The most prominent and the abrupt change occurs for the feature nN-N [see Fig. ]. For both the situations, it is zero for all the bins except for the bin at the brush-bulk interface (bin 6). In fact, in this bin, it becomes significantly large ~20% for both the cases. This feature nN-N represents the presence of one {N(CH3)3} + group of the PMETA chain in close vicinity of another {N(CH3)3} + group. Given that nN-N=0 for bins deep inside the brushes implies that inside the brush layer, such an occurrence (where one {N(CH3)3} + group of the PMETA chain comes in close vicinity of another {N(CH3)3} + group) is not possible. This implies that something with regards to the structure of the PMETAC brushes is changing at the brush-bulk interface (or bin 6) that is making nN-N suddenly change to a finite value (for both the situations) at the brush-bulk interface (bin 6).