Investigating aluminum salt containing hydrogels in water versus sweat mimics

Aluminum salts are used in a wide variety of applications including water treatment, clay ceramics and antiperspirants/deodorants. Their unique ability to interact with sweat components to form a sweat plug has been widely studied as well as debated over the years. Industry has moved from traditional AlCl3 salt to zirconium-aluminum-glycinate (ZAG) salts owing to the irritation and yellowing caused by AlCl3. Although people have studied aluminum chemistry a systematic study of aluminum salts in relation to sweat plugs has not been studied. Herein, we have studied a range of Al and ZAG salts as a function of pH. Specifically, we have probed into how hydrolysis chemistry impacts Al-Keggin polymerization of salts in water versus a sweat mimic. We observed how pH plays a critical role in shifting equilibria of Al-Keggin polymers in various salts. This study will provide guidance to optimize newer salts and to develop novel metal-mediated hydrogels for application in sweat chemistry.