A novel bio-adsorbent was fabricated via grafting an amino-terminated hyperbranched polymer (HBP-NH2) onto bagasse cellulose. The morphology and microstructure of the HBP-NH2-grafted bagasse cellulose (HBP-g-BC) were characterized and its adsorption capacity for Cr(VI) ions in aqueous solutions was investigated. The rough surface structure of HBP-g-BC that is beneficial for improving the adsorption capacity was observed by scanning electron microscopy (SEM). The grafting reaction was confirmed by Fourier-transform infrared (FT-IR) spectroscopy. The adsorbent performance was shown to be better with a lower pH value, a higher adsorbent dosage, or a higher initial Cr(VI) concentration. Moreover, the kinetics study revealed that the adsorption behavior followed a pseudo-second-order model. The isotherm results showed that the adsorption data could be well-fitted by the Langmuir, Freundlich, or Temkin models. Moreover, HBP-g-BC could maintain 74.4% of the initial removal rate even after five cycles of regeneration. Thus, the high potential of HBP-g-BC as a bio-adsorbent for heavy metal removal has been demonstrated.
Based on transfer printing technology, Micro-LED pixels can be transferred to different types and sizes of driver substrates to realize the display of different application scenarios. To achieve a successful...
In this study, the STM32 microcontroller is used to drive a passive matrix (PM) Micro-LED through two-wire serial transmission and row-column integration. STM32 exhibits superior properties, including simple-to-operate, cost-friendly, and flexible programming. Moreover, it has a lower cost and more straightforward implementation for testing the quality of the device and realizing the graphics. In this design, the connection between the STM32 and the PM array is realized by an LED driver board and flexible printed circuit (FPC) structure. The two-wire serial protocol and row-column integration are adopted, which not only optimizes the circuit structure but also avoids coupling problems. Compared to the existing structures, it is more concise that only four connecting wires are required to transmit data in display devices of any resolution. Besides, the problem of graphics distortion is solved through two buffers to form a data handshake. Using this method, the blue PM array, which has a resolution of 48 × 48, a refresh rate of 60 Hz, a pixel size of 300 μm, and a luminous area of 50 μm, is successfully realized. In addition, p-metal fractures caused by the bulge in the p-lines are also resolved by adding the GaN as a raised substrate.
We
propose that electroless plating is a superb approach to preparing
metallic bumps with an ultrafine pitch for the integration of a micro
light-emitting diode (micro-LED). Electroless plating does not suffer
from lift-off-related issues, which are ubiquitous in thermal evaporation.
Besides, it can result in much more uniform bumps than electroplating
because the bump height is not affected by the current distribution.
This study reports ultrafine pitch Ni/Au bumps fabricated by electroless
nickel immersion gold (ENIG) plating. Furthermore, cheap metals iron
and nickel are selected to catalyze the electroless nickel process.
The results indicate that uniform and consistent Ni/Au bumps can be
obtained through the iron sheet and nickel layer method. Besides,
no voids and impurities are found inside the bumps, which is beneficial
for the following interconnection process. Moreover, the change in
Ni bump height values with the electroless plating time is also provided.
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