Time evolution of moduli of a polymer-induced liquid precursor (PILP) of calcium carbonate.

AFM observations show that when PILP droplets contact a surface, their initial properties are either a liquid with a high interfacial tension (350 mJ m) or a soft gel-like material with a low modulus (less than 0.2 MPa). These findings suggest that PILP may initially be liquid-like to infiltrate collagen fibrils, enabling the production of interpenetrating composites, and/or become viscoelastic, to provide a means for moulding minerals.

Erosion-Driven Enamel Crystallite Growth Phenomenon at the Tooth Surface In Vitro.

The erosion of tooth enamel is a common oral disease. The erosion pattern and location and the effects of nanoscale chemical composition on the erosion susceptibility of enamel have been well documented. However, the enamel remineralization accompanied by erosion and its underlying physicochemical mechanisms still remain poorly understood.

Investigation of the AgCl Formation Mechanism on the Ag Wire Surface for the Fabrication of a Marine Low-Frequency-Electric-Field-Detection Ag/AgCl Sensor Electrode.

One of the most widely used electric field sensors for low-frequency electric field detection (LFEFD) in seawater uses the Ag/AgCl electrode. The surface structure of the electrode including AgCl layers plays a critical role in the electrode's electrochemical performance required for the sensor. In this study, the sequential AgCl formation process under the constant current was examined on the Ag wire in an electrode size for actual applications, and an optimal electrode surface structure was suggested for the LFEFD Ag/AgCl sensor.

An Investigation on the Feasibility of Fabricating Composites Using Outdated Waste Carbon Fibers and Easily Disposable Polyolefin Resins.

Outdated-waste-carbon-fiber-reinforced olefin composites (oCFOCs) were fabricated with easily disposable polyolefin resins, polypropylene (PP), high-density polyethylene (HDPE), and low-density polyethylene (LDPE), by compressive molding using a hot press. The flexural and impact strengths of the oCFOCs from each respective resin type and oCF content, ranging from 35 to 70 wt.%, were increased by the aging treatment (120 °C and 95% humidity under a pressure of 0.

Mechanistic Pathways for the Molecular Step Growth of Calcium Oxalate Monohydrate Crystal Revealed by In Situ Liquid-Phase Atomic Force Microscopy.

Calcium oxalate monohydrate (COM) crystal is the most common crystalline component of human kidney stones. The molecular-scale inhibitory mechanisms of COM crystal growth by urinary biomolecules such as citrate and osteopontin adsorbed onto the crystal surface are now well understood. However, the pathways by which dissolved calcium and oxalate ions are incorporated into the molecular step of the COM crystal surface, leading to COM crystal growth-a prerequisite to be elucidated for developing effective therapeutics to inhibit COM stones-remain unknown.

Flexible Magnetic Polymer Composite Substrate with BaSrZ Hexaferrite Particles of VHF/Low UHF Patch Antennas for UAVs and Medical Implant Devices.

Our goal is to fabricate flexible magnetic polymer composites as antenna substrates for very high frequency (VHF)/low ultra high frequency (UHF) antennas for unmanned aerial vehicles (UAVs) and medical devices. Magnetodielectric materials, which have permeability () similar to permittivity (), have attracted great attention, because they facilitate miniaturization of microwave devices while keeping or enhancing electromagnetic characteristics. Mechanically millled BaSrCoFeO (BaSrZ) hexaferrite particles were used to increase permeability in the interesting frequency band.

Multifunctional reduced graphene oxide-CVD graphene core-shell fibers.

The insufficient electrical conductivity and mechanical stretchability of conventional graphene fibers based on reduced graphene oxide liquid crystals (rGO-LCs) has limited their applications to numerous textile devices. Here, we report a simple method to fabricate multifunctional fibers with mechanically strong rGO cores and highly conductive CVD graphene shells (rGO@Gr fibers), which show an outstanding electrical conductivity as high as ∼137 S cm-1 and a failure strain value of 21%, which are believed to be the highest values among polymer-free graphene fibers. We also demonstrate the use of the rGO@Gr fibers for high power density supercapacitors with enhanced mechanical stability and durability, which would enable their practical applications in various smart wearable devices in the future.

Effect of Enhanced Thermal Stability of Alumina Support Layer on Growth of Vertically Aligned Single-Walled Carbon Nanotubes and Their Application in Nanofiltration Membranes.

We investigate the thermal stability of alumina supporting layers sputtered at different conditions and its effect on the growth of aligned single-walled carbon nanotube arrays. Radio frequency magnetron sputtering of alumina under oxygen-argon atmosphere produces a Si-rich alumina alloy film on a silicon substrate. Atomic force microscopy on the annealed catalysts reveals that Si-rich alumina films are more stable than alumina layers with low Si content at the elevated temperatures at which the growth of single-walled carbon nanotubes is initiated.

Direct observation of mineral-organic composite formation reveals occlusion mechanism.

Manipulation of inorganic materials with organic macromolecules enables organisms to create biominerals such as bones and seashells, where occlusion of biomacromolecules within individual crystals generates superior mechanical properties. Current understanding of this process largely comes from studying the entrapment of micron-size particles in cooling melts. Here, by investigating micelle incorporation in calcite with atomic force microscopy and micromechanical simulations, we show that different mechanisms govern nanoscale occlusion.

Calcium carbonate nucleation driven by ion binding in a biomimetic matrix revealed by in situ electron microscopy.

The characteristic shapes, structures and properties of biominerals arise from their interplay with a macromolecular matrix. The developing mineral interacts with acidic macromolecules, which are either dissolved in the crystallization medium or associated with insoluble matrix polymers, that affect growth habits and phase selection or completely inhibit precipitation in solution. Yet little is known about the role of matrix-immobilized acidic macromolecules in directing mineralization.

Stochastic transport through carbon nanotubes in lipid bilayers and live cell membranes.

There is much interest in developing synthetic analogues of biological membrane channels with high efficiency and exquisite selectivity for transporting ions and molecules. Bottom-up and top-down methods can produce nanopores of a size comparable to that of endogenous protein channels, but replicating their affinity and transport properties remains challenging. In principle, carbon nanotubes (CNTs) should be an ideal membrane channel platform: they exhibit excellent transport properties and their narrow hydrophobic inner pores mimic structural motifs typical of biological channels.