title: Reply to "Comment on 'Long-range electrostatic interactions between like-charged colloids: steric and confinement effects' ".
abstract: In his Comment to [Phys. Rev. E 60, 6530 (1999)], Mateescu shows that while the effective interactions remain repulsive when the specific size of the microions is taken into account via a Modified Poisson-Boltzmann equation, a similar conclusion cannot be reached for the situation of complete lateral confinement. This point is correct but has already been considered in a more general study [Phys. Rev. E 62, R1465 (2000), where repulsion is generically obtained]; moreover, we argue that it illustrates the irrelevancy of the notion of pair potential in completely confined configurations, as shown in a simple example.
authors.affiliation: Laboratoire de Physique Théorique, Unité Mixte de Recherche UMR 8627 du CNRS, Bâtiment 210, Université de Paris-Sud, 91405 Orsay Cedex, France. Emmanuel.Trizac@th.u.psud.fr
authors.forename: E
authors.initials: E
authors.lastname: Trizac
authors.forename: J L
authors.initials: JL
authors.lastname: Raimbault