Cleaning using nanobubbles: Defouling by electrochemical generation of bubbles

• Published in: Journal of colloid and interface science Vol. 328; no. 1; pp. 10 - 14
• Main Authors: Wu, Zhihua, Chen, Hongbing, Dong, Yaming, Mao, Huiling, Sun, Jielin, Chen, Shenfu, Craig, Vincent S.J., Hu, Jun
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.12.2008; Elsevier
• Subjects: Adsorption; Animals; Atomic force microscope (AFM); Bovine serum albumin (BSA); Cattle; Chemistry; Colloidal state and disperse state; Defouling; Detergents; Electrochemistry; Exact sciences and technology; General and physical chemistry; Graphite; Microscopy, Atomic Force; Nanobubble; Nanostructures; Nonfouling; Serum Albumin, Bovine - pharmacokinetics; Surface cleaning; Surface physical chemistry; Surface Properties; Surface cleaning; Atomic force microscope (AFM); Bovine serum albumin (BSA); Nonfouling; Defouling; Nanobubble; Gas liquid interface; Atomic force microscopy; Fouling; Bovine; Electrochemical treatment; In situ; Serum albumin; Air water interface; Protein; Vertebrata; Bubble; Mammalia; Adsorption; Stainless steel; Graphite; Electrochemistry; Artiodactyla; Ungulata
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2008.08.064

Here we demonstrate that nanobubbles can be used as cleaning agents both for the prevention of surface fouling and for defouling surfaces. In particular nanobubbles can be used to remove proteins that are already adsorbed to a surface, as well as for the prevention of nonspecific adsorption of proteins. Nanobubbles were produced on highly oriented pyrolytic graphite (HOPG) surfaces electrochemically and observed by atomic force microscopy (AFM). Nanobubbles produced by electrochemical treatment for 20 s before exposure to bovine serum albumin (BSA) were found to decrease protein coverage by 26–34%. Further, pre-adsorbed protein on a HOPG surface was also removed by formation of electrochemically produced nanobubbles. In AFM images, the coverage of BSA was found to decrease from 100% to 82% after 50 s of electrochemical treatment. The defouling effect of nanobubbles was also investigated using radioactively labeled BSA. The amount of BSA remaining on a stainless steel surface decreased by ∼20% following 3 min of electrochemical treatment and further cycles of treatment effectively removed more BSA from the surface. In situ observations indicate that the air–water interface of the nanobubble is responsible for the defouling action of nanobubbles. Protein desorbtion from solid–liquid interface driven by nanobubbles.