scholarly journals Robust Amino-Functionalized Mesoporous Silica Hollow Spheres Templated by CO2 Bubbles

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 53
Author(s):  
Hongjuan Wang ◽  
Xuefei Liu ◽  
Olena Saliy ◽  
Wei Hu ◽  
Jingui Wang
Keyword(s):  
Mesoporous Silica ◽  
Condensation Reaction ◽  
High Surface ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Production Costs ◽  
Hollow Structures ◽  
Functionalized Mesoporous Silica ◽  
Hollow Silica Spheres ◽  
Knoevenagel Condensation Reaction

Hollow-structured mesoporous silica has wide applications in catalysis and drug delivery due to its high surface area, large hollow space, and short diffusion mesochannels. However, the synthesis of hollow structures usually requires sacrificial templates, leading to increased production costs and environmental problems. Here, for the first time, amino-functionalized mesoporous silica hollow spheres were synthesized by using CO2 gaseous bubbles as templates. The assembly of anionic surfactants, co-structure directing agents, and inorganic silica precursors around CO2 bubbles formed the mesoporous silica shells. The hollow silica spheres, 200–400 nm in size with 20–30 nm spherical shell thickness, had abundant amine groups on the surface of the mesopores, indicating excellent applications for CO2 capture, Knoevenagel condensation reaction, and the controlled release of Drugs.

Synthesis and capacitive properties of carbonaceous sphere@MnO2 rattle-type hollow structures

2010 ◽  
Vol 25 (8) ◽  
pp. 1476-1484 ◽  
Author(s):  
Jintao Zhang ◽  
Jizhen Ma ◽  
Jianwen Jiang ◽  
X.S. Zhao
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
High Surface ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Experimental Conditions ◽  
X Ray ◽  
Hollow Structures ◽  
Capacitive Properties

Carbonaceous sphere@MnO2 rattle-type hollow spheres were synthesized under mild experimental conditions. The as-prepared hollow structures were characterized using scanning electron microscope, transmission electron microscope, x-ray diffraction, x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and nitrogen adsorption techniques. The characterization data showed the formation of rattle-type hollow structures with a mesoporous MnO2 shell and a carbonaceous sphere core. The composition and shell thickness of the hollow spheres can be controlled experimentally. The capacitive performance of the hollow structures was evaluated by using both cycle voltammetry and charge–discharge methods. The results demonstrated a specific capacitance as high as 184 F/g at a current density of 125 mA/g. The good electrocapacitive performance resulted from the mesoporous structure and high surface area of the MnO2-based hollow spheres.

Efficient Removal of Cd2+ by the Mesoporous Silica Functionalized by APTES

2013 ◽  
Vol 726-731 ◽  
pp. 2409-2412
Author(s):  
Xiao Feng Cai ◽  
Kang Wei Ji ◽  
Wan Hao Wu ◽  
Jie Hou ◽  
Shi You Hao
Keyword(s):  
Aqueous Solution ◽  
Mesoporous Silica ◽  
Ph Value ◽  
High Surface ◽  
High Surface Area ◽  
Efficient Removal ◽  
Structure Directing Agent ◽  
Functionalized Mesoporous Silica ◽  
Adsorption Desorption ◽  
Large Pore Size

Amino-functionalized mesoporous silica (AFMS) with high amino loading, high surface area, and large pore size was synthesized using the anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as template and 3-aminopropyltriethoxysilane (APTES) as co-structure directing agent (CSDA). The synthesized AFMS was characterized by N2adsorption-desorption, TEM and elemental analyzer. The results of the removal of Cd2+from aqueous solution showed that the pH value of aqueous solution affected the removal efficiency of Cd2+greatly, and that unary adsorption isotherm of Cd2+on the AFMS was well described by the Sips isotherm model, in which the adsorption capacity was 2.43 mmol/g for Cd2+, much higher than the literature data.

Hierarchical flowerlike magnesium oxide hollow spheres with extremely high surface area for adsorption and catalysis

2016 ◽  
Vol 4 (2) ◽  
pp. 400-406 ◽  
Author(s):  
Shuliang Yang ◽  
Peipei Huang ◽  
Li Peng ◽  
Changyan Cao ◽  
Yanan Zhu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Surface Area ◽  
Magnesium Oxide ◽  
Heavy Metal Ions ◽  
Catalytic Properties ◽  
Condensation Reaction ◽  
High Surface ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Adsorption Properties

3D hierarchical flowerlike MgO hollow spheres with extremely high surface area showed excellent adsorption properties for heavy metal ions and catalytic properties for the Claisen–Schmidt condensation reaction.

The Synthesis of High-Surface Area Silicon Carbide by Conversion Method Using Carbosilane Polymer

2014 ◽  
Vol 353 ◽  
pp. 244-247
Author(s):  
Eun Jin Jung ◽  
Yoon Joo Lee ◽  
Woo Teck Kwon ◽  
Y. Kim ◽  
Dong Geun Shin ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Mesoporous Silica ◽  
Surface Area ◽  
High Surface ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Bet Analysis ◽  
Fibrous Morphology ◽  
High Surface Area Materials ◽  
Mcm 41

Since mesoporous silica such as MCM-41 and SBA-15 was developed, the study of the properties of high-surface area materials was accelerated. Moreover, the mesoporous silica is used as a template to produce high-surface materials by nanocasting technology. The purpose of this paper is the synthesis of a high surface silicon carbide sphere by the nanocasting technology. In this study, KCC-1 silica sphere was used as a template, and polycarbosilane and poly (phenyl carbosilane) were selected for precursor of silicon carbide. Carbosilane polymer gives advantage of synthesis silicon carbide under low temperature, and hollow spheres were produced. In this study, the polycarbosilane was more effective for the synthesis of SiC hollow spheres by inversion of template structure showing a fibrous morphology on the sphere wall. And it was confirmed that the sphere was composed of nanosized SiC crystals, and has high surface area using TEM, XRD and BET analysis.

scholarly journals Folic Acid/Methotrexate Functionalized Mesoporous Silica Nanoflakes from Different Supports: Comparative Study

2020 ◽  
Vol 10 (18) ◽  
pp. 6465
Author(s):  
Martyna Trukawka ◽  
Krzysztof Cendrowski ◽  
Wojciech Konicki ◽  
Ewa Mijowska
Keyword(s):  
Drug Delivery ◽  
Folic Acid ◽  
Mesoporous Silica ◽  
Drug Delivery Systems ◽  
High Surface ◽  
High Surface Area ◽  
Physicochemical Characterization ◽  
Delivery Systems ◽  
Functionalized Mesoporous Silica ◽  
Low Cytotoxicity

Herein, we present a facile synthesis route for the mesoporous silica nanoflakes on two types of templates and evaluate their potential as potential drug delivery systems. Silica materials are attractive due to their biocompatibility, low cytotoxicity, high surface area, and tunable pores. In addition, they can be multifunctionalized. These properties were used to create multifunctional drug delivery systems combining folic acid as a target molecule and methotrexate (MTX) as an anticancer drug. The silica nanoflakes were formed using graphene oxide and double-layered hydroxide as templates, respectively. After the removal of matrices, the silica flakes were functionalized by folic acid and loaded with methotrexate. The differences in drug release performance and structural stability were analyzed with respect to the detailed physicochemical characterization of the produced silica nanoflakes.

scholarly journals Comparison of Structure and Adsorption Properties of Mesoporous Silica Functionalized with Aminopropyl Groups by the Co-Condensation and the Post Grafting Methods

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 628
Author(s):  
Ana-Maria Putz ◽  
Mihaela Ciopec ◽  
Adina Negrea ◽  
Oana Grad ◽  
Cătălin Ianăşi ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
High Surface ◽  
High Surface Area ◽  
Adsorption Properties ◽  
Amino Groups ◽  
X Ray ◽  
Functionalized Mesoporous Silica ◽  
X Ray Scattering ◽  
Post Synthesis ◽  
Grafting Methods

The adsorptive potential has been evaluated for the aminopropyl functionalized mesoporous silica materials obtained by co-condensation and post grafting methods. Nitrogen sorption, small angle neutron and X-ray scattering (SANS and SAXS) demonstrated high surface area and well-ordered hexagonal pore structure suitable for applications as adsorbents of metals from waste waters. A comparison of Cr(VI) adsorption properties of the materials prepared by different functionalization methods has been performed. The obtained results demonstrated the adsorption capacity due to the affinity of the chromium ions to the amino groups, and showed that co-condensation of tetraethoxysilane (TEOS) and 3-aminopropyl triethoxysilane (APTES) resulted in higher metal sorption capacity of the materials compared to post-synthesis grafting of aminopropyl groups onto the mesoporous silica particles.

Effects of Surfactant Concentration on the Microstructures of TiO2 Hollow Spheres by Hydrothermal Method

2013 ◽  
Vol 634-638 ◽  
pp. 2189-2192 ◽  
Author(s):  
Lian Ying Lu ◽  
Lin Xu ◽  
Ting Ting Yin ◽  
Guo Hong Wang
Keyword(s):  
Hydrothermal Method ◽  
Surface Area ◽  
High Surface ◽  
Photovoltaic Cells ◽  
Hollow Spheres ◽  
High Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hollow Structures ◽  
Good Penetration

TiO2 hollow spheres were prepared by hydrothermal method using CTAB, glucose and (NH4)2TiF6 as surfactant, template and titanium source, respectively. The microstructures of hollow spheres TiO2 were characterized with X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared (FTIR). The results showed the concentration of the CTAB obviously influenced the morphology of hollow spheres TiO2. This synthesis route may also extend to the preparation of hollow structures of other metal oxides. Because of the large specific surface area, porous structure, and good penetration, the hierarchical TiO2-derived hollow spheres may find great applications in catalysis, photovoltaic cells and high surface area electrodes.

Microporous Silicon Nitride-Based Solid Bases

1998 ◽  
Vol 549 ◽  
Author(s):  
J. S. Bradley ◽  
O. Vollmer ◽  
R. Rovai ◽  
F. Lefebvre
Keyword(s):  
Surface Area ◽  
Condensation Reaction ◽  
High Surface ◽  
High Surface Area ◽  
Organic Content ◽  
Gaseous Ammonia ◽  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Knoevenagel Condensation Reaction

AbstractHigh surface area, microporous, amorphous silicon imidonitride, characterized by infrared spectroscopy, MAS 29Si NMR and surface area and porosity measurements has been prepared by the treatment of co-oligomers of methylsilazane and dimethyl silazanes with gaseous ammonia at temperatures up to 700°C. The material has a narrow pore-size distribution showing a maximum in the range associated with wide- pore zeolites (ca. 0.72 nm mean). Variation of the organic content of the silazane is a means of controlling the surface area of the resulting solid. The Knoevenagel condensation reaction of benzaldehyde with a series of active methylene compounds has been used to probe the basicity and size-selectivity of these microporous solid base catalysts.

scholarly journals Recent Advances in Functionalized Mesoporous Silica Frameworks for Efficient Desulfurization of Fuels

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1116 ◽  
Author(s):  
Shruti Mendiratta ◽  
Ahmed Atef Ahmed Ali
Keyword(s):  
Mesoporous Silica ◽  
Sulfur Content ◽  
Active Sites ◽  
Fossil Fuels ◽  
High Surface ◽  
High Surface Area ◽  
Sulfur Removal ◽  
Jet Fuels ◽  
High Porosity ◽  
Functionalized Mesoporous Silica

Considerable health and climate benefits arising from the use of low-sulfur fuels has propelled the research on desulfurization of fossil fuels. Ideal fuels are urgently needed and are expected to be ultra-low in sulfur (10–15 ppm), with no greater than 50 ppm sulfur content. Although several sulfur removal techniques are available in refineries and petrochemical units, their high operational costs, complex operational needs, low efficiencies, and higher environmental risks render them unviable and challenging to implement. In recent years, mesoporous silica-based materials have emerged as promising desulfurizing agents, owing to their high porosity, high surface area, and easier functionalization compared to conventional materials. In this review, we report on recent progress in the synthesis and chemistry of new functionalized mesoporous silica materials aiming to lower the sulfur content of fuels. Additionally, we discuss the role of special active sites in these sorbent materials and investigate the formulations capable of encapsulating and trapping the sulfur-based molecules, which are challenging to remove due to their complexity, for example the species present in JP-8 jet fuels.

scholarly journals Bifunctional acid–base mesoporous silica@aqueous miscible organic-layered double hydroxides

RSC Advances ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 3749-3754 ◽  
Author(s):  
Hongri Suo ◽  
Haohong Duan ◽  
Chunping Chen ◽  
Jean-Charles Buffet ◽  
Dermot O'Hare
Keyword(s):  
Mesoporous Silica ◽  
Pore Size ◽  
Layered Double Hydroxides ◽  
High Surface ◽  
High Surface Area ◽  
Core Shell ◽  
Acid Base ◽  
Double Hydroxides ◽  
Hierarchical Morphology ◽  
Size And Structure

Core@shell materials which exhibit hierarchical morphology with ultra high surface area and controllable pore size and structure have been synthesised.

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