MXene is an emerging class of 2D materials exfoliated from ternary carbide and nitride ceramics. The exfoliation process, which is an acid etching approach, functionalizes the MXene surface with -OH, -O and -F groups. These functional groups offer significant opportunities for tuning the colloidal properties of the MXene nanoblocks; importantly, this tunability points the way towards a facile route for assembling these nanoblocks into 3D architectures that are in demand for many applications. This route, presented for the first time here, uses water/oil interfaces for assembling Ti3C2-MXene in 3D architectures. It shows that cetyl trimethylammonium bromide (CTAB) can be used to tune the hydrophilic-hydrophobic balance of Ti3C2-MXene via the interaction of positively charged -N(CH3)3 and -O groups on the MXene surface. Crucially, it is found that this interaction can be controlled via the hydrogen ion concentration in the aqueous phase. Stable oil-in-water emulsions are the only product when the aqueous phase is neutral or basic. This understanding led us to fabricate a high internal phase Pickering emulsion with more than 70 vol% oil droplets and also a solid porous monolith based on this emulsion template.