Continuous amination of aryl/heteroaryl halides using aqueous ammonia in a Teflon AF-2400 tube-in-tube micro-flow reactor

Aqueous ammonia was applied as the ammonia source in the continuous amination of aromatic and heteroaromatic halides assisted by a Teflon AF-2400 tube-in-tube reactor to generate densely substituted aryl/heteroaryl amines in high yields.

Bifunction-Integrated Dielectric Nanolayers of Fluoropolymers with Electrowetting Effects

Fluoropolymers play an essential role in electrowetting (EW) systems. However, no fluoropolymer possesses the desirable properties of both hydrophobicity and dielectric strength. In this study, for the first time, we report the integration of two representative fluoropolymers—namely, Teflon AF (AF 1600X) and Cytop (Cytop 809A)—into one bifunctionalized dielectric nanolayer. Within this nanolayer, both the superior hydrophobicity of Teflon AF and the excellent dielectric strength of Cytop were able to be retained. Each composed of a 0.5 μm Cytop bottom layer and a 0.06 μm Teflon AF top layer, the fabricated composite nanolayers showed a high withstand voltage of ~70 V (a dielectric strength of 125 V/μm) and a high water contact angle of ~120°. The electrowetting and dielectric properties of various film thicknesses were also systemically investigated. Through detailed study, it was observed that the thicker Teflon AF top layers produced no obvious enhancement of the Cytop/Teflon AF stack.

Thermal Lesion of Renal Tumour as a Function of Catheter Material Property

The extent of lesion achieved during microwave ablation is dependent on some factors which include the time period of application, its intensity, antenna geometry, and relative permittivity of the tissue. Several studies have been conducted on microwave ablation for the treatment of tumours and have focused on different antenna geometries, its intensity, and time of application. This work seeks to find a correlation between the relative permittivity of the catheter and the temperature distribution which determines necrosis of the tissue by using Tefzel ETFE, Teflon FEP, PFA Teflon type A, PFA Teflon type B, Teflon AF, and PTFE Teflon type B while modelling using COMSOL Multiphysics. The extent of the thermal lesion was observed to be dependent on the relative permittivity of the catheter material, with Tefzel ETFE giving the best performance and Teflon AF providing the least.

BaTiO3/ Teflon Nanocomposite Ferroelectric Thin Films for Low Voltage Electrowetting Systems

We present a simple and cost effective method for the design and fabrication of electrowetting devices using a nanocomposite thin film of BaTiO3 and Teflon-AF as the dielectric layer to achieve low voltage operation. The nanocomposite film is prepared by using Teflon-AF as matrix and BaTiO3 nanoparticles as the filler material. The solution is spin coated to deposit thin film on metal electrodes. The characterization results show that the nanocomposite thin film can serve as the dielectric for EWOD with a high dielectric constant and a crack free hydrophobic film. To test the electrowetting effect, the variation of droplet contact angle achieved with DC voltage, AC voltage and AC frequency change are fully experimented. The EWOD device with nanocomposite dielectric layer also manipulates water droplet at low driving voltages. This study shows the potential of using ferroelectric nanocomposite film as the dielectric layer in high-performance EWOD devices.