supplementary figure 9

SEM images of Pactive brackets gates post exposure to ageing conditions; A: Pactive bracket gate after water storage, B: at a higher magnification (10000X) the gate surface demonstrates score 2 after water storage, C: Pactive bracket gate after acid challenge, D: at a higher magnification (10000X) the gate surface depicts a rough surface with pits, scratches/grooves and marked surface irregularities (score 3) after acid challenge.