  For Schr\"odinger equations with a class of slowly decaying repulsive
potentials, we show that the solution satisfies global-in-time Strichartz
estimates for any admissible pairs. Our admissible class of potentials includes
the positive homogeneous potential $Z|x|^{-\mu}$ with $Z>0$ and $0<\mu<2$ in
three and higher dimensions, especially the repulsive Coulomb potential. The
proof employs several techniques from scattering theory such as the long time
parametrix construction of Isozaki-Kitada type, propagation estimates and local
decay estimates.
