Synthesis and Physical Properties of Choline Carboxylate Ionic Liquids Muhammad, N.; Hossain, M.I.; Man, Z.; El-Harbawi, M.; Bustam, M.A.; Noaman, Y.A.; Mohamed Alitheen, N.B.; Ng, M.K.; Hefter, G.; Yin, C.Y.; Journal of Chemical & Engineering Data 2012, 57, 2191-2196