Lauryldimethylamine oxide Lauryldimethylamine oxide Lauryldimethylamine oxide (LDAO), also known as dodecyldimethylamine oxide (DDAO), is an amine oxide based nonionic surfactant, with a C (dodecyl) alkyl tail. It is one of the most frequently-used surfactants of this type. Like other amine oxide based surfactants it is antimicrobial, being effective against common bacteria such as "S. aureus" and "E. coli", however it is also non-denaturing and may be used to solubilize proteins. At high concentrations, DDAO forms liquid crystalline phases. Despite having only one polar atom that is able to interact with water – the oxygen atom (the quaternary nitrogen atom is hidden from
U Should've Known Better backbeat, the song's instrumentation consists of screeching guitars and an understated harp pattern. Lyrically, Monica, as the protagonist, delivers a message of loyalty to her imprisoned love interest and sings about staying down for him despite his doubts. The song was generally well received by contemporary music critics who highlighted the heartfelt emotion and sadness. Released as the fourth and final single from "After the Storm" in May 2004, the single marked Monica's first balladic release in over five years. On the charts, "U Should've Known Better" peaked at number 19 on the US "Billboard" Hot 100 and number 6