Controlled Etching of Internal and External Structures of SiO₂ Nanoparticles Using Hydrogen Bond of Polyelectrolytes

Abstract

We have demonstrated a novel strategy for the synthesis of mesoporous silica nanoparticles (MSNPs) using a surfactant-free method under ambient conditions. By the simple addition of an amine-based polymer (polyethylenimine; PEI) with a high molecular weight to a silica nanoparticle (SNP) solution, two types of MSNPs, including rambutan-like MSNPs (R-MSNPs) and hollow MSNPs (H-MSNPs), were produced. The structural changes of the MSNPs were systematically studied using various reaction conditions (reaction time, molar ratio and molecular weight of PEI, etc.) and were observed using electron microscopic techniques. The formation mechanisms of both MSNPs were carefully investigated using XPS, Raman, and IR spectroscopies. Because the synthesized MSNPs are highly porous materials that contain internal organic/inorganic networks, we investigated the removal/adsorption properties of these MSNPs with respect to pollutants toward possible future use in environmental remediation applications. The H-MSNPs exhibited better environmental remediation capabilities relative to the R-MSNPs because PEI is present between the cobweb-like internal structures of the H-MSNPs, thereby providing a significant number of reaction sites for the adsorption of pollutants. The approach presented here can also be used as a direct method for the preparation of intraconnected networks within the substructures.

Y2O3:Yb,Er@mSiO2–CuxS double-shelled hollow spheres for enhanced chemo-/photothermal anti-cancer therapy and dual-modal imaging

“…The lattice distance of 0.304 nm in d2 zone is consistent with (102) plane of hexagonal-phased CuS (JCPDS No. 63,64 The as-prepared Y 2 O 3 :Yb,Er@mSiO 2 -Cu x S (Fig. Thus, the HRTEM image confirms the successful formation of Cu x S onto the surface of Y 2 O 3 :Yb,Er hollow spheres.…”

Optogenetic Control of Programmable Genome Editing by Photoactivatable CRISPR/Cas9 Nanosystem in the Second Near-Infrared Window

“…After coating of CP, the peak A (401.9 eV) decreased, whereas peak B and peak C (400.2 eV, 398.4 eV) that were attributed to the CP clearly increased (Supplementary Fig. 5c) 44,45 . When APC was complexed with plasmid DNA, the elimination of peak A was due to the shielding effect after DNA complexation with APC (Supplementary Fig.…”

Colloidal Mesoporous Silica Nanoparticles

“…Furthermore, various selective etching methods have been reported, such as a cationic surfactant-assisted method. 209,235,253,259,265,283 As we mentioned above, MSNs with various structures and morphologies can be prepared by tuning the properties of silica. However, their dissolution behavior was not clearly investigated in most studies.…”