FT-IR Spectra Collection. FT-IR measurements were performed in the mid-infrared region (4000−650 cm−1) using a Nicolet 6700 (Thermo Scientific Co.) FT-IR spectrophotometer, configured with an attenuated total reflectance (ATR) sampling technique, deuterated triglycine sulfate (DTGS) detector, and KBr beam splitter controlled by OMNIC software. Samples to be analyzed were placed on a diamond crystal sampling plate and clamped with a pointed tip. A background scan was obtained before every sample scan with an empty sample plate. In addition, the ATR crystals and pointed tip were cleaned to remove any interference from the preceding sample. A total of 32 successive scans from each sample were collected at 4 cm−1 intervals, and averaged spectra of each sample were used for analysis.