Synthesis Of Mesoporous Silica Particles Research Articles

Continuous Flow Synthesis of Mesoporous Silica Particles with Tunable Size and Structure

Continuous Flow Synthesis of Mesoporous Silica Particles with Tunable Size and Structure

Synthesis of Mesoporous Silica Particles as Inhibitor Containers for Anticorrosive Applications.

Herein, we introduce an innovative experimental assembly based on a high-speed disperser and a water recirculator connected to a double-wall stainless steel container as a new and effective pathway for an eco-friendly and controlled synthesis of mesoporous silica particles (MSPs). With the setup, we demonstrated a one-pot encapsulation of the particles with an inhibitor benzotriazole (BTA) to produce a smart nano/microcontainer for potential use in anticorrosive coatings. One advantage of the experimental setup is the high volume of reactant solution that can be used, yet with good control of solution temperature and stirring conditions, which increases the yield and saves laboratory time. The results obtained from the modified Stöber method show the successful preparation of near-spherical and "bean-shaped" nanometer-size (∼310 nm) MSPs with high benzotriazole encapsulation capacity (46 wt %). More so, the one-pot BTA encapsulated mesoporous silica approach revealed monodispersed spherical particles at optimal temperature and stirring conditions with a mean diameter of ∼1.1 μm and a BTA encapsulation of 23 wt %. The synthesized particles show pH responsiveness and can be further optimized and applied as nanocarriers in smart anticorrosive coatings. The experimental assembly adopted in this work represents a new, scalable approach for the synthesis of mesoporous silica particles.

Morphological control of mesoporous silica particles by dual template method

Unique hollow mesoporous silica particles (MSP) were synthesized using dual templates. We focused on the synthesis of MSP using templates with triblock copolymer P123 (P123) and various ionic liquid surfactants. Interestingly, when using ionic liquid surfactants with different head groups, the resulting products exhibited hollow, larger hollow, and sheet-like morphologies. We also demonstrate that hollow MSP with surface amino groups can be used for selective absorption of negatively charged organic substances.

PH-Tunable Fluorescence and Photochromism of a Flavylium-Based MCM-41 Pigment.

Incorporation of flavylium-derived chalcones in the cetyltrimethylammonium bromide-templated synthesis of mesoporous silica particles with no subsequent removal of the micellar phase leads to high luminescence (0.3 < ϕf < 0.5) and strong color-contrast photochromic pigments finely tunable over a large pH range (1 < pH < 11).

Tunable Synthesis of Mesoporous Silica Particles with Unique Radially Oriented Pore Structures from Tetramethyl Orthosilicate via Oil-Water Emulsion Process.

Numerous studies of the synthesis of mesoporous silica (MPS) particles with tailored properties have been published. Among those studies, tetraethyl orthosilicate (TEOS) is commonly used as a silica source, but tetramethyl orthosilicate (TMOS) is rarely used because its reaction is fast and difficult to control. In this study, MPS particles were synthesized via one-step controlled polymerization of styrene and hydrolysis of TMOS, followed by the addition of hexadecyltrimethylammonium bromide (CTAB) and n-octane. The MPS particles obtained from TMOS generally have small inner pores, but the MPS particles obtained in this study had a unique radially oriented structure, a high surface area up to 800 m2 g-1, and large pores, of size 20 nm. The content of styrene in the emulsion system played a key role in increasing pore sizes of the MPS particles. A plausible mechanism for particle formation based on the phase behavior and type of the emulsion system is proposed. For further research, this material is expected to be useful for various applications, such as in drug delivery, filtration, and catalyst supports.

Synthesis of Mesoporous Silica Particles with Fibrous Morphology via Self-Assembly Process in Microemulsion System

In this research, several precursors were chosen to solve the drawbacks of using toxic and expensive chemicals in the synthesis of fibrous mesoporous silica particle via self-assembly process in microemulsion system. The synthesis of this emerging material normally is realized by using toxic cetylpyridinium bromide (CPB) as common structure directing agent in conjunction with combined cyclohexane and n-pentanol as expensive solvent and co-solvent, respectively. Less toxic cetyltrimethylammonium bromide (CTAB) can be the replacement for CPB but the use of this surfactant may drastically reduce the surface area of the resulting product. Herein, we report that the use of CTAB with combined toluene and n-butanol as affordable solvents can be used to synthesize fibrous mesoporous silica particle with high surface area. The material was well characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), N2 adsorption/ desorption, X-ray difraction (XRD)and thermal gravimetry (TG). This material might be applied in potential applications such as catalysis, drug delivery and adsorption. Moreover, it can be used as a hard-template for fabricating another novel fibrous materials.

Synthesis of Mesoporous Silica Particles by Polymerization Induced Colloid Aggregation and Its Application for High-Performance Liquid Chromatography

Synthesis of Mesoporous Silica Particles by Polymerization Induced Colloid Aggregation and Its Application for High-Performance Liquid Chromatography

Synthesis of Mesoporous Silica Particles and Capsules by Miniemulsion Technique

Mesoporous silica particulate structures of different morphologies from particles to capsules have been prepared by combining the sol−gel process with the cooperative self-assembly in inverse miniemulsion. We report a novel synthetic approach at room temperature, with low surfactant concentrations (5 and 10 mol %, relative to the precursor), and a short synthesis time of only a few hours. As a precursor, glycol-modified silane (tetrakis(2-hydroxyethyl)orthosilicate, EGMS) is used, which shows the advantage of being highly water-soluble. The precursor (EGMS) and the structuring surfactant (cetyltrimethylammonium bromide, CTAB) were dissolved in hydrochloric acid and dispersed in a mixture of hydrocarbons (Isopar M) by ultrasonication. In this synthesis, two different surfactants were used simultaneously. One surfactant (CTAB) acts as a lyotropic template, whereas the second surfactant is an amphiphilic block copolymer (PE/B-b-PEO) that stabilizes the droplets. For template removal, the final material was calcined. The obtained materials were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and nitrogen sorption (Brunauer−Emmett−Teller (BET) methodology). The effect of synthesis conditions such as the amount of templating surfactant (CTAB), the temperature during ultrasonication, the reaction time, the pH value, and the amount of stabilizing surfactant (PE/B-b-PEO) on cooperative self-assembly, morphology, and specific surface area were investigated. Shortly after ultrasonication, porous particles a few hundreds of nanometers in size are formed, which are transformed to capsules and finally to porous flakes with increasing reaction time. This transformation is strongly influenced by the amount of stabilizing surfactant (PE/B-b-PEO). By simply varying the amount of PE/B-b-PEO, the morphology and mesostructural ordering, as well as the porosity, can be tuned over a wide range.

Synthesis of mesoporous silica particles with controlled pore structure

Silica particles, with controllable porosity, were synthesized using two different precursors, tetraethylortosilicate (TEOS) and sodium silicate, but without the addition of template. Characteristics of silica particles (aggregates) prepared by these two methods were compared. The pore structure was tuned only by changing the processing parameters, such as precursor concentration, base concentration, temperature and reaction time. The pore structure of prepared silica particles (aggregates) is strongly influenced by processing conditions and easy controllable in broad range of the specific surface area, pore size, size distribution and pore volume. However, the silica particles synthesized from TEOS have very low total pore volume (ranging from 0.06 to 0.2 cm 3/g) and a large portion of pores smaller than 4 nm. On the other side, the silica particles prepared from sodium silicate can be defined as a mesoporous silica with the average pore size up to ∼20 nm and much higher total pore volume (ranging from 0.8 to 1.5 cm 3/g), which are important advantages for their application in encapsulation of enzymes.

Self‐Assembly of Ultrabright Fluorescent Silica Particles

Light shines through: A one-step self-assembly synthesis of mesoporous silica particles with encapsulated organic dyes (see image) is described. The dyes are physically encapsulated inside nanosize channels/tubes in micrometer-size silica matrix particles. There is virtually no leakage of the dyes and the fluorescence of the assembled particles is very stable. Much brighter fluorescence can be obtained from the encapsulated dyes than from the same dye in aqueous solution.