The present invention relates generally to polyelectrolyte-layer forming block copolymers adsorbed at colloid interfaces in aqua solution and compositions and uses thereof. In particular, the present invention relates to agricultural material compositions comprising particles of at least one agricultural material and a polyelectrolyte-layer forming block copolymer. The present invention also relates to non-agricultural material compositions comprising particles of at least one non-agricultural material and a polyelectrolyte-layer forming block co-polymer.