Facet dependent ultralow thermal conductivity of zinc oxide coated silver fabric for thermoelectric devices.

The conversion efficiency of a thermoelectric power generator depends on the dimensionless figure-of-merit (ZT) of the constituent thermoelectric materials, which is mainly determined by their Seebeck coefficient as well as the electrical and thermal conductivity. ZnO holds promise for thermoelectric applications, yet its use is currently limited by low electrical conductivity and high thermal conductivity. Herein, we demonstrate how thermal conductivity of ZnO can be significantly reduced by intelligently combining it with a cellulose-based Ag fabric using a one-step hydrothermal method, and how different ratios of zinc nitrate hexahydrate (ZNH) to hexamethylenetetramine (HMT) can be used to fine-tune the thermoelectric performance of the resulting composite.

Pros and Cons of (NH)S Solution Treatment of p-GaN/Metallization Interface: Perspectives for Laser Diode.

The impact of wet treatment using an (NH)S-alcohol solution on the interface state of the p-GaN/Ni/Au/Pt contact system and laser diode processing was investigated. Sulfur wet cleaning resulted in reduced surface roughness and contact resistivity. The lowest specific contact resistance ( < 1 × 10 Ω·cm) was achieved with samples treated with an (NH)S-isopropanol solution, whereas the highest resistivity ( = 3.

Nanocarbon-Polymer Composites for Next-Generation Breast Implant Materials.

Most breast implants currently used in both reconstructive and cosmetic surgery have a silicone outer shell, which, despite much progress, remains susceptible to mechanical failure, infection, and foreign body response. This study shows that the durability and biocompatibility of breast implant-grade silicone can be enhanced by incorporating carbon nanomaterials of sp and sp hybridization into the polymer matrix and onto its surface. Plasma treatment of the implant surface can be used to modify platelet adhesion and activation to prevent thrombosis, postoperative infection, and inflammation disorders.

One-step rapid formation of wrinkled fractal antibiofouling coatings from environmentally friendly, waste-derived terpenes.

Wrinkled coatings are a potential drug-free method for mitigating bacterial attachment and biofilm formation on materials such as medical and food grade steel. However, their fabrication typically requires multiple steps and often the use of a stimulus to induce wrinkle formation. Here, we report a facile plasma-based method for rapid fabrication of thin (<250 nm) polymer coatings from a single environmentally friendly precursor, where wrinkle formation and fractal pattern development are controlled solely by varying the deposition time from 3 s to 60 s.

The fractal geometry of polymeric materials surfaces: surface area and fractal length scales.

Using three common polymeric materials (polypropylene (PP), polytetrafluoroethylene (PTFE) and polycaprolactone (PCL)), a standard oxygen-plasma treatment and atomic force microscopy (AFM), we performed a scaling analysis of the modified surfaces yielding effective Hurst exponents ( ≃ 0.77 ± 0.02 (PP), ≃0.