Synthesis of Chemically Asymmetric Silica Nanobottles and Their Application for Cargo Loading and as Nanoreactors and Nanomotors

Abstract

We report the synthesis of chemically asymmetric silica nanobottles (NBs) with a hydrophobic exterior surface (capped with 3-chloropropyl groups) and a hydrophilic interior surface for spatially selective cargo loading, and for application as nanoreactors and nanomotors. The silica NBs, which have a "flask bottle" shape with an average diameter of 350 nm and an opening of ca. 100 nm, are prepared by anisotropic sol-gel growth in a water/n-pentanol emulsion. Due to their chemically asymmetric properties, nanoparticles (NPs) with hydrophilic or hydrophobic surface properties can be selectively loaded inside the NBs or on the outside of the NBs, respectively. A high-performance nanomotor is constructed by selectively loading catalytically active hydrophilic Pt NPs inside the NBs. It is also demonstrated that these NBs can be used as vessels for various reactions, such as the in situ synthesis of Au NPs, and using Au NP-loaded NBs as nanoreactors for catalytic reactions.

Self‐Propelled Micro/Nanoparticle Motors

“…The polymeric nanocavities were prepared by synthesis and self‐assembly of a series of amphiphilic block copolymers, followed by selective nanoparticle entrapment. Asymmetric nanostructures resembling nanobottles were recently reported, based on silica nanostructures with a hydrophilic inner surface aimed for selective cargo loading and a hydrophobic exterior surface (Figure B) . They are prepared by anisotropic sol–gel growth and have a diameter of 350 nm and an opening of ≈100 nm.…”

“…B) Chemically asymmetric silica nanobottle and its corresponding transmission electron microscopy (TEM) image. Reproduced with permission . Copyright 2016, Wiley‐VCH.…”

“…B) In situ preparation of Au nanoparticles in silica nanobottles. Reproduced with permission . Copyright 2016, Wiley‐VCH.…”

“…Other alternative applications are focused on the enhanced reactivity associated to the micromotors' motion. On the one hand, nanobottle‐like catalytic micromotors are conceived as future nanoreactors, where reactions are confined inside their bodies . As a proof of concept, Au nanoparticles were synthesized inside the silica nanobottles (Figure B).…”

Noncontinuous Super‐Diffusive Dynamics of a Light‐Activated Nanobottle Motor

“…[1][2][3][4] These micro/nanomotors can convert various types of energy into efficient propulsion and present great potential for future applications.D ifferent architectures have been designed and fabricated in the shape of tubes,r ods,h elices, spherical particles,a nd polymeric stomatocytes,a mong others. [5][6][7][8][9] Meanwhile,c onsiderable efforts have been committed to establishing the fuel-free propulsion of motors by using magnetic,ultrasonic, and electrical fields, [10] so that the motors can move efficiently and stably in ad emanding environment.…”