STUDIES
Semiconductors
This study demonstrated that using nano-ozone bubbles enhances the ozone/Hâ‚‚Oâ‚‚ process for breaking down tetramethylammonium hydroxide (TMAH) in semiconductor wastewater. Compared to macro-ozone bubbles, nano-ozone bubbles significantly improved ozone transfer efficiency and had a half-life 23 times longer, making them more effective for TMAH degradation. Adding Hâ‚‚Oâ‚‚ further boosted the degradation rate due to hydroxyl radical (·OH) production. Optimal TMAH removal was achieved at 25°C and pH 10, with 65% total organic carbon removal and 80% nitrogen converted to nitrate after 90 minutes. This process reduced acute toxicity by 40-fold and chronic toxicity by 2-fold, showing nano-ozone/Hâ‚‚Oâ‚‚ as an efficient, less toxic treatment method for TMAH wastewater
Green Cleaning of 3D-Printed Polymeric Products by Micro-/Nano-Bubbles
Micro- and nano-bubble technology offers an efficient, eco-friendly solution for cleaning oil contaminants from 3D-printed polymer products, which are often challenging to clean due to complex, porous structures. The high surface area and Zeta potential of the bubbles enhance contaminant adhesion and attraction, while their rupture, especially when combined with ultrasound, generates jets and shock waves that dislodge sticky residues. This method holds promise for various applications requiring effective and sustainable cleaning of intricate surfaces.
Auxiliary mechanism of in-situ micro-nano bubbles in oxide chemical mechanical polishing
This study introduces a novel slurry with in-situ micro-nano bubbles to enhance chemical mechanical polishing (CMP) of oxide wafers, crucial for integrated circuits. The slurry, using a nano-hydrophobic film, generates micro-nano bubbles that improve material removal rates by 30% and maintain low surface roughness (0.14 nm). These bubbles, characterized by optical microscopy and other techniques, improve the wafer's surface cleanliness and modify both wafer and pad surfaces, promoting effective abrasive adsorption and chemical reactions. This in-situ micro-nano bubble method shows promise for broader application across different slurry types in CMP processes
Environmentally friendly buff cleaning of ceria nanoparticles using bubbles in gas-dissolved water
Buff cleaning is an essential step after chemical mechanical polishing to remove particles from wafer surfaces. Traditional cleaning solutions often contain complex and potentially harmful chemicals, complicating wastewater recycling and impacting the environment. This study introduces an eco-friendly alternative using oversaturated gas-dissolved water to effectively remove colloidal ceria nanoparticles. In buff cleaning, bubbles formed by heating and shear assist in particle removal. Optical analysis showed nitrogen (N2) bubbles are around 1 µm, while carbon dioxide (CO2) bubbles range from 1 to 10 µm. CO2 bubbles demonstrated higher particle-removal efficiency (PRE) compared to N2, with negatively charged bubbles attracting positively charged ceria particles from various surfaces. Additionally, CO2 water helped achieve better particle dispersion, with particle sizes reducing to 149.8 nm, compared to 158.1 nm in N2 water and 162.5 nm in regular water. This improved dispersion minimizes the risk of recontamination in the cleaning process
Microbubbles for Effective Cleaning of Metal Surfaces Without Chemical Agents
Microbubble technology presents an eco-friendly alternative to traditional cleaning methods that rely on surfactants and ultrasound, which produce significant wastewater. This study investigated microbubbles for removing oil from metal surfaces. By generating air microbubbles at concentrations up to 10610^6106 particles/mL through hydrodynamic cavitation, researchers achieved oil removal efficiencies of 78.5% for carbon steel and 49.8% for stainless steel after 15 minutes, compared to minimal removal without microbubbles. When combined with ultrasound, microbubble cleaning reached an 85.5% efficiency in just 3 minutes versus 69.0% with ultrasound alone. The cleaning mechanism, observed with fluorescence, showed that oil attaches to microbubble surfaces, floats to the water surface, and is easily removed, reducing emulsified wastewater and enabling water recycling. This microbubble-based method enhances cleaning efficiency and minimizes environmental impact, making it a sustainable option for degreasing processes.
Environment-friendly surface cleaning using micro-nano bubbles
Using a solution enriched with micro- to nanoscale bubbles for surface cleaning offers substantial environmental benefits. This review begins by outlining the cleaning mechanisms of micro-nano bubbles (MNBs), including both physical and chemical effects. It then explores the applications of MNBs in cleaning metal components, precision parts, cultural artifacts, and food items. The review also discusses the enhanced cleaning performance achieved by combining ultrasound with MNBs. Finally, it examines methods for assessing cleaning effectiveness, focusing on changes in physical and chemical properties such as mass, cleaning area, infiltration, colony count, and light scattering intensity of the cleaned items, as well as the conductivity of the cleaning solution. MNB technology shows great potential for expanding its use in a wide range of surface cleaning applications