Which wavelength is better? 222nm VS 265nm killing ability competition
Traditionally, disinfection methods are mainly to inactivate pathogens, thereby reducing infection. With the COVID-19 pandemic, there is an increasing need to kill viruses in the air and on the surface. According to relevant facts, UVC light can effectively inactivate most pathogens.
Related products have been developed for conventional ultraviolet disinfection based on mercury (Hq) lamps, but with the safety issues surrounding the ban on the use of mercury and the entry into force of regulations, the development of Pudai ultraviolet disinfection sources has been promoted.
UVCLED is regarded as a natural substitute for mercury lamps for the following reasons: it does not contain mercury and is easy to operate (such as instantaneous on/off, has the ability to cycle without affecting the service life, and absorbs heat in the opposite direction of UVC light. , High-performance possibility control, low maintenance cost. These advantages make UVCLED can be integrated into various disinfection applications of water and high contact surfaces, thereby improving the quality of products and functions for end users, and reducing OEM costs
The influence of far ultraviolet rays and germicidal ultraviolet rays on disinfection
In the sterilization UVC range, 260nm to 270nm is regarded as the ideal wavelength. In this wavelength range, the efficacy of nucleic acid damage only slightly decreases (peak DNA/RNA absorption is observed between 263nm and 265nm).
Recently, scientists have studied the application of Australian and ammonia excimer lamps to generate primary photon emission peaks at 207nm and 222nm, respectively. The UVC in the range of 207nm to 222nm is usually called far UVC. Although the photons emitted in this range are absorbed by the nucleic acid of DNA/BNA to a certain extent, the main factor that reduces the infectivity is believed to be due to absorption and protein The destruction taught, this has been in the brand’s disease balance, methyl-resistant staphylococcus aureus
In water applications, it seems unlikely to use 222nm because the ultraviolet transmittance (UVT) in the water becomes too large. The UVT of filtered water is constant around 260nm, and due to common chemical contaminants (such as nitrates), it begins to drop sharply at shorter wavelengths. In addition, the pathogen of interest is biofilm forming bacteria, such as peak absorption Pseudomonas between 260nm and 265nm exhibits lower photon absorption at shorter wavelengths.
Therefore, it is much more likely to use photon sources from 205nm to 230nm to treat pathogens. Depending on the protein aspect of the pathogen, this aspect may have a significantly different absorption coefficient, rather than the verified nucleic acid DNA/RNA that uses the DNA absorption peak. The method, in the wavelength range of 260nm to 270nm, has been shown to be able to inactivate pathogens consistently and predictably.
Application in business
The commercially available UVCLED is based on a half-size body made of Al1-xGaxN alloy, and its emission wavelength is controlled by its alloy content, which means that UVCLEDs can also be made to emit at wavelengths below 225nm (including 222nm). Therefore, the wavelength issue is not just a problem of excimer lamps and UVCLEDs. UVCLEDs require higher AI mole fractions to emit at these shorter wavelengths, which leads to reduced efficiency.
Up to 10 times (1 ink level), but even here, current LEDs below 230nm have lower power and shorter lifespan. Compared with the sterilization range, the cost of LED solutions in this wavelength range is greatly increased,
When comparing excimer lamps with UVCLEDs, other factors need to be carefully considered. Compared with UVCLED lamp beads (usually a cuboid, a cuboid with a length of 0.3 cm), the footprint of an excimer lamp (a tube that is usually longer than 10 cm) means that the flexibility of installation will be very different. For early applications where the excimer lamp is directly exposed to the skin (so far, although the results seem to indicate no permanent damage, only limited research has been carried out), the excimer lamp will require an expensive bandpass filter to remove Longer wavelengths (for example, the KrC lamp used for the 222m period has secondary emission peaks in UVC and UVB around 258nm).
Conclusion
The preference for specific UVC wavelengths (such as 222nm vs. 265nm) depends on the application. Excimer lamps seem to be important in the treatment of large areas where humans continue to pass, but there are limited studies (so far, although the results seem to indicate that no permanent Sexual damage, only limited research has been conducted) has been studying the effects of prolonged exposure on humans
Time to prepare. He said: "The angle and duration of the exposure have not yet been determined."
Compared with mercury lamps. The use of UVCLED is not only green and environmentally friendly, but also more attractive commercially in a variety of applications. Although humans should not be directly exposed to UVC light, due to the small footprint of UVCLED and almost star-like light generation, Allows the design of targeted disinfection applications in which UVC radiation is well controlled and unnecessary exposure is eliminated, which can prevent health hazards. In addition, although in continuous operation, the WPE of UVCLED is lower than that of mercury lamps , But the ability to turn on/off the LED on demand without fog preheating can be converted into higher electrical efficiency throughout the lifespan
