Wetting Behavior of Surface Nanodroplets Regulated by Periodic Nanostructured Surfaces.

Surfaces with nanostructure patterning are broadly encountered in nature, and they play a significant role in regulating various phenomena such as phase transition at the liquid/solid interface. Here, we designed two kinds of template substrates with periodic nanostructure patterns [i.e.

Formation and Stability of Bulk Nanobubbles in Different Solutions.

The existence of bulk nanobubbles is still controversial in spite of their significance in a large range of applications. Here, we developed a new method of compression-decompression to produce controllably bulk nanobubbles. Then, we further investigated the generation of bulk nanobubbles in pure water, acid, alkaline, and salt solutions using nanoparticle tracking analysis.

Force Spectroscopy Revealed a High-Gas-Density State near the Graphite Substrate inside Surface Nanobubbles.

The absorption of gas molecules at hydrophobic surfaces may have a special state and play an important role in many processes in interfacial physics, which has been rarely considered in previous theory. In this paper, force spectroscopic experiments were performed by a nanosized AFM probe penetrated into individual surface nanobubbles and contacted with a highly ordered pyrolytic graphite (HOPG) substrate. The results showed that the adhesion force at the gas/solid interface was much smaller than that in air measured with the same AFM probe.

The Role of Nanobubbles in the Precipitation and Recovery of Organic-Phosphine-Containing Beneficiation Wastewater.

Dissolved air flotation (DAF) is broadly applied in wastewater treatment, especially for the recovery of organic pollution with low concentration. However, the mechanism of interaction between nanoscale gas bubbles and nanoparticles in the process of DAF remains unclear. Here, we investigated the role of nanobubbles in the precipitation of styryl phosphoric acid (SPA)-Pb particles and recovering organic phosphine containined in beneficiation wastewater by UV-vis (ultraviolet-visible) spectra, microflotation tests, nanoparticle tracking analysis, dynamic light scattering, and atomic force microscopy measurements.

Formation and Stability of Bulk Nanobubbles Generated by Ethanol-Water Exchange.

Bulk nanobubbles have unique properties and find potential applications in many important processes. However, their stability or long lifetime still needs to be understood and has attracted much attention from researchers. Bulk nanobubbles are generated based on ethanol-water exchange, a method that is generally used in the study of surface nanobubbles.

Size-Dependent Stiffness of Nanodroplets: A Quantitative Analysis of the Interaction between an AFM Probe and Nanodroplets.

The interfacial properties of nanodroplets are very significant for the exploration of the basic law governing the fluid behavior at the nanoscale and also the applications in some important processes in novel materials fabrication by forming a special and local reaction environment. However, many basic factors such as the interfacial tension or stiffness of nanodroplets are still lacking, partially because of the difficulty of making quantitative measurements of the interfacial interactions at the nanometer scale. Here, we used a novel atomic force microscopy (AFM) mode, PeakForce mode, to control the interaction between an AFM probe and nanodroplets, by which we could obtain the morphology and stiffness of nanodroplets simultaneously.

The origin of the "snap-in" in the force curve between AFM probe and the water/gas interface of nanobubbles.

The long-range attractive force or "snap-in" is an important phenomenon usually occurring when a solid particle interacts with a water/gas interface. By using PeakForce quantitative nanomechanics the origin of snap-in in the force curve between the atomic force microscopy (AFM) probe and the water/gas interface of nanobubbles has been investigated. The snap-in frequently happened when the probe was preserved for a certain time or after being used for imaging solid surfaces under atmospheric conditions.

Study on nanobubble generation: saline solution/water exchange method.

In a recently introduced method for nanobubble generation, water is replaced with NaCl solution. It has the same mechanism as alcohol/water exchange: a liquid of higher gas solubility is used to replace one of lower gas solubility. Herein, the opposite process is realized by replacement of saline solutions with water.

Understanding the stability of surface nanobubbles.

Surface nanobubbles emerging at solid-liquid interfaces show extreme stability. In this paper, the stability of surface nanobubbles in degassed water is discussed and investigated by AFM. The result demonstrates that surface nanobubbles are kinetically stable and the liquid/gas interface is gas impermeable.

Imaging interfacial micro- and nano-bubbles by scanning transmission soft X-ray microscopy.

Synchrotron-based scanning transmission soft X-ray microscopy (STXM) with nanometer resolution was used to investigate the existence and behavior of interfacial gas nanobubbles confined between two silicon nitride windows. The observed nanobubbles of SF6 and Ne with diameters smaller than 2.5 µm were quite stable.

Volume transition and adhesion force of nanosized bifunctional spherical polyelectrolyte brushes observed by dynamic light scattering and atomic force microscopy.

Stimuli-responsive nanoparticles have attracted considerable interest due to their enormous potential applications. In this paper, nanosized bifunctional spherical polyelectrolyte brushes (BSPBs) were prepared through grafting random copolymer chains from N-isopropylacrylamide (NIPA) and acrylic acid (AA) onto polystyrene core by photoemulsion polymerization. The pH- and thermo-responses of the BSPB with different ratio of NIPA and AA were investigated by dynamic light scattering.

Investigation on the temperature difference method for producing nanobubbles and their physical properties.

In recent years, the possibility of nanobubbles at the solid-liquid interface has drawn wide attention in the scientific community and industry. Thus the search for evidences for the existence of nanobubbles became a scientific hotspot. To produce interfacial nanobubbles, a systematic experiment, called the temperature difference method, is carried out by replacing low temperature water (LTW) with high temperature water (HTW) at the highly-oriented pyrolytic graphite (HOPG)-water interface.

Defouling and cleaning using nanobubbles on stainless steel.

The present work demonstrates that nanobubbles can be used as cleaning agents on stainless steel (SS) surfaces. Cleaning efficiency has been quantified. Using an Atomic Force Microscope (AFM), it was demonstrated that nanobubbles can be produced by electrochemical treatment on a SS surface either with or without adsorbed bovine serum albumin (BSA).

Cleaning using nanobubbles: defouling by electrochemical generation of bubbles.

Here we demonstrate that nanobubbles can be used as cleaning agents both for the prevention of surface fouling and for defouling surfaces. In particular nanobubbles can be used to remove proteins that are already adsorbed to a surface, as well as for the prevention of nonspecific adsorption of proteins. Nanobubbles were produced on highly oriented pyrolytic graphite (HOPG) surfaces electrochemically and observed by atomic force microscopy (AFM).

Magnetic force microscopy analysis of apoptosis of HL-60 cells induced by complex of antisense oligonucleotides and magnetic nanoparticles.

Magnetic force microscopy (MFM) has been employed to observe antisense oligonucleotides (ASOs)-coupled silica-coated magnetic iron oxide nanoparticles (SMNPs) internalized into human leukemia (HL-60) cells. The experiment demonstrated that the ASOs-coupled SMNPs delivery into the cells really occurred. The nanoparticles were internalized into the cells and the apoptotic topography can be directly visualized simultaneously with MFM technology.