Generalized Fluorocarbon‐Surfactant‐Mediated Synthesis of Nanoparticles with Various Mesoporous Structures

Abstract

Research on the synthesis of mesoporous materials has mainly focused on mesostructural diversity, [1][2][3][4] compositional flexibility, [5][6][7][8] and morphological control. [9][10][11][12] The ability to obtain mesoporous particles with a controlled particle size would be important for many practical applications. For example, ultrafine mesoporous particles would be very useful in catalysis and gas adsorption, since they would provide greater pore accessibility and facilitate molecular diffusion. They could also act as the host matrix for the synthesis of quantum dots and magnetic nanoparticles in functional materials and bio-imaging applications.[13] Ultrafine mesoporous particles could also act as carriers for drugs, genes, and proteins for novel biomedical applications. [14,15] Some examples of ultrafine mesoporous particles have been sporadically reported, [16][17][18][19][20][21][22][23] but the type of mesostructure, the degree of structural ordering, and the range of pore sizes are limited. Herein we describe a simple wet-chemical method that enables the synthesis of nanometer-sized particles (50-300 nm) with tunable pore sizes in the range 5-30 nm. This fluorocarbon-surfactant-mediated synthesis can be generalized to achieve various pore structures, including 3D cubic Im3 m, 3D cubic Fm3 m, 2D hexagonal p6m, foamlike, and disordered pores, as well as different material compositions.Our syntheses were carried out in a weakly acidic medium (pH 1.6-1.8), in which a homogeneous solution was formed by mixing a soluble silica precursor, a nonionic triblock copolymer surfactant EO x PO y EO x (EO = ethylene oxide, PO = propylene oxide), and the cationic fluorocarbon surfactant

Surface-Functionalized Periodic Mesoporous Organosilica Hollow Spheres

“…59 Different from common hydrocarbon surfactants that are hydrophobic and lipophilic, FC4 is a kind of hydrophobic and highly lipophobic surfactant, 67 with a strong positively charged -N + . Thus, in the present work, it may interact with ethyl chains, functional groups, together with negatively charged silica species of organosilanes (terminally functionalized organosilane/BTME), generating composite vesicles as a "nucleus" through a vesicle templating process.…”

Mesoporous Silica Nanoparticles with Large Pores for the Encapsulation and Release of Proteins

“…This technique was replicated here and, in addition, the cationic fluorocarbon surfactant FC-4 was utilized to confine the diameter of the MSNs. 34 Additionally, a hydrothermal treatment, similar to the procedure reported by Han, 34, 61 but with a higher temperature (120 °C) and a longer reaction time (48 h) was employed to improve mesoscopic regularity and to further extend pore size. Analysis of the TEM images revealed the MSNs had lengths of 90 ± 20 nm and widths of 43 ± 7 nm, giving them an elongated cuboidal-like geometry.…”

“…[31][32] Numerous synthetic protocols for the preparation of MSNs have been developed with the aim of controlling the size and morphology of these nanoparticles. [33][34][35][36] Encapsulating proteins in MSNs is still challenging however, and only a few publications concerning the design of MSNs with a morphology that enables the effective encapsulation of a broad range of proteins are available. [37][38] Typically, proteins are only adsorbed onto the external surface of MSNs due to the small pore diameter (< 3 nm) preventing the proteins from entering the MSNs' interior pores.…”

“…To obtain the desired large pores in a sub-200 nm particle, a double-surfactant system consisting of a high molecular weight block copolymer (Pluronic P123), 34,37,46 and fluorocarbons, 34,49 was employed as the structure-directing template. The swelling agent 1,3,5-trimethylbenzene (TMB) was added to expand the diameter of the pores.…”

“…The swelling agent 1,3,5-trimethylbenzene (TMB) was added to expand the diameter of the pores. 34,46 These MSNs were synthesized as stable colloidal suspensions with a narrow size distribution and channels aligned parallel to the short axis. This mesostructure favors efficient mass transfer, 50 as it possesses a high density of entrances enabling rapid and efficient encapsulation of proteins.…”