“…These peaks indicate that CTAB exists in CTAB-PTP [23,24]. The band at 2960 cm À1 , attributed to the N-CH 3 stretching vibration, is not observed for CTAB-PTP, implying that there was an interaction between the quaternary ammonium and PTP [25]. and 3440 cm À1 (m NH ) [27,28].…”