One-Step Preparation of Fuel-Containing Anisotropic Nanocapsules with Stimuli-Regulated Propulsion

Abstract

One of the dreams of nanotechnology is to create tiny objects, nanobots, that are able to perform difficult tasks in dimensions and locations that are not directly accessible. One basic function of these nanobots is motility. Movements created by self-propelled micro- and nanovehicles are usually dependent on the production of propellants from catalytic reactions of fuels present in the environment. Developing self-powered nanovehicles with internally stored fuels that display motion regulated by external stimuli represents an intriguing and challenging alternative. Herein, a one-step preparation of fuel-containing nanovehicles that feature a motion that can be regulated by external stimuli is reported. Nanovehicles are prepared via a sol–gel process confined at the oil/water interface of miniemulsions. The nanovehicles display shapes ranging from mushroom-like to truncated cones and a core–shell structure so that the silica shell acts as a hull for the nanovehicles while the core is used to store the fuel. Azo-based initiators are loaded in the nanovehicles, which are activated to release nitrogen gas upon increase of temperature or exposure to UV light. Enhanced diffusion of nanovehicles is achieved upon decomposition of the fuel.

Tailoring the mechanoresponsive release from silica nanocapsules

“…They are ideal candidate as a delivery system for various applications 10,21,22 because their properties can be tuned by controlling their shape, size, shell thickness, or chemical composition. [23][24][25] Here, we precisely manufactured SiNCs with a controlled structure (Fig. 1) to yield a class of tunable and controllable mechanoresponsive nanocarriers.…”

Polydopamine Nanobottles with Photothermal Capability for Controlled Release and Related Applications

“…Nanobottles have received considerable attention in recent years owing to their capability for the quick loading of chemical reagents, biological effectors, theranostic agents, and nanoscale objects. [ 1–5 ] They have found use in an array of applications related to catalysis, pollutant separation, controlled release, and drug delivery. [ 6–10 ] Among these applications, encapsulation of theranostic agents or biological effectors has attracted the most attention.…”

Investigating Time‐Dependent Active Motion of Janus Micromotors using Dynamic Light Scattering

“…For smaller JMs, specialized equipment setups such as high speed cameras or nanoparticle tracking analyzers are needed to capture both the ballistic and diffusive behaviors. [ 10,35,45–48 ] Lastly, the number of tracks captured must be large enough to produce statistically valid results and eliminate the potential to falsely indicate a system as exhibiting enhanced motion. [ 45,49 ]…”

“…Previous works using DLS to characterize micromotor active motion have almost exclusively examined steady‐state behaviors. [ 10,30,31,46,47,51 ] Lee et al. [ 46 ] demonstrated the ability to deconvolute translational and rotational motion of Au–Pt nanomotors by purposefully inducing shape anisotropy into the micromotor design.…”