Sunscreen Chemistry in Daily Life - SCI02 3460 PDF

SCI02 3460 Chemistry in Daily Life Part 2 Sunscreen ศาสตราจารย์ ดร.จตุพร วิทยาคุณ Office: C2-410 Tel: 4256 Email: [email protected]; [email protected] 1 SCI02 3460 Chemistry in Da...

SCI02 3460 Chemistry in Daily Life Part 2 Sunscreen ศาสตราจารย์ ดร.จตุพร วิทยาคุณ Office: C2-410 Tel: 4256 Email: [email protected]; [email protected] 1 SCI02 3460 Chemistry in Daily Life Part 2 Sunscreen ศาสตราจารย์ ดร.จตุพร วิทยาคุณ Office: C2-410 Tel: 4256 Email: [email protected]; [email protected] 1  ja Sunlight components Visible light: wavelengths between 400 and 800 nm Ultraviolet light: wavelengths shorter than 400 nm Infrared radiation: wavelengths longer than 800 nm https://www.britannica.com/science/sunlight-solar-radiation 2 UV index un neunaissa index viridians 1s : es ou - - In : coned) - ·is win doing https://www.myuv.com.au/understanding-uv/ 3 UV index during the day uv index finis at 14 5. - - https://www.myuv.com.au/understanding-uv/ 4  UV index and protection Wr :, hiu sinternistan Sinowlis) UN : https://www.cbc.ca/news/canada/british-columbia/sunscreen-time-5-things-you-need-to-know-1.3524804 5 UV index in Thailand 6  Skin tanning Tar ur nicneitsosistr ? involves polymers called melanins mininensi no , Dictate color of hair and skin vidusa The major types of Disin - melanin present in humans are eumelanin, structure of melaning pheomelanin and neuromelanin Ben Selinger and Russell Barrow, Chemistry in the marketplace, 6th Edition 7 Melanins react to the sun’s UV radiation End In the first stage, pale (unoxidised) melanin granules produced by - melanocytes near our skin’s surface are changed by UV light to their -ms/knw) dark-brown (oxidised) form. inventi libirise vide gives an immediate tan, usually within an hour. It fades within a day. - einsinuat - A more lasting tan results from the second stage. - In this process, new quantities of melanin are produced from tyrosine - - – an abundant amino acid in our skin’s protein. This second-stage tan endures for several days without further - exposure. 8 Melatonins and tanning Wi w no shar disor w cinsion linania melanine a lo melamin romnione Mrotunad Additional sunbathing not only produces more melanin but also - lengthens the polymer chains and deepens the color. - - However, the final effect of UV radiation is the damage to the - - proteins that make up the skin’s connective and elastic tissue. - This leads to an irreversible wrinkled, leathery and sagging skin. is wine- 9 Sunscreen fou freedo lo-20 min standar Diverse Canna si mos un An average untanned white skin will be affected by sunburn after exposure to the midday sun at around 10–20 minutes unlcum Uringorbol The actual reddening will not appear until about 6 h later. - ) (inner : ohr. This reddening will still be visible 24 h later and beyond. Id zehr) : wine b - Sunscreen can protect skin from UV Sun protection factor (SPF) 10  2no tio visivenes wound Sun Protection Factor (SPF) naus, dann Ninvir mrichz ↓ SPF is the inverse of the transmittance = Io/I nehi, ↓ - in insusesuammsteiroutasmis maald SPF is a measure of how much solar energy (UV radiation) is required to produce sunburn on protected skin (i.e., in the presence of - sunscreen) relative to the amount of solar energy required to produce sunburn on unprotected skin. SPF = 10 : the UV dose received will be a tenth of that without the sunscreen. wirkston I read mo sunscreennotim d 10110 runs fac 1/10 As the SPF value increases, sunburn protection increases. 11 Ultraviolet (UV) range UVA 315–400 nm · uniques ve un fat einui UVB 280–315 nm far UVC 200–280 nm All of UVC and most of the- ~ UVB inve are removed by the - ozone in the gi0 Ozone O Earth’s upper atmosphere While most of the UVA (required -- O for photosynthesis) is transmitted. -- UVB does not penetrate the skin O to a significant extent but UVA can penetrate through to the Trimmermans - hypodermis. WUB Kniqu WA Ben Selinger and Russell Barrow, Chemistry in the marketplace, 6th Edition 12 UV can damage DNA and cause skin cancer - & g/eyelyratin Ben Selinger and Russell Barrow, Chemistry in the marketplace, 6th Edition 13 Type of sunscreen susuchs one - Hybrid sunscreens Contain both organic and inorganic UV filter narst milli wissen Physical sunscreens or mineral sunscreens Active ingredient: zinc oxide G and/or titanium dioxide Absorb and reflect UV rays ( absorb · cate Const ↓ Nehwessz Chemical sunscreens Sinorms reflect , absorb Absorb UV rays 14  · Mirnownhous dadriver sunscreen Ingredients in Witot ot sunscreen Sir was dir Mushr min hun Uhrwersto - ·wit nich nam - - - -In d gar of - I Val https://cen.acs.org/business/consumer-products/What-in-sunscreen-and-how-does-it-protect-your-skin-from-the-sun-rays/99/i27 15 Ingredients in sunscreen - sitamin abauch Inkuma mind 16 Ingredients in sunscreen wire 190 : wo https://www.merchantsgroup.com/blog/17471-2/ 17 Organic screens endiris customardiovanidus Absorb the sun’s radiation and re- radiate it at lower harmless frequencies (fluorescence) or Absorb and convert into heat. Enr - e or Benzophenone is the basis of common screens Ben Selinger and Russell Barrow, Chemistry in the marketplace, 6th Edition 18 Other components in sunscreen -training Ben Selinger and Russell Barrow, Chemistry in the marketplace, 6th Edition 19 Benzoate- and salicylate-based UV absorbers Ben Selinger and Russell Barrow, Chemistry in the marketplace, 6th Edition 20