Charge regulation enables anionic hydroxypropyl guar-borate adsorption onto anionic and cationic polystyrene latex

► Borate ions bind to hydroxypropyl guar (HPG) converting a nonionic polymer to an anionic polyelectrolyte. ► Bound borate ions do not influence HPG adsorption onto anionic or cationic polystyrene latex. ► HPG-borate anionic charge density increases near a cationic surface and decreases upon approach to an anionic surface.