | biostudies-literature
Project description:(1) Background: A proposed approach to promote periodontal tissue regeneration in cases of peri-implantitis is the local administration of growth factors at the implant site. Recombinant human bone morphogenetic protein-2 (rh-BMP-2) can effectively promote bone regeneration and osseointegration and the development of appropriate carriers for its delivery is of paramount importance. The aim of the present study was to develop SBA-15 mesoporous nanoparticles (MSNs) with varying porosity, evaluate their biocompatibility with human Periodontal Ligament Cells (hPDLCs) and to investigate their effectiveness as carriers of rh-BMP-2. (2) Methods: SBA-15 type mesoporous silicas were synthesized via sol-gel reaction. The calcined SBA-15 samples were characterized by N2 porosimetry, Fourier transform-infrared spectrometry (FTIR), Scanning (SEM) and Transmission Electron Microscopy (TEM). Rh-BMP-2 loading and release kinetics were evaluated by UV spectroscopy. (3) Results: MSNs presented hexagonally arranged, tubular pores of varying length and diameter. Slightly higher loading capacity was achieved for SBA-15 with large pores that presented good hemocompatibility. MTT assay revealed no cytotoxic effects for all the tested materials, while SBA-15 with large pores induced a significant upregulation of cell viability at day 5. (4) Conclusions: SBA-15 MSNs may prove a valuable delivery platform towards the effective release of bone-inducing proteins.
| S-EPMC8912683 | biostudies-literature
Project description:The mixture containing alloy and oxide with iron-based phases has shown interesting properties compared to the isolated species and the synergy between the phases has shown positive effect on dye adsorption. This paper describes the synthesis of Fe2SiO4-Fe7Co3-based nanocomposite dispersed in Santa Barbara Amorphous (SBA)-15 and its application in dye adsorption followed by magnetic separation. Thus, it was studied the variation of reduction temperature and amount of hydrogen used in synthesis and the effect of these parameters on the physicochemical properties of the iron and cobalt based oxide/alloy mixture, as well as the methylene blue adsorption capacity. The XRD and Mössbauer results, along with the temperature-programmed reduction (TPR) profiles, confirmed the formation of Fe2SiO4-Fe7Co3-based nanocomposites. Low-angle XRD, N2 isotherms, and TEM images show the formation of the SBA-15 based mesoporous support with a high surface area (640 m2/g). Adsorption tests confirmed that the material reduced at 700 °C using 2% of H2 presented the highest adsorption capacity (49 mg/g). The nanocomposites can be easily separated from the dispersion by applying an external magnetic field. The interaction between the dye and the nanocomposite occurs mainly by π-π interactions and the mixture of the Fe2SiO4 and Fe7Co3 leads to a synergistic effect, which favor the adsorption.
| S-EPMC7071072 | biostudies-literature