One-Step Synthesis of Monodisperse and Hierarchically Mesostructured Silica Particles with a Thin Shell

Abstract

Monodisperse, uniform, and hierarchically mesostructured silica particles with a thin shell have been fabricated via one-step synthesis using dodecanethiol (C(12)-SH) and CTAB as dual templates. A series of hierarchically mesostructured silica particles with a morphology similar to that of pomegranate can be obtained by simply adjusting the mass ratio of C(12)-SH to CTAB. When the mass ratio is increased, a mesophase transformation occurs from an ordered 2D hexagonal structure to a mesostructured cellular foam in the core of the hierarchically mesoporous silica particles. These unique silica particles are characterized by small-angle X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and nitrogen adsorption-desorption measurements. The formation mechanism of the hierarchically mesostructured silica particles with a thin shell is proposed according to the experimental results. Synergistic self-assembly of C(12)-SH and CTAB in the solution is believed to play a key role in mediating the formation of these hierarchical silica mesostructures, and the hydrophobic dodecanethiol can act as both the swelling agent for CTAB micelles and coagent for the formation of a microemulsion with CTAB micelles. This synthesis method is simple, straightforward, and suitable for the preparation of the other biomineral nanostructures that are unique scaffolds in biological, medical, and catalytic applications.

Dendritic Silica Particles with Center-Radial Pore Channels: Promising Platforms for Catalysis and Biomedical Applications

“…It seems to be difficult to control the silica growth along the free radial directions or the restricted tangential direction. However, the complex dynamic self‐assembly (occurring on molecular scale) of abundant silicate species and surfactants (or amphiphilic copolymers) at unstable curved solution–solution (oil‐in‐water or water‐in‐oil), solution–gas, and solution–solid interfaces occasionally results in the formation of novel structures and morphologies . Special biphase layering (or “stratification”) of oil‐water systems, emulsion systems, surfactant template systems, and some other methods have been developed to achieve the synthesis of dendritic silica particles with center‐radial pore channels, and even simultaneously with uniform small mesopores (2–5 nm).…”

3D Hierarchical Rutile TiO2 and Metal-free Organic Sensitizer Producing Dye-sensitized Solar Cells 8.6% Conversion Efficiency

“…When employed as the photoanode in a Dye-sensitized Solar Cell (DSC), hierarchical architectures can offer larger surface areas for dye adsorption while simultaneously enhancing light scattering for efficient photon harvesting, and thereby, improving power conversion efficiency15161718. Chemical vapor deposition, applications of templates, catalysts and electrochemical methods are known to be used for the direct growth of inorganic material with controlled morphologies and architectures192021222324, however, in most cases, the mechanisms involved in the formation of these hierarchical structures are complicated and not well-understood.…”

Facile Fabrication of Hollow Mesoporous Silica Nanospheres for Superhydrophilic and Visible/Near‐IR Antireflection Coatings

“…Thus, the hydrophobic C 12 À SH molecules function as a pore expander. [29] After the addition of tetraethoxysilane (TEOS), hydrolysis of TEOS, self-assembly between partially hydrolyzed products [a] Calculated from the N 2 adsorption data according to P/P 0 = 0.04-0.25 (6 points collected) using the BET method.…”

“…[29] Magnetic stirring rates of 600 and 2600 rpm were used in different syntheses, respectively. To further enhance the porosity of the nanoparticles, TMB was added as a swelling agent (micelle expander) to this mixture at the beginning of the reaction.…”

“…In a very recent work, [29] a series of hierarchically mesostructured silica nanoparticles (MSNs) with pomegranatelike morphologies were prepared at slow stirring rate simply by adjusting the mass ratio of dodecanethiol (C 12 À SH) to cetyltrimethylammonium bromide (CTAB). In the current work, MSNs of < 100 nm in size and of varied morphologies and structures, including mesoporous silica nanoparticles with tunable pore size, mesoA C H T U N G T R E N N U N G porous silica nanoparticles with a thin shell, hollow mesoA C H T U N G T R E N N U N G porous silica nanospheres with tunable cavity size and hollow mesoporous silica nanospheres with a thin shell, were fabricated by means of a one-step synthesis by regulating the trimethylbenzene (TMB)/CTAB molar ratio and the stirring rate with the assistance of C 12 À SH.…”