Tuning the interactions between different surfaces has technological benefits in areas such as adhesion, compatibilisation and nano-actuators. We shall study the interaction between a grafted polybase (brush) on an inorganic substrate and a polyacid hydrogel in the different pH solutions. We have shown that the brush and the gel do not adhere at pH 3. This adhesion is strongly dependent on the load applied to the gel before adhesion. We are interested in measuring the pressure dependence of the adhesion in order to understand the mechanism of the adhesion. In particular, we are interesting in seeing whether there is a regime whereby interdigitation of the brush into the gel contributes to the adhesion, a phenomenon that can only be determined by neutron reflectometry. Previous measurements were with minimal applied load, and showed no such effect.