Thermal, Mutual, and Self-Diffusivities of Binary Liquid Mixtures Consisting of Gases Dissolved in n-Alkanes at Infinite Dilution.

In the present study, dynamic light scattering (DLS) experiments and molecular dynamics (MD) simulations were used for the investigation of the molecular diffusion in binary mixtures of liquids with dissolved gases at macroscopic thermodynamic equilibrium. Model systems based on the n-alkane n-hexane or n-decane with dissolved hydrogen, helium, nitrogen, or carbon monoxide were studied at temperatures between 303 and 423 K and at gas mole fractions below 0.06.

Geometric asymmetry driven Janus micromotors.

The production and application of nano-/micromotors is of great importance. In order for the motors to work, asymmetry in their chemical composition or physical geometry must be present if no external asymmetric field is applied. In this paper, we present a "coconut" micromotor made of platinum through the partial or complete etching of the silica templates.

Marangoni self-propelled capsules in a maze: pollutants 'sense and act' in complex channel environments.

Environmental remediation is a highly pressing issue in society. Here we demonstrate that autonomous self-propelled millimeter sized capsules can sense the presence of pollutants, mark sites for visible identification and remove the contamination, while navigating in a complex environment of interconnected channels, the maze. Such long-range self-powered capsules propelled by the Marangoni effect are capable of releasing chemicals to alter the pH and induce aggregation during pollutant flocculation at a faster rate than convection or diffusion.

Biomimetic artificial inorganic enzyme-free self-propelled microfish robot for selective detection of Pb(2+) in water.

The availability of drinking water is of utmost importance for the world population. Anthropogenic pollutants of water, such as heavy-metal ions, are major problems in water contamination. The toxicity assays used range from cell assays to animal tests.

Beyond platinum: bubble-propelled micromotors based on Ag and MnO2 catalysts.

Autonomous bubble-propelled catalytic micro- and nanomachines show great promise in the fields of biomedicine, environmental science, and natural resources. It is envisioned that thousands and millions of such micromachines will swarm and communicate with each other, performing desired actions. To date, mainly platinum catalyst surfaces have been used for the decomposition of a fuel, hydrogen peroxide, to oxygen bubbles.

Towards biocompatible nano/microscale machines: self-propelled catalytic nanomotors not exhibiting acute toxicity.

Recent advances in nanotechnology have led to the evolution of self-propelled, artificial nano/microjet motors. These intelligent devices are considered to be the next generation self-powered drug delivery system in the field of biomedical applications. While many studies have strived to further improve the various properties of these devices such as their efficiency, performance and power, little attention has been paid to the actual biocompatibility of nanojets in vivo.

Blood proteins strongly reduce the mobility of artificial self-propelled micromotors.

Autonomous self-propelled catalytic microjets are envisaged as an important technology in biomedical applications, including drug delivery, micro/nanosurgery, and active dynamic bioassays. The direct in vivo application of these microjets, specifically in blood, is however impeded by insufficient knowledge on the in vivo viability of the technique. This study highlights the effect of blood proteins on the viability of the microjets.

Blood electrolytes exhibit a strong influence on the mobility of artificial catalytic microengines.

The developments in biomedical sciences foresee the inclusion of self-propelled catalytic micromotors for in vivo therapeutic strategies in the near future. We show here that blood electrolytes, such as Na(+), K(+), Ca(2+), Cl(-), SO4(2-) and phosphates, decrease the mobility of the Pt catalyzed tubular microjets. This effect is significant and in many cases, the microjets are completely disabled at physiologically relevant concentrations of the ions.

Corrosion of self-propelled catalytic microengines.

Here we show that rolled-up and electroplated catalytic microjet engines undergo dramatic corrosion in fuel solution.

Reynolds numbers influence the directionality of self-propelled microjet engines in the 10(-4) regime.

The motion directionality of self-propelled bubble-jet microengines is influenced by their velocities and/or viscosity of the media in which they move. The influence of the fuel concentration from 1 to 3 wt% of H2O2 in 0.5% steps and of the glycerol fraction from 0 to 64% in aqueous solution on the directionality of the microjets motions is examined systematically.

Influence of real-world environments on the motion of catalytic bubble-propelled micromotors.

Self-propelled autonomous micromachines have recently been tasked to carry out various roles in real environments. In this study, we expose the microjets to various types of water that are present in the real world, examples include tap water, rain water, lake water and sea water, and we sought to investigate their behaviors under real world conditions. We observed that the viability and mobility of the catalytic bubble jet engines are strongly influenced by the type of environmental water sample.

Artificial micro-cinderella based on self-propelled micromagnets for the active separation of paramagnetic particles.

In this work, we will show that ferromagnetic microjets can pick-up paramagnetic beads while not showing any interaction with diamagnetic silica microparticles for the active separation of microparticles in solution.

Challenges of the movement of catalytic micromotors in blood.

Catalytic microjet bubble-propelled engines have attracted a large amount of interest for their potential applications in biomedicine, environmental sciences and natural resources discovery. One of the current efforts in this field is focused on the search of biocompatible fuels. However, only a minimal amount of effort has been made to assess the challenges facing the movement of such devices in a real world environment, especially with regards to the components of blood and their interactions with the catalytic microjets.

Poisoning of bubble propelled catalytic micromotors: the chemical environment matters.

Self-propelled catalytic microjets have attracted considerable attention in recent years and these devices have exhibited the ability to move in complex media. The mechanism of propulsion is via the Pt catalysed decomposition of H2O2 and it is understood that the Pt surface is highly susceptible to poisoning by sulphur-containing molecules. Here, we show that important extracellular thiols as well as basic organic molecules can significantly hamper the motion of catalytic microjet engines.

Magnetotactic artificial self-propelled nanojets.

Self-propelled catalytic bubble-ejecting nanotubes (nanojets) are expected to perform a variety of autonomous tasks. Herein, we will show that with the introduction of a Ni segment into the Au/Ni/Pt nanotube design followed by consequent magnetization a permanent change in the magnetic domain orientation of the Ni segment can be induced. Consequently, this results in the presence of a permanent magnet within the nanojet with its north/south domains oriented along the tube axis.

Self-propelled nanojets via template electrodeposition.

In this paper, we present a rapid, high-yield, low-end and low-cost fabrication of nanojet motors using a template directed electrochemical deposition method. Using an electrochemical deposition method, the bubble-ejecting nanojets were grown within the alumina template, which is commercially available. These fabricated nanosized devices have typical dimensions of 300 nm (diameter) by 4.

Inherently electroactive graphene oxide nanoplatelets as labels for single nucleotide polymorphism detection.

Graphene materials are being widely used in electrochemistry due to their versatility and excellent properties as platforms for biosensing. However, no records show the use of inherent redox properties of graphene oxide as a label for detection. Here for the first time we used graphene oxide nanoplatelets (GONPs) as electroactive labels for DNA analysis.

Micromotors with built-in compasses.

We demonstrate here that iron containing rolled-up microtubular engines can be magnetized and act as compass needles - they sense the direction of an external magnetic field from afar and align the directionalities of their movements according to the external field, in a similar fashion to magnetotactic bacteria.

Liquid-liquid interface motion of a capsule motor powered by the interlayer Marangoni effect.

A novel thin capsule motor has been described in this report. It utilizes the Marangoni effect for the solid capsule to run at a water-oil interlayer, which has not been reported previously. Intrinsic and environment factors influencing the motion were investigated.

Noble metal (Pd, Ru, Rh, Pt, Au, Ag) doped graphene hybrids for electrocatalysis.

Metal decorated graphene materials are highly important for catalysis. In this work, noble metal doped-graphene hybrids were prepared by a simple and scalable method. The thermal reductions of metal doped-graphite oxide precursors were carried out in nitrogen and hydrogen atmospheres and the effects of these atmospheres as well as the metal components on the characteristics and catalytic capabilities of the hybrid materials were studied.

Macroscopic self-propelled objects.

Self-propelled systems are currently in the spotlight of the research community. We review the progress of the construction of both millimeter- and centimeter-sized self-propelled macroscopic objects. We will also discuss the various sources of energy used by these systems, such as the electromagnetic field, electric field, thermal gradient, and chemical energy, and present how these millimeter- and centimeter-sized devices can move at velocities of tens cm s(-1) and distances of several tens of meters.

Graphenes prepared by Staudenmaier, Hofmann and Hummers methods with consequent thermal exfoliation exhibit very different electrochemical properties.

Large-scale fabrication of graphene is highly important for industrial and academic applications of this material. The most common large-scale preparation method is the oxidation of graphite to graphite oxide using concentrated acids in the presence of strong oxidants and consequent thermal exfoliation and reduction by thermal shock to produce reduced graphene. These oxidation methods typically use concentrated sulfuric acid (a) in combination with fuming nitric acid and KClO(3) (Staudenmaier method), (b) in combination with concentrated nitric acid and KClO(3) (Hofmann method) or (c) in the absence of nitric acid but in the presence of NaNO(3) and KMnO(4) (Hummers method).

Reynolds numbers exhibit dramatic influence on directionality of movement of self-propelled systems.

Self-propelled artificial objects are at the current forefront of research. We demonstrate here that the motion directionality of millimetre sized self-propelled objects is highly dependent on the Reynolds numbers (Re) of the systems, with emphasis on the "intermediate" Re region (1-600). Our findings have strong implication on the motion controllability and predictability of these independent self-propelled systems.

External-energy-independent polymer capsule motors and their cooperative behaviors.

The design and development of mobile nano-, micro-, and millimeter-scale autonomous systems have been perused over several decades. Here, we introduce a millimeter-sized polymer capsule motor with specific features and functionalities. It runs without any external energy sources or the consumption of external fuels such as H(2)O(2) or glucose.