Bactericidal light action

Ultraviolet light - A form of energy occupying a position in the spectrum of sunlight beyond the violet, and having wavelengths of less than four micrometers which is the limit of visible light. UV (ultraviolet) rays are very active chemically, exhibit bactericidal action, and cause many substances to fluoresce. UV rays accelerate deterioration of rubber parts exposed to them and can initiate polymerization. 

Among the various types of cellulose derivatives, it is the cellulose esters that find the widest practical application and complete succesfully in a number of branches of the industry with synthetic polymers. The complete or partial esterification of the hydroxyl groups of cdlulose can yield cellulosic materials having such technically valuable properties as thermoplasticity, hydrophobicity, resistance to heat and light, stability to the action of putrefying microorganisms, bactericidal action, etc. 

When titanium dioxide nanoparticles and nanocrystallines are irradiated with UV-visible light, this semiconductor can exhibit strong bactericidal activity. For instance, Chang et al. showed that the irradiation of suspensions of Escherichia coli and Ti02 (P-25) with of wavelengths longer than 380 nm led to bactericidal action within minutes [26]. Furthermore, the trends in these simulated laboratory experiments were mimicked in outdoor tests conducted under the summer, noonday sun [27]. Elsewhere, Maness et al. presented the first evidence that Hpid peroxida-... 

Gates, F.L., A study of the bactericidal action of ultraviolet light. III. The absorption of ultraviolet... 

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