# Micro-Nanobubble Technology in Surface Cleaning and Defouling
## 3 Advanced Applications of NBs in Precision Surface Cleaning
### Textile Surface Cleaning and Treatment  
Conventional cleaning and finishing methods frequently use large quantities of chemicals, water, and detergents, which raise environmental concerns. Through physical and chemical interactions, researchers have shown that adding NBs improves the cleaning effectiveness and surface treatment, including water repellence and color degradation [60]. Better surface cleaning and treatment performance is achieved by NBs because they reduce surface tension, facilitate efficient dirt and contaminant detachment, and improve chemical agent activation. By using less water and chemicals, this method not only maximizes textile cleaning but also promotes environmentally beneficial alternatives [68].  
[PERSON] et al. [69] examined how different surfactants and combinations of NB and MB water wash in an alternate flow system. The findings indicated that while MB water (with a diameter of 30 \(\upmu\)m) did not improve, NB water (with an average particle diameter of 80 nm) obtained a washing rate that was almost 5% greater than water without NBs. NBs increased the pace of washing when paired with surfactants, especially when used with anionic surfactants such as LAS or a commercial cleaning solution (Liquid A), which showed gains of approximately 3% and 7%, respectively. However, neither cationic nor nonionic surfactants exhibited discernible changes. Furthermore, compared with water or surfactants alone, the surface tension of NB water and NB-surfactant mixtures was lower, indicating that the addition of NBs, particularly to anionic detergents, can increase the washing efficiency and reduce the environmental impact by using fewer detergents.  
[PERSON] et al. [70] investigated the creation of environmentally friendly, water-repellent cotton textiles using short-chain fluoropolymers and NB technologies (Figure 9). An e-flow NB approach was used in conjunction with an exhaustion procedure to treat the fabrics. The treated cotton exhibited improved mechanical qualities, air permeability, water resistance, and washing durability. Analytical methods including attenuated total reflectance-Fourier transform infrared and SEM verified the fabric's morphological and chemical alterations, proving that NBs are a useful addition to water quality and treatment procedures. The e-flow process was found to be an effective and sustainable method to achieve water-repellent coatings, providing the textile industry with an eco-friendly substitute without sacrificing performance or durability.  
[PERSON] et al. [71] reviewed the application of H\({}_{2}\)O\({}_{2}\) and NB technology to improve the photodegradation of Direct Blue 71 (DB 71) dye using a CdS/MIL-88A photocatalyst. This study showed that the addition of H\({}_{2}\)O\({}_{2}\) and NBs significantly increased degradation efficiency, removing almost 99% of DB 71 (70 mg/L) in 80 min under ambient conditions.  
Figure 9: **(a)** ATR-FTIR of the treated and untreated cotton fabrics. **(b)** Compression–decompression curve of untreated and treated cotton fabrics using the e-flow and exhaustion finishing techniques recorded with an MT–LQ dynamometer in a compression test according to the IUP 52 standard. Reproduced with permission from [70], CC-BY license, Copyright © 2023, the authors. Licensee MDPI, Basel, Switzerland.  
With R\({}^{2}\) values above 0.918, the process exhibited pseudo-first-order kinetics. The process produced reactive species, including HO\(\bullet\) and O\({}_{2}\bullet^{-}\) radicals, which were essential for dye breakdown. Up to five cycles of successful recycling were achieved using the CdS/MIL-88A photocatalyst with a removal efficiency of more than 78%. The ideal parameters for photodegradation were 500 mg/L of catalyst, 0.3 M H\({}_{2}\)O\({}_{2}\), 70 mg/L DB 71, and pH 7.0. This method provided an effective and eco-friendly dye removal solution with great potential to reduce environmental contamination.