# Micro-Nanobubble Technology in Surface Cleaning and Defouling
## 3 Advanced Applications of NBs in Precision Surface Cleaning
### Eco-Friendly Surface Cleaning and Contamination Prevention
(**c**) Removal rate of nanoparticles as a function of treatment cycles for ethanol–water exchange, ethanol rinsing, and water rinsing. Reproduced with permission from [60], Copyright © 2011, American Chemical Society. gas bubbles worked better for pollutants with weak adhesion, whereas vapor bubbles were more successful in eliminating those with strong adhesion. Vapor bubbles were also a more efficient way to clean hydrophobic surfaces. The study offered a better understanding of the principles underlying ultrasonic cleaning and suggested a novel method to improve cleaning by employing liquids that have been degassed or not, depending on the properties of the surface that needs to be cleaned. [PERSON] et al. [64] provided an environmentally friendly buff cleaning solution that used gas-dissolved water (oversaturated gas-dissolved water) to effectively remove colloidal ceria nanoparticles, which is an essential step in cleaning wafer surfaces following chemical mechanical polishing. It was discovered that gas bubbles produced during the cleaning procedure, particularly those of nitrogen (N\({}_{2}\)) and carbon dioxide (CO\({}_{2}\)), significantly increased the particle removal efficiency (PRE). The performance of CO\({}_{2}\) bubbles was better than that of N\({}_{2}\) bubbles. Through physical adsorption and electrostatic attraction, these negatively charged MNBs successfully ensnared positively charged ceria particles, improving particle dispersion and avoiding recontamination. Using gas-dissolved water, especially CO\({}_{2}\)-enriched water, instead of pure deionized water, excellent cleaning efficiency was achieved without the negative environmental effects of chemical additives. [PERSON] et al. [65] proposed a technique for controlling fouling in wastewater treatment systems using NBs. Two application techniques (prevention and removal), six oxygen concentrations, and three NB types were assessed for their antifouling efficacy. According to these findings, when compared with non-NB treatments, NBs successfully reduced composite fouling, including particulate fouling, inorganic scaling, and biofouling. The self-collapse of NBs produced hydroxyl radicals that specifically oxidized organics and destroyed bacteria in wastewater. In addition to lowering ion precipitation, the negatively charged surfaces of the NBs changed the crystalline structure of CaCO\({}_{3}\) from calcite to the looser aragonite. Moreover, the NBs' gas-liquid interfaces improved the removal of particles from wastewater by serving as \"bridges\" between colloidal particles. Although NBs prevented fouling, they did not considerably eliminate fouling that had already adhered to groups that did not receive treatment. This research indicated that NBs may resolve serious fouling problems in wastewater distribution systems, which could help address the worldwide problem of sustainable water supplies. [PERSON] et al. [66] demonstrated that a solution comprising electrolyzed NBs could effectively remove oil droplets from hydrophilic and hydrophobic surfaces. In both microchannel tests and on a larger scale, the NB water outperformed a control solution (Milli-Q water) in terms of removing oil contaminants from glass and porcelain surfaces. These findings demonstrated that NBs may remove oil without the use of abrasive agents or surfactants, providing a safer and more effective substitute for conventional cleaning techniques. This inexpensive and environmentally friendly technique has the potential to be a useful tool for various real-world applications because it shows promise in cleaning delicacies. [PERSON] et al. [67] summarized the application of chitosan-modified NBs to treat dangerous cyanobacteria (_Microystis aeruginosa_). The interaction with negatively charged _M. aeruginosa_ was improved by the chitosan-modified NBs, which produced a notably greater number of hydroxyl radicals than negatively charged NBs owing to their positive zeta potential. This procedure totally stopped _M.