Abstract
A temperature above which an ionic surfactant dissolves well is called Krafft point and below which, surfactant solubility in solution is very small. Hence, the Krafft point of a given surfactant should be lower than each temperature for practical usage. Based on the physical meaning of Krafft point, various ionic surfactants whose Krafft point are low were synthesized. Depending on the practical purposes, respective ionic surfactant suitable for the applications may be used, such as detergent in hard water, surfactants for tertially oil recovery and so on.
