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Fabrication Techniques for Capacitive Silicon Resonators
Published in Nguyen Van Toan, Takahito Ono, Capacitive Silicon Resonators, 2019
Generally, wafers are cleaned with weak acids to remove particle contaminants. The small particles can also be efficiently removed by using ultrasonic cleaning or fluid jet spray cleaning [1]. Piranha solution, which is a mixture of sulfuric acid (H2SO4) and hydrogen peroxide (H2O2), is widely used to clean metallic and organic residues off substrates. Additionally, another cleaning method, a process known as RCA cleaning, is based on hot alkaline and acidic hydrogen peroxide solutions. It was developed by Werner Kern in 1965 at Radio Corporation of America (RCA) [2–4]. Therefore, these procedures are also named as RCA cleaning. The general cleaning procedures performed in this work are as follows.
Long-Time Recording of Single-Molecule Dynamics in Solution by Anti-Brownian Trapping
Published in Shuo Huang, Single-Molecule Tools for Bioanalysis, 2022
Quan Wang, Elif Karasu, Hugh Wilson
After ensuring that the trap is completely dry, it is then transferred to a fume hood. A beaker of Piranha solution is prepared by adding 10 mL hydrogen peroxide to 30 mL sulfuric acid. One drop of the freshly prepared Piranha solution is immediately dropped onto one port of the trap. Capillary action will draw the solution inside the chip so that the chip is filled. Once the inner chamber is completely filled with Piranha, the whole chip is submerged in the beaker with Piranha solution. The whole chip is incubated for 40 minutes and is then transferred to the storage beaker filled with water and later rinsed using nanopure water and completely dried.
Sensitivity improved tapered optical fiber sensor for dissolved oxygen detection
Published in Instrumentation Science & Technology, 2021
Zhuo-Hui Wu, Qi Wang, Jia-Xing Duan, Hong-Zhi Sun, Qiang Zhao
The optical fiber was prepared by chemical etching to prepare a tapered fiber fluorescence probe. The specific experimental processes of the first step are as follows:A multimode fiber with a core diameter of 600 μm was cut into fiber segments 6 cm in length. 2 cm of the cladding were removed. Using a pull coating machine, the immersion depth was set to 2 cm, the pull speed to 1 mm/s, and the soaking time to 20 min. The sensing area of the fiber was treated with 40% hydrofluoric acid in a centrifuge tube. This protocol was employed to provide a model for the fiber probe.Piranha solution was prepared using 7:3 sulfuric acid:hydrogen peroxide.[28] The etched fiber was immersed in the Piranha solution to remove residual hydrofluoric acid from the surface of the fiber, rinsed with deionized water, and allowed to dry.
Insignificant influence of the matrix on the melting of ice confined in decorated mesoporous silica
Published in Philosophical Magazine, 2018
Yunbo Xu, Zhenyan Zhao, Lianwen Wang
For hydrophobicity characterisation of decorated SBA-15, although measuring water contact angle to pressed porous silica [15] was applaudable at first sight, it did not work well and we have to recognise that liquid contact angle determination for porous powders remain unresolved [18,19]. For this reason, commercial silica platelets were decorated using XSi(OEt)3 in the same way as SBA-15 powders and the water contact angle to these decorated silica platelets was tentatively taken as that for SBA-15 powders. Before decoration, the silica platelets were pretreated using a Piranha solution (mixture of H2SO4 and H2O2, 70:30 volume ratio) [20] to prepare hydroxyl groups [21,22] on the surface of silica platelets [23] and to avoid possible contamination of silica surfaces [24]. (Caution: Piranha solution is extremely corrosive and should be used with absolute carefulness [25].) Water contact angle measurements to the decorated silica platelets were carried out on a KRUSS DSA100 instrument.
Detection of anti-SARS-CoV-2 antibody for the diagnosis of past-COVID-19 infection cases using a liquid-crystal-based immunosensor
Published in Liquid Crystals, 2022
Dong Yoon Jeon, Chang-Hyun Jang
Microscopic glass slides were cleaned following previously procedures reported [47,48]. Briefly, microscopic glass slides were immersed in ‘piranha solution’ (70% H2SO4/30% H2O2) at 80°C for 1 h. After cooling to 25°C, the cleaning solution was removed and the glass slides were sequentially rinsed with DI water, ethanol, and methanol to remove the residual acid. The cleaned slides were then dried under a stream of nitrogen gas and stored in an oven at 120°C overnight. (Caution: ‘piranha solution’ reacts violently with organic materials and should be handled with extreme caution; do not store the solution in closed containers).