Well-aligned and randomly grown multiwall nanotubes (MWNTs) fabricated by the radio-field-induced self-bias hot-filament chemical vapour deposition method demonstrate that the growth mechanisms are either 'tip growth' or 'base growth' depending on the size of the catalyst metal particles involved. The carbon nanotubes (CNTs) can also be successfully grown on iron-like bulk alloys when preceded by hydrogen plasma etching. The high yield of CNT fabricated on oxidized metal alloys is attributed to the high active surface area that ensues from etching. The change in field emission currents of MWNTs with temperature is not sensitive but is detectable within the range 300-20 K. This is interpreted to be due to the high aspect ratio of CNTs.

This study reports a laser irradiation process to enhance the field emission properties of buckypaper, which is a thin sheet of high-loading carbon nanotube networks. The scanning laser treated the selected regions of buckypaper to activate carbon nanotube (CNT) emitters. This post-process causes a decrease in turn-on field and increases the field enhancement factor (beta), luminance intensity, and uniformity of buckypaper emitters. The phosphorescence luminance intensity and uniformity of buckypaper emitters are measured and characterized. The low turn-on field of 0.56 V microm(-1), highest average luminance intensity of 235.9/255, and uniformity of 99.8% are achieved by adjusting the machining parameters of laser power, laser lens motion speed, laser resolution, laser beam size, and pattern orientation. Those parameters relate to the field emission properties of beta, turn-on electric field, luminance intensity, and uniformity. Using design of experiment (DOE) methodology, the optimal parameter settings for high and uniform electron emission of a buckypaper emitter are obtained within fewer experimental runs.

This paper proposed implementing a water and air monitoring system using sensor development and a LoRa Network. To transmit data, a self-made PCB board integrates the terminal sensors with Renesas RX64M MCU and LoRa. There are 16 monitoring point stations for the media experiment. The sensors were used to measure the water and air parameters such as PM2.5, CO2, DO concentration, pH level, temperature, and humidity. In addition, the Grafana system was implemented to present the status and variation in the monitoring parameters in the environmental area. To evaluate the monitoring system, we also collected public information provided by the environmental protection department of the Taiwan government at the same monitoring point for comparison.

Alumina (Al2O3)-filled multiwalled carbon nanotube buckypapers (BPs) with different Al2O3 loadings (5–50 wt%) were successfully synthesised. Structural and morphological analysis performed with x-ray diffraction and field-emission scanning electron microscopy, respectively, confirmed the presence of stable α-phase Al2O3 particles in the Al2O3-BP composites. The formation of flexible Al2O3-BP hybrid nanocomposites (5–15 wt%) was attributed to the strong interfacial polarisation and high conductivity; compared with pure Al2O3 and BP. The nanocomposites with optimised alumina loadings demonstrated enhanced microwave absorption (>90%) and a broader absorption bandwidth in the investigated high-frequency region.

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