transparent sunscreen lasts a month or longer

Henna is keratin reactive actually forming a chemical compound at the skins surface which is why it lasts a month This idea is just attaching a UV absorbing molecule to an abbreviated form of henna to give a transparent keratin reactive sunscreen that lasts a month

easily described how though do you actually come up with the molecule

well only part of the henna molecule is needed just the part that wikipedia says does the michael reaction to keratin Then attach that directly to a polywer like Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate which is transparent Then you add a side group if necessary to keep it transparent

The notable part is actually finding a UV absorber that lasts a month there are plastics additives that last months yet a metallorgic based around Ce or Y might be physiologically beneficial

some of these long lasting plastic additives like Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate are at the link

Creating a sunscreen around an metallorganic molecule We could use Ce Yttrium or Sn then earnestly prefer that it keeps absorbing UV while the decay products are at least likely to be beneficial to the human body

Monthlong sunscreens are also treatments that block skin aging more than 4/5 of which was associated with UV

I don't remember the names of the oranometallic chemicals that absorb UV nevertheless just attach the Ce Y Sn Ti metallorganic UV absorber to 2-hydroxy-1,4-naphthoquinone (henna) or just the Michael reaction part of that molecule then see if the nude mice like it

I think everyone has the right to be nude thus a monthlong transparent sunscreen is a high priority